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FISHeRIES RESEARCH'COUN'OlL; 1958. ~ ....­

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ANNUAL REPORT OF THE

EAST AFRICAN AGRICULTURAL

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FISHERIES RESEARCH COUNCIL, 1958

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EAST AFRICAN AGRICULTURAL AND FISHERIES RESEARCH COUNCIL

Chainnan Major Sir rerdinanu Cavendish-Bentinck, K.B.E., C.M.G., M.e.

Members

A ppointed by the High COl1ll1lissioll­

Sir Bruce HUll, K.B.E., C.M.G. Two vacancies.

Appointed by the Governor of Kenya-

The Minister for Agriculture, Animal Husbandry and WaleI' Resources.

The Earl of Portsmouth.

Appointed by the Govemur of Tarzganyika­

The Minister for Natural Resources. Mr. J. M. Hunler.

Appointed hy the Governur of Ugufldll'­

The Mjnister for Natural Resources. Mr. H. L. Manning,

Appointed by the British Resident, Zanzibar­

The Financial Secretary.

Appointed by the' Secretary of Sfate~

Two representa lives.

Secretary Lieut.MColonel S. P. Fearon .•

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CONTENTS

PART I PAGE

GENERAL REVIEW

PART U

REPORTS OF THE ORGANIZA1-10NS:

I.-The East African Agriculture and Forestry Research Organiz.ation. . 3

APPENDIX

List of Members attending the ninth and tenth meetings of the Council.

2.-The East African Fishery Research Organization 23

3.-The East African Marine Fisheries Research Organization 27

4.-The East African Trypanosomiasis Research Organization 33

5.-The East African Veterinary Research Organization 38

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EAST AFRICA HIGH COMMISSION

ANNUAL REPORT OF THE EAST AFRICAN AGRICULTlJRAL AND FISHERIES RESEARCH COUNCIL, 1958

PART I-GENERAL REVIEW

Two meetings of the Council were held during the ealendar year 1958. the ninth at Nairobi on 6th and 7th February and the tenth at Muguga on 30th Septem­ber. Attendance at these meetings is shown in the Appendix. The main business of the ninth meeting was concerned with the consideration of the Estimates for 1958/1959, and with the procedure to be followed for the submission of policy statements for the next Colonial Development and Welfare quinquennium, 1960/1965. The records of the Agricultural, Forestry, Animal Industry. Veterinary, Inland Fisheries and Trypanosomiasis Research Co-ordinating, Committees were also considered by the Council.

At the tenth meeting the Council considered the policy statements for 1960/1965 submitted by the Directors of the research organizations. This followed a closed session at which a frank re-appraisal was made of the research need\ of the territories in the light of the prevailing financial stringency. The statements were referred back to the Committees for critical examination with a direction to report back to the Council at its meeting in January, 1959.

An important financial decision was taken at the tenth meeting when the Council agreed in principle that the East African contributions to the research organizations controlled by the Council should be subject to a maximum of Boo,OOO a year in the C.D. & W. period 1960/1965. to be paid in equal shares by the three mainland territories and including an increased contribution from Zanzibar to enable the Madne Fisheries Research Organization to be supported equally by Kenya, Tanganyika and Zanzibar. The Council also accepted proposals for an overall scheme covering all the research organizations controlled by the Council to which all contributions would be made. This is a distinct departure from the present practice whereby each organization is supported by its OWI\

individual scheme, and should allow greater flexibility in dealing with the finances of the organizations.

The future of the E.A. Trypanosomiasis Research OrganizatIOn was considered at the tenth meeting and the Council agreed to the closing of the sub-stations at Shinyanga and Tinde to enable all aspects of research work to be concentrated at Sukulu; substantial financial savings will be made by this concentratjon. In the next C.D. & W. quinquennium the Council directed that expenditure on E.A.T.R.O. must be limited to a maximum of £100,000 a year as compared with £142,000 in the estimates for 19;8(1959.

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The Council laid down the following equal priorities of research for the E.A. Marine Fisheries Research Organization in the next C.D. & W. quin· quennium:­

(a) the deep sea fisheries;

(b) the inshore estuarine fisheries of the Tanganyika coast, particularly potential prawn fisheries; and

(c) the fisheries off the north Kenya coast.

The Inland Fisheries Research Co-ordinating Committee met in January; the Marine Fisheries Research Co-ordinating Committee in July; and the Agricultural, Animal Industry, Veterinary. Forestry and Trypanosomiasis Research Co-ordinating Committees in December. The Trypanosomiasis Committee met for the first time without the Directors of Medical Services and members considered generally that this was a retrograde step. The question of the co-ordination of trypanosomiasis research is to be considered by the Council and the E.A. Council for Medical Research when they meet in January, 1959. when it is hoped that a satisfactory solution to the problem will be found. The main difficulty at the moment is that there is no single policy-making body in East Africa which c~n view the Organization's programme as a whole or can take decisions on the degree of emphasis to be given to each of the di~rent

aspects of research. ..

The decision taken by the Governments to disband the Lake Victoria Fisheries Service from July, 1960, its present functions becoming the responsibility of the territorial departments, will affect the Council in so far as the E.A. Inland Fishery Research Organizati9n is concerned. The future part which the Organization wil( play in respect of the accumulation and analysis of catch data and sampling methods is to be considered by two committees early in January. 1959, a statistical committee and the Inland Fisheries Research Co-ordinating Cdmmittee. The Council will consider the recommendations of these committees at its eleventh meeting in January, 1959.

Mr. J. M. Hunter and Mr. R. E. T. Hobbs were appointed to the Council for a period of two years from lSt January. 1958. Mr. Hobbs unfortunately had to resign on his appointment as Chairman and Chief General Manager of the Tanganyika Agricultural Corporation, and Mr. Crosskill who had been a member since 1955 also had to resign on his appointment as Minister for Tourism and Common Services in the Government of Kenya. Their places were taken for a period of two years from I st July. 1958, by Mr. H. L. Manning and the Earl of Portsmouth respectively.

There have been no changes of Directors in the organizations. Other changes of staff are noted in the reports which follow in Part II. These reports are abbreviated versions of the technical and scientific reports published separately by each organization. They are written as far as possible in non­technical language and are designed chiefly to provide the layman with as much information as he will require on the lactivities of the research organizations. Visits to the laboratories can be arranged in consultation with the Directors who are always very willing to welcome members of the public.

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PART II-THE R

THE EAST AFRICAN AI

DIRECTOR:

The principal programn Research Council have been new Research Officers joinec temporarily attached to the of the Sorghum Breeding Re~

of the Animal Husbandry D Entomology Division. Mr. " the other Research Officer a arrive until M,arch or April, abeyance since April, 1957, Mr. A. Whitehead, who had <:. Colonia! Research Fellowsh nematodes transferred to the

We have lost this year members of the old East Afl predecessor of this Research. who joined the staff in 1948 I, Greenway, who has been in inception and before that of has been in charge of the breeding work at EIdoret, an Amani Sub-St,ation until Sep -a biochemist in the Animal B Rowett Research Institute, Ab

The Eldorel Sub-Slallon Amani Sub·Station is effecti~

maintained in the nursery a the Sorghum Breeding Rese Agricultural Experiment Stal thanks to the willing co-open: Resources and the Director oj

The Director is a meO' Forestry and Tsetse and Try and Chairman of the Soil Committees. He is a member Advisory Committee, the Ker Research Committee of the 1 of the Research Committee member of the Governing B, and of the Namulonge A( Corporation. He is a member Sahara (C.S.A.), and attend. Chairman at the first meeti' Catchment Area Research he 3rd Fwmal Hydrology Confe

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pnorIties of research for the the next C.D. & W. quin­

mganyika coast, particularly

Committee met in January; ommittee in July; and the md Trypanosomiasis Research panosomiasis Committee met ~:lical Services and members

step. The question of the , considered by the Couneil I they meet in 1anuary, 1959,i problem will be found. The 'ogle policy-making body in

ramme as a whole or can en to each of the different

disband the Lake Victoria becoming the responaibility

in so far as the E.A. Inland e future part which the tion and an'alysis of catch

1by two committees early in Inland Fisheries Research

ider the recommendations of " 1959.

rere appointed to the Council S8. Mr. Hobhs unfortunately d Chief General Manager of r. Crosskill who had been a tment as Minister for Tourism rlya. Their places were taken Mr. H. L. Manning and the

~ organizations. Other changes , in Part II. These reports .f'-scientific reports published 1 as far as possible in noo­'ide the layman with as much .f the research organizations. !f.ation with the Direetors who oe public.

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PART II-THE REPORTS OF THE ORGANIZATIONS

THE EAST AFRICAN AGRICULTURE AND FORESTRY RESEARCH ORGANIZATION

DtRECTOR: DR. E. W. RUSSELL, M.A., Ph.D.

The principal programmes of work described in the 3rd Report of the Research Council have been kept in being during the period under review. Four new Research Officers joined the staff, Mr. O. Kerfoot, Silviculturist. who is temporarily attached to the Physics Division, Mr. H. Doggett. to take charge of the Sorghum Breeding Research Scheme, Dr. W. 1. A. Payne, to take charge of the Animal Husbandry Division, and Mr. W. Wilkinson to join the Forest Entomology Division. Mr. Wilkinson only arrived at the end of the year, and the other Research Officer appointed to this Division. Mr. T. Jones, does not arrive until M'arch or April, 1959, so the work of this Division has been in abeyance since April, ]957, when Mr. Gardner left on retirement. In addition Mr. A. Whitehead, who had been working at E.A.A.F.R.O. for two years on 2 Colonial Research FeJlowship on a survey of the importance.of plant parasitic nematodes transferred to the staff as Nematologist. ,

We have lost this year by retirement four officers, three of whom were members of the old East African Agricultural Research Institute at Amani, the -predecessor of this Research.. Organization. They -are Mr. G. 'H. Gethin Jones. who joined the staff in 1948 to take charge of the Soil Survey Division, Dr. P. J. Greenway, who has been in charge of the East African Herbarium since its inception and before that of the Amani Herbarium, Mr. L. R. Doughty, who has been in charge of the cassava breeding work at Amani and the maize breeding work at Eldoret, and Mr. D. W. Gourlay, who w'as in charge of the Am.ani Su.b-S.tlat~on un~il September this year. In addition Dr. J. Quartennan. a blOthemlst In the Ammal Husbandry Division, resigned to join the staff of the Rowett Research Institute, Aberdeen.

1?e Eldore~ Su?-Statio~ is being closed at the end of the year, and the Amant Sub-StatIOn lS effectIvely closed, although some cassava clones will be 'maintained in the nursery area until 1960. On the other hand, the work of the Sorghum Breeding Research Scheme is being carried out at the Serere Agricultural Experiment Station of the Department of Agriculture Uganda thanks to the wilJing co-operation and help given us by the Minister ~f Natural Resources and the Director of Agriculture.

The Director is a member of ~he. E.A. Agricultural, Animal Industry, Forestry and Tsetse and TrypanosomIasIs Research Co-ordinating Committees and ~hairman ,of the Soil Fertility and the Pasture Research Specialist Co~mlttees. He ?S a member of the Kenya Agricultural and Veterinary Research AdVISory CommIttee, the Kenya Pasture Research Committee. Chairman of the Research Committee of the Tanganyika Coffee Growers Association a member of the Research Committee of the Tanganyik,a Sisal Growers As~ociation a member of the Governing Body of the Tea Research Institute of East Af;ica and of .the Na~ulonge Advisory Bo.ard. of the .Empire Cotton Growing CorporatIOn. He IS a member of the SClentltk CouncIl for Africa South of the Sah~ra (C.S.A.), and attend~d the 9th Meeting at Accra in August. He Was ChaIrman at the first meetIng of the East African Standing Committee on Catchment Area Research held in Kampala in August, and Chairman of the 3rd F?rmal Hydrology Conference of East and Central African Territories also

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held in Kampala then. He attended a C.S.A. Specialist Committee on Physical Hydrology with Dr. Pereira, who was invited by the C.S.A. as an official delegate, and Dr. McCulloch; and he attended the First Inter-African Weed Control Conference held at Victoria Falls in July.

Dr. H. H. Storey is a member of the E.A. Medical Research Council and the B.A. Industrial Research Board, a Trustee of the CoryodoD Museum, Chairman of the Specialist Committee on Agricultural Botany and Chairman of the E.A. Standing Technical Committee on Plant Import and Export, of which Dr. F. M. L. Sheffield is also a member, and Mr. P. J. Dickinson of the B.A. Plant Quarantine Station is the Secretary. Dr. Storey was also Chairman of the Meeting of Experts called by the Inter-African Phyto-Sanitary Commission which met in Nairobi in April. He also attended the 7th International Microbiology Congress at Stockholm in August.

Dr. Pereira is the Secretary of the E.A. Catchment Area Research Committee, the Kenya Catchment Area Research Committee and the E.A. Regional Committee for the Conservation and Utilization of Soils. Dr. A. L. Griffith is a member of the E.A. Timber Advisory Board and Chairman of the Specialist Committee on Forestry. He attended the 2nd Inter-African Forestry Conference held at Pointe Noire in July organized by the Commission for Technical Co-operation in Africa South of the Sahara (C.C.T.A.). Dr. Payne is a member of the Kenya Pasture Research Ctlmmittee. Mr. J. Glover is a member of the Kenya Pyrethrum Technical Consultative Committee, and Dr. H. F. Birch is a member "f the Kenya "'neat Baking Quality Committee. Mr. H. P. Ledger attended by invitation meetings of the Kenya 'pig Industry Board.

Physics Division

CA.TCHMENT AREA RESEARCH

As described in previous Reports of the Research Couneil the Physics Division is co-operating with the Territories in carrying out a series of experiments cn the effects of changes of land-use in catchment areas on the amount of water in the rivers flowing out of them. The problem facing Ministers of Natural Resources is tha,t if one leaves the catchment areas in natural forest one usually has very well regulated rivers, but this gives a very low economical return per acre; whilst if one replaces these natural forests by other methods of land use, which will give a higher financial return per acre, river flows are likely to be very badly upset. In a country such as East Africa where water and well­watered land is scarce, and which has a climate having a pronounced wet and dry season, it is essential that one should use methods of land-use which encourage rivers to have a maximum flow in the dry season, and a minimum liability to flood in the rains. Most of the numerous procedural and financial complications of these inter-departmental research projects have been solved :during the past two years, -and none of the difficulties have interrupted the field progress of the four main investigations.

One experiment is situated in the Mbeya Range of Tanganyika where steep hill sides are cultivated for a few years before they are abandoned and allowed to revert to scrub forest. The effect of clearing this forest and cultivating the land is being compared with recently abandoned land and with land which is being kept in protected forests. During the year difficulties were experienced in measuring the stream flow from the _cultivated land on the steep hill sides due to the amount of soil being carried in the river, but the Tanganyika Water Development Department has installed silt traps to ovcrcome this difficulty.

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A second experiment is a 1,700-acre catchment is be bouring catchment is being Bond have already started 0t of the Ministry of Works .. Forest Department has c1ea have completcd the detailed a complete year's data on soil is on the east side of the Al catchments covered with ba steep slopes are planted wit are being collected on three catchments, each of 2,000 a other problems requiring in\l have received considerable l

of rainfall in high forest cc on platforms on the tops ( moisture changes under high

The fourth experiment test the effect of controlIin: soils in the semi-arid region. yet been fully overcome. n water in a flash flood loadec in tensively by the Uganda V more difficult form here thai problem which will be les: maintaining law in this ven possible 10 protect all the s, and deliberate damage.

A full report of the pre5 by Dr. Pereira who is in c1 African Standing Committel Kampala in June.

AGRICULTURAL METEOROLOG'

The two problems on the application to East Afn the evaporation of water by and the estimation of the tOI distribution of rain gauges. B ·area experiments outlined J

problem have been to confi found by this Division, that used by crops well supplied on them. Two factors of con: the speed of the wind and th in East Africa.

The principal work on been the development of me already mentioned. Two m. at tree-top level on which clearings in the forest of di

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A second experiment is in progress in the tall rain forest at Kericho where a 1.700-acre catchment is being converted into a tea plantation, and the neigh­bouring catchment is being left in undisturbed dense forest. Messrs. Brooke Bond have already started opening up this area; the Hydraulic Engineer's Branch of the Ministrv of Works has installed the autographic streamflow gauges, the Forest Depart~ent has cleared the perimeter traces and the Physics Division have completed the detailed topographical survey of the catchments and have a complete year's data on soil moisture changes under forest. The third experiment is on the east side of the Aberdare Mountains in which the effect of converting catchments covered with bamboo forest into catchments in which all the less steep slopes are planted with softwoods is being studied, All the requisite data are being collected on three small catchments and during the year two further catchments, each of 2,000 acres, have been brought into the experiment. Two other problems requiring investigation have arisen in these two experiments, and have received considerable attention during the year, namely the measurement .of rainfall in high forest country. which is being done by putting rain gauges on platforms on the tops of 100 ft. high trees, and the measurement of soil moisture changes under high forest over a complete year.

The fourth experiment in the Karamoja District of Uga'nda is designed to test the effect of controlling grazing on flash flooding in an area of shallow soils in the semi-arid region. Two major difficulties have arisen and neither have yet been fully .overcome, The first is the problem of measuring the amount of water in a flash flood loaded with silt. This is a .technical problem being studied intensively by the Uganda Water Development Department, and arises in a still more difficult form here than in the Mbeya experiment in Tanganyika, A second problem which will be less easy to overcome arises from the difficulty of maintaining law in this very under-developed country, and it has not yet been possible to protect all the scientific equipment installed in this area from theft and deliberate damage.

•A full report of the present position of these four expl;riments was presented

by Dr. Pereira who is in charge of this work to the first meeting of the East African Standing Committee on Catchment Area Research which was held in Kampala in June.

AGRICULTUR:\L METEOROLOGY

The two problems on which most attention has been given this year are the application to East African conditions of Penman's method for estimating the evaporation of water by soils and crops from primary meteorological data. and the estimation of the total rainfall over a catchment area with a fairly close distribution of rain gauges. Both these studies are an integral part of the catchment -area expedments outlined above. The results of the work done on the first problem have been to confirm in much more detail what has been previously found by this Division, that the dominant factor controlling the amount of water used by crops well supplied with water is the amount of solar energy falling on them. Two factors of considerable importance in the United Kingdom, namely the speed of the wind and the humidity of the air, are rarely of much importance in East Africa.

The principal work on the estimation of rainfall over catchment areas has been the development of methods for measuring rainfall in high forest areas, as already mentioned. Two methods are being investigated, the use of platforms at tree-top level on which the rain gauge is placed, and the comparison of clearings in the forest of different sizes to ensure that a rain gauge at ground

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level will give a true reading of the rainfall over the area. The prindpal develop­ment in the use of rain gauges at the tree-top level has been checking the accuracy of using i-inch diameter PVC tubing from the rain gauge to a measuring reservoir below ground level, so avoiding the need to climb these trees. The method which has now been developed appears to be fully accurate for the needs of the experiment.

IRRIGATION STIJDIES

Work has continued on measuring the amount of water crops are using day by day at different stages of their growth, and comparing this use with the amount caleulated from the Penman formula for which constants for East African conditions are being developed by the agricultural meteorologist. The reason why it is so important to check the validity of this equation is that, knowing the depth of rooting of the crop and the amount of water the soil can hold in this depth, one can then follow by calculation the rate at which the crop exhausts this water and the rainfall replenishes it, and can therefore predict both the periods whcn crop growth is being limited by water shortage, and later on the yield responses to be obtained by applying irrigation water. The field work has been confined to continuing the measurements of watcr use by coffec trees in Kenya's irrigation experiments at Ruiru, and by annual crops in the Muguga terrace cxperiments and evapo-transpiration tanks. An important point which has come out from the latter work is that the way in which water is added to the evapo-transpiration tank affects vcry apprcciably the amount of water the crop appears to be usmg.

•SOIL STRUCTURE STUDIES The work this year has been mainly confined to studying the effcct of the

trampling of cattle on the structure of the surface soil. Last year an analysis was made of the soil from the farmyard manure experiment at the Serere Agricultural Experiment Station, Uganda, and it showed the benefit of farmyard manure on soil structure. This year an analysis was made on another Serere experiment, designed to show the effects of night paddocking cattle on grass before it was ploughed up for a cotton crop. The results have shown that night paddocking has vcry scriously reduced the ability of the soil to accept a heavy rainstorm compar,ed with the ungrazed'plots, but that after the land had been ploughed out for ~otton the effects of trampling was no longer apparent.

Work has continued on producing new pressure plate equipment for dctermining the moisture characteristics of soils in the neighbourhood of their wilting point.

THE EFFEGr OF SHADE TREES IN TEA PLANfATIONS The planting and maintaining of shade trees in East African tea plantations

is common field practice, yet very little is known about the advantage or dis­advantage of this practice. A new experiment, jointly undertaken by the Physics Division of E.A.A.F.R.O., the Tea Rcsearch Institute, Kericho, and Messrs. Brooke Bond East Africa Ltd., has been started to find the effect of Grevillea robusta shade on mature tea under two contrasting systems of pruning. Accurate measurcments of radiation and of light intensity are in progress. An initial problem needing investigation was to seek a simple and cheap method for \ measuring the amount of light falling on various tea bushes throughout the day, and it was in this connexion that Mr. Friend, of the Analytical Division, developed and tested in detail the use of a solution of anthracene in benzene as a radiation integrator. The work is also involving a detailed study of the effect of trees on micro-climate around the tea bushes. The experiment is now under way and yields are already available from bushes with different degrees of shading and at different distances away from the shade trees.

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ADVISORY V tSITS

Dr. Pereira was invited b: to co-operate with their Techl visits, normally concerned \Ii

land use on the water resou" proposals.

CLIMATE OF EAST AFRICA

Miss Kenworthy, a Le, 'Ytorking here until the mid completed the first part of h temperatures in East Africa, primarily controlled by the longitude, in that places at <l

are likely to have slightly dri

EFFEcrs OF DROUGIIT ON MA

Mr. Glover. the Plant I in the recovery of wilted mai At thc end of last year he hal of sorghum behave different] shown that the stomata of m, been severely droughted, whiJ function quite normally afteJ behaviour of wilted sorghum in the same way as in the ] behaviour of the stomata in from a drought.

THE DECOMPOSITION OF ORGAN

Dr. Birch has continued 'Which organic matter or hurr. show, as one would expect, tl low, and therefore decompos the rains decomposition begin as moist conditions continue. is only during the decomposit soil, and these are essential easily be washed out by rain, can use these nitrates as soon ithe land without being killel nitrates produced which will t

This year his work has for this flush of decompositi(J show that there are at least tVl in such a way that on being in the soil water, and this dis~

that held on the soil particles soil crumbs to shrink and cra from the water is now exposed

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~ area. The principal develop­11.8 been checking the accuracy :auge to a measuring reservoir hese trees. The method which :urate for the needs of the

I1t of water crops are using comparing this use with the

ieh constants for East African leteorologist. The reason why luation is that, knowing the ater the soil can hold in this

at which the crop exhausts 1 therefore predict both the ~r shortage, and later on the In water. The field work has water use by coffee trees in mnual crops in the Muguga

An important point which , in whicb water is added to ly the amount of water the

to studying the effect of the ~ soil. Last year an analysis ·e experiment at the Serere lwed the benefit of farmyard las made on another Serere paddocking cattle on grass

esults have shown that night f the soil to accept a heavy bat after the land had been ~ no longer apparent. ~ssure plate equipment for the neighbourhood of their

East African tea plantations about the advantage or dis­y undertaken by the Physics itute, Kericho, and Messrs. , find the effect of Grevillea ;ystems of pruning. Accurate are in progress. An initial

lple and cheap method for , bushes throughout the day, 6f the Analytieal Division, of anthracene in benzene as

L detailed study of the effect be experiment is now under 1 different degrees of shading

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ADVISOR"l VISITS

Dr. Pereira was invited by the Natural Resources Ministries of the Territories to co-operate with their Technical Officers on various reconnaissance or advisory visits, normally concerned with the effect of existing or proposed changes of land use on the water resources of the district, or on the erosion hazards of new proposals.

Plant Physiology

CLIMATE OF EAST AFRICA

Miss Kenworthy, a Leverhulme Fellowship Research Student, continued ,",orking here until the middle of June when she returned to England. She >::ompleted the first part of her study on the effect of altitude on the dew point temperatures in East Africa, and showed that the mean annual dew point is primarily controlled by the altitude, though there is a slight dependence on longitude, in that places at a given altitude in the western part of East Africa are likely to have slightly drier air than on the eastern side.

