I. The effect of Aureomycin in pelleted or whole grain creep rations fed to suckling lambs II. The effectof Thyroprotein, Thiouracil, and Stilbestrol on gains of fattening lambsby Charles A Daley

A THESIS Submitted to the Graduate Faculty in partial fulfillment of the requirements for the degreeof Master of Science in Animal IndustryMontana State University© Copyright by Charles A Daley (1956)

Abstract:I. The first portion of the thesis presents the results of a study to determine the effect of Aureomycin inpelleted and whole grain creep rations fed to suckling lambs. ' Thirty-two ewes of three breeds, all withtwin lambs, were randomly divided by breed into four equal groups. Variables consisted of four creepfeeds which were offered free choice to the month-old lambs in a fifty-day feeding trial. Rate of gain,feed efficiency, and general health of the lambs were observed to determine (l) the effect of pelleting asimple oat-beet pulp ration, (2) the effect of adding Aureomycin at 20 mg. per pound of a simpleoat-beet pulp pellet, and (3) the effect of using a commercial type creep pellet containing Aureo-mycinat 20 mg. per pound of ration. Addition of Aureomycin apparently increased rate of gain during thefirst two weeks of the trial. Lambs on a whole grain ration (without Aureomycin) had the lowest rate ofgain and feed consumption per lamb during this period. At the end of the fifty-day trial, feed cost andfeed cost per hundredweight of gain were lowest for the whole grain group (without Aureomycin), andhighest for the group on the commercial type pellet (with Aureomycin. The lambs on the whole grainration appeared "pot-bellied" which would have adversely affected carcass grades, had the lambs beenmarketed then. The cost of including Aureomycin at 20 mg. per pound in an oat-beet pulp pellet wasmore than repaid through increased feed efficiency. Rate of gain was not affected. Incidence of scourswas approximately equal among the four groups. Because of the low occurrence of scours, the value ofAureomycin in controlling scours could not be determined.

II. In the second trial, eleven lots of three wether lambs each were hand-fed a grain and alfalfa hayration; weight gains were observed. Variables included combinations of thyroprotein, thiouracil, orstilbestrol in a soybean meal carrier, and stilbestrol pellets implanted subcutaneously. Lambs showed amarked dislike for thiouracil when it was included in the ration. There was a highly significantdifference ((P<0.01) in gains per lamb among lots. A 12 mg. stilbestrol implant gave the highest rate ofgain (0.60 pounds per day), while 0.5 gm. thiouracil orally per head daily gave the lowest (0.23 poundsper day). Addition of 0.3 gm. thiouracil orally per head daily to the ration of lambs already implantedwith a 12 mg. stilbestrol pellet lowered daily gains by 0.07 pounds per day. Levels of 0.5, 1.0, and 2.0mg, stilbestrol orally per head daily resulted in rate of gain increases of 0.14, 0.08, and 0.13 pounds perday respectively over the controls. Feed requirement per hundred pounds of gain was improved by 99,101, and 68 pounds, respectively. Oral intake of stilbestrol with either thyroprotein or thiouracilincreased feed efficiency over that of the controls but did not affect rate of gain. Carcass grades of oneanimal from each lot showed the lambs were not fat. The control animal graded average choice, thehighest of all the eleven lots. The pituitary, adrenal, and thyroid glands were removed and weighed,after which the glands were preserved for future histological study* 

I . THE EFFECT OF AUEEOMYGIN IN PELLETED OR MOLE GRAIN CREEP RATIONSFED TO SUCKLING LAMBS

I I . THE EFFECT OF THYROPROTEIN, THTOURACIL, AND STILBESTROL ON GAINSOF FATTENING LAMBS

by

CHARLES A. DALEY

A THESIS

Subm itted to th e Graduate F a c u lty

' - ■ ' ""

■ p a r t i a l f u l f i l lm e n t o f th e requ irem en ts

f o r th e deg ree o f

M aster o f Science in Animal In d u s try

a t

Montana S ta te C ollege

Approved:

Head, Major Department

Chai'rm; lin ing Committee

Bean,' Graduated/D ivision

Bozeman, Montana ■ June, 1956 ' ■ % ( hj

- 2 -H37yT) /ff e

ACKNOWLEDGEMENT

The au th o r w ishes to exp ress h is s in c e re a p p re c ia tio n to th e

fo llo w in g s t a f f members o f Montana S ta te C o llege; Bozeman, Montana:

D r, 0 , 0 . Thomas and P ro fe s s o r J , L, Van Horn o f th e Animal In d u s try

and Range Management Department f o r t h e i r in v a lu a b le a s s is ta n c e in

o rg an iz in g the t r i a l s and fo r t h e i r guidance in th e p re p a ra t io n o f

the m anuscrip t; Dr. E. B. Harvey o f th e Zoology and Entomology D epart­

ment f o r h is co o p era tio n in th e c o l le c t io n o f th e endocrine glands

and h is su g g es tio n s in th e review o f th e m an u scrip t.