EFFECTS OF DROUGHT ON MAIZE AND SORGHUM

Mr. Glover, the Plant Physiologist, continued his work on the difference in the recovery of wilted maize and sorghum leaves after water has been added. At the end of last year he had laboratory evidence that the stomata in the leaves of sorghum behave differently from those of the leaves of maize, for he had shown that the stomata of maize leaves were permanently injured if the leaf had been severely droughted, whilst the stomata in wilted sorghum leaves appear to function quite normally after water had been added. This year he studied the behaviour of wilted sorghum plants in the field, and showed that they behaved in the same way as in the laboratory. Work has now started to examine the behaviour of the stomata in the leaves of groundnuts during and after recovery from E. drought.

The Chemistry Division

THE DECOMPOSITION OF ORGANIC MATTER IN TROPICAL SOILS

Dr. Birch has continued work on the factors which influence the rate at which organic matter or humus oxidizes in tropical soils. He has been able to show, as one would expect, that when the soil is dry, microbiological activity is low, and therefore decomposition is almost at a standstill; but at the start of the rains decomposition begins with a flush but quickly falls off to a low level ,as moist conditions continue. The practical importance of this process is that it is only during the decomposition of humus that nitrates can be produced in the soil, and these are essential for good crop growth. But since the nitrates can easily be washed out by rain, the crop must be managed in such a way that it can use these nitrates as soon as possible; so the earlier the crop can be got in ;the land without being killed by drought, the greater the proportion of the nitrates produeed which will be used for crop growlh.

This year his work has mainly been concerned with finding the reasons for Lhis flush of decomposition on wetting a dry soil, and .he has been able to show that there are at least two. The first is that when a soil is dried, it changes in such a way that on being re-wetted some of the humus it contains dissolves in the soil water, and this dissolved humus decomposes much more rapidly than that held on the soil particles. This may be because drying the soil causes the soil crumbs to shrink and crack, and 50 some of the humus that was protected from the water is now exposed and will disperse in it.

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The second reason involves both beating and drying, for this combined process will kill many of the bacteria and other micro-organisms in the soil, and these dead cells are decomposed very easily by the micro.organisms introduced when this sterilized soil is Ie-inoculated with a little fresh soil. This killing need nul be done by heat, it can be done equally by poisons such as formaldehyde, a chemical often used to sterilize or partially sterilIze glasshouse and other valuable soils.

This work has therefore shown why a soil is more productive during the early part of the wet season than later on, a result which has been confirmed by the many field ex.periments which have shown a rapid decline of yield as crops are planted progressively later after the start of the rains.

Some small field experiments have started in which it is hoped to study both the rate of decomposition of humus in soils throughout the year, and also the build·up under gras~es and under legumes, of readily decomposable humus.

The Analytical and Spectrochemical Divisions

The primary function <:>f these two Divisions is the analysis of soils and plant materials submitted either by other E.A.A.F.R.O. Divisions or by the Natural Resources Departments of the Territories, and this work occupies a very considerable propo,rtion of the time of the Divisions.

I

Mr. M. T. Friend the Analyst, was able to continue work on checking or improving chemical methods for analysing soils likely to be of impo$.ncc in the Territories. The three lines of work he was mainly concerned with were checking the reliability of a standard method for determining the organic carbon or humus in soils very low in humus, for the normal method in use appears to give too low a value, checking methods for determining the copper content of forages. and continuing his work on the fractionating of some of the phosphorous compounds in. East African soils. His results suggest that one reason why most chemical methods of soil analysis for assessing the probability that a crop will respond to a phosphate fertilizer have been disappointing in East Africa is because the Plain source of phosphorus for plant growth comes from the decomposition uf organic phosphorous which takes place by the same mechanism as the production of nitrates. which Dr. Birch has been studying.

He has also been developing a chemical method for estimating the amount of light falling on the land in conjunction with the Physics Division's work on the effect of shade trees. The normal methods of measuring solar energy is with instruments such as the Kipp Solari meter, which are accurate but very expensive, and since in the lree-shade experiment, it is desirable to measure the solar radiation at a large number of sites simultaneously, a much simpler method is required. The method under trial, which appears to be salisfactory, consists of et\posing glass tubes filled with a solullon of anthracene dissolved in benzene to the sky for a definite length of period and then determining the reduction in the concentration of the anthracene. which in sunlight becomes polymerized (Q

the insoluble dianthracene. •Most of the work of the Spectrochemical Division has been the analysis of I

soils and plant material, but as opportunity permits, work is conlinuing on finding chemical solutions which extract aboul the same proportion of the essential trace elements from a soil as plants growing in that soil take up from it. There can be no simple answer to this problem, for different species of plants take up different proportions of the important trace elements from the same soil, but there is little question 1hat the extraclants in use at the present time are far from satisfactory for many of the plants grown here.

Ir:'

15

...... •<i

~~

The work of Dr. Mil .15 studying the factors w which JS produced during the form of nitrogen plants

Two problems are bei in the field. the oxidation to get going; and the SCCI

in some soBs" i:! partial 0

the soil before it becomes significance, for quite sma harmful effects on crop g growth.

Nitrite accumulation soils whose pH has been r: such as calcium or magne often very acid. and exp consistently shown the ben done in East Africa, and t

but the general experience reJuces rather than incre. possible that this could be The work has not yet pro,g of nitrites is due to the lirr. the nitrite oxidisers.

The second major ta~

which nitrogen gas in the in the soil humus, which being studied by Dr, Birc is known that, in many s compoun.ds but poor in nill nitrogen-fiXing bacteria wil organic nitrogen compoun soil. The second aspect can up the nitrogen-containing improving the nilrogen sta lucerne crop for a few yea for equatorial soils what cJ stage of the work on bOl

techniques for quantitative will have relevance in the til

Mr. Gethin Jones re having completed 26 year has been continuing comp' Tanganyika on the scale oj memojr. A few vjsits were

Some further work ha and the paper on the preSI Specialist Committee whic minor modifications have at a special conference te il suitable system of dassiti

od drying, for this combined ~cro.organisms in the soil, and be micro~organjsms introduced tie fresh soil. This killing need )i5005 such as formaldehyde, a : glasshouse and other valuable

is more productive during the lull which has been confirmed 'n a rapid decline of yield as rt of the rains. n which it is hoped to study throughout the year, and also

eadily decomposable humus.

:cal Divisions

IS is the analysis of soils and o\.F.R.O. Divisions or by the and this work occupies a very

ns.

continue work on checking or lik.ely to be of importance in I mainly concerned with were detcrminlng the organic carbon :mal method in use appears to rmining the copper content of ng of some of the phosphorous ~est that one reason why most le probability that a crop will sappointing in East Africa is )lant growth comes from the ; place by the same mechanism as been studying.

hod for estimating the amount he Physics Division's work on measuring solar energy is with Lre accurate but very expensive. ~esirable to measure the solar sly, a much simpler method is

to be satisfactory, consists of Iracene dissolved in benzene to L determjning the reduclion in nlight becomes polymerized to

vision has been the analysis Qf ~. work is continuing on finding le proportion of the essential hat soil take up from it. There 'erent species of plants tak.e up nents from the same soil, but "tn use at the present time rown here.

9

The Microbiology Division

The work of Dr. MiHbank is complementary to that of Dr. Birch, for he .is studying the factors which control the rate of oxidation of the ammonia, which is produced during the decomposition of humus, into nitrates which is the form of nitrogen plants usually use.

Two problems are being looked into. The first is why in some surface soils in the field. the oxidation of added ammonia to nitrate takes a fairly long time to get going; and the second, of much greater agricultural significance, is why in some soils, a partial oxidation product of ammonia, nitrite, accumulates in the soil before it becomes oxidised to nitrate. This can be of great agriGulturaf significance, for quite small amounts of nitrites in the soil can have noticeable harmful effects on crop growth, 'Whereas the nitrate is essential for good crop growth.

Nitrite accumulation in soils seems to be confined to alkaline soils, or to soils whose pH has been raised appreciably by the addition of a liming material, such as calcium or magnesium carbonates. Since many soils in East Africa are often very acid, and experience in the temperate regions of the world has consistently shown the benefit of liming acid soils. many experiments have been done in East Africa, and elsewhere in the tropics, to demonstrate these benefits; but the general experience in East Africa has been that this practice of limfng reduces rather than increases yields unless the soils are vdy acid, and it is possible that this could be due, in part at least, to this accumulation of nitrites. The work has not yet progressed far enough to prove whether this accumulation of nitrites is due" to the liming stimulating the ammonium oxidisers or depressing the nitrite oxidisers.

The second major task of this Division is the study of the methods by which nitrogen gas in the soil air becomes converted to nitrogenous compounds in the soil humus, which in turn will decompose to nitrates by the processes being studied by Dr. Birch. Two aspects of this work are being looked at. It is known that, in many soils, if one adds material to the soil rich in carbon comr'bunds but poor in nitrogen. a group of bacteria known as the non-symbiotic nitrogen-fixing bacteria will multiply and convert nitrogen !l:as from the air into organic nitrogen compounds, some of which forms part of the humus in the soil. The second aspect concerns the role of certain leguminous crops. in building up the nitrogen-containing humus. In temperate agriculture. a normal way of improving the nitrogen status of a soil is to put the land down to a clover or lucerne crop for a few years, but no tropical legume crop is yet available to do for equatorJal sons what clovers and lucerne will do for temperate. The present stage of the work on both these aspects is the development of the necessary techniques for quantitative work under conditions in which the results obtained wilt have relevance in the field.

Soil Survey Division

Mr. Gethin Jones retired from this Division at the end of March after having completed 26 years in East Africa. The principal work of the Division has been continuing completing lhe Second Provisional Soil Map of Kenya and Tanganyika on the scale of I : 2 million, and the preparation of the accompanying memoir. A few visits were paid to areas which had not been adequately surveyed.

Some further work has been done on the classification of East African soils. and the paper on the present classification was submitted to the last Soil Fertility Specialist Committee which met at Muguga in February. Since then some more minor modifications have been made, and it is hoped that these will be discussed at a special conference to be called early next year on the general problem of a suitable system of classification for East African soils.

I

10

,Mr. Scott spent part of his time conducting reconnaissance surveys in some of the catchments being used in the catchment area experiments. He has also been paying more attention to reliable methods for recognizing the presence of volcanic ash in soils. There is no difficulty in recognizing soils which are almost entirely derived from volcanic asb, but- it is much more difficult when the ash has been incorporated with soil derived from an underlying rock. The reason why this problem may be of agricultural importance is that the chemical com­position of ash normally differs appreciably from that of the underlying rock, and many soils with a proportion of ash in them appear to be characterized by plants growing in them showing trace element deficiencies.

Soil and Vegetation Suneys

One of the primary problems facing the ecologists in East Africa is recogmzmg areas that were ecologically similar under natural conditions, that is areas carrying the same types of plants, but in which the natural vegetation has been so altered by the agency of man that it has become very difficult to deduce what the original vegetation was from the small remnants that are left. The lmportanee of this work is that one would expect the same crops to grow equally well, or the same weeds and bush to encroach on grazings and to be controlled by similar methods on areas which, under natural conditions, were ecologically similar. One result of the work carried out by Mr. Trapnell, the E.A.A.F.R.O. Ecologist, and the Territorial ecologists, is that there is now a far more reliable basis for recognizing original vegetation zones, particularly in areas of rea~nable

agricultural potential.

This ecological work has now reached a stage at which it is worth while planning to make a detailed map of the natural vegetation zones of the south­western part of Kenya, in which the larger part of the population of the country is concentrated. Plans are therefore being made for a co-operative project between the ecolpgist and possibly the soil surveyor E.A.A.F.R.O., the Land-Use Officer of the Directorate of Overseas Surveys, England, and the field staff and other officers of the Department of Agriculture, Kenya, to produce such a map on a scale of 1: t million. The map win be based on an intensive study of air photos, comlJined with existing knowledge of the distribution of the principal types of natural'vegetation in the area. This map can then be used as the basis both for the planning of the agricultural research projects and also of the most profitable lines of agricultural development in the major natural vegetation zones.

An incidental result which Mr. TrapneU has just established from the preliminary work needed for this project is that there are two boundaries dividing the central area of Kenya into three basic ecological zones; one separating a zone flanking Lake Victoria from the central highlands about the Rift Valley and a second separating this central zone from the region to the east of it. These two lines clearly separate the areas of high African population, namely those of the Kikuyu and kindred tribes to the east and of the Nyanza tribes to the west, from the central area with a low to very low population which includes most of the White Highlands. The climatic characteristic which gives this division has also been recognized. It is that the high population areas have an annual rainfall which is well in excess of 6 in. per 1,000 ft. elevation, whereas in the central RifL zone the mean annual rainfall is less than 6 in. per 1,000 ft. elevation. This has the consequences that where the rainfall is adequate for the usual tropical crops in the central Rift zone, the temperatures are getting too low for them, because the height for a given rainfall is considerably greater in this zone than outside it.

--:. _ " 4.',...

Plant'"

These two lines of work.1 as they were in the old B.A. } much of the plant breeding w( plants immune to, or highly TIl:

work on improved systems 0

confined to testing the Briege better maize varieties. A new Ii is a sorghum breeding research sorghums more resistant to th yields,

MAIZE: BRIEGER METHOD FOR.

This work has been done L R. Doughty. The metho,( i' maize, based on local varietie yields comparable to hybrid r. retaining a high level of vigoll two or three generations, selec yield whilst maintaining other I

of this group among themsel't' progeny are then grown togetl of commercial seed.

The stage the work has r these breeding units are being from which they were produce: season was extremely unfavour and erratic during the early pa rain fell later, yields will be I are not yet available, but the produced any outstanding maize

For this, and other reasoO! of the year, the Eldoret sub-stal over to the Department of Ag producing better synthetic variel

SORGHUM BREEDlNG

This is a new research sel Agricultural Experiment Station the Director of Agriculture. Tl yields of East African sorghun characters from a wide range a and out~de East Africa which diseases which are obviouslY re

• to assemble together in anum j likely to reduce the damage do

few fungal diseases and insect storage propcrties.

A second line of work is 1 many desirable characters as pc first is to test the possibility tb as a true "hybrid sorghum". The

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........ ''''-'k'~",. '·\.I~'4J~,

',~W'., '~~S'.i.~~,Mi<,i¥"~ :; ...;~

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•

wnnaissance surveys in some ea experiments. He has also

recognizing the presence of oiling soils which are almost more difficult when the ash

underlying rock. The reason ce is that the chemical com~

that of the underlying rock, ~ppear to be charncterized by ncies.

yo

:cologists in East Africa is ler natural conditions, that is c:h the natural vegetation has :come very difficult to deduce remnants that are left. The e same crops to grow equally ;razings and to be controlled conditions, were ecologically . Trapnell, the E.A.A.F.R.O. e is now a far more reliable ~ularly in areas of reasonable

~ at which it is worth while ~getation zones of the south­he population of the country

for a co-operative project E.A.A.F.R.O., the Land-Use

lland, and the field staff and Kenya, to produce such a

lsed on an intens.ive study of ~ distribution of the principal an then be used as the basis Irojects and also of the most .,.jor natural vegetation zones.

i just established from the :: are two boundaries dividing Ical zones; one separating a lands about the Rift Valley egion to the east of it. These population, namely those of

Ie Nyanza tribes to the west, ulation which includes most which gives this division has ueas have an annual rainfall ltion, whereas in the central . per 1,000 ft. elevation. This :quate for the usual tropical :e getting too low for them, ~ greater in this zone than

11

Plant Breeding and Plant Pathology

These two )ines of work have always been closely linked at E.A.A.F.R.O .. as they were in the old E.A. Agricultural Research Institute. at Amani•.bc:cause much of the plant breeding work is concerned with producmg new varieties of plants immune to, or highly resistant to, spe~ific diseases. B.ut in addition s~me

work on improved systems of plant breeding has been In progress, mamly confined to testing the Brieger method as an efficient method for producing better maize varieties. A new line of work has started this year. however, which is a sorghum breeding research scheme, again with the .basic obje~t of producin.g sorghums more resistant to the principal pests and diseases which lower thelI yields.

MAIZE: BRIEGER METHOD FOR PRODUCING IMPROVED LINES

This work has been done at the Eldoret sub-station under the direction of L. R. Doughty. The method-is a possible technique for producing varieties of maize based on local varieties which are known to do well, which will give yields' comparable to hybrid maize but form a balanced heterotic population retaining a high level of vigour. The principle of the method is to inbreed for two or three generations, select those lines which show the least· falling off in yield whilst maintaining other desirable characters, and then cross the members of this group among themselves, and those parents giving the best all round progeny are then grown together to form a breeding unit for the production of commercial seed.

The stage the work has reached is that this year the yields. of several of these breeding units are being compared with the yields of the original varieties from which they were produced in a number of field trials. Unfortunately the season was extremely unfavourable, as the rains came late and were very light and erratic during the early part of the growing season. and although adequale rain fell later, yields will be light. The results from most of the experiments are not ~et available, but the indications are that the Brieger method has not produced any outstanding maize stocks.

For this, and other reasons, including Mr. Doughty's retirement at the end of the year, the Eldoret sub~station is being closed. The seed is all being handed over to the Department of Agriculture. Kenya, who will continue working on producing better synthetic varieties.

SORGHUM BREEDING

This is a new research scheme, and the work will be done at the Serere Agricultural Experiment Station, Uganda, through the very kind co-operaHon of the Director of Agriculture. The object of the work is to study how far the yields of East African sorghums can be increased by incorporating into them characters from a wide range of sorghums and related species from both within iJnd out~de East Africa which will confer resistance to a number of pests and diseases which are obviously reducing yields seriously. In particular it is hoped to assemble together in a number of sorghum varieties a range of characters 'likely to reduce the damage done by Quelea birds, as well as by Stdga and a few fungal diseases and insect pests, whilst maintaining palatability and good storage properties.

A second line of work is the production of tetraploid sorghums having as many desirable characters as possible. This is being done for two reasons. The first is to test the possibility that a suitable tetraploid can be as high yielding as a true "hybrid sorghum". These have given yields 20·25 per cent above normal

)

to East Africa for many ties can be produced, this if a useful tetraploid variety Itivators, and they can grow

aI thai the seed they produce the local varieties. This would .loid variety was issued in each me.

ich causes white lines running 7th of the plant and may put "arried from plant to plant by varieties of maize, originating ct of the work in progress is e Hnes of maize. resistant or Jse. have been isolated from md the first crosses have been Once seed from these crosses ible to form some idea of the the resistant South African to

idERICAN MAIZE RUST

,f the two rust races, on Iy one )f a number of resistant lines ar in the field. we shall be in g resistance to this new race. produced in East Africa are

10 indications of any new races

BROWN STREAK

to produce cassavas having as ~s Mosaic and Brown Streak, ,jJ.ity. The work was initially amme based on incorpora ting ~ally got under way after the appreciable improvement over a much larger and long-term

led.

luced in thIS programme have :ulture of Kenya, Tanganyik<l )f those produced in 1946 and vators in the Tanga Province; ,e still being tested at Amani. lem can be distributed to the umber of variety trials in the Ice of Tanganyika have been ny clones issued from Amani arently endemic around Lake es likely to be of value there reak by the end of next year.

13

Plant Patbology

RATOON STUNTING OF SUGAR CANE

This is a virus disease which causes sugar cane faloons to grow much more weakly than they should, so giving a rapid decrease in yield of sugar cane fields which in turn involves the re-planting of the fields with new healthy canes at much too short intervals. The great hindrance to research on this disease is the difficulty of diagnosing if a plant is infected or not, 'for so far no reliable symptoms of the disease in the plant have been recognized: the only symptom of infection which may take many months to show is that the plant makes increasingly poor and stunted growth compared wHh a healthy plant.

Dr. Sheffield has been searching for reliable diagnostic symptoms for the presence of the disease. She has tested all the published methods based on an examination of the sugar cane plant and has found that none are reliable. She has also been inoculating other plants with the virus, including plants which are susceptible to many plant virus diseases, and other monocotyledons including graminaceous species, some of which are known to be symptomless carriers of .the disease. in the hope of finding at least one plant which would develop recognizable symptoms fairly rapidly and reliably when infected with the virus.

STEM-PIITING CONDITION IN COFFEE

This is a disorganization of the xylem cells at the base of stems of Arabica coftee, causing the base to swell into a bottle-shape, and when the bark is peeled oIT the wood has vertical grooves and pits. It was first ,recognized at the Tanganyika Coffee Research Station, Lyamungu. in 1956, ""here some young 'Coffee trees having this disorder were also chlorotic and died. and the plant pathologist there was unable to isolate any visible pathogen. Since it could be due to a plant virus, Dr. Sheffield was called in, and the work reported here has been done in close co-operation wjth the pathologist.

The present stage of the investigation is that this disorder has been recognized in Arabica coffee at a wide range of sites in Kenya and Tanganyika, mainly in trees up to seven years old. but it is possible it has occurred in older trees but symptoms become hidden as the tree ages. The disorder has now been accurately described, and the chlorosis originally noticed is not a part of it, although trees wittr this disorder may be more liable to suffer from a chlorosis if they are allowed to over-crop when young. But the cause of the'disorder has not yet been found. though work is in progress to check if it could be due to a virus.

PLANT NEMATODE DISEASES

These diseases are caused by minute round worms or nematodes which live on living plant tissue and usually attack the roots of the plant, giving them a stunted and inefficient root system and so reducing their yield and their liability to suffer during periods of drought or jn poor soils. Some of these nematodes live in the roots of the plant, forming galls, and others live in the sojt around the roots feeding on their surface.

Mr. A. G. Whitehead has nearly completed a two~year survey of the incidence uf these diseases on the more important crops in East Africa, but his work On identifying the various species of nematode attacking the crops will take longer than expected because he has found a considerable number of new species which (have not before been recognized, and the crops here are often attacked by a greater range of closely related spedes simultaneously than normally occurs in temperate agriculture. During the course of the year a number of new specie~

·- ..~...:. ~ .,>~--"

14

belonging sometimes to new genera, and even new sub-families, have been recog­nized and described. The correct separation of the nematodes into their correct species is of great practical importance because each species is likely to attack a different range of plants. Until these species can be properly separated it will • not be possible to start work devising methods for their control.

PROTECTtON OF EAST AFRICA FROM INTRODUCED PLAtH PESTS AND DISEASES

E.A.A.F.R.O. and its predecessor, The East Afrjcan Agricultural Research Institute at Amani, has been intimately concerned with trying to prevent new plant pests and diseases from entering East Africa ever since 1934, when a conference was held under the auspices of the Conference of Governors of British East African Territories, the forerunner of the East Africa High Commission, to formulate a set of rules for regulating the import of plants. There is now a Standing Technical Committee of Plant Import and Export on which officers from the three mainland Territories and from Zanzibar and Dr. Sheffield from E.A.A.F.R.O. sit under the chairmanship of Dr. H. H. Storey. Considerable additional work fell on these two virus pathologists this year, because an Inter-African Phyto-Sanitary Convention had been signed by the British Government and in consequence measures laid down ~y its Commission regulating all plant imports into Africa became binding on the East African Governments. Policy was discussed_ and agreed by a meeting of Experts called by the Inter-African Phyto-Sanitary Commission in Nairobi in April this year. The problem for this meeting was to ensure that the recommendations passed would be neither so stringent as to prevent territories importing plants needed for improving their agriculture, nor so lax as to permit entry of diseases dangerous not only to the importing territory but also to its neighbours. Fortunately owing to the large amount of previous experience gained in East Africa .the agreed procedures were very largely based on our practice. The framing and criticism of recommendations has involved our staff in a considerable amount of additional work.

The E.A.A.F}R.O. pathologists have a further responsibility because the East African PlatH Quarantine Station is situated at Muguga, and they are responsible for its scientific supervision. No plant can be released from quarantine until it has been proved free from disease. Unfortunately some of the diseases which it is most important should be prevented from entering East Africa can be carried in species of plants that show no signs of the disease; but if the disease spreads to other plants they will be severely affected. This testing of plants which are symptomless carriers of disease is a further major commitment for Dr. Sheffield.

The Animal Husbandry Division

The Animal Husbandry Division is primarily concerned with problems of the nutrition of farm animals, but its programme includes general problems of animal management. particularly as these affect the efficiency of food utilization. and some attention is also being paid to the strictly local problems of finding out how to raise the carrying capacity of pastures at Muguga. The work of the Division is divided into five principal sections: the nutrition and management of pigs, whether for bacon or for pork; the nutrition of beef cattle, sheep and goats, which has hardly been started; the biochemistry of foods, which is really ancillary t to the two preceding lines of work; the assessment of the carrying capacity of pastures and rangeland which has not yet been started; and the assessment of the quality of beef carcasses whether on the slaughtered or in the live animal.

~

The pig work last year fell into two groups: that concerned with the nutrition of the bacon pig. and that concerned with pig management, particularly farrowing and the raising of piglets. The pig nutrition work principally dealt with the problems of feeding rations high in maize. The first experiment tested the effect

of a high maize ration on belief that this gives a fat thl containing between 15 and and although the high maiz, on carcass quality; but the pigs appreciably without he food consumed to liveweigh to find the cause of this sIo\1 acid, a member of the vital acids, and it is also known tI and nicotinic acid in vadou 75 per cent of the cereal wa added per 1()() lb. of ration. of pigs fed on normal cereal produced top-grade bacon c. material, the cost of the raj and a low maize content.

The next group of tria: content can be still further high in one or two of the health in maize.

Two problems of pig IT

suitable farrowing houses characteristic of many areas piglets warm at night at tbl showing that the round faJ with an infra-red lamp for 1 ably at little additional cos of piglets apart from their be of practical importance more than 10 to 12 piglets, 0

The preliminary trials sugg substitute, though the stane it to be of practical importa

CARCASS BvALUATION

The reason for underu and during this year the wor Boran carcasses have been our analyses has shown that those of beef breeds in the l way fat is laid down as the increasing proportion of the the skin, whereas the Bora: inter-muscular fat; and this adaptation of indigenous caU fore to test if British breew do in temperate climates, practical importance in t muscular fat must be sold bad one for the African

t..~ .> -."

ub-famiLies, have been recog· nematodes into their correct

ch species is likely to attack be properly separated it wHi beir control.

'lIT PESTS AND DISEASES

.frican Agricultural Research th trying to prevent new plant nce 1934, ~hen a conference vernors of British East African Commission, to formulate a

e is now a Standing Technical icers from the three mainland from E.A.A.ER.O. sit under .ble additional work fell on Inter·African Phyto-Sanitary ~mment and in consequence aU plan1 imports into Africa ts. Policy was discussed and Inter~African Phyto-Sanitary roblem for this meeting was :I be neither so stringent as

improving their agriculture, lS not only to the importing ;ving to the large amount of ,procedures were very largely 'ccommendations has involved vork.

~r responsibility because the I at Muguga, and they are l be released from quarantine unately some of the diseases om entering East Africa can the disease; but if the disease . This testing of plants which commitment for Dr. Sheffield.

Ision concerned with problems of [neludes general problems of efficiency of food utilization. local problems of finding out

Muguga. The work of the lUtrition and management of . beef cattle, sheep and goats, )ooS, which is really ancillary

of the carrying capacity of Irted; and the assessment of red or in the live animal.

concerned with the nutrition ieIllent, particularly farrowing I: principally dealt with the I experiment tested the effect

15

of a high maize ration on the hardness of the carcass fat, for it is a common belief that this gives a fat that is too soft for a good quality bacon carcass. Rations containing between 15 and 90 per cent of the cereals as maize were fed to pigs; and although the high maize ration gave a slightly softer fat, this had little effect on carcass quality; but the high maize rations reduced the rate of growth of the pigs appreciably without however affecting very much their convertion ration of food consumed to liveweight gain. In a second experiment an attempt was made to find the caUse of this slower growth rale, Maize is known to be low in nicotinic acid, a member of the vitamin H complex, as well as in certain essential amino­acids, and it is also known that there is some inter-relationship between tryptophan and nicotinic acid in various body processes; so a ration was made up in which 75 per cent of the cereal was maize, but to which 1 gramme of nicotinic acid was added per 100 lb. of ration. This addition brought the growth rates bac!, to that of pigs fed on nonnal cereal rations. and eight of the ten pigs receiving this ration produced top-grade bacon carcasses. Further, since nicotinic acid is a fairly cheap material. the cost of the ration was no more than one based on barley, pollards and a low maize content.

The next group of trials wlll be concerned with finding out if a high maize content can be still further improved by choosing a protein supplement which is high in one or two of the amino acids considered to be too low for adequate health in maize.

Two problems of pig management have been looked into. The first is finding suitable farrowing houses to reduce the rather high pig mortality which is characteristic of many areas in Kenya, due apparently to the difficulty of keeping piglets warm at night at the altitudes of Kenya' Highland fafms. Our results are showing that the round farrowing house, developed at Ruakura, New Zealand. with an infra·red lamp for the piglets, is likely to reduce mortality very consider­ably at little ad.d.itional cost. The second problem concerns the artificial raising of piglets apart from their dams after they have received colostrum. This could be of practical importance for several reasons, such as when dams give birth to more than 10 to 12 piglets, or if she loses her milk, or if she dies during farrowing. T!t'e preliminary trials suggest that we can raise piglets at Muguga on a milk substitute, though the standard of management necessary may be too high for it to be of practical importance under farm conditions.

C.\RCASS EVALUATION

The reason for undertaking this work was described in last year's Report, and during this year the work has continued on much the same lines. Twenty-four Boran carcasses have been analysed during the year, and an examination of all our analyses has shown that the carcasses of these animals differ appreciably from those of beef breeds in the Unhed Kingdom. The difference basically concerns the way fat is laid down as the animals come to maturity. British cattle lay down an increasing proportion of the fat they put on as subcutaneous fat, that is fat under• the skin, whereas the Borans in Kenya lay down an increasing proportion as inter-muscular fat; and this difference is probably the consequence of the better adaptation of indigenous cattle to a hot climate. One of our next problems is there­fore to test if British breeds of beef cattle raised in East Africa behave as they do in temperate climates, or as East African cattle behave. This point is of practical importance in that subcutaneous fat can be sold as fat, whilst inter­muscular fat must be sold as meat, a good point for the European market, but a bad one for the African who will often pay more for fat than for meat.

1

]

t

l

16

The method of work has been changed during the year in that cattle are no longer killed at Muguga, but thanks to the full co-operation of the Kenya Meat Commission, all cattle are now slaughtered at the Athi River factory, and one side from each animal is returned to Muguga for dissection. Mr. Ledger, who is doing this work, is given every facility to follow the animal through the factory, and this ensures that carcasses are dressed in such a way that they are all strictly comparable, and they are all graded by the Kenya Meat Commission staff. The main advantage of this arrangement is that fOUf carcasses can now be dissected a week instead of one, and the principal disadvantage that offal records are no longer being obtained.

One of the problems on which we have been working in co-operation with the Veterinary Department of Tanganyika has been to test how far an analysis of a joint cut at the tenth rib can give a reasonably accurate estimate of the proportion of bone, meat and fat in the carcass as a whole. We have shown that an analysis of a full tenth rib joint, including the flank, enables very accurate estimates of the percentage of fat, lean and bone in the animal to be made, at a considerable saving of time.

A further problem on which we have done some work this year, in conjunc­tion with Dr. Roger,son of E.A.V.R.O., is testing the reliability of a method for estimating the total fat in a live animal, based on injecting antipyrine into the blood stream of the animal, and then determining its concentration in the p'asma. The results so far have been rather disappointing. but work will continue on this for a little longer.

THE CARRYING CAPACIlY OF MUGUGA PASTURES

A trial lasting for nearly two years has been completed in which 49 Boran­type steers were ,grazed on 70 acres of pasture consisting of one-third star grass and two-thirds couch grass. We found that at this grazing density of It. acres per beast the pastures could maintain average liveweight gains of 0.75 lb. per head per day from an initial weight of 500 lb. up to weight of 800 lb., but that from 800 to 900 lb. livewelght the rate of gain was very much less. They in fact took 60 weeks to put On 300 lb., and they put on another 100 lb. in the next 30 weeks, showing that in a pasture such as this the grazing density was definitely too high for stock coming to maturity.

The Silviculture Division

The field work of this Division falls into four main classes, namely research into methods for raising better plants from seed in the nursery; the best practices for lifting the plants from the nursery and planting them out ;n the forest, so they have the maximum chance of making rapid growth; comparisons of the growth rates,' habits of growth, and liability to disease of different exotic tree species for picking out any that are likely to be of commercial or practical use in East Africa; and finally observations on the rates at which pruning wounds heal, and the way in which they heal. All these lines of work involve observations over a number of years, and they are all being carried out in close co-operation with the silvi­culturists in the Territorial Forestry Departments. In addition the Division runs a Forestry Bureau, which is an infonnation service, and which issues periodical lists of results of recent forest research likely to be of interest to the Territorial Departments.

Some nursery problems which were not mentioned in last year's Report include an investigation on whether the size of the seed of any particular tree is of importance. that is whether the larger seeds give better plants than the smaller seeds. So far the plants raised from the larger and the smaller seeds have not

sho~n any difference in eit investigation is whether see(j than the average give bette! difference has been found in continued on whether pine Sl

under the same species of pi to the soil in which the seei in transplant beds, and on " during dry weather.

The experiments on tra type of root system the pIa plants before planting, and work is in progress on the n the year is that one can anI) trees are regularly pruned; the site at which wood bori heavy a pruning reduces the an intensity and a time of p as possible, and which gives to attack the trees.

In the longer-term trials strains of Eucalypts are beir growing well. In the Arborel containing up to 49 trees, a Pinus [Xl/ufa raised frorp vari and better than their neighb

The Herbarium has be Dr. Greenway retired at th service in East Africa mainly to replace him. Fortunately Herbarium of the Imperial F culture, Uganda, joined the s to prevent work accumulatin

The staff have continued the very large amount of inf This has involved neglecting very large accumulation of n limited very severely the tin revising families and genera Africa. However both these various parts of East Africa.

• Tbe East.

E.A.A.F.R.O. maintains , African Governments. The 5t of experts of the Inter-Afrie: April, and it is gratifying to the Station and the methods quarantine requirements WID' Convention will require 5011)1

~.

,.-. .,.;:-......J#... '... .".~;.. ~.

, .. ' ­

e year in that cattle are no eration of the Kenya Meat thi River factory, and one ection. Mr. Ledger, who is 'Dimal through the factory, ray that they are all strictly [eat Commission staff. The asses can now be diss.ected e that offal records are no

)rking in co-operation with ~o test how far an analysis y accurate estimate of the ~hole. We have shown that ank, enables very accurate le animal to be made, at a

work this year, in conjunc­reliability of a method for Ijecting antipyrine into the oncentration in the plasma. work will continue on this

lpleted in which 49 Boran­ting of one-third star grass :ing density of 11 acres per gains of 0.75 lb. per head t of 800 lb" but that from Ilcb less. They in fact took lO lb. in the next 30 weeks, dty was definitely too high

in classes, namely research nursery; the best practices n out in the forest, so they :omparisons of the growth rent exotic tree species for ractical use in East Africa; wounds heal, and the way rvations over a number of .-operation with the silvi­lddition the Division runs ld which issues periodical interest to the Territorial

led in last year's Report d of any particular tree is ler plants than the smaller Ie smaller seeds have not

17

shown any difference in either height, growth or survival percentage. Another investigation is whether seedlings of a given species producing more cotyledons than the average give better plants than those producing fewer, and again no difference has been found in the subsequent plants. Then experiments have been continued on whether pine seedlings should be transplanted into a soil taken from under the same species of pine, on the amounts of fertilizer that should be added to the soil in which the seedlings are grown, on the spacing between the plants

• in transplant beds, and on whether it is possible to restrict evaporation from soil during dry weather.

The experiments on transplanting into the forest concern such things as the type of root system the plant is given, the eITect of exposing the roots of the plants before planting, and the effect of the date of planting. The reason that work is in progress on the rate of healing of pruning wounds at different times of the year is that one can only obtain clean knot-free timber from softwoods if the trees are regularly pruned; but pruning wounds until they are healed over are the site at which wood boring insects attack and enter the living trees, and too heavy a pruning reduces the rate of growth of the tree, One has therefore to find an intensity and a time of pruning that sets back the growth of the tree as Uttle as possible, and which gives the minimum opportunity for the wood boring insects to attack the trees.

In the longer-term trials an international Eucalypt trial in which 12 species, or strains of Eucalypts are being compared is now two years old uf}-d t.he trees are growing well. In the Arboretum, which consists of plots about l/lOth of an acre containing up to 49 trees, another nine new plots were planted, six of them to Pinus patula raised frorp various Kenya trees which are growing appreciably faster and better than their neighbours. .

East African Herbarium

The Herbarium has been running short-staffed for most of the year as Dr. Greenway retired at the end of March after completing nearly 30 years service in East Afriea mainly on herbarium work, and it has not yet been possible to repli:l&e him. Fortunately Mrs. M. E. Church, previously on the staff of the Herbarium of the Imperial Forest Institute, Oxford. and the Department of Agri­culture, Uganda, joined the staff for four months whieh helped very considerably to prevent work accumulating after Dr. Greenway's retirement.

The staff have continued naming the collections sent in to them, and supplying the very large amount of information which is continually being asked of them. This has involved neglecting the laying away in their proper cupboards of the very large accumulation of named and mounted sheets on the one hand, and has limited very severely the time Dr. Verdcourt and Miss Napper can spare for revising familjes and genera of plants for inclusion in the Flora of Tropical East Africa. However both these officers had opportunities for making collections in various parts of East Africa.

> The East African Plant Quarantine Station

E.A.A.F.R.O. maintains and operates this Station on behalf of the four East African Governments. The Station was visited by specialists attending the meeting

• of experts of the Inter-African Phyto-Sanitary Commission held in Nairobi last April, and it is gratifying to report that they expressed their general approval of the Station and the methods employed. They made some recommendations..on quarantine requjrements which if accepted by the Governments signatory to the Convention will require some alterations to the buildings.

I

ntine Station continue to be at Muguga before cane can

.Iion at Kawanda has recently ~released this year was less than

hree varieties of banana, some meso The Pinus radiata scion m Australia and grafted on to

Jourual

the four issues which appeared :ludiog animal husbandry, crop

and management, agricultural prodl.lCt~n and management.

d entomology, silviculture and !Ceived has increased during the e is over 10 pages. Publication ~ increased volume of suitable has also added to the annual

roltural and Fisheries Research )uld be raised from Sh. 10 to :h the July issue. It is too early iption list and on the revenue, n January, but it is hoped that be three East African Govern­50 per cent, but a substantial ~uired in order to balance the

1\1 AGRICULTURE AND i\T 31st DECEMBER, 1958

>r.

Officer-in-Charge. nist.

lt Farm Manager.

19

Chemical Analysis, General

M. T. Friend, M.Sc., AR.1.C., General Chemical Analyst.

Spectrochemistry

G. T. Chamberlain, Spectrochemist. A. J. Searle, Scientific Assistant. C. A. Spinage, Scientific Assistant.

• Ecology

C. G. Trapnell, O.B.E., B.A, Ecologist.

Forestry

A 1.. Griffith, O.B.E., M.A., D.Sc., Silviculturist-in-Charge. P. Howland, Forester.

Forest Entomology W. Wilkinson, B.Sc., M.I.Biol., Forest Entomologist.

Horticulture W. B. May, F.R.H.S., Horticulturist.

Microbiology J. W. MiUbank, B.Sc., Ph.D., Microbiologist. Mrs. M. Ledger, Scjentific Assistant.

Nematology A. G. Whitehead, B.Sc., A.R.C.S., Nematologist.

Plant Breeding and Genetics

L. R. Doughty, B.Sc. (Agric.), N.D.A., Geneticist. H. Doggett, M.A., A.I.C.T.A., Plant Breeder. T. Graham, Agricultural Assistant.

Plant Pathology

II. H. Storey, C.M.G., M.A, Ph.D., F.R.S., Pathologist-in-Charge. Miss F. M. L. Sheffield, D.Sc., Plant Pathologist. Mrs. A. K. Howland, B.Sc., Scientific Assistant.

Plant Physiology J. Glover, M.Sc., Plant Physiologist.

Physics

(H. C. Pereira, B.Sc., Ph.D.), Physicist-in-Charge. O. Kerfoot, B.A., B.Sc., Silviculturist. J. S. G. McCulloch, B.Sc., Ph.D., Soil Physicist. M. Dagg, B.Sc., Ph.D., Soil Physil:ist. P. H. Hosegood, Scientific Assistant. J. W. Simmons, Scientific Assistant.

Soil Survey R. M. Scott, B.Sc., Soil Surveyor.

• Systematic Botany

B. Verdcoust, B.Sc., Ph.D., Botanist-in-Charge of the East African Herbarium. Miss D. M. Napper, B.Sc., Scientific Assistant. J. G. B. Newbold, B.A., Scientific Assistant.

,

20

DEPARTURES FROM RESEARCH DIVISION SINCE 31sT DECEMBeR. 1957

J. Quarterman, Ph.D., A.R.Le., Biochemist, resigned. D. W. Gourlay, B.A. (Agric.), Field Experimentalist, on leave pending retire­ ...

ment from 6-10-58. J\1iss J. M. Kenworthy, B.A. Research Student. G.H. Gethin Jones, M.Sc., Soil Surveyor-in-Charge, retired on completion of

agreement. ,•P. J. Greenway, O.RE., D.Se., F.L.S.• Botanist-in-Charge of the East African

Herbarium, on leave pending retirement from 1-4-58.

MISCELLANEOUS SCIENTIFIC SERVICES

loin! E.A.A.F.R.o.! E.AY.R.O. Library

Mrs. L. Verdcourt. A.L.A.. Librarian.

The East African Agricultural Journal

(D. W. Duthie. M.A., Ph.D., F.RJ.C.), Editor. Mrs. P. D. HQsegood, Assistant Editor.

Plant Quarantine Station • (Miss F. M. L. Sheffield, D.Se.), Pathologist-in-Charge. P. J. Dickinson, Dip.Hort., Scientific Assistant.

ADMINISTRATION

Lt.-Col. G. G. Robson, Secretary. D. Stephenson, A.LM.T.A., Aceountant. J. B. Drummond, Maintenance Superintendent. L. R. F. D'Souza, Storekeeper.

List of Papers Published Duriug 1958

BIRCH, H, F, (1958).-The effect of soil drying on humus decomposition and nitrogen availability. Plant and Soil, 10, 9-31.

BiRCH, H. F. (1958).-The pattern of humus decomposition in East African soils. Nal"re. Land., 181. 788.

CHAMBERLA1N, G. T. (I 958).-Trace elements in East Africa. Nairobi sci. phil. Soc., 1958.

DUTHIE, D. W. and GLOVER, J. (1958).-The digestible protein of ruminant feeds by calculation. E. Afr. agric. J., 24, 33-36.

DUTHIE, D. W., DENT. A. F. and LEDGER, H.P. (I958).-Maize in pig feeding. Bull. Pig. Industr. Bd. Kenya, 3, 6-7.

DUTHIE. D. W., DENT, A. F. and LEDGER. H. P. (1958).-EtIeet of maize on fat hardness and growth rate in bacon pigs. Nature, Land., 182, 953-954.

DUTHIE, D. W., DENT, A. F. and LEDGER, H. P. (1958).-The effects of maize in pig rations. E. Atr. agric. J., 2~, 106-110. ~

GLOVER, J. and MCCULLOCH, J. S. G. (1958).-Empirical relation between solar radiation and hours of sunshine. Qutlfl. J. R. met. Soc., 84, 172-175.

GLOVER. J. and DUTHIE, D. W. (1958).-The nutritive ratio/crude-protein relation­~

ships in ruminant and non-ruminant digestion. J. agric. Sci" 50, 227-229.

GLOVER, J. and McCULLOCH, J. S. G. (l958).-The empjrical relation between solar radiation and hours of bright sunshine in the high-altitude tropics. Quart. J. R. met. Soc., 84, 56-60.

GREENWAY, P. J. (I958).-East . November.

GRIFFIllI. A. L. (1956).-Eueall Conj., Rome, 1956.

GRIFFlllI, A. L. (J957).-East C. lusitanica group. Emp. j

GRIFFITH, A. L. (1958).~A list snout beetle Gonipterus sc Note No.9.

GRIFFITH, A. L. (J958).-The , forest. E.A.A.F.R.O. For,

HESSE, P. R. (1958).~Fixation

biologia, 171-181.

HOWLAND, P. and GRIFFITH, A E.A.A.F.R.O. Forestry Te< Tech. Note NOle No.8.

KENWORTHY, JOAN M. and GLO~

Kenya. E. Afr. agric. I., 23,

MAY, W. B. (1957).-Raising COl

MAY. W. B. (1958).-ln my Ker July-December.

PEREIRA, H. C. (1958).-The lir Irrigation Scheme, Kenya.

PEREIRA, H. C. (I958).-May te

PEREIRA, H. c.. WOOD, R. H., BR Water conservation by fallj expo Agric., 26, 213-228.

RUSSELL, E. W. (J958).-Manag and Farm, 23, 12.

SHEFFIELD, F. M. L. o958).-Vil Transmission to alternative

SHEFFIELD, F. M. L. (1958).-] F.A.O. Plant Prot. Bull., 6,

STOREY. H. H., HOWLAND, Au breeding maize resistant tc Emp. I. expo Agric., 26, 1-11

VERDCOURT, B. (1957).-Notes Description of new species Lond., 32. 241-244.

VERDCOURT, B. (I958).--The Gu N.E. Tanganyika. Tanganyi

VERDCOURT, B. (I958).-Flora c Crown Agents for the Colo

VERDCOURT, B. (l958).-Dr. P. I,

VERDCOURT, B. (I958).-Notes <> VERDCOURT, B. (I958).-A mysl.

Soc., 23. 15.

ICE 31sT DECEMBER, 1957

resigned. entalist, on leave pending retire­

:nt. Jharge, retired on completion of

st-in-Charge of the East African from 1-4-58.

SERVICES

r.

.i-in-Charge. t.

nl.

Iring 1958

~ on humus decomposition and ;1.

>mposition in East African soils.

ast Africa. Nairobi sci. pldl. Soc..

estible protein of rumInant feeds

. (1958).-Maize in pig feeding.

. (1958).-Ellect of maize on fat 'ure, Land., 182, 953-954. (l958).-The effects of maize in

Empirical relation between solar ~. mel. Soc., 84, 172-175. ·itive ratio Icrude-protein relation­n..I. agric. Sci., 50, 227-229.

-The empirical relation between tine in the high-3.1titude tropics.

21

GREENWAY, P. J. (1958).-East African botanist. Parts 1-3. Corona, 10, Septemher­November.

GRIFFlTIf, A. L. (l956).-Eucalypts in British East Africa. Proc. World Eucalyptus Conf" Rome, 1956.

GRIFfITH, A~ L. (l957).-East African quality classes for the cypresses of the C. lusitanica group. Emp. For. Rev. 37, 117-118.

GRIFFITH, A. L. (I958).-A list of Eucalyptus species known to be attacked by the snout beetle Gonipterus scufellafus (Circulionidae). E.A.A.F.R.O. For. Tech. Note No.9.

GRIFFITH, A. L. (l958).-The stock mapping to quality classes of an even aged forest. E.A.A.F.R.O. For, Tech. Nole No. 10.

HESSE, P. R. (I958).-Fixation of sulphur in the muds of Lake Victoria, Hydro­biologia, 171-181.

HOWLAND, P. and GRIFFITH, A. L. (I957).-Muguga Arboretum. (A revision of E.A.A.F.R.O. Forestry Technical Note No.4 of 1954). E.A.A.F.R.O. For. Tech. Note Note No.8.

KENWORTHY, JOAN M. and GLOVER, J. (1958).~The reliability of the main rains in Kenya. E. Afr. agric. J., 23, 267-272.

MAY, W. B. (I957).-Raising conifers in East Africa. Gdnrs. Chron .. 142, 385.

MAY, W. B. (l958).-ln my Kenya garden, Parts 1-6. E. Afr. Field and Farm. 23, July-December.

PEREIRA, H. C. (l958).-The limited utility of flood-water in the Perkerra River Irrigation Scheme, Kenya. E. Afr. agric. .I., 23, 246-252.

PEREIRA, H. C. (l958).~May tea plantations replace forests? Corona, December.

PEREIRA, H. C., WOOD, R. H., BRZDSTOWSKI, H. W. and HOSEGOOD, P. H. (1958).­Water conservation by fallowing in semi-arid tropical East Africa. Emp. J. expo Agric., 26, 213-""8.

RUSSELL, E. W. (l958).-Managing semi-arid pastures in East Africa. E. Afr. Field and Farm, 23, 12.

SHEFFIELD, F. M. L. (l958).-Virus diseases of sweet potato in East Africa. Part 2. Transmission to alternative hosts. Phytopathology, 48. 1-6.

SHEFFIELD. F. M. L. (l958).~Requirements of a post-entry quarantine station. F.A.o. Plant Prot. BIlJl., 6, 149-152.

STOREY, H. H., HOWLAND. AUDRIE, K., et al. (l958).~East African work on hreeding maize resistant to the tropical American rust, Puccinia polysora, Emp. J. expo Agrie., 26, 1-17.

VERDCOURT, B. (l957).-Notes on the snails of N. E. Tanganyika Territory, 8. Description of new species of Enidae and Stenogyridae. Proc. malac Soc. Land., 32, 241-244.

VERDCOURT, B. (1958).-The Gulellae (Moll. Streptaxidae) of the Usambara Mts., N.E. Tanganyika. Tanganyika Noff:'~, 47 and 48, 92-102.

VERDCOURT. B. (l958).-F10ra of Tropical East Africa, Atangiacaea, Cornacaea. Crown Agents for the Colonies, 1958.

VERDCOURT, B. (I958).-Dr. P. J. Greenway. Taxon 7, 69-71.

VERDCOURT, B. (1958).-Notes on Ipomoea L. Ta.ton 7, 84-85.

VERDCOURT, B. (1958).-A mystery shell from Ihe Kenya Coast. J. E. Afr. nat. Hisl. Soc., 23, 15.

22

~

l f

! !i'l"

r I

I'

lt

~,

II

"

VERI>COURT, B. ([958).-Notes on Kenya [and and freshwater snails. 5. Records of Vertiginadae and Valloniidae from Kenya, Zanzibar and Tanganyika. Basteria 22, [-9.

VERDCOURT, B. (I958).-A new species of Ptychotrema Morch (Mollusca: Gastro· poda) from Tanganyika, together with a check list of the East African species and keys for their determination. I. Linn. Soc. (Zool.), 43, 7[4-720.

VERDCOURT. B. (l958).-An odd behaviour in a species of crane fly Limonia (Euglochina) cOllnectans A[exander (Dipt. Tipulidae). Ent. man. Mag., 94, [53.

VERDCOURT, B. (I958).-Remarks on the classification of the Rubiaceae. Bull. lard. bot. Brux., 28, 209,281.

VERI>COURT, B. (I958).-Notes from the East African Herbarium, Parts VI, VII, VIII, and IX. Kew Bull., 1958.

WHITEHEAD, A. G. ([958).-Nematoses of pyrethrum in East Africa. Nature, Land.. 182, 542.

•

EASf AFRICAN

DlR&: ... Over the past few yea

several species of non-dd analysed using punch caT food taken by these fishf'~

nature of the habitat frorr

The first results avail datory fish of considerab hundred specimens have b on insect larvae. but by th€ eXclusively on fish. The de possible. but the main COl

they depend almost entire

Laboratory and field satisfactorilY. Among thes economic importance, bu! lungfish will also be useful show that, under a given grows slowest and T. zi/lj

In one batch of fish, identical conditions, then by different individuals. T form the subject of futul genetical strains with a growth rate, a high food foods. However. these futl will have to wait till the requirements of these fist accumulated on the factol

An intensive study h kannume, the elephant Sf

Lake Victoria, but unfort nol eat it. However, it js l not fully exploited.

..

Spawnjng seems to 01

outcrops of rock. It bas r young stages of these fi~

laboratory conditions anc these fish are very small Some difficulty was experil by culturing certain small

The sexual cycle of 1

the, lake. Gonad developr annual breeding season. T

~ considerable amount of vi out the period of the inve included elaborate morpbl of the whole fiah and to i of this work will be llUb;

,p', ",::,j:;- .­

':' ...,~",. • '."..,lI.'

~~:;._••. '. .,.• _' 40~ .~

""~>-"~ ~ ,:11·,tr ".--" -~' :~. . . ..~".

I

freshwater snails. 5. Records of nzibar and Tanganyika. Basteria

. ema Morch (Mollusca: Gastro­:k list of the East African species /c. (Zoo/.), 43, 714-720.

a species of crane fly Limonia ,uUdae). En!. mono Mag., 94, 153. lion of the Rubiaceae. Bull. lard.

rican Herbarium, Parts VI, VII,

1m in East Africa. Nature, Lond.,

J

23

EAST AFRICAN FISHERY RESEARCH ORGANIZATION

DIRECTOR-R. S. A. BEAUCHAMP, M.A.

Over the past few years investigations have been carried out on the food of several species of non-cichlid fishes. The results of these observations are being analysed using punch cards in order to sort out the data with regard to the food taken by these fishes throughout their size ranges and according to the nature of the habitat from which they were caught.

The first results available are those for Bagrus docmac (Semitundu), a pre­datory fish of considerable commercial value in Lake Victoria; over thirteen hundred specimens have been examined. When very young these fish feed largely on insect larvae, but by the time they reach a length of six inches they feed almost exclusively on fish. The detailed results of this study will be published as soon as possible, but the main conclusion is that once they are over six inches in. length they depend almost entirely on Haplochromis for their food.

Laboratory and field studies on the growth rate of fish are proceeding very satisfactorily. Among these studies those on species of Tilapia are of immediate economic importance. but the knowledge gained on the growth of catfish and lungfish will also be usefu1. Observation on T. variabiUs, T. esculenta and T. zillii show that, under a given set of conditions, of these three species T. variabilis grows slowest and T. ziWi the fastest.

In one batch of fish, raised from the same batch of eggs .and grown under identical conditions, there are considerable variations in the growth achieved by different individuals. This variation in growth rate between 'individuals should form the subject of furure research, as it indicates the possibility of breeding genetical strains with a combination of desirable characteristics such as high growth rate, a high food conversion factor and the ability to d.igest a variety of foods. However. these future studies which may be of great economic importance will have to walt till the pre!';ent programme designed to discover the essential requirements of these fish has been completed and until more data have been accumulated on the factors which accelerate the onset of maturity.

An intensive study has been made over the last two years on Mormyrus kanftllme. the elephant snout fish. This is one of the more abundant fishes in Lake Victoria. but unfortunately certain sections of the Aftican community will not eat it. However. it is a fish of considerable commercial value and one that is not fully exploited.

Spawning seems to occur in moderately deep water in areas where there are outcrops of rock. It has not yet been possible to capture from the lake the very young stages of these fish. though eggs have been successfully fertilized under laboratory conditions and ·young Mormyrus reared to fingerlings. The eggs of these fish are very small and the newly hatched young are very small indeed. Some difficulty was experienced in feeding these minute fish but this was overcome by cuhuring certain small organisms for their consumption.

The sexual cycle of these fish is rather different from that of many fish in the, lake. Gonad development is very protracted and individuals have only one annual breeding season. The elucidation of this simple conclusion entailed a very considerable amount of work; fish had to be caught at regular intervals through­out the period of the investigation and a wide range of observations made. These in~ruded elaborate morphometric studies which were in turn related to the weight of the whole fish and to the weight of various tissues and organs. A fun account of this work will be puhlished shortly.

I

24

Some special field observations and marking experiments have been carried AboUI 90 per cenf out on T. variabilis. This fish is assuming slightly greater relative importance in found to be carrying pa the commercial catches as the numbers of T. esculento de<;line.

Pilot experiments to test the value of restocking Lake Victoria with Tilapia 1fry were started four years ago. The results achieved indicate that Lake Victoria may provide an example where applied research will lead to a real improvement in the fisheries and an increased economic return. Only too frequently a fisheries ! research service can do no more than recommend a policy of cautious exploitation. While such a policy is still necessary on Lake Victoria, there are hopeful signs that a vigorous programme of restocking, designed to overcome the shortage of natural spawning sites. may increase the annual yield of fish. Development work of this nature normally falls outside the scope of a research organization. However. the Lake Victoria Fisheries Service provides a two-way link for the implementa­tion of control and development measures and the passage to E.A.F.R.O. of information relating to the commercial fisheries.

Experiments with tagged fish have yielded useful results from which estimates of growth rate under natural conditions are being determined. The success of' such a programme depends on the recapture of these fish and a suitable reward is being given to the commerCial fisherman or angler who brings one back to the laboratory. A return of five or ten per cent of marked fish over a period of a year or so is consldered good; however, in one small experiment with 27 fish. seven were caught on rod and line and returned to us within ten days.•Within two months three more were returned to the Laboratory and one particular fish was recaptured three times in the same period. Needless to say, such a high rate of return is not desired. but this example serves to illustrate how unpredictable some fish may be!

Forecasting future prospects may be included among the functions of a fishery research service and can be done with some degree of confidence in an established fishery in which equilibrium between the fishing effort and yield has been reached. In 1956 this organization was called upon to predict the probable future of the fishcries of Lake Victoria at a time when the industry was expanding I and when changes in control measures were occurring. There has not been time for our predictions to be fulfilled completely; however. as forecast, an increase in yield of Tilapia occurred in those areas where four and a half inch nets came into general lise but the yield is now falling rather more rapidly than was expected.

The retention of restrictions in the Kenya waters of the lake and their relaxation elsewhere has Jed to some slight changes in the distribution of the fishermen. While it is normal for many JaJuo to fish outside their own territorialI waters, this habit has been encouraged by the opportunity to use fOUf and a half inch nets in the Tanganyika and Uganda waters. The fish they catch are sold~ however, in the areas in which they are caught. Thus the intention to exploit fully the Tanganyika and Uganda fisheries is being assisted by these

f' nomadic fishermen and at the same time Kenya may be glad to "export" some

I· of her surplus fishermen. \ As little is known about the food of aquatic snakes it is worth recording

that a water cobra was scen swallowing a young Clarias not much smaller than 1itself.

While the. fish in Lake Victoria are rarely heavily parasitized, the occurrence of crustacean parasites belonging to several genera is frequent. About 40 per cent of T. variabilis are parasitized and about 60 per cent of T. ~sculenta.

Barbus from the Ri fish wh2n taken from the from the river very freq! water mussel. These fish c the mussel, which is the

The Director of E.• Dr. D. L. Gunn, Direct( visit Abercorn and advis ~tipa. Dr. Gunn has con

"In Northern Rhode is an outbreak area of th by the International Rec occurs after several dry ~

no outlet, fan consideral l.R.L.C.S. to withdraw fr River, concerns both I.R Dire<:lor of E.A.F.R.O. w certain aspects. upon whi

The Dire<:lor of E.} hospitality and the very aircraft one of the more

While in Northern ) of the work being done b: Research Organization ar Tanganyika.

G. Fryer.

D. J. Garrod.

R. B. lies.

c. C. Cridland.

J. D. Roberts.

Mrs. E. Cartmell, Y,

L D'Costa.

Pragii Dossa Mesva

:xperiments have been carned greater relative importance in lenta decline.

19 Lak.e Victoria with Tilapia lei indicate that Lake Victoria 11 lead to a real improvement lnly too frequently a fisheries )Olicy of cautious exploitation. toria, the~e are hopeful signs to overcome the shortage of

Id of fish. Development work search organization. However. :way Jink: for the implemcnta­'e passage to EA.F.R.O. of

I results from which estimates ~ determined. The success of­:se fish and a suitable reward l' who brings one back to the ~rked fish over 3 period of a nail experiment with 27 fish. o us within ten days. Within 'atory and one particular fish dless to say, such a high rate I illustrate how unpredictable

I among the functions of a e degree of confidence in an the fishing effort and yield called upon to predict the

at a time when the industry lsures were occurring. There lIed completely; however, as 1 those areas where four and d is now falling rather more

raters of the lake and their es in the distribution of the 1 outside their own territorial ,portunity to use four and a lers. The fish they catch are mght. Thus the intention to :s is being assisted by these ay be glad to "export" some

snakes it is worth recording 'larias not much smaller than

I J

1 !

25

AboUl 90 per ceoC of all Profopterus. Clarias and Bagrlts examined were found to be carryi~g parasites, but the degree of infestation was usually low.

Borbus from the River Nile are usually heavily parasitized whereas these fish when taken from the lake are found to have relatively few parasites. Barbur from the river very frequently carry the parasitic larvae of the common fresh­water mussel. These fish clearly have an important influence on the distribution of the mussel. which is the principal food of the larger lungfish.

The Director of E.A.F.R.O. was very glad to accept an invitation from Dr. D. L Gunn, Director of the International Red Locust Control Service, to visit Abercorn and advise on the particular problem presented by Mweru wa ~tipa. Dr. Gunn has contributed the following statement:­

"In Northern Rhodesia, the flood plain surrounding Lake Mweru wa Ntipa is an outbreak area of the Red Locust. where it is controlled rather expensively by the International Red Locust Control Service, using insecticides. Swarming occurs after several dry yeaTs when !be level and ""_ of flle lake, which has no outlet. faIl considerably. A project for maintaining the level and enabling J.R.L.C.S. to withdraw from the area, by diverting water from the Kalungwishi River, concerns both I.R.L.C.S. and the Game and FisherieS Department. The Director of E.A.F.R.O. was invited to visit the area. to advise and adjudicate on certain aspects. upon which agreement was then readily reached."

The Director of E.A.F.R.O. gratefully acknowledges Dr. Gunn's generous hospitality and the very valuable experience of surveying from a low-flying aircraft one of the more interesting and undisturbed areas in Africa.

While in Northern Rhodesia the opportunity was taken to see something of the work being done by the Joint Northern Rhodesia and Nyasaland Fisheries Research Organization and recent fishery developments at M pu)ungu on Lake Taqganyika.

Stalf

DIREcrOR

R. S. A. Beauchamp.

RESEARCH OFFICERS

G. Fryer. D. J. Garrod. R. B. Des.

SENIOR FIELD OFFICERS

c. C. Cridland. J. D. Roberts.

SECRETARIES

Mrs. E. Cartmell. M.B.E. L D'Cosla.

iJy parasitized, the occurrence .s frequent About 40 per cent SENIOR ARTISAN

nt of T. esculentQ. Pragji Dos~a Mesvania.

]

26

E.A.F.R.O. Publications 1957/1958

~\ ". BEAUCHAMP, R. S. A. (1958).,-Utilisation of the natural resources of Lake 'Vi~toria

for the benefit of fisheries and agriculture. Nature, 181.

<;l~ ,CORBET. P. S. (J958).-Some effect. of D.D.T. on the fauna of the Victoria Nile. 01. Rev. Zool. BOI. Atr.• 57. . b .. ----(1958).-Effects of simj{j~m control on insectivorous fishes. Nature," ,1.~i.

~~. --(l958).-Lunar periodicity of aquatic insects in Lake Victoria. Nat~r~. 182.

11- CRIDLAND, c. C. (l957).--Ecological factors affecting the numbers of :'i~\t.s in temporary bodies of water. J. Trap. Med. Hyg., 1·7.

I~ / ----{1958).-Ecological factors affecting the numbers of snails in a peFmammt ! stream. J. Trop. Med. Hyg., 3-7.

%{' , FRYER. G. (l958).-Occurrence of spermatophores in the genus Dotops (crusiacea: Branchiura) Nature, 181. '. "::,

--{1958).--A note on Lerneae bistricornis Harding, a parasitic copepod ,from C;~ . Lake Tanganyika. Rev. Zool. Bot. Afr.

GARROD, D. J.• AND NEWELL, B. S. (1958).-Ring fonnation in Ti/apia esculenla.. ~\" Nalure, 181. . ',,'

GARROD, D. J. (l958L-The growth of Til'lpja. esculetlta Graham in Lake Victoria. Hydrohiologia. (in press.) 94' ..

1'1 ,GREENWOOD. P. H. (I958).-The fishes of Uganda. (Complete in book form.) Oc.. ......--(I958).-Evolution and speciation in the Haplochromis (Pisces: Gichlidae) u1 of Lake Victoria. Proc. XVtll Int. Congo Zool. Sect. 1/, Paper 2.

qc _-----{1958).-Reproduction in tbe East African Lung-fish Protopterus tJ~/~iOp'~cus

Heckel. Proc. Zoot. Soc.. Lond.. 130.'. '.q\_ 12. . . --I L958l.-African Lung-fishes. Wild Life Observer.

L'-I --(l958).-A new genus and species of Catfish (Pisces: Clariidae) from the , c;.... ~ deeper waters of Lake Victoria. Ann. & Mag. Nat. Hist., I-S.

~t. HESSE, P . R. (l958).-Fixation of sulphur in the muds of Lake Victoria. Hydrobiotogia, II. .

C\:J -LOWE, R. H. (MCCONNELL) (1958).--{)bservalions on the Biology of TilapiaIJ niloticu Linne in East African waters (Pisces: Cichlidae). Rev. Zool. Bot.

Afr. 67.

~l """TALLING. J. F. (l958).-Diurnal changes of stratification and photosynthesis in some tropical African waters. Proc. Roy. Soc.. B 147. ' I

. ,

EAST AFRICAN M.4

B. E.

The Director and M Mr. Williams acted as D

Dr. Morgans went Q

with his wife and family

Mr. B. E. Bell, M.A. his appointment as Hydr after three years service He has been hydrologist His wife and children 'i

Captain Alex Slater leave on the 3ed Noveml but as most of the hands of training and experier

The lahoratory buil, good order and conditio storage has been passe( shortly. The installation has filled a gap in the e< storage of specimens for for the accumulation of

Subsequent to her a: African Marine and Gel at sea on scientific cruisl 4,023 miles. A further pc survey demanded by LII

In 1958 &he spenl 98 to the slipway in June, (yacht) after supervising having the propeller shaf

The work of the C and although the field a of staff vacancies the tel sharper definition of the 1

i

~l~~i . ."

R:es of Lak.e 'Victoria

.of the Victoria Nile.

ish... Natu'e, ,I~l.

{ictoria. Nature. 182.

numbers of s~~l1s in

nails in a permanant

lS Dolop$ (Crustacea :

~rasitLC copep<)d :from

in Tilapla espu~enla_

" ham in Lake Victoria.

,plele in book.. form.) is (Pisces: Gichlidae) • Paper 2.

roropterus ~hiQ~icw; -. ":

Clariidae) from the lit., 1-5.

Is of Lake Victoria.

~ Biology of Tilapia dae). Rev. Zool. Bor.

lod phot()syntbesis in .,

"

I

27

EAST AFRICAN MARINE FISHERIES RESEARCH ORGANIZATION

DIRECTOR

J. F. G. Wheeler, D.Se.

Slaft

RESEARCH OFFICERS

F Williams, M.Sc.

J. F C. Morgans, M.A., Ph.D.

B. E. Bell, M.A., FR.Met.S. (Hydrologist).

SECRETARY

Mrs. L. Cameron.

MASTER M.V. "MANlHINE"

A. Slater.

The Director and Mrs. Wheeler returned from leave on the 13th April, 1958. Mr. Williams acted as Deputy during the Director's absence. . ,

Dr. Morgans went on long leave to SOlJth Africa 00 the 10th of September with his wife and family.

Mr. B. E. Bell, M.A., arrived in Zanzibar on the 9th of December to take up his appointment as Hydrologist. Mr. Bell took an Honours degree at Cambridge after three years service with the Royal Engineers in India, Egypt and Kenya. He bas been hydrologist to the Ministry of Works, Kenya. for the last four years. His wife and children will join him in January, 1959.

Captain Alex Slater has commanded m.v. Manihine since his return from leave O'B the 3rd November, 1957. There have been few changes in the crew Ust but as most of the hands from the Research transferred to the new ship the years of training and experience have not been lost. '

The laboratory buildings, staff houses and ships have been maintained in good order and condition. The plan for a second open shed for two cars and storage has been passed by the Town Planning Authority and will be built shortly. The installation of a deep-freeze refrigerator (capacity 9·10 cubk feet) has filled a gap in the equipment of the laboratory. It is used for the temporary storage of specimens for examination but its more urgent and important use is for the accumulation of longJine bait.

Subsequent to her arrival at Mombasa and eight days on the slipway at the African Marine and General Engineering Company's works m.v. Manihine was at sea on scientific cruises for 62 days before the end of 1957 and she covered 4,023 miles. A further period of four days in August was taken up by an engine survey demanded by Lloyd's representative.

In 1958 she spent 98 da·ys at sea and covered 5,888 miles. On her annual visit to the sHpway in June, Lloyd's representative renewed her Certificate as 100 AI (yacht) after supervising the replacement of some headless rivets in her hull and having the propeller shafts drawn for examination. This survey occupied 12 days.

The work of the Organization has gone forward steadily during the year and although the field of endeavour has been narrowed to some extent because of staff vacancies the tempo of current investigations has increased owing to the sharper definition of the problems involved. The phase of preliminary enquiry which

".

••

, •

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28

ended with the advent of the Manihine has provided the essential background for this new period of limited lines of research. Over the years since the establishment of the Organization. "llsing what can be called conventional fishing methods known and used by fishermen of the coast, we have acquired a fairly comprehensive knowledge of the fishes in the area and we have obtained some inkling of the lives and movements of a few of them. We have an outline of the physical and chemical attributes of the environment in which they live and a sketch of the changes, some cyclical and some less predictable, which occur therein. Putting these data together 'Ae could build up a picture of the distribution of fishes in the conditions given, that is, wc could predict the likely catch of fishes of certain species at certain times and places provided these methods were used; but we have always been aware that such a picture would be far from complete even excluding its own imperfections. The most obvIous omission concerns the shoals that are often seen ruffling the surface. For there is no doubt that the fishes are there but so far they have evaded capture. There are other less evident omissions. The possibility that fishes which are rarely or never caught at the surface during the day might nevertheless be present, but at sub-surface levels, was deduced from the capture of a Swordfish at the surface at night on one of the earliest cruises of Research. This portent was repeated three years later, again at night, in the same month (November) though at a very different position. The investiga­tion of the potential offshore depths is a field that is now being undertaken. In rather similar fashion the deeper bottoms of the coastal outline have been ,sampled as a routine. Now attention is focused on the extended continental shelf off north Kenya where patchy grollnds of considerable promise have been fuund. •

~

These two lines of research-longEne fishing and the investigation of the north Kenya hanks-were set out as items 4 and 8 in the programme of work for 1958-59 in the Annual Report 1956-57. Actually they have grown out of the past. Attempts at longlining, limited in size by the cramped conditions of m.v. Research, have been made since 1953; and although the survey of the'I north Kenya grounds was not undertaken untii 1956 and is nOw being carried on in Manihine under conditions of wind and sea that would have precluded such work from Research we have records of bottom fishing there collected when our main concern was to establish the presence or otherwise off that coast of surface pelagic fishes during the southerly monsoon.

The Tuna Longline Investigation

Thc first experiments in this direction were made by Mr. Williams in May, 1953, with a floating line 60 x 60 fm. long, with cork floats at intervals, and 28 hooks on wire traces each suspended on 20 fm. of light line leaders. This kind of set with shortened leaders was used off the Presgrave Bank (N. Kenya) and off Mafia Channel South. Some small sharks were caught.

In May, 1953, (Cruise 47) in the Pemba Channel a nearer approximation to the true longline technique was used. The 120 fm. of main line Of-in. rope) was set 50 fm. down from floats 10 fm. apart. Four Mustad No.1 hooks at 2 fm. intervals on wire traces and with a 1 fm. light line leader were suspended between each floatline. One such set was laid free and a second was attached to the ship at one end. This latter drifted approximately 42 miles overnight. from 5 p.m. tLl 7 a.m. and caught nothing. The free set was not found until the following day and again there was no catch.

The first mention of tunny in connexion with a deep longline occurs on Cruise 58 in November, 1953, when 60 hooks with fish bait were laid before 9 a.m. and picked up between 4 and 5 p.m. the same day having drifted 11 mile'i off the northern end of Mafia. There was again no catch.

In January, 1954, (, sisal rope buoyed for ~

at 10 fm. intervals witlJ between 3 and 4 p.m. 11

depth was adjusted to traced by bathythermo

Interest in the deeI each of 120 fm. of p( Buoy lines on this oec. 50-55 fm. After a seV, due to rust patches on for the work and once

Then in August, 19 was made. This took cach) were laid from 1 was set at thermocline a very strong souther away from the markel conditions it is not SUI]

ary lapse on the part 0

to find it again. After, ing sea and fading Ughl received. The branch 11 knotted to the longline I had to be done withol mile of longline took u: or found it would havi that any catch made ... Like the previous aUel for this type of fishin! that would almost cert larger sca Ie.

Where five basket it was evident in Manl the size of the gear. V earried out by the lal bc such that our catel mercial .,exploitation as effective bait, the are~

changes in the latter c

The longline pre] American practice. In together for our ear1 in advance, the new branch and buoy line~

no longer laboriously the U.S.A.-an operal ·'press".

The basket of lin now lIsed to each basi of line (or 35 hooks)

l

~e essential background for ~ars since the establishment lila] fishing methods known ed a fairly comprehensive ained some inkling of the mUine of the physical and live and a sketch of the

occur therein. Putting these stribution of fishes in the catch of fishes of certain ~thods were used; but we e far from complete even lissioo concerns the shoals ) doubt that the fishes are :her less evident omissions. ught at the surface during Iface levels, was deduced ~ht on one of the earliest {ears later, again at night, ~nt position. The investiga­is now being undertaken. coastal outline have been the extended continental

erable promise have been

I the investigation of the the programme of work

ey have grown out of the ~ cramped conditions of hough the survey of the and is now being carried vould have precluded such : there collected when our e off that coast of surface

.. by Mr. Williams in May, floats at intervals, and 28 ht line leaders. This kind ve Bank (N. Kenya) and lht.

. nearer approximation to f main line (I t·in. rope) slad No.1 hooks al 2 fm. T were suspended between was attached lo lhe ship

o'¥ernight from 5 p.m. to nlil the following day and

deep 10ngJine occurs on ish bait were laid before .y having drifted 11 miles :h.

29

In January, 1954, (Cruise 61) off Mtwara seven baskets each of 110 fm. 7/ 8ths sisal rope buoyed for a depth of 30 fm. were laid at about 8 a.m. Hooks were at 10 fm. intervals with galvanized traces and 2 fm. leaders. This set was hauled between 3 and 4 p.m. and produced one Barracuda. On this oceasion the fishing depth was adjusted to approximate to the depth of the thermocline which was traced by bathythermograph at 240 ft.

Interest in the deep longlinc was rcnewed in October, 1955, when six baskets each of 120 fm. of point line were laid off Ras Mkumbi over 195 fm. depth. Buoy lines on this occasion were 40 fm. long. The thermocline was reckoned at 50-55 fm. After a seve~-hour drift the set was retrieved with many oreakages due to rust patches on the main and buoy lines which were found to be too light for the work and once again there was no catch and no bait missing.

Then in August. 1956, (Cruise 98) the last attempt at longlining from Research was made. This took place about 25 miles from Lamu. Five baskets (l20 fm. each) were laid from buoy lines in a heavy sea and the fishing depth at 60 fm. was set at thermocline level (59 fm.) as found by bathythermograph. There was a very strong southerly wind and consequently Research continually drifted away from the marker buoy and had to be brought up tp it again. In these conditions it is not surprising that the marker was lost sight of during a moment­ary lapse on the part of the watching seaman and the wrong direction was taken to find it again. After a search continued for more than two hours in a worsen­ing sea and fading light the gear was abandoned and no word of it has since been received. The branch lines (with the hooks) of,this set and 'the buoy lines were knotted to the tongline beforehand, and the whole operation-setting and hauling­had to be done without mechanical aid, Baiting and laying this two~thirds of a mile of longline took up a full hour and I have no doubt that had it been followed or found it would have been retrieved at whatever cost in labour and time and that any catch made would have justified the scientists in the eyes of the crew. Like the previous attempts it was a demonstration of Research's ineffectiveness f~ this type of fishing, of the faults in the gear and of some of the difficulties that would almost certainly be encountered when attempts could be made on a larger scale.

Where five baskets of longline crowded the working deck of the Research it was evident in Mallihine that something other thon lack of space would limit the size of the gear. We did not envisage work on the full commercial scale as carried out by the Japanese exploratory vessels but we did require our gear to be such that our catches could be used to make convincing estimates of com­mercial,.exploitation as well as providing data for the determination of the most effective bait, the areas of good and bad fishing. the optimum depth and lhe changes in the latter correlated wHh the changing seasons.

The longline prepared for use in MOflihine was based on Japanese and American practice. In essence, it is merely a much enlarged version of that pUl together for our early attempts; but where previously the set was prepared in advance, the new technique calls for the use of flag clips with swivels for branch and buoy lines. Moreover, the "eyes" at each end of the wire traces are no longer laboriously spliced. They are made fasl with Nicopress sleeves from the U.S.A.-an operation completed in a moment with one firm squeeze of the "press".

The basket of lines still consists of 120 fm., but only five branch lines are now llsed to each basket which means thal there are approximately seven baskets of line (or 35 hooks) to the mile. The branch lines with baited hooks and the

I

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i

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30

buoy lines are now clipped to the longline as it is paid out and they are unclipped

ift on hauling as they reach the motor line-hauler.

On the 28th of August, ·Mr. Williams made his first training cruise in Mallihine with 22 baskets and unbaited hooks in the Pemba Channel north of Zanzibar. On tbe following day he set 32 baskets (160 hooks) at the rate of 16 baskets per hour. About 35 hooks were baited with small fishes caught during the night. For an hour and a half the buoys were patrolled; then hauling began and was completed at a rate of 13 haskets per hour. To his gratification and the surprise of the crew a 32 lb. Yellowfin Tuna had been taken. The fishing depth was 71 fm. at the buoys. Naturally the intermediate hooks fish more deeply owing to the sag of the line. Taking into consideration th~ time required for the operations and the manpower available, Mr. Williams coneluded that a reasonable longline for our purposes would be 50 baskets, Le.) seven miles or 250 hooks.

The provision of sufficient bait for several consecutive days of fishing on this scale was another problem but the tuna of the August cruise had been caught on a small Lethrinid and we had dis<:overed at Latham Island a rich ground of a closely related Lethrinid so that on his trip in mid-September Mr. Williams took 1,675 bait fishes in refrigeration of which 657 were Lethrinids, 460 were salted mackerels from Aden, 425 were sardines from local sources and the rest were a mixed bag of assorted species. Working north from Latham Island to the Pemba Channel and altering the fishing depth from 57 fm. to 71 fm. his eatch eonsisted of three Lancet fishes, one Striped Marlin, four Ycllowfin Tunas. four 4:surid sharks and two Car<:harinid sharks.

In mid~O<:tober, one day's fishing at Latham Island produced 400 Lethrinids and a number of other fishes. With a <:ol1ection of Half-beaks (Hemirhamplms) from the market these were used on a 3rd longlining cruise (28th October to 8th November) when six days of fishing produ<:ed 56 fishes, including 49 Yellowfins.

I This experiment' took place mainly to the east of Mafia at a fishing depth of 61 fm. (buoy to line) with the thermocline bet",een 345 and 380 ft. The Half-beak, being silvery were suecessful as bait. Latham Island was fished going and coming

,I' on the next refuelling trip to Dar es Salaam, and the 1.350 Lethrinids caught were used as bait on the last longlining cruise of 1958 which started with another day for bait fishing at" Latham and ended some 25 miles north-east of Kilifi Lighthouse on the north Kenya coast. The eatch included 13 Striped Marlin, one Sailfish, one Yellowfin, various sharks, and, strangely enough, two Epinephelids. The presence of these fishes indkates the proximity of the Kenya Continental Shelf. These longlining experiments have been described at some length in order to illustrate the kind of problems that have been met and the data obtainep.

It is, of course, satisfa<:tory to make a <:atch, and here the seven-mile longline has an obvious advantage over the less-than-a-mile sets used from Research; but in spite of the fa<:t that one fish only resulted from the efforts made with her certain tentative <:onclusions can be drawn from them. It is possible that the bait fishes used (Nemipferus sp.) may have been distasteful or unattractive; or it may be that the fishing depth was insufficient. (It will be notked that the hooks were set to fish above the thermocline in all except the last attempt in which the gear was lost.) It is possible that the fishings in January. May, October and November were made at the wrong time for the area in whkh they were made. From the results of the Manihine fi.shings it appears that some baits are more favoured than others, that fishing just below or at the thermocline is more productive than just above and that although heavy <:atches of large pelagic fishes are possible, we cannot as yet predkt where or when they can be made nor <:an we hazard a guess at the Quantity available over a given period.

fl !; 11

Survey of the Fish

Bottom fishing on <:arried out to a small e those days was concen when the grounds to thl of Malindi Bank in 14 f May of that year when ing 218 lb., the 17 surf month of S.E. winds am that they were present while still trolling for Sl

bottom-mainly for san of Malindi Bank in 25 cruises that year the ide was continued.

On Cruise 95 in } problems of the Tene\! Warden (Coast), Mr. W made good catches in Sl

questions--{I) Why are present all the year TO'

similar rkhly populated

Sin<:e then <:ruises 1956), 112 (5th-12th M: September, 1957), 122 Deeember, 1957), 127 (I 1958) have been made pockets have been taken by one or two <:harted a t the northern corner again at r S latitude. I arrival of Manihine an~

are the soundings in th survey was forwarded to 1958. This request was! not be carried out for:

The 'shoaling fishes An answer would open a of supplying bait for II

While the main ac specimens brought in ra too large for preservati and most species of sha. of spedmens may be ob or few specimens may

There is, in fact, at to be cleared up. For iI depths are frequently fishes, mollus<:s, worms the migrations of the fi~

food.

:

lout and they are unclipped

his first trammg crUIse in ~ Pemba Channel north of (160 hooks) at the rate of b small fishes caught during Ltrolled; then hauling began To his gratification and the en taken. The fishing depth JOles fish more deeply owing th! time required for the concluded that a reasonable ren miles or 250 hooks.

secutive days of fishing on (gust cruise had been caught am Island a rich ground of eptember Mr. Williams took Lethrinids, 460 were salted sources and the rest were a ..atham Island to the Pemba o 71 fm. his catch consisted ellowfin Tunas, four Isurid

.nd produced 400 Lethrinids Half-beaks (Hemirhamplms) cruise (28th October to 8th

lei, including 49 Yellowfins. ~afia at a fishing depth of 5 and 380 ft. The Half-beak. vas fished going and coming 1,350 Lethrinids caught were ch started with another day .rth-east of Kilifi Lighthouse :triped Marlin, one Sailfish. Igh, twn Epinephclids. The Ie Kenya Continental Shelf. It some length in order to d the data obtaineo1.

I, and here the seven-mile han-a-mile scts used from ,y resulted from the efforts e drawn from them. It is ay have been distasteful or Isufficient. (It will be noticed n all except the last attempt

fishings in January, May. :ime for the area in which lShings it appears that some below or at the thermocline :1gb heavy catches of large where or when they can be ailable over a given period.

31

I Survey of tbe Fisbing Grounds of the North Kenya Continental Sbelf

Bottom fishing on the nearer banks off the north Kenya coast had been carried out to a small extent during cruises in 1952 and 1953, but the work in those days was concerned witb surface pe1agics and it was even so in 1954, when the grounds to the east of Leopard Reef from 5·30 fm., and to the south of Malindi Bank in 14 fm.. and on Presgrave and Vidal banks, were sampled. In May of that year when fishing on these last two banks produced 43 fishes weigh­ing 218 lb., the 17 surface pelagics weighing 200 lb. caught by trolling in that month of S.E. winds and sea were of greater import because their capture proved that they were present and could be caught at that season. In Febru~ry, 1955, while still trolling for surface pelagics Research spent more time fishing on the bottom-mainly for sampling purposes-in deep gullies at the south-east corner of Malindi Bank in 25-50 fm. and on Presgrave and Vidal Banks. On later cruises that year the identification of the species living on and about these banks was continued.

On Cruise 95 in April, 1956, the emphasis changed. After discussing the problems of the Tenewi-Lamu grounds with Mr. Allfree, the Assistant Fish Warden (Coast), Mr. WilHams worked a number of fishing stations in the area, made good catches in some of them and, after considering his data, posed these questions-{l) Why are the fish concentrated in particular, areas? (2) Are they present all the year round and, if so, in what numbers?' (3) Are there other similar richly populated spats in the area?

Since then cruises 99 (13th-22nd August, 1956), 104 (13th-21st November, 1956), 112 (5th-12th March, 1957) were made in Research: and 120 (3rd-14th September, 1957), 122 (18th-26th October, 1957), 124 (26th November to 6th December, 1957), 127 (10th-21st February, 1958) and 133 (26th May to 4th June, 1958) have been made in Manihine. Quantities of fishes in restricted patches or pockets have been taken over the very considerable area that is vaguely indicated by one or two charted depths from where the loo-fm. contour veers to the east a.i the northern corner of Formosa Bay and disappears and closes the coast again at 2°S latitude. Dr. Morgans has been in charg~ of this work since the arrival of Manihine and he is preparing a map of fish distribution. So scattered are the soundings in this area and so featureless the coast that a request for a survey was forwarded to the Admiralty through the Research Council in February, 1958. This request was strongly endorsed by the Kenya Government, but it may not be carried out for some time. In the meanwhile our own survey continues.

Other Work of the Organization

The 'shoaling fishes remain a problem which we are endeavouring to solvc. An answer would open a new field of exploitation and perhaps solve the difficulties of supplying bait for longlining.

While the main activity is concerned with the work at sea some of the specimens brought in raise problems of identification, particularly those that are too large for preservation or are rarely caught. The Marlins are one example and most species of shark are others. It is now evident that considerable numbers of specimens may be obtained at one time and taxonomic papers based on single or few specimens may be critically revised.

There is, in fact, after each cruise a considerable amount of laboratory work to be cleared up. For instance the stomachs of the Tunas caught at thermocline depths are frequently packed with planktonic organisms-squids, crustacea, fishes, molluscs, worms ... most of them young stages. If we are to understand the migrations of the fishes we must have some knowledge of the history of their food.

~2

It has been suggested that the patchiness of fish on the north Kenya grounds EAST AFRICAN TRY!' may be connected with the level of the thermocline (Newell) but apart from observations made by readings of the bathythermograph the hydrography of the DIRECTOR region is unknown.

Until a few years ago Each year about September, according to the native fishermen, there is a control of the trypanosorn

period which lasts for some weeks when catches are extremely poor either nagana in cattle-were thos. hecanse the fishes will not bite or because they are not there. This phenomenon these diseases-the tsetse flj, was certainly noticed on Cruise 120 (3rd-14th September, 1957). The natives in the last thirty years has b incline to the helief that the fishes migrate. In either case it may well be that relating to tsetse flies has a profound though temporary change in the water conditions occurs at the change very great use in planning c of the monsoon but on the other hand it may be that the outflow of the Tana understanding of the me<:h~

River, swollen by up-country rains, is the more direct influence on the lives of Its value cannot be overest the fishes. The recent appointment of a hydrologist wHl allow hydrographic have recently led to a ch; observations to be made concurrently with the fishing survey, and data will then corning into use of more d be obtained for correlating the catch with the existing water conditions. the human and animal disf

[n the animal sphere t Since the Report of 1957 was printed the paper "A preliminary report on possibility of keeping prodl deep-water fishing off the North Kenya Coast" by Mr. Williams has been tsetse: complete eliminatiopublished in the East African Agricultural Journal. Piipers on the Carangidae

(Kole Koles) and Sphyraeoidae (Barracudas) by Mr. Williams aod 00 "Three Interest in these drugs, confusing species of Serranid Fish" by Dr. Morgans have heen accepted for nol only with regard to tIpublication in the Annals and Magazi.ne of Natural History.

respects-their interactions • the possibility of the appea

Visitors and Meetings On the human side, als lives of many advanced cas For some four months this year Miss G. Trace worked at the laboratory drugs together with the amaking plaster casts of local fishes for exhibition in the Zanzibar Museum. occupation the huge-andHer painted representa1ives have added greatly to the attraction of the Natural Africa which are infected.History section. Sllccess only hrings into gl

Sir Bruce H utl paid a very short visit on the 11th of September and went sickness persists apparently to sea in Manihine. Unfortunately no fishes were seen until the ship returned ditions it may be expected tc to moorings, when a shoal of small fishes pursued by Kole Kale broke the are better understood, re surface a short (distance away. uninhabited. will not be a

Professor C. M. Yonge visited the Organization on the 28th September and The considerations oull sailed with the Director in Mani/dne to Mombasa on the way to the meeting of research effort of EA.T.RJ the Research Council at Muguga on the 30th of that month. iog the biology of the tsetse

several aspects at one ti: The Director again arranged the exhibit at the Royal Agricultural Show. epidemiology of the humar

Mitchell Park, and he attended each day with Mr. Coutinho, clerk to the area, using all the skills'll Organization. . sante time specialists on th

which appear to provide th~

There was a meeting of the Research Co-ordinating Committee in Zanzibar on the veterinary side, studi on the 18th July. Me. Adie and Mr. Smith represented the Kenya Government, parasites resistant to the dl Me. Forbes (Director of Agriculture) and Mr. Lockley (Chief Fisheries Officer) the antmals and on measUI outlined the views of the Tanganyika Government and Me. Briant (Director of to infection by tsetse flies-Agriculture, Zanzibar) and Mr. King (Fisheries Officer) spoke for Zanzibar. Me. Shearer (Chairman) and Mr. Harris (Secretary) represented the High . This reorientation has Commission. the laboratories at Tororo.

on both the human and ani be applied or confirmed a Publications during the Year outstation at Tinde, Tanga

WILLIAMS. F.-A preliminary report on deep.water fishing off the North Kenya made for the running dov Coast. EA. Agricultural lournal. XX/V. No. I, luly, 1958. Shin)/anga, Tanganyika. ai

I

~

fish on the north Kenya groun'ds loc1ine (Newell) but apart from nograph the hydrography of the

the native fishermen. there is a :hes are extremely poor either ue not there. This phenomenon September, 1957). The natives

either case it may well be that , conditions occurs at the change ~ that the outflow of the Tana direct influence on the lives of 'I~gist will allow hydrographic hmg survey, and data will then dsting water conditions.

aper "A preliminary report on " by Mr. Williams has been nal. Papers on the Carangidae Mr. Williams and On "Three

lrgans have been accepted for lral History.

race. worked at the laboratory on In the Zanzibar Museum.

the attraction of the Natural

11th of September and went : seen until the ship returned Jed by Kole Kole broke the

n on the 28th September and on the way to the meeting of It month.

he Royal Agricultural Show Mr. Coutinho. clerk to th~

,ating Committee in Zanzibar nted the Kenya Government, kley (Chief Fisheries Officer) and Mr. Briant (Director of :::>fficer) spoke for Zanzibar. 'lary) represented the High

••r

fishing off the North Kenya , July, 1958.

EAST AFRICAN TRYPANOSOMIASIS RESEARCH ORGANIZATION

DIRECTOR: W. H. R. LUMSDEN, D.Se.. M.B.

Until a few years ago the only measures which appeared likely to lead to control of the trypanosome diseases of Africa-sleeping sickness in man and nagana in cattle-were those directed against the insects which mainly transmitted these diseases-the tsetse flies. Thus by far the greatest part of the research effort in the last thirty years has been devoted to their study. A vast body of information relating to tsetse flies has been accumulated and this information has, been of very great use in planning control schemes as well as in helping towards a deeper understanding of the mechanisms of transmission and persistence of the diseases. Its value cannot be overestimated. However, some other advances in knowledge have recently led to a change in emphasis. Chief among these has been the coming into use of more efficient drugs for the treatment and prevention of both the human and animal diseases.

In the animal sphere these drugs have, in the last ten years, opened up the possibility of keeping productive cattle in at least areas only lightly infested by tsetse: complete elimination of tsetse has ceased to be an absolute necessity.

Interest in these drugs, and in the possibility of better 'ones, has increased. not only with regard to their direct action on the parasites but also in other respects-their interactions with the mechanh;ms of "immunity" in the host and the possibility of the appearance in nature of parasites resistant to drugs.

On the human side, also, new drugs have improved the chances of saving the lives of many advanced cases who would formerly have been beyond cure. These drugs together with the administrative measures which exclude from human occupation the huge-and often potentially highly productive-areas of East Africa which are infected, have reduced the immediate dangers. However, this Sll~ess only brings into greater prominence the main problems-how sleeping sickness persists apparently continuously in infected area, and under what con­ditions it may be expected to spread more widely in Africa. Until these mechanisms are better understood, reoccupation of infected areas, at present virtually uninhabited, will not be accomplished without great cost to man and animal.

The considerations outlined above have decided a general reorientation of the research effort of E.A.T.R.O., away from studies specifically directed to elucidat­ing the biology of the tsetse fly, and towards concerted studies taking into account several aspects at one time. For instance, the necessity to understand the epidemiology of the human disease dictates a combined approach in an infected area, using all the skills which can be of application-medical men, and at the same time specialists on the parasites. on the tsetse flies and on the wild animals which appear to provide the reservoirs for the persistence of the disease. Similarly. on the veterinary side, studies on the efficiency of the drugs and the appearance of parasites resistant to the drugs require to be linked to studies on the reactions of the animals and on measurement of the degree to which the animals are exposed to infection by tsetse flies-the trypanosome challenge.

. This reorientation has begun. It is intended to concentrate all disciplines at the laboratories at Tororo, Uganda, near field areas suitable for integrated studies on both the human and animal diseases. The results of these studies will, of course, be applied or confirmed as necessary in the other East African territories. The outstation at Tinde, Tanganyika, was closed in 1958 and preparations are being made for the running down of the Entomological Research Laboratory at Old Shinyanga, Tanganyika, and transference of its staff to Tororo.

1

,

34

A considerable number of staff changes took place during the year:-

Dr. K. C. Willett, Chief Protozoologist, left on transfer to the West African Institute for Trypanosomiasis Research as Deputy Director.

Drs. M. T. Ashcroft, Medical Research Officer, K. R. S. Morris, Epidemiologist, and J. R. Baker, Protozoologist and Mr. F. Isherwood, left on completion of their contracts.

Mr. A. R. Jenkins, Biochemist, resigned and has been replaced by Dr. R. H. Knight.

Miss E. C. Craigie, Veterinary Research Officer, joined on recruitment.

Human Trypanosomiasis

The EATRO hospital unit has continued to be operated and has allowed invaluable contact. with people infected with T. rhodesiense sleeping sickness in the north-eastern regions of Lake Victoria. This contact has been most ~aluable

for clinical and epidemiological studies.

CLINICAL AND CHEMOTHERAPEUTIC STIJDIES

Although evident jaundice is uncommon in T. rhodesiense sleeping sickness, biochemical studies have been shown that liver function is upset especially in the acute febrile phases of .the disease.

For treatment, melarsen oxidejBAL continues the drug of choice in thc late stage cases where the central nervous system is involved. Although it is occasionally tbxic, fatalities are rare. For cases unresponsive to this drug, investigations have shown that nitrofurazone holds promise.

EPIDEMIOLOGY

From the histories and the "follow-up" examinations of patients treated in the E.A.T.R.O. hospital, a great deal of epidemiological informaUon has been derived. The T. rhodesiense disease in the north-eastern regions of Lake Victoria is transmitted, apparently, mainly by G. pallidipes. The bite of an infected fly usually gives rise to a tender swelling, the chancre; 65 per cent of these chancres occur below the knee which distribution indicates G. pallidipes as the tsetse fly corlcerned, as it habitually bites the legs. G. palpaJis, the other possible trans­mitting fly, usually bites about the head and shoulders. In the dry season the disease is mainly confined to fishermen and fishtraders, suggesting that the persisting infected foci are strictly coastal, but in the wet season infection extends more widely, involving people living on the inland fringe of the flybelt. The region, generally, offers a very suitable area for the study of the details of the epid. emiology of the disease.

Besides the studies mentioned above, which relate to East Africa's most I, important problem, T. rhodesiense sleeping sickness, the main areas in East

Africa which are infected by the T. gambiense disease, have been visited and investigated. A great deal of information has been extracted from archives and a series of reports have been prepared which give coherent pictures of the progress of the disease in the past as well as the present situation. The areas concerned are the Aswa River region, Busongora County, West Nile District and Bunyoro District, Uganda, and Nyanza Province, Kenya.

AJ

Fundamental studies on exposed to infection-the tryp Some progress has been made the actual occurrence of trypal are that the latter may provi involved.

A drug trial designed te trypanocidal substances was Prothidium (Boots Pure Drug (Imperial Chemical Industries Baker). The metamidium com of more extensive field trials.

The trypanosome straim examined for drug resistan( (Fabwerke Hoochst A.G.) ani high dosage levels.

The toxicities of new drul drugs at high dosage levels, ~

of the established drugs may not subjected to the stress of to the importance of drug effE at meat inspection.

Further evidence has bee repeated doses of a drug aD( trypanosome strain has beel maintained against infectiOn!

The establishment of a "j deep-frozen, was reported las' on strain characteristics, drug augmented during the year.

Trypanosoma vivax is iJ its study in the laboratory animals, white rats and miD avenues have been explored­rat in Uganda, the simu]tanl the use of embryonated egg

Studies on the reactions have attempted to explain the species-and to recognize su latter have been partially suj await a more intensive at ance epidemiologically have of wild animals likely to be the species of trypanosome:

i

- ..... ,... ;' '.'.""'.•...

;»lace during the year:­

left on transfer to the West b. as Deputy Director.

1 Officer, K. R. S. Morris, it and Mr. F. Isherwood, left

and has been replaced by

)fficer. joined on recruitment.

be operated and has allowed odesiense sleeping sickness in ,ntact has been most valuable

rhodesiense sleeping sickness. mction is upset especially in

the drug of choice in the is involved. Although it is unresponsive to this drug. promise.

linations of patients treated logical information has been em regions of Lake Victoria The bite of an infected fly

is per cent of these chancres ;. pallidipes as the tsetse fly 'is, the other possible trans­ders. In the dry season the :raders, suggesting that the wet season infection extends ge of the flybelt. The region. of the details. of the epid­

bte to East Africa's most s, the main areas in East :elSe, have been visited and :xtracted from archives and c coherent pictures of the )fesent situation. The areas :Olmty, West Nile District ~J Kenya.

35

Animal Trypanosomiasis

Fundamental studies on the estimation of the degree to which animals are exposed to infection-the trypanosome challenge---continued tbroughout the year. Some progress has heen made in relating the density and infection rates of fly to the actual occurrence of trypanosomiasis in unprotected cattle; present indications are that the latter may proVide an adequate measurement of the many factors involved.

A drug trial designed to compare the prophylactic properties of various trypanocidal substances was completed in July. The drugs tested included Prothidium (Boots Pure Drug Company), two formulations of Antrycide Prosalt (Imperial Chemical lndustries) and three formulations of metamidium (May and Baker). The rnetamidium compounds were promising and were considered worthy of more extensive field trials.

The trypanosome strainS' isolated from the cattle in this trial are being examined for drug resistance. None of the strains <!ore resistant to Berenil (Fabwerke Hoechst A.G.) antrycide methyl sulphate or metamidium chloride at high dosage levels,

The toxicities of new drugs under East Afrlcan conditions. and. of established drugs at high dosage levels, have been investigated. It appears that high dosages of 1.he established drugs may be used in animals free from liver fluke if they are not subjected to the stress of exercise or dehydration. Attention has been drawn to the importance of drug effects not reducing the value of the carcass as assessed at meat inspection.

Further evidence has been obtained of an "immunity" conferred on cattle by repeated doses of a drug and inoculations of trypanosomes but so far only one trypanosome strain has heen involved and whether this "immunity" will be maintaiaed against infections with other strains is not yet known.

Protozoology

The estahlishment of a "library" of trypanosome strains at E.A.T.R.O. stored deep-frozen, was reported last year. This collection, of first importance to studies on strain characteristics, drug resistance, immunology and so on, has been greatly augmented during the year.

Tl'ypollmorna vivax is important as a parasite of cattle in East Africa but its study in the laboratory is impeded by the fact 1:hat the usual laboratorr animals, white rats and mice and rabbits are normally not susceptible. Several avenues have been explored-the use of AJ'vicamhis ahyssinicus, a common wild rat in Uganda, the simultaneous inoculation of sheep serum in white rats, and the use of embryonated eggs-so far without success.

Studies on the reactions between the trypanosornes and their animal hosts have attempted to explain the variability of form of some species-the polymorphic species-and to recognize substances in the blood inimical to the parasites. The latter have been partially successful but significantly. advances in this field must await a more intensive attack than is at present possible. Other studies of import~

ance eoidemiologically have been concerned with the determination of the species of wild animals likely to be of importance as reservoirs of trypanosomes and with the species of trypanosomes occurring in tsetse flies in Nyanza Province, Kenya.

I L

j

I 36

Entomology Sampling methods for wild tsetse populations continue to be improved. The

shortcomings of the ordinary "fly-round", in which assistants catch flies attracted to them while marching over a set route, have been increasingly recognized. New methods of sub·division of the round and analysis of results have improved the prospects of relating fly catches to environmental far;lors. Traps, also, have been increasingly used and offer the advantage that they catch a larger proportion of female flies than does the fly-round, a consideration of importance when infection rates are to be examined. The importance of locating resting flies has been realized in the last few years-both for deciding the most effective ways of applying insecticides and for obtaining blood-fed flies to determine the species of animal host important in affording .them their food. It has been known for some years that flies disappear from their daytime resting sites on the trunks and branches of trees at about sunset, The introduction of a marking technique using reflecting paints has allowed the location of considerable numbers of flies by night-on the leaves of the trees.

Physiological studies on the water and fat consumption of fiies have continued and offer valuable possibHities for assessing the degree to which the metabolism of flies is upset by interference with their habil~t by various methods of bush clearing. A study of the effects of a particular method is in progress in Ankole, Uganda.

The identification of the animals fed on by tsetse has continued and a large body of information is now available. It appears possible that tsetse mav,.be more catholic in their choice of host than was previously thought: in Ugand~ in areas in which game is being destroyed. percentages of blood meals from cattle as high as 60 have been recorded.

Studies on the predators attacking tsetse have indicated that certain flies and spiders may be important.

Stall·List as at 31st December, 1958

DIRECTOR

Dr. W. H. R. Lumsden, D.Sc., M.B., Ch.B., D.T.M., D.T.H.

DEPUTY DIRECTOR

Major W. N. Scott. M.R.C.Y.S.

CHIEF ENTOMOLOGIST

Dr. J. P. Glasgow, M.Sc., Ph.D.

RESEARCH OFFICERS

J. R. Welch, B.5c.-A.

Dr. D. H. H. Rohertson, M.B., Cb.B., D.T.M, D.T.H.. M.R.C.P.-M.R.O. I. Dr. E. Bursell, B.Sc., M.Sc., Ph.D.-P.S.O. (Entomologist). R. D. Pilson, B.Sc.-S.S.O. (Entomologist). Dr. D. L. Johns, B.Sc., Ph.D.-S.5.0. (Entomologist). I. M. Smith, M.Sc., M.R.CV.S.-S.S.O. !Vet.). B. D. Rennison, B.A., M.Sc.-S.S.O. (Entomologist). J. M. R. Harley, B.Sc.- ~S.S.O. (Entomologist). H. A. W. Southon. B.A.-S.O. (Entomologist). M. J. H. Cawdrey, B.Sc. (Vet.), M.R.CV.S.-S.O. (Vel.). Dr. R. H. Knight, B.Sc., Ph.D.-S.O. (Biochemist). Miss E. C Craigie, B.Y.M.s.. M.R.C.Y.S.-S.O. (Yet.).

OFFICERS ON Ll

Dr. M. T. Ashcroft, M.A. Dr. J. R. Baker, B.Sc., Ph F Isherwood, B.Sc.-S.D.

011

Dr. K. C. Willett, M.A. transfer to W.A.I.T.R.

A. R. Jenkins, B.SC.-S.S.1 Dr. K. R. S. Morris. Ph.I (Two vacancies at 31-12-51

C. J. Webb, A.I.S.T., A.I.! E. B. Grainge, A.S.T.A. K. L Cockings. B. L Griffiths-on leave a

D. Gellatly, A.I.M.L.T.-<>I

G. R. Jewell.

W. A. Hilton-on retireme B. J. Duffy-on retirement.

ADMINI:

J. S. McClay, M.A.-Secre1 F. V. Summerfield-Office G. J. Rankin-Livestock 0

J. N. L. Pereira-Accounts C. S. Patel-Assistant Store Vacancies of Senior Fan

appointments.

Sohindar Singh-Accounts

Meetings and ConfereDI

Tsetse Fly and Trypanosol1 East African Agricultural East African Medical Rese: Trypanosomiasis Research Specialist Committee on H Specialist Committee on Ar Tsetse, Trypanosomiasis, al

mittee; Uganda. Fauna Research Committ~

OS continue to be improved. The Lich assistants catch flies attracted ~en increasingly recognized. New (sis of results ha ve improved the aL factors. Traps, also, have been :hey catch a larger proportion of ion of importance when infection : locating resting flies has been iing the most effective ways of ed flies to determine the species ~ir food. It has been known for rIe resting sites on the trunks and ion of a marking technique using onsiderable numbers of flies by

nsumption of flies have continued degree to which the metabolism tat by various methods of bush nethod is in progress in Ankole,

tsetse has continued and a large possible that tsetse may be more

1S1y thought; in Uganda in areas of blood meals from cattle 1S

e indicated that certain flies and

ber, 1958

b.B., D.T.M., D.T.H.

:.C.V.S.

'T , PhD.

'.T.H.. M.R.C.P.-M.R.O. I. nologis!).

gist).

st).

. (Vel.). ).

Vet).

_____'L~

37

OFFICERS ON LEAVE AT 31ST DECEMBER. 1958. FOLLOWING COMPLETION OF COmRACf

Dr. M. T. Ashcroft, M.A, B.M., B.Ch., D.T.M. and H.-M.R.O. n. Dr. J. R. Baker, B.Sc.• Ph.D.-S.O. (Protozoologist). F. Isherwood, B.Sc.-S.O. (Entomologist).

OTIIER DEPARTURES DURING 1958

Dr. K. C. Willett, M.A., M.B., B.S., L.R.C.P., M.R.C.S.-S.M.R.O. II.-on transfer to W.A.I.T.R.

A. R. Jenkins, B.Sc.-S.S.O. (Biochemist)-Resigned. Dr. K. R. S. Morris, Ph.D., D.Sc.-P.S.O. (Completion of contract.) (Two vacancies at 31-12-58.)

LADORATORY TECHNICIANS

C. J. Webb, A.I.S.T., ALB.P., AR.P.S. E. B. Grainge, AS.T.A. K. L. Cockings. B. L. Griffiths~on leave at 31-12-58 following completion of contract.

DEPAKIURE DURING 1958 D. Gellally, AI.M.L.T.-on Iransfer to Nigeria.

F [ELD OFFtCERS G. R. Jewell.

DEPARTURES DURING 1958

W. A. Hilton-on retirement. B. J. Duffy~on retirement.

ADMINISTRATION AND GENERAL SERVICES

J. S. McClay, M.A.-Secretary. F."V. Summerfield-Office Superintendent. G. J. Rankin-Livestock Officer. J. N. L. Pereira~Accounts Officer. C. S. Patel~Assistant Storekeeper. Vacancies of Senior Foreman and Personal Secretary filled by temporary

appointments.

DEPARTURE DURING 1958

Sohindar Singh~Accounts Officer-on transfer to Accountant-General.

Meetings and Conferences Attended by the Director or his Representati~es

Tsetse Fly and Trypanosomiasis Committee, Colonial Office. East African Agricultural and Fisheries Research Council. East African Medical Research Scientific Advisory Committee. Trypanosomiasis Resellrch Co-ordinating Committee. Spedalist Committee on Human Trypanosomiasis. Specialist Committee on Animal Trypanosomiasis. Tsetse, Trypanosomiasis, and Game Sub.commiUee of Natural Resources Com­

mittee; Uganda. Fauna ~esearch Committee; Uganda.

--_­

38

EAST AFRICAN VETERINARY RESEARCH ORGANIZATION

DIRECTOR: MR. H. R. BINNS, C.M.G., O.B.E., M.A., B.Sc., M.R.C.V.S.

The recent reports on E.A.V.R.O. in the annual reports of the East African Agrjcultural and Fisheries Research Council have covered a period of rapid development following the completion of the new research centre of 1he Organiz­ation early in 1954. These reports recorded considerable increases in the research and technical staff, and described the initiation of new research or expansion in existing work which became possible when the new members of the scientific staff had settled in at Muguga.

The year 1958 has been a period of consolidation rather than expansion. By the end of 1957 the establishment of laboratories, equipment and experimental animal accommodation for a number of new lines of research had been completed. and the training of junior staff for various specialized fields of work was well advanced. Good progress has been made during the year under review by the Divisions for ""hich these new facilities had been provided, and a number of important research results have been achieved by the Organization, which are described below in this report.

•The Stall of E.A.V.R.O.

The rapid expansion of the scientific staff of E.A.V.R.O. which has been reported in receat years has not been maintained in 1958. This has been partly due to inability to find suitable candidates for remaining vacancies, but also to the restriction on recruitment caused by the present financial stringency. Three posts of Research Officer, two of Laboratory Technician and five of Laboratory Assistant have been placed in abeyance in the draft estimates for 1959/60, token provision of £1 only being made for each vacancy. It appears most probable that the need for drastic economy will make it impossible to fill most, if not all. of these posts dur~ng the coming quinquennium. This reduction in the approved scientific establishment of the Organization is a serious set-back. It is earnestly to be hoped that if there is an improvement in the economies of the East African territories during the coming two or three years, it may be possible to restore some or most of these sciennfic posts, and ~hus enable E.A.V.R.O. to carry out in fuJI the functions for which it was created.

Dr. D. Horrocks, B.Sc., Ph.D. (Liverpool) took up his appo,ntmenI of Biochemist in May. He first spent about three months at Kabete, assisting the Department of Veterinary Services during a temporary staff shortage and acquir­ing general experience of the application of biochemical methods to the investiga­tion of 'diseases of livestock in Kenya.

Mr. S. D. Coombes was appointed Secretary in October in succession to Dr. A. Huddleston. He was a member of the staff of E.A.V.R.O., as Senior Accountant, in 1954/55. and has valuable experience of the administration of the Organization,

Dr. S. E. Piercy proceeded on vacation leave in May. pending retirement from the post of Deputy Director. He had held this post since early 1954 and played a most important part in helping to build up the Organization during the formative years and period of expansion which followed the completion of the new headquarters at Muguga.

Cool

The Director attended t South of the Sahara, which

Dr. S. F. Barnett attendt Tick-borne Diseases of Lives

Mr. G. R. Scott did res, July in the Department of E submitted a thesis for the Ph. a paper to the Second Interl was held in London 011 the 1

Mr. G. H. Lampkin reI ments at the Xth Internatioll to the 27th August. He was a the International Biometrica They took the opportunity pi ing establishments in Hollan,

While on leave Mr. R. weekS at the Bundesforschm Germany. and for a week II

Establishment at Porton, Wi

Mr. A. K. MacLeod sp Wear Glass Works, Sunderh the Managing Director of tl

The Specialist CommiUt the 27th and 28th October. <I

research and specialist officen

The S

The following notes des out by the several Divisions indicated streSS the purpose This report on the scientific than that included in the 1as1 a period of 18 months. Mo whom were appointed at vacation leave for varying J the total volume of work mentioned under each Divis

I

The research of the Db leave for periods of about s Brown and Mr. R. D. Fen assisted Mr. W. Plowright il

Mr. Scott has extende described last year. A poo inactivated by treatment witl the addition of adjuvants. Rl

,. .. ::~ ... ,~,.,.,~ .ro-~

' ..... ..;.. .'

CD ORGANIZATION

M.A., B.Sc., M.R.C.V.S.

I reports of the East African covered a period of rapid

iearch centre of the Organiz­lble increases in the research lew research or expansion in nembers of the scientific staff

ltion rather than expansion. equipment and experimental research had been completed. zed fields of work was well e year under review by the provided, and a number of ~he Organization, which afe

E.A.V.R.O. whIch has been 1958. This has been partly

ining vacancies, but also to financial stringency. Three

:ian and five of Laboratory stimates for 1959/60. token

It appears most probable .sible to fill most, if not all, i reduction in :the approved tus set-back. It is earnestly Inomies of the East African may be possible to restore Ie E.A.V.R.O. to carry onl

k up his appointment of hs at Kabele, assisting the r staff shortage and acquir­LI methods to the investiga­

:lober in succession to Dr. l.O., as Senior Accountant ration of the Organjzation~

May, pending retirement post sinee early 1954 and le Organization during the ~ed the completion of the

39

Conferences and Scientific Visits

The Director attended the 9th Meeting of the Scientific Council for Africa South of the Sahara, which was held in Accra from the 7th to the 16th August.

Dr. S. F. Barnett attended the meeting of the F.A.O.{O.T.E. Expert Panel on Tick~borne Diseases of Livestock in London from the 24th to the 29th November.

Mr. G. R. Scott did research on viruses from the beginning of the year until July in the Department of Bacteriology of the University of Edinburgh, and has submitted a thesis for the Ph.D. of the University. During this period he presented a paper to the Second Tnternational Symposium On Freezing and Drying which was held in London on the 1st and 2nd April by the Institute of Biology.

Mr. G. H. Lampkin represented E.A.V.R.O. and the East African Govern­ments at the Xth International Congress of Genetics at Montreal from the 20th to the 27th August. He ""as accompanied by Dr. Lampkin and they both attended the International Biometrical Congress held at the end of August in Ottawa. They took rthe opportunity provided by their vacation leave to visit animal breed­ing establishments in Holland and Belgium.

While on leave Mr. R. D. Ferris studied tissue culture techniques for two weeks at the Bundesforschungsanstalt fur Viruskrankheiten d~r Tiere. Tubingen, Germany, and for a week at the Ministry of Supply Microbiological Research Establishment at Porton, Wilts.

Mr. A. K. MacLeod spent a month studying glass blowing methods at the Wear Glass Works, Sunderland, by arrangements made through the courtesy of the Managing Director of the Company.

The Specialist Committee on Animal Disease Research met at Muguga on the 27th and 28th October. and was attended by 22 territorial and interterritorial research and specialist officers.

• The Scienlific Work of E.A.V,R.O.'

The following notes describe briefly the research and allied activities carried out by the several Divisions of E.A.V.R.O. and by visiting scientists, and where indicated stress the purposes and potential practical advantages of the work. This report on the scientific activities of the Organ~zation is appreciably shorter than that included in the last report of the Research Council as the latter covered a period of 18 months. Moreover, ten members of the scientific staff, most of whom were appointed at the end of 1954 or early in ]955, were on vacation leave for varying periods in 1958, which had a significant influence on the total volume of work of the Organization; these periods of leave are mentioned under each Division.

Division of Virus Diseases

The research of the Division was limited during the year by tbe absence on leave for periods of about six months of Mr. G. R. Scott, the Head, Dr. R. D. Brown and Mr. R, D. Ferris. While the latter was away. Mr. M. A. Witcomb assisted Mr. W. Plowright in the Tissue Culture Section.

Mr. Scott has extended his research on inactivated rinderpest vaccines described last year. A poor but safe vaccine results when rinderpest virus i~ inactivated by treatment with formalin, and efficiency in such vaccines necessitates the addition of adjuvants. Recent preliminary experiments indicate that rinderpest

I

40

virus inactivated by slow dessication is an excellent immunizing agent without the addition of adjuvants; this promising work is at an early stage and is being extended to larger numbers of cattle and an investigation of the duration of the immunity produced.

Mr. Scott continued his research on the strains of rinderpest which he first adaj:ted to the hamster and the mouse. The hamster-adapted strain has reached the 346th 'passage. It is stin non-lethal and characterized by complete absence of clinical signs in the hamster, but is now attenuated for cattle. The two mouse­adapted strains, one originally from hamsters and the other a bovine strain, are also clinically inapparent in mice and attenuated for cattle.

While at Edinburgh University, ~'1r. Scott completed his studies On the pathogenesis of Rift Valley fever virus in hamsters. He has shown that contact transmission of the vinis occurs frequently between infected and healthy hamsters; natural transmission of the disease is by insect vectors. He has confirmed and extended the findings of Dr. M. P. Weinbren of the Virus Research Institute, Entebbe, on the propagation of Rift Valley fever virus in Arvicanthis rats. He found that viraemia persists for 14 days after inoculation and thereafter the rats were immune; the infections ""ere clinic<llly inapparent and the C<lse mortality rate low. The search for possjbl~ reservoir hosts of the virus in nature will continue. Earlier findings that guinea pigs are refractory to Rift Valley fever were confirmed. Virus could only be recovered from guinea pigs immediately after ;noculation. thereafter vln:s disappeared completely and permanently_

• Dr. R. D. Brov.n returned from leave in August and began research on

Nairobi sheep disease, which has increased in significance in recent years follow~

ing its detection in Uganda. He is studying the pathogenesis of the virus in sheep and goats and is beginning serological research on the disease.

The successful application of the gel diffusion reaction to rinderpest by Mr. G. Vv'hite at the end of 1957, and his development by this means of a rapid specific diagnostic t~st for the disease. was mentioned last year. This test has been used on a number of occasions to establish a diagnosis at Muguga of rinderpest in material from fiQld outbreaks, notably in game in Tanganyika where the disease was detected by this JT.ethod in wildebeeste, buffalo, eland and wart hog. Mr. White is \\orking on refinements in the ,test designed to make it more sensitive and thus to detect very small qUllntitics of antigen, and is also attempting to elaborate the gel diffusion reaction as a quantitative means of measuring antibody as well as antigen. His work during the year has fully confirmed the importance of th~

gel diffusion reaction for rinderpest, which was tentatively forecast last year and has provided an additional laboratory technique which will be especially valuable in the differentiation of rinderpest from similar diseases.

In the Tissue Culture Section of the Division, Mr, Plowright, assisted by Mr. ferris and ~'1r. Witcomb, has made excellent progress in studies on the propagation in cell culture of several viruses of East African diseases, and in the application of tissue culture methods to the investigation of a number of outstanding disease problems, notably in rinderpest. The research is briefly semmarized below. An indication of the succeSses. achieved is givcn by the fact that late in 1957 and during 1958, eight important scientific papers by Mr. Plowright, Mr. Ferris and Mr. Witcomb have bccn published or accepted for publication in Nature, the Jouf1Iol of Pathology and Bacteriology, the British Journal of Experimentol Pathology, the Journal of Comparative Pathology and Therapeutics, the Veterinary Record and the Bulletin of Epizootic Diseases of Africa.

The research on the grow culture and on the attenuation A ]ong·term -experiment was the immunity produced, and t of cattle with 40th passage cuI after vaccination and were ft culture serum neutralization Mr. Ferris has been applied t included the immune respom received lapinized rinderpest in Friesian dairy cattle inocu antibody response to Kabete used as a routine measure purchas.ed experimental catt expensive retesting of batche test animals. It will be me incidence and distrib-ution 0

which is becoming increasin~

The studies. on the gro\\ culture have been complete,

'possibility of developing a mt tion of the virus in tissue cult one in sheep testis cells and c results have been ob-tained. the traditional method of "c of Nairobi sheep disease h, kidney cells and restricted 1 demonstrated. The virus was passages.

Mr. Plowright continued "Neethling" strain of lump collaboration with Dr. R. A This work was begun durilJ Inter-African Foundation fo was described in the last repe on the growth and cytopatl producing maximum yields direct practical application il for lumpy~skin disease.

Mr. Plowright and Mr stomatitis during the year. and is of importance in the of cattle, including foot-and, as one of the rinderpest-lik in the final stages of the pathological study was rna and calves. Four strains. of these cascs, and cytopathc resemble the histological cl

The Division produce~

5everal other territories. As rinderpest vaccines have pi

factorily controlled by the

~

l immunizing agent without the t a~ e~r1y stage and is being ~estlgatJOn of the duration of

ns of rinderpest which he tirst Iter-adapted strain has reached :erized by complete absence of ~d for cattle. The two mouse­ld the other a bovine strain ed for cattle. .

:ompleted his studies On the '~. He has shown that contact mfected and healthy hamsters' ectors. He has confirmed and the Virus Research Institute virus in Arvicanthis rats. H~

ulation and thereafter the rats larent and thc case mortality

of the virus in nature will :tory to Rift Valley fever were :uinea pigs immediately after y and permanently.

Jgust and began research on icance in recent years follow_ agenesis of the virus in sheep the disease.

lc~ion to rinderpest by Mr. G. :hlS means of a rapid specific rear. This test has been used at Muguga of rinderpest in

ranganyika where the disease land and wart hog. Mr. White make it more sensitive and

; also attempting to elaborate ~ measuring antibody as well lfmed the importance of the entatively forecast last year ue Which will be especiallv lilar diseases. -

Mr. Plowright, assisted by progress in studies on the

lst Mrican diseases and in vestigation of a m{mber of st.. The research is briefly chleved is given by the fact lrtant seientific papers by ~n published or accepted for !d Bacteriology, the British ~omparative Pathology and n of EpizoOfic Diseases of

' ...... " .;-' .

41

The research on the growth and cytopathogenicity of rinderpest virus in tissue culture and on the attenuation of the virus in culture was completed and published. A long~term -experiment was started at the beginning of the year to determine the immunity produced, and to measure the antibody levels, following inoculation of cattle with 40th passage culture virus; the first group was challenged six months after vaccination and were found to be solidly immune. The quantitative tissue culture serum neutralization test for rinderpest developed by Mr. Plowright and Mr. Ferris has been applied to the investigation of a number of problems. These included the immune response to inactivated spleen vaccine in cattle which had received lapinized rinderpest virus 15 months previously, the antibody response in Friesian dairy cattle inoculated with K.A.G. rinderpest virus vaccine, and the antibody response to Kabete "0" virus challenge. The test has been successfully used as a routine measure for determining the susceptibility to rinderpest of purchased experimental cattle and has materially reduced the need for the expensive retesting of batches of vaccine due to occasional immunes among the test animals. It will be most useful in serological surveys to determine the incidenCe and distribution of rinderpest in antelopes and other game animals, which is becoming increasingly significant as rinderpest is eliminated from cattle.

The studies on the growth and cytopathogenicity of shee.\' pox virus in cell culture have been completed and published. Research is in progress on the fossibility of developing a method of immunization against she1ep pox by attenua­tion of the virus in tissue culture. Two lines of viru," passage are being investigated. one in sheep testis cells and one in ealf testis cells, and very promising preliminary results have been obtained. A vaccine prepared. from culture virus, to replace the traditional method. of "ovination" would be a distinct advantage. The virus of Nairobi sheep disease has been successfully propagated in sheep testis and kidney cells and restricted but characteristic cytopathogenic changes have been demonstrated. The virus was still pathogenic for sheep and mice after 11 culture passages.

.Mr. Plowright continued the research on the cultivation of the South African "Neethling" strain of lumpy-skin disease virus v.hich he started in 1957 in collaboration with Dr. R. A. Alexander and Dr. D. A. Haig of Onderstepoort. This work was begun during his visit to South Africa under the aegis of the Inter-African Foundation for the Exchange of Scientists and Technicians which was described in the last report. Valuable additional information has been obtained on the growth and cytopathogenicity of the virus, and on optimal methods for producing maximum yields of virus in culture. The latter data would have a direct practical application in any investigations on the development of a vaccine for lumpy-skin disease.

Mr. Plowright and Mr. Ferris made an intensive stUdy of bovine papular stomatitis during the year. This appears to be a relatively widespread disease, and is of importance in the differential diagnosis of diseases causing mouth lesions of cattle, including foot-and-mouth disease and rinderpest. It is thus of significance as one of the rinderpest-like diseases, which will. become increasingly important in the final stages of the eradication of rinderpest in East Africa. A clinico­pathological study was made of the naturally occurring disease in adult cattle and calves. Four strains of a pox-like virus were isolated in tissue culture from these cases, and cytopathogenic changes in culture were demonstrated which resemble the histological changes occurring in the tissues of affected cattle.

The Division produces all rinderpest vaccines used in East Africa, and in ~everal other territories. As was stressed last year, the requirements for E.A.V.R.O. rinderpest vaccines have progressively diminished as the disease has been satis­factorily controlled by the use of these vaccines. The level of issues in 1957

i

I

42

Was mamtained during the 'year under review, and 4.262,910 doses of K,A.G. (caprinized) rinderpest virus vaccine and 652,070 doses of lapinized virus vaccine. produced by Mr. ~. A. Evans and Mr. C. S. Rampton, were sold in the East African and adja::ent territories in 1958.

Division of Bacterial Diseases

Dr. S. E. Piercy. Deputy Director, was in charge of the Division until May when he went on leave pending retirement. Mr. C. R. Newing was on Leave from July until the end of the year, and Mr. A. K. MacLeod from February to August. The work of the Division, which consists solely of research on contagious bovine pleuropneumonia and production of vaccine for this disease.. was therefore considerably reduced during the year.

The experiments mentioned last year to attempt to elucidate the reasons for severe reactions to avianized pleuropneumonia vaccine were completed by Dr. Piercy and Mr. G. J. Knight. Little additional information was obtained on the causes of these reactions, but the results of this work were satisfactory ,n that there was no evidence in support of the slight suspicion that this vaccine may very rarely produce cases of pleuropneumonia.

Adverse reactions to avianized vaccine were referred to in the last report. These were particularly severe in the Loliondo arca of Tanganyika Masailaml where 3 per cellt mortality followed inoculation of about 40,000 cattle. As a reSUlt, it was necessary to discontinue the use of vaccine prepared fro1h all but the mildest egg-passaged strain of the organism; indeed the Veterinary Department had difficulty in persuading the cattle owners to accept any vaccination. During 1958 a serious outbreak of pleuropneumonia occurred in Kenya Masailand. and the disease spread further in Tanganyika. Vaccine prepared from relatively virulent strains of organism could not be used due to the danger of severe reactions, and mild vaccine failed to control the acute, rapidly spreading type of disease which was encountered. The position towards the end of the year was that the Kenya and Tanganyika Veterinary Departments had lost faith in avianized pleuropneumonia vaccine.

Experience during the past two years or so indicates that the favourable opinions on the value of avianized vaccine which developed fol1owing its early use in Kenya were not wholly justified, and that the ideas then current on its efficacy in controlling and eradicating pleuropneumonia were perhaps over­optimistic. The ability to dry the vaccine, and therefore to store it for long periods and to transport it easily in the field, are significant advances over the old culture vaccine. However, the avianized vaccine has the same ess.ential dis­advantage as culture vaccine, namely that vaccine strains of the organism which do not cause severe reactions-which are now quite unacceptable to stock~

owners-do not give adequate protection, especially against acute virulent out~

breaks of the disease. The difficulty of satisfactorily combining safety and immunizing potency remains, and this is still the principal problem in research on the development of an effective vaccine.

Much more E.A.V.R.O. research is very evidently required on the develop­ment of a wholly effective avianized or other type of vaccine, and it must be recognized that it may be a long time before success is achieved. Future work will include investigations on the possibility that there may be strain differences in antigenicity and immunizing potency. with a view to the selection of satisfactory vaccine strains of the organism. A large-scale experiment is in progress at Muguga to compare avianized vaccine produced by the normal E.A.V.R.O. method from a strain of moderate attenuation, with culture vaccine produced by the method

i~l

,I

which is reported as being avianized and Australian-ty added, in order to determir pleuropneumonia vaccine. 1 from the V.5 strain of or~

in Australia for many ye, laboratories of the Common in Melbourne.

Serious problems were I

Newing on the techniques 1

complement fixation test antigen produced by the me and unreliable, and this de was used at Kabete in May break in Masailand. The situation developed, since dependent on quarantine an in their endeavours to conl

Following Mr. Newing' the production of cornplerr method used by Campbell a several batches of satisfact what in potency. He found ~atisfaetorily had apparent1~

Mr. White has also workel development of an antigen I as vo'ell as serum, and whic1 llsed.

DivisioD of P

Mr. D. W. Brockle,by and Miss B. O. Vidler from

Dr. S. F. Barnett, the 1 the stlIvey of the incidence Kenya. Studies on the epiz collaboration with the terf' tioDs in Tanganyika.

Dr. Barnett and Mr. theileria I disease of buffalc this was briefly mentioned been shown to have char lawrencei as described in S( to be this species. T. lawr. field investigations made tl in cattle and game in F,ast buffalo and maintained in cattle. and the behaviour: C)lOtcnsivc1y studied. The cI E.C.F. T. lawrencei and T from one parasite are US\]

parasites are differentiated

$~I~~{;r' 'J~~' '. . ..,. .

aDd 4,262,910 doses of K.A.G. doses of lapinized virus vaccine bmpton, were sold in the East

large of the Division until Mav r. C. R. Newing was on leav~ K. MacLeod from February to solely of research on contagious e for this disease, was therefore

rIpt to elucidate the reasons fo!' ~acdne were completed by

11 mformation was obtained on this work were satisfactory in ght suspicion that this vaccine ia.

referred to in the last report. rea of Tanganyika Masailand of about 40,000 cattle. As a vaccine prepared from all but eed the Veterinary Department ccept. any vaccination. During rred 10 Kenya Masailand. and -ine prepared from relatively due to the danger of severe acute, rapidly spreading type yards the end of the year was eots had lost faith in avianized

indicates that the favourable dev~loped following its early the Ideas then current on its umonia were perhaps over­lerefore to store it for long signifieant advances over the e has the same essential dis­oe ~trains of the organism , qUIte unacceptable to stock­{ against acute virulent out­Jrily combining safety and rincipal problem in research

Uy required on the develop­of vaccine, and it must be

ss is achieved. Future work re may be strain differences ) the selection of satisfactory ent is in progress at Mugug; at E.A.V.R.O. method from Ie produced by the method

43

which is reported as being successful in Australia. The experiment also includes avianized and Australian-type vaccines to whkh aluminium hydroxide has been added, in order to determine whether the addition of an adjuvant will improve pleuropneumonia vaccine. The two Australian-type vaccines have been prepared from the V.5 strain of organism which has been used for vaccine production in Australia for many years, and which was kindly supplied to us by the laboratories of the Commonwealth Scientific and Industdal Research Organization in Melbourne.

Serious problems were experienced early in the year in the work of Mr. C. R. Newing on the techniques of preparation of antigen and other reagents \for the complement fixation test for bovine pleuropneumonia. Some batches of the antigen produced by the method employed by Mr. Newing proved to be unstable and unreliable, and this defect caused considerable difficulties when the antigen was used at Kabete in May and June in the testing of bovine sera from the out­break in Masailand. The results of these tests were unreliable and a serious situation developed, since the Kenya Veterinary Department were largely dependent on quarantine and sanitary measures and the complement fixation test in their endeavours to control the disease.

Following Mr. Newing's departure on leave in July, Me. G. White undertook the production of complement fixation antigen, and by the application of the method used by Campbell and Turner in Australia he was successful in producing several batches of satisfactory antigen although different batches varied some~

what in potency. He found that the previous failure of antigen .to fix complement satisfactorily had apparently been due to premature harvesting of the organism. Me. White has also worked on the rapid slide agglutination test, including the development of an antigen for the test which is suitable for use with whole blood as Yo'ell as serum, and which appears to be more stable than the antigen hitherto used.

Division of Protozoal and Arthropod-borne Diseases• Mr. D. W. Brocklesby was on leave from October until the end of the year

and "Miss B. O. Vidler from January to May.

Dr. S. F. Barnett, the Head of the Division, and Me. K. P. Bailey completed the survey of the incidence and nature of East Coast fever in enzootic areas in Kenya. Studies on the epizootiology of E.C.F. in "fringe" or epizootic areas in collaboration with the territorial Departments have been started with investiga~

tions in Tanganyika.

Dr. Barnett and Mr. Brocklesby have carried out much research on the theilerial disease of buffaloes resembling E.C.F. which is transmissible to cattle; this was briefly mentioned in the last reDort. The causal Darasite of this disease has been shown to have characters which are very similar to those of Theileria lawrencei as described in South Africa and Southern Rhodesia. and it is considered to be this species. T. lawrencei infection has been studied at the laboratory and field investigations made to determine the distribution and nature of the disease in cattle and game in East Africa. A strain of the parasite obtained from a wild buffalo and maintained in tame buffaloes at Muguga has been transmitted to cattle, and the behaviour and morohology of the narasite in this host have been extensively studied. The clinical picture and oathology resemble closely those of E.C.F. T. lawrencei and T. parva are antigenically similar. since cattle recovered from one parasite are usually immune to infection with the other, but the two parasites are diITerentiated by morphological characters and absence of piroplasms

44

in the blood of cattle. It hBS hitherto been considered that although T. Jawrencei could comparatively easily be transmitted from buffalo to cattle, most cattle reacting to the parasite are not infective to ticks and the disease could not there­fore be transmitted from cattle to cattle. In a recent experiment at Muguga ticks fed on a reacting ox were found to be infective for other cattle. and it is now more difficult to define the differences between the two diseases.

A herd of about 50 Zebu cows derived from an enzootic E.C.F. area and previously used in research on this disease at Muguga, and the progeny of this herd, have been grazed without dipping throughout the year in a forest area heavily infected with T. lawrencei and a study made of the disease occurring in these cattle. Calves becamc infected at an early age and the majority recovered; the rate of recovery was similar to that following exposure to natural E.C.F.

Thc study of the distribution of T. lawrellcei in East Africa is incomplete, but it is known to occur in some of the highland forest areas of Kenya and very probably exists in similar areas elsewhere which are inhabited by bUffaloes. Rhipicephalus appendicularus is the principal if not the only natural vector of the parasite.

Future research will determine whether the natural disease in buffaloes is due to an aberrant 'type of r. parl-'a adapted to game or to a different species of Theileria, but for the present it 1S regarded as T. lawrencei. Whate~r the decision may be, the important consideration is that there exists in East Africa a theilerial disease transmiEs~ble by ticks to cattle which closely resembles E.C.F., and that the eradication of RC.F.-and of this disease-will be complicated in affected areas by the fact that it is carried by wild game.

Dr. Barnett and Mr. Bro.cklesby have continued the collection and study of Theilerias from' the field, nnd several interesting strains have been obtained. One strain has all the characters of T. parva but is of low pathogenicity. In the first passage of this strain in 19 cattle, 85 per cent recovered and all were sub­sequently immune to infection with fully virulent T. pana. The recovery rate was influenced by the number of ticks fed; when this was ten ticks or less it Was over 90 per cent. The mild character of this strain was retained after three passages in ticks. It therefore has promise as a means of immunizing cattle and this is being followed up. Two olher strains have been studied which have the general characters of T. nil/tans. They are transmitted by R. oppendicularus and prodllee Koch's bodies and a disease in experimental cattle resembling very mild E.C.F.; all animals recover and are thereafter fully susceptible to T. parva. The chief interest and importance of strains such as these is the confusion which they would cause in the field, where they are likely to be diagnosed as mild E.C.F. since there is no means of differentiation other than cross immunization. The OCCllrtence of such a strain on a farm and its diagnosis as E.C.F. has already been encountered. .

The research on Theilerias has included immunogenic analysis to determine 1,l,

l hether there is any difference between field strains. This is of importance in the development and application of the method of immunization by the use of Aurofac which was described in the last report. Four recently isolated Kenya strains were found to be identical by cross immunity tests with the laboratory strain used in the MlIguga immunization process. This is being extended to Tanganyika and Uganda.

An investigation has hi manufacture of the antibiQ action against T. parva. COl same way as Aurofac. It 11

Aureomycin is effective. Fur Terramycin.

Following her return ff( in the tick, and also started

Miss J. B. Walker's Ion on the taxonomy, breeding al steadily. She has given ver Veterinary Departments in tl of the rarer species from the an important part in the wo taken by the territorial depa

Div

Dr. J. A. Dinnik and MI systematics and Hfe-cycles of ruminants of East Africa al1

liver fluke.

A comparative study of I P. microbothrium, P. Philler, published shortly. Studies 01

exoporus have been complete A nisus nGwlensis; this is the larval development of a SPCl

long-term work on the Paral determination of the snail hI identified, will be completed research will then begin on I

The research of Dr. ani Lymnaea mweruensis can sen the work on the effect of ten ~tages of the liver fluke. The' that miracidia may remain d, ':;0 days and then hatch nOfl

An investigation was m nyanzi, a liver fluke collected first described by Leiper in experiments to be a snail hos whether this parasite may al

Dr. G. M. Urquhart ha ticularly the factors detern experimental calves, and thei East Africa. The factors invt eggs, the age of the calves, the influence of pre-natal aml to subsequent experiment~l

obtained indicating that con~

life. Older experimental caU high degree of resistance. Tb

I

red that although T. lawrellcei buffalo to cattle, most cattle nd the disease could not there­It experiment at Muguga ticks :or other cattle, and it is now Ie two diseases.

an enzootic E.C.F. area and guga, and the progeny of this )ut the year in a forest area de of the disease occurring in :e and the majority recovered; :xposure to natural EC.F.

in East Africa is incomplete, Jrest areas of Kenya and very

are inhabited by buffaloes. the only natural vector of the

!atural disease in buffaloes is ne or to a different species of T. lawrencei. Whatever the

at there exists in East Africa 'hich closely resembles E.C.F.. disease-will be complicated ild game.

d the collection and study of strains have been obtained.

• of low pathogenkity. In the . recovered and all were sub­parva. The recovery rate was was ten ticks or less it was

ain Was retained after three lOS of immunizing cattle and been studied which have the ted by R. appendiculatus and ::II cattle resembling very mild susceptible to T. parva. The

.hese is the confusion which I) be diagnosed as mild E.C.F. an cross immunizaHon. The gn~s[s as E.C.F. has already

lOgenic analysis to determine ns. This is of importance in immunization by the use of

;our recently isolated Kenya lity tests with the laboratory

This is being extended to

45

An investigation has been made to determine whether a by-product of the manufacture of the antibiotic Terramycin, which has some chemotherapeutic action against T. pana, could be used for immunization against E.C.F. in the same way as Aurofac. It was found to be ineffective at dose levels at which Aureomycin is effective. Further attempts are being made with a soluble form of Terramycin.

Following her return from leave Miss Vidler contjnued her work on T. pant.! in the tick, and also started studying T. lawrence; in the tick.

Miss J. B. Walker's long-term researches on East African ticks, particularly on the taxonomy. breeding and life-cycles of the vectors of disease have progressed steadily. She has given very valuable assistance and advice to officers in the Veterinary Departments in the identification of ticks, especially the differentiation of the rarer species from the common vectors of disease, and has thereby played an important part in the work on the distribution of t;cks which is being under­taken by the territorial departments.

Division of Helminth Diseases

Dr. J. A. Dinnik and Mrs. N. N. Dinnik have continued their studies on the systematics and life-cycles of the Paramphistomes. or stomach flukes, of domestic ruminants of East Africa and their research on Fmdola gigarlt;ca, the African liver fluke.

A comparative study of the morphology of three species of Paramphistomum, P. microbothrium, P. Phillerouxi and P. daubneyi is nearly finished and will be published shortly, Studics on the life-cycles of P. phillerollxi and Carmyerius exoporus have been completed. The snail host of the latter has been shown to be An;su,}' natalens;s; this is the first time that investigations have been made on the larval development of a species belonging to the family Gastrothylacidae. This long-term work on the Paramphistomes of East Africa, which has included the determination of the snail hosts of nine of the twelve species of fluke hitherto identified, will be completed and discontinued in 1959 and it is anticipated that research will then begin on Bilharzia infections of domesti~ ruminants .

The research of Dr. and Mrs. Dinnik on liver flukes has established that L,Vl11flaea mweruensis can serve as a snail host of F. gigantica. They have continued the work on the effect of temt:eralure on tbe development of the eggs and larval stages of the liver fluke. Their observations have included the significant finding that miracidia may remain dormant in the egg during the cold season for up to $0 days and then hatch normally and infect snails when the temperature rises.

An investigation \\as made on the morphology and life-cycle of Fasciola nyanzi, a liver fluke collected from hippopotamus in Western Uganda, which was first described by Leiper in 1910. Lymnaea natalensis was found by laboratory experiments to be a snail host of this fluke, Attempts are in progress to determine whether this parasite may also infect domestic ruminants.

Dr. G, M. Urquhart has done much research on bovine cysticercosis, par~ ticularly the factors determining susceptibility or resistance to infection in experimental calves, and their significance in the epizootiology of beef measles in East Africa. The factors investigated have included varying sources of tapeworm eggs, the age of the calves, the possible effects of colostrum in protection, and the influence of pre-natal and immediate post-natal natural infection on resistance to subsequent experimental infection. Much interesting information has been obtained indicating that considerable resistance appears to be acquired early in life. Older experimental cattle, aged 18 to 24 months, were found to possess a high degree of resistance. There is little doubt that the failure of earlier attempts

I

1

f

46

at M uguga and elsewhere to produce consistently successful experimental infection ~ was due to this resistance of Kenya cattle. The epizootiology of the disease in

cattle is very evidently complex, and much work requires to be done in order to provide the basic knowledge essential to its proper understanding. TnformMion is also urgently needed on the period of survival of beef measles cysts in infected cattle, and a long-term experiment has been planned to investigate this problem, in collaboration with the University of Glasgow, in fully susceptible calves in Scotland.

Dr. Urquhart is making a laboratory study of fascioliasis including th~

experimental disease, pathology, pathogenesis and haematology by infecting a group of calves and slaughtering them at regular intervals from 10 to 120 days post-infection. Similar clinico.pathological investigations are being made on experimental Parartlphislomum microbothrium infection of calves at Muguga.

Division of Deficiency and Metabolic Diseases

The functions and programme of the Division were outlined in the Ja~t report. The appointment of Dr. D. Horrocks as Biochemist enabled the Division to be established and a start to be made in its work. He has established and equipped a laboratory at Muguga and begun two main lines of research. His principal work will be on the development of techniques for chemical estimation of minerals and trace elements of importance in animal disease in East Africa, and these studies will conceA-trate on cobalt and manganese. He will also investigate the significance of sodium chloride in nutrition and disease of livestock, in cCJIlabora­tion with the Veterinary Departments of Tanganyika and Uganda.

Pathology Division

Mr. W. Plowright, assisted by Mr. W. G. MacLeod, has continued the long­term research of the Division on the morbid anatomy. histopathology and. pathogenesis of the major East African diseases of livestock. In their studies on the pathogenesis of virulent rinderpest in cattle, pathological data have been collected on 80 animals infected with two strains of bovine virus and standards for the pathological changes produced by these strains have been established. These will pr0"Ye valuable as a basis for comparison in investigations of other strains of rinderpest virus. Me. MacLeod has done much work on the haematology of cattle infecte'd with bovine, caprine and lapinized rinderpest viruses.

An important aspect of Mr. Plowright's pathology research has been his studies on the correlation between the histological changes produced by viruses in infected animals and the cytopathogenic efft:cts caused by the same viruses in cells growing in tissue culture. Similar cytological effects in the intact animal and in cell culture have been found 1n rinderpest, sheep pox and bovine papular stomatitis. This experimental approach has assisted materially in the early recog­nition of virus growth in attempts to cultivate newly investigated viruses. It also elucidates the specific effects produced by viruses in cells free from the influenee of extraneous factors, such as. the condition or antibody level of the infected animal.

Studies have also been made on the pathology and haematology of natural cases of bovine petechial fever, which occurs relatively commonly at Muguga as an intercurrent disease in experimental or vaccine cattle, and the pathology of sheep pox and Nairobi Sheep Disease has been investigated.

The Photography Section has flourished throughout the year. In particular, Me. MacLeod has continued to prepare excellent rniero·pbotographs which have done much to enhance the value of E.A.V.R.O. scientific papers; his photographs of pathological changes caused by viruses in monolayer cell cultures have been especially noteworthy.

A

The ncw Division. whie:: joint Animal Industry Div down well. The arrahgeme E.A.A.F.R.O. Farm al MUgl F.A.A.F.R.O. and the Ani described in last year's rep(

The Animal Production Metabolism and Geneties, t

Mr. G. D. Phillips and of work of the Physiology S research is a study and co Zebu and exotic types of cal to utilize the kind of hcrbag, of East Africa. Their main the three main factors of thl digestion, in ten pairs of catt steer, and the pair is kept UI

the experiment being pIanne: been completed on five pail

An ancillary study is 1 conditions on the water re( variations within types of all ing, and the relation betwee is still in progress, but it Zebus. An experiment is dependent on dry matter in from this work that water dependent factor, and that intake; an important practi problem.

Dr. A. Rogerson and M tendent. have overcome a v~

struction of the respiration Section, and a unit for the Preliminary tests of the caI~

about to begin research on different types of cattle in t1 Africa.

Mr. G. H. Lampkin an Genetics Section from early N.D.A., N.D.D., was appoin Boran cattle and to ensure of weights, measurements,

The main purposes of 1: gro~h and production of t relative jrnportance of bree quality, and to determine quality by the use of sire pi

of improving them genetical

ccessful experimental infection pizootiology of the disease in ~uires to be done in order to ~r understanding, Information beef measles cysts in infected

~d to investigate this problem, in fully susceptible calves in

of fascioliasis including the haematology by infecting a

otervals [rom 10 to 120 days gations are being made on ;lion of calves at "Muguga.

ltic Diseases

'ere outlined in the last report. it enabled the Division to be as established and equipped a , research. His principal work mica! estimation of minerals ie in East Africa, and these He will also investigate the

ase of livestock, in col1abora~ a and Uganda.

Jeod, has continued the long­natomy, histopathology and livestock. In their studies on pathological data have been [ bovine virus and standards rains have been established. In in investigations of other Ich work on the haematology rinderpest viruses.

'logy research has been his loges produced by viruses in sed hy the same viruses in effects in the intact animal eep pox and bovine papular laterially in the early recog­lewly invesHgated viruses. ruses in cells free from the In or antibcdy level of the

nd haematology of natural y commonly at Muguga as lttle, and the pathology of tigated.

Jut the year. In particular,� ro-photographs which have� fic papers; his photographs� ler cell cultures have been�

47

Animal Production Division

The new Division, which was created in July, 1957. on the abolition of the joint Animal Industry Division of E.A.V.R.O. and E.A.A.F.R.O. has settled down well. The arrangements for the apportionment of the grazing on the E.A.A.F.R.O. Farm at Muguga South between the Animal Nutrition Division of E.A.A.F.R.O. and the Animal Genetics Section of E.A.V.R.O., which were described in last year"s report, are working very satisfactorily.

The Animal Production Division consists of three sections, namely Physiology, Metabolism and Genetics, the work of the first two being inter-related.

Mr. G. D. Phillips and Mr. A. MacGregor have continued the programme of work of the Physiology Section on ruminant digestion. Their principal line of research is a study and comparison of the digestive physiology of indigenou'i Zebu and exotic types of cattle, with a view to determining their relative cflpacity to utilize the kind of herbage generally occurring in the drier and semi-arid areas of East Africa. Their main werk has been a long-term experiment comparing the three main factors of the digestive process, namely rate, time and amollnt of digestion, in ten pairs of cattle. Each pair consists of a grade Hereford and a Zebu steer, and the pair 15 kept under observation in metabolism crates for five weeks, the experiment being planned to last a year. Observations and estimations have been completed on five pairs and valuable data already obtained.

An ancillary study IS being made under precisely controlled experimental conditions on the water requirements of grade and Zebu ste~rs. This includes variations within types of animal, the effects of different intervals between water~

ing, and the relation between water intake and dry matter intake. This research is still in progress, but it has shown that grades require more water than Zebus. An experiment is being done to determine whether water intake is dependent on dry matter intake or vice versa. There is already some evidence from this work that water intake may be the independent and dry matter the dependent factor. and that limitation of water results in a reduction of food intake~ an important practical point in areas where provision of water is a problem.

Dr. A. Rogerson and Mr. C. A. May, the E.A.V.R.O. Maintenance Superin~

tende~t. have overcome a variety of technical problems and completed the con­struction of the respiration calorimeter to be used by the ,Animal Metabolism Section, and a unit for the training of experimental cattle has been established. Preliminary tests of the calorimeter are now being made, and Dr. Rogerson is about to begin research on the energy requirements and utilization of food of different types of cattle in this region. This field of research is quite new to East Africa.

Mr. G. H, Lampkin and Dr. K. Lampkin were on leave from the Animal Genetics Section from early July until the end of the year. Mr. J. G. O. Stewart, N.D.A., N.D.D., was appointed temporarily to take charge of the genetics herd of Boran cattle and to ensure the continuity of the breeding programme. recording of weights, measurements, etc. during their absence.

The main purposes of this long-term research of the Genetics Section on the growth and production of beef-type indigenous Zebu cattle are to ascertain the relative importance of breeding and management in the improvement of beef quality, and to determine the heritabilities of beef characteristics and carcass quality by the use of sire progeny groups. and thus to investigate the possibility of improving them genetically.

,..," . .'

~-.>.,y;.- ~,

" -~ .. ;,;"

: I

48

The original aim was to produce steers weighing 1.000 Th. and ready for slaughter at three years old. The first of the steers born at Muguga are now approaching this age and preliminary observations suggest that the target of 1,000 lb. is not optimic;tic. Twelve steers have already exceeded it, their average weight being 1,043 lb. and average age 148 weeks. However, it appears at this stage that Muguga.bred steers. reared solely on grass will not be finished and ready for slaughter at 1.000 th. weight, and the original objective has therefore been proYisionally altered to t, 176 lb. The first steer to reach this weight has just been slaughtered at the age of 153 weeks.

The foUo,""ing average weights of the last tcn steers and ten heifers bred <.t Mugllga to reach the weaning age of 36 weeks, and 72 and 108 weeks respectively, ~lso show that the herd of Northern Frontier Province Borans continues to thrive s,cili",factorily at Muguga,

UTeeks Sfeers Rei/as • 36 463 lh. 407 lb. 12 634 lb. 555 lb.

108 822 lb. 658 lb.

The figures [or heifer weIghts are noteworthy. The objective first set was to produce heifers which have reached a minimum weight of 550 lb., and which can then be served, at 90 weeks of age; this weight is being exceeded at 7'2 weeks.

It is necessary to stress that the ge£ldics herd of cattle is being maintained solely on 2ra5S. The rainfall at Mllguga in 1957 and the first half of this year was exceptionally good and the grass plentiful. During the dry conditions of the ~econd half of I958 the general rate of weight increases in the herd was not entirely mainta·ined. which served 10 emphasize the obvious fact that satisfactory progress is dependent on a reasonable level of rainfall and grazing.

Visiting Scientists

The scheme for co-operative research on virus diseases at Muguga by E.A.V.R.O. and the United States Department of Agriculture, which was first described in the last report. has made excellent progress. When Mr. Scott returned from {eave, the organization of the scheme was adjusted so as to bring the research of the American team into closer contact and inter-relation wilh the Divi9ion of Virus Diseases; this has proved to be a most satisfactory arrangement. In October. Dr. K. M. Cowan was posted to Muguga by the U.S. Department for the usual two-year tour. He is a very experienced serologist whose knowledge will be most valuahle, not only to the co-operative research at Mugugn, but also to other laboratories doing serological research on animal disease in East Africa, which will benefit from his advice.

A notable advance was achieved by Dr. W. A. Malmquist in his research on the growth of the virus of African Swine Fever in tissue culture. The celIs used were macro phages from the bone marrow and the peripheral blood of domestic pigs. He has found tnat a focal haemagglutination. or clumping of red blood cells. occurs around rnacrophages infected with the virus, and that the macropha£es undergo evenlual destruction or cytol)'sis. This procedure provides for the first time a method for the identification of African Swine Fever virus without the inoculation of pigs, and opens up an entirely new field for in vitro studies. Foltowing Dr. Malmquist's successful demonstration of focal haemagglutination in African Swine Feyer. experiments were done at the Animal Disease Laboratory of the U.S. De;::artment of Agriculture at Belsville. Md. to determine whether this

phenomenon occurs in eel is clinically and pathologi,

ologicaUy distinct. This" these effects in identlcal is now available for the cholera virus, and import main objectives of the co­a rapid laburatory rnetho<J recognizing African Sv..int Arrangements are in prog tour at Muguga.

Dr. D. E. DeTriiY co Fever in the indigenous v Department. Plans are bein and future research will c hush pig and giant forest \

Dr. A. W. Slablefortb Laboratory at Weybridge, : valuable opportunity for di! and the United Kingdom. parasitism \n cattle at the wealth ScientIfic and Indu week with E.A.V.R.o. in ]I.

Panel on Tick-borne Dise: Veterinary Laboratory at production of bovine pleur in November.

A notable occasion \\ from London University II

visited East Africa to consil Qualification at the Makere of the following distingu Veterinary Officer, Ministr: College of Veterinary Sw Royal Veterinary College.. London: Dr. W. R. W, Mr. S. L. Hignelt, Weilcol

Labo

Mrs, J. Palmer and continued most effectively of the rabbits. guinea pig~

production by EAV.RO. experimental animals to 1

Mr. E. S. Palmer, the internal system for the SUl

for the various activities ( rainfall of the first half 01

North.

.....�~

"log 1,000 lb. aod ready for rs born at Muguga are now s suggest that the target of ,dy exceeded it, their average

However, it ::lppears at this ass. will not be finished and iginal objective has therefore

to reach this weight has just

,leers and ten heifers bred Co t '2 and 108 weeks respectively, x Borans continues to thrive

reijers

17 lb. ,5 lb. ,8 lb.

e objectiYc first set wus to 'ight of 550 lb., and which being ex:cccded at 72 weeks.

of cattle is being maintained d the first half of this year Ig the dry conditions of the reases in the herd was not bviollS fact thai satisf~ctory 11 and grazing.

} diseases at Muguga bv griculture. which was fir~t s. When Mr, Scott returned jusled so as to bring the Lod inter-relation with the it satisfactory arrangement. l by the U.S. Department :ro!ogist whose knowledge ~arch at Ml1g11ga, but also 1al disease in East Africa,

'mquist 10 his research on� Je culture. The cells used� pheral blood of domestic� mpin.,g of red blood ceUs.� ld that the rnacrophages� re provides for the first� Fever virus without the� :ld for in vitro studies.� focal haemagglutination� imal Disease Laboratory� } determine whether this�

49

phenomenon occurs in cell cultures o[ the virus of American Hog Cholera, which is clinically and pathologically very similar to African Sv.'ine Fe..'er. but immun­ologically distinct. This work showed that hog cholera virus does not produce these effects in identical tissue culture systems. Comequently an in vitro test is now available for the differentiation of African Swine Fever virus and hog cholera virus, and important progress has thus been made towards one of the main objectives of the co-operative research project, namely the uevelopment of a rapid laboratory method of distinguishing the two disea5es and of immediately recognizing African Swine Fever should it ever gain access to North America. Arrangements are in progress to extend to three years Dr. Malmquist's present tour at Muguga.

Dr. D. E. DeTray continued his epizootiological studies on African Swine Fever in the indigenous wild swine of Kenya in collaboration with the Game Department. Plans are being made to extend this work to TanganyiKa and Uganda, and future research wHI concentrate on determining the incidence in wart hog, bush pig and giant forest hogs and the meehanism of transmission.

Dr. A. W. Stableforth, Director of the Ministry of Agriculture's Veterinary Laboratory at Weybridge, spent a week at Muguga in June; his visit provided a valuable opportunity for discussions on problems of mutual interest to East Africa and the Lnited Kingdom. Dr. R. F. Riek, who works on host reactions to parasitism in cattle at the Veterinary Parasitology Laboratory of the Common­wealth Scientific and Industrial Research Organization -in Queensland, spent a week with E.A.V.R.O. in November, on his way to attend the FAO lOrE Expert Panel on Tick-borne Diseases of Livestock. Dr. R. Sobrero.· Director of the Veterinary Laboratory at Merca. Somaliland, studied E.A.V.lt.O. methods of production of bovine pleuropneumonia and rinderpest vaccines for three week'i in November.

A notable occasion was the visit to E.A.V.R.O. in April of the mission from London University and the Royal College of V ~terinary Surgeons which visited East Africa to consider the introduction of a London University veterinary qualification at the Makcrere College Veterinary School. The delegation consisted of the following distinguished veterinarians. Mr. J. R. Ritchie, c.a., Chief Veterinary Officer, Ministry of Agriculture; Mr. H. Sumner, President, The Roy,,1 Colleg" of Veterinary Surgeons; Professor R. E. Glover, Principal and Dean. Royal Veterinary College, London; Professor R. Lovell, Roya~ Veterinary Coltcge, London; Dr. W. R. Wooldridge, Scientific Director, Anima! Health Trust~ Mr. S. L. Hignett, Wellcome Veterinary Research Station, Frant.

Laboratory and Expnimental AnimaIs

Mrs. J. Palmer and her staff in the Laboratory An.imals Section have continued most effectively throughout 1958 the large-scale breeding and production of the rabbits, guinea pigs, hamsters and mice reqUired for research and vaccine production by E,A.\'.R.O. She has again supplied foundation breeding stock and experimental animals to other laboratories in East Africa.

Mr. E. S. Palmer, the Livestock Officer, has continued to operate his efficient internal system for the supply of all cattle and other experimental animals needed for the various activities of the Organization. He took advantage of the abundant rainfall of the first half of 1958 to produce about 40.000 bales of hay at Muguga North.

'. ~"

50

Publications by E.A.V.R.O. 1958

BAR.~EIT, S. F.-The chemotherapy of tick-borne diseases. Presented to the FAO/OlE Expert Panel on Tick-borne Diseases of Livestock, London, November, 1958.

BARNETT, S. F.-Research methods and techniques in the study of tick-borne diseases. Presented to the FAO/OIE Expert Panel on Tick-borne Diseases of Livestock, London, November, 1958.

BARNEIT, S. F. and BROCKLESBY, D. W.-Wild animals as carriers of tick-borne diseases. Presented to the East African Fauna Conference. Nairobi, April, 1958.

DINNIK, J. A.-Identification of liver fluke and stomach fluke eggs recovered from faeces of infested animals. Bull. epiz. Dis. Afr. 6. 135-139 (1958).

DINNIK. J. A.-The succession of redial generations in the development of Paramphistomidae and Fasciola species in a snail host. Presented to the XVth International Congress of Zoology, London, July, 1958.

KNIGHT, G. l---Quality control of lapinized rinderpest vaccine. Bull. epil.. Di.<{~ Afr. 6, 165·110 (1958).

MALMQUIST, W. A. and HAY, D.-An if! vitro test for African Swine Fever. Science. In press..

PHILLIPS. G. D.-A simple mouth-gag and stomach-tube guide for ruminants. Ve,. Rec. 70, 887 (1958).

PIERCY, S. E.-Present methods of control of contagious bovine pleuropneumonia. Bull. eph. Dis Afr. 6. 155-164 (1958).

PIERCY, S. E. and (KNIGHT, G. J.-Studies with avianized strains of the organism of contagious bovine pleuropneumonia. V. Experiments with avianized vaccines at various levels of attenuation. Brit. vet. J. 114, 245-253 (1958).

PLOWRIGHT, W. and FERRIS, R. D.-Studies with rinderpest virus in tissue culture: l----Growth and cytopathogenicity. n.-Pathogenicity for cattle of culture passaged virus. J. compo Path. (In press.)

PLOWRIGHT, W. and WncoMB, M. A.-The growth in tissue cultures of a virus derived from lumpy-skin disease of cattle. J. Path. Bact. (In press.)

PLoWRIGHT, W. and FERRIS, R. D.-Papular stomatitis of cattle in Kenya and Nigeria, Vet. Rec. (In press.)

PLOWRIGHT. W. and FERRIS, R. D.-The growth and cytopathogenicity of sheep pox virus in Hssue cultures. Brit. J. expo Path. 39, 424 (1958).

ROBSON, J., ARNOLD, R. M.. PLOWRIGHT, W. and ScOIT, G. R.-The isolation from an eland of a strain of rinderpest virus attenuated for cattle. Bull. eph.. Dis. Afr. (In press.)

Scon, G. R.-Rinderpest in sheep (correspondence). Vet Rec. 70, 521-522 (1958).

Scon, G. R.-Mortality of rabbits inoculated with lapinized rinderpest virus. J. compo Path. (In press.)

Scon, G. R. and RAMPTON, C. S.-·Dricd virus vaccines: lhe problem of batch size. Recent Researches in Freezing and Drying, (In press.)

URQUHART, G. M.-The experimental production of cysticercosis in calves in Kenya. Bull. epiz. Dis, Afr. (In press.)

WALKER, JANE B.-Notes on tl Rhipicephalus Qppendicul,

WALKER, JANE B. and WILEY,

idea, Ixodidae), a new spc (In press.)

WHITE, G.-A specific diffu: the agar double diffusion

E.A.

H. R. Binns, C.

S. E. Pierey,

S. F. Barnett, Ph.D.. B.S D. W. Brocklesby, M.R.I

R. D. Brown, M.A.• B.S J. A. Dinnik, o.Sc., Hell S. A. Evans, M.R.C.V.S.,

D. Horrocks, RSc., Ph.! G. H. Lampkin, B.Sc., ~

C. R. Newing, M.R.C.V. G. D. Phillips, B. SC., B

W. Plowright, M.R.C.V.

A. Rogerson, B. Sc., Ph.

G. R. Scott, B.Sc., M.S

G. M. Urquhart, Ph.D., Miss J. B. Walker, R.Sc

G. White, M.A., V.M·B.

K. P. Bailey, Protozoo!<

Mrs. N. Dinnik, M.Sc., R. D. Ferris, F.I.M.L.T

D. Hay, F.I.M.L.T., Vir

G. J. Knight. F.I.M.L: Mrs. K. Lampkin, B.Sc.

A. MacGregor, A.I.M.l A. K. MacLeo<!, A.I.M

W. G. MacLeod, Patho

C. S. Rampton. A.I.M.

I J. G. O. Stewart, N.D.!

Miss R O. Vidler. Pro M. A. Witcomb, AJ.:rv.

t I,

~ 1958

le diseases. Presented to the

I'~ases of Livestock London ,

:s in the study of tick-borne ,Del on Tick-borne Diseases of

mals as carriers of tick~borne

1 Conference. Nairobi, April,

ach fluke eggs recovered from 6. 135-139 (1958).

ions in the development of snail host. Presented to the on. July. 1958.

;t vaccine. Bull. epiz. Dis. Afr.

:st for African Swine Fever.

:h·tube guide for ruminants.

ous bovine pleuropneumonia.

lized strains of the organism Experiments with avianized '. J. 114, 245-253 (1958).

erpest virus in tissue culture: enicity for cattle of culture

in tissue cultures of a virus !tlr. Bact. (1n press.)

titis of cattle in Kenya and

i cytopathogenicity of sheep I, 424 (1958).

r, G. R.-The isolation from ~d for cattle. Bull. epiz. Dis.

Ver Rec. 70, 521-522 (1958).

lapinized rinderpest virus.

ines: the problem of batch (In press.)

E cysticercosis in calves in

51

WALKER, JANE B.-Notes on the common tick species of East Africa. Introduction. RMpicephalus appendiculatus and R. praVlIS. East African Veld. (In press.)

WALKER, JANE B. and WILEY, A. J.-Rhipic<,pha/us came/oparda/is n. sp. (Ixodo­idea, Ixodidae), a new species of tick from East Afrjcan giraffes. Parasitology. (In press.)

WHITE, G.-A specific diffusible antigen of rinderpest virus demonstrated by the agar double diffusion precipItation reaction. Nature, 181, 1409 (1958).

E.A.V.R.O. Staft List for 1958

DIRECTOR

H. R. Binns, C.M.G., O.B.E., M.A., B.Sc., M.R.C.V.S.

DEPUTY DIRECTOR S. E. PIercy, Ph.D., B.Sc. F.R.C.V.S., Dip. Agric.

RESEARCH OFFICERS

S. F. Barnett, Ph.D., B.Sc., M.R.C.V.S., Protozoology.

D. W. Brocklesby, M.R.C.v.S.. Protozoology.

R. D. Brown, M.A., B.Sc., M.R.C.V.S., D.v.M. & S., Virology. J. A. Dinnik, D.Sc., Helminthology.

S. A. Evans, M.R.C.V.S., Virology.

D. Horrocks, B.Sc., Ph.D., Biochemistry.

G. H. Lampkin, B.Se., N.D.A., Dip. Anim. Gen., Geneti~s.

C. R. Newing, M.R.C.v.S., Bacteriology.

G. D. Phillips, B. Sc., B.V.Sc., M.R.C.V.S., Physiology.

W. Plowright, M.R.C.V.S., Pathology.

A. Rogerson, B, Sc., Ph.D., Biochemistry.

G. R. Scott, B.Sc., M.Sc.. M.R.C.v.S., Virology. G. M. Urquhart, Ph.D., M.R.C.V.S., Helminthology.�

Miss 1. B. Walker, B.Sc., Entomology.�

• G. White, M.A., V.M.B., M.R.C.V.S., Bacteriology.

LABORATORY TECHNICIANS K. P. Bailey, Protozoology.�

Mrs. N. Dinnik, M.Sc., Helminthology.�

R. D. Ferris, F.LM.L.T., Virology.

D. Hay, ELM.L.T., Virology.

G. J. Knight, ELM.L.T., F.S.S., Bacteriology.�

Mrs. K. Lampkin, B.Sc., Ph.D., Genetics.�

A MacGregor, A.LM.L.T., Physiology.�

A K. MacLeod, ALM.L.T.. Bacteriology.�

W. G. MacLeod, Pathology.

C. S. Rampton, A.I.M.L.T., Virology.

J. G. O. Stewart, N.D.A., N.D.D., Genetics.�

Miss B. O. Vidler, Protozoology.� M. A. Witcomb, A.LM.L.T., Virology.

52

GENERAL SEln'JCES

A. E. Arbury, Con~truclion.

C. A. May, Maintenance Superintendent.

E. .s. Palmer, Livestock Officer.�

Mr~. J. Palmer, Laboratory Animals.�

S. N _ D'Souza, Storekeeper.

\hs. L. D. Vcrdcourt, Librarian.

AD'VIINISTRATION

S. D. Coombes, Secretary.

A. S. Fernandes. Accounts Officer.�

Mrs. D. J. DanieJli, Personal Secretary.�

Mrs. J. W. Dent, Personal Secretary.�

Mrs. T. E. MacLeod, Personal Secretary.�

Attend'

NI

Sir Ferdinand Cavendi:� Sir Bruce HuH. K.B.E.,� Mr. M. Blundell, M.B']� Mr. W. E. CrosskilL� Mr. A. E. Trotman, C.� Me. J. M. Hunter.� Mr. F. R. J. Williams,� Mr. R. E. T. Hobbs.� Mr. R. P. Read.� Dr. J. C. F. Hopkins.� Professor C. M. Yonge� Mr. C. A. Kirkman.�

'!l A !tendallce

Mr. O. L. Blunt, C.M.C Dr. E. W. Russell. Mr. H. R. Binns, O.RE • Mr. R. S. A. Beauchal� Mr. E Williams.� Dr. W, H. R. Lumsden.� Major W. N. Scott.� Mr. H. J. Hinchey, C.B� LI.~Colonei S. P. Fearm�

TENTH I

Sir Ferdinand Cavendish Sir Bruce Hutt, K.B.E., 'I1r. M. Blundell, M.C. The Earl of Portsmouth. Mr. A. E. Trotman, c.rv Mr. A. B. Killick, C.M. Mr. A. H. Hawker. Professor C. M. Yonge. Dr. G. O. H. Bell.

1/1 Afll'lIdance

Mr. D. L. Blunt, C.M.G . Mr. H, J. Hinchey, C.I Dr. E. W. RusselL Dr. S. F. Barnett. Mr. R. S. A. Beauchar Dr. J. F. G. Wheeler. Major W. N. Scott. Lt.-Colonel S. P. Fcarol

G.P~K:-4())-=450-lj59

53

APPENDIX

Attendance a( (hl;; Ninth and Tenth Meetings

)JINIH MEETJNG, 6TH FEBRUAR'k', 1958

Sir Ferdinand Cavendish-Bentinck. K.B.E, CM.G., M.e.� Sir Bruce Hutt, K.B.E, C.M.G.� Mr. M. Blundell, M.B.E. M,r. W. E. Crosskill. Mr. A. E. Trotman, CM.G. Mf. J. M. Hunter. Mr. F. R. J. Williams. M.B.F. Mr. R. E. T. Hobbs. ML R. P. Re"ld. Dr. J. e. F. Hopkins. Professor C. ~1. Yang::, CRE.. F.R.S.� Mr. C. A. Kirkman.�

/11 Attemlance

Mr. D. L. Blunt, eM.G. Dr. E. W. Russel1. Mr. H. R. Binns, O.B.E. Mr. R. S. A. Beauchamp.� Mr. F. Williams.� Dr. W. H. R. Lumsden.� ~ilajar W. N. Seal\.� MI'. H . .T. Hinchey. c,B.E. Lt.-Colonel S. P. Fearon. Secretary.

TENTH ~IEEllNG, 30TH SEPrE~tBER, J958

Sir Ferdinand Cavendish-Bentinck, K.B.£., e.M.G., M.e. Sir Bruce Hutt, K.B.E., C.M.G. Mr. M. Blundell. M.e. The Earl of Portsmouth. Mr. A. E. Trotman, C.M.G.� ~1r. A. B. Killick, C.M.G.� Mr. A. H. Hawker.� Professor C. M. YangI..', C.B.E., F.R.S. Dr. G. D. H. Bell.

/!I A "c,rdance

Mr. D. L. Blunt. eM.G.� Mr. H. J. Hmchey, eB.E.� Dr. E. W. Russell.� Dr. S. F. Barnett. Mr. R. S. A. Bcauchnmp. Dr. J. F. G. Wheeler. Major W. N. Scott. Lt.-Colonel S. P, Fearon. Secretary.

-�':~~~lt. ­

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