G ra te fu l acknowledgement i s made to s tu d e n ts S. H. Smyrl and

Vernon R obertson who a s s i s te d in th e feed ing and w eigh ing , re s p e c tiv e ly ,

o f th e anim als in th e second t r i a l .

A p p rec ia tio n i s extended to Dr. R. F . E l l i o t t o f The American

Cyanamid Company fo r supp ly ing th e Aurofac 2A and th io u r a c i l , to D r.

Wm. S . Davidson of Wick and Fry , In c . fo r fu rn is h in g th e s t i l b e s t r o l

im p la n ts , to D r. C. F. Chappel o f E li L i l ly and Company fo r the S t i l -

b oso l prem ix, to Dr. G. 0 . Kohler o f th e Cerophyl L a b o ra to r ie s , In c .

f o r th e c o n tr ib u tio n o f th e Protam one, and to W. A. H a rris o f the H olly

Sugar Co. f o r th e Sugapulp used .

118856

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A b s t r a c t ............................................ ■ * ............................................ ........ . . ^

JJxperiment X • • # « # ♦ » » « » » * * * . * 6

Introduction . . . . . . . . . . . . . 6

Review o f L i te r a tu r e . ..................................................................... . . . 8

A n tib io t ic s . ................................................................................................ 8

Aureomycin.i n Chick R a tio n s . .................................................................. 10

Aureomycin in Swine R a tio n s . ........ ........................................................ 11

Aureomycin in Young C alf R a tio n s . . . . . . . . Ili

Aufeomycin in S te e r Rumen S tu d ie s . , . . . . . 1 7

Aureomycin in Sheep F a tte n in g R ations . . . . . * 18

Aureomycin in Suckling Lamb R a tio n s ................................................... 25

Summary: Aureomycin i n R ations o f Farm Anim als. . . . 28

O b jec tiv es • . . . . . . . . . . . . . 3 0

Procedure .......................................................................................................................31

R e su lts and D iscussion .. .............................................................................................31;

Summary lj.3

L i te r a tu r e C ite d . ...................................................................... ........ . ,. It5

Experim ent I I . . 50

In tr o d u c t io n ................................................................................................................ 50

Review o f L i t e r a tu r e ............................................ ....................................................52

E ffe c t o f Feeding S t i l b e s t r o l to Farm Animals . . . 5 2

E f fe c t o f Feeding T h io u ra c il and Thyroprotein . to Farm Animals 6l

O b j e c t i v e s ..................................................... ........ . . . . . 7 1

Procedure , ' . . . ..................................................... ........ . . 7 2

R e su lts and D i s c u s s i o n ........................................... 75

- U -Smmary . , . ....................................................................... .... . . . 8 0

L i te r a tu r e C ite d . . . . . . . . . . . . . . 8 2

- 5 -

ABSTRACT

I . The f i r s t p o r t io n o f th e t h e s i s p re s e n ts the r e s u l t s o f a s tudy to determ ine th e e f f e c t o f Aureomycin i n p e l le te d and whole g ra in creep r a t io n s fe d to su ck lin g lam bs. ' T h irty -tw o ewes o f th re e b re e d s , a l l w ith twin"lambs," were random ly d iv id ed by b reed in to fo u r equal g roups. V ari­a b le s c o n s is te d o f fo u r creep feeds which were o ffe re d f r e e choice to th e m onth-old lambs i n a f i f ty - d a y feed in g t r i a l . R ate o f g a in , feed e f f i ­c ien cy , and g e n e ra l h e a l th o f th e lambs were observed to determ ine ( l ) th e e f f e c t o f p e l l e t in g a sim ple o a t-b e e t pu lp r a t io n , (2 ) th e e f f e c t o f add­ing Aureomycin a t 20 mg. p e r pound o f a sim ple o a t-b e e t p u lp p e l l e t , and (3) th e e f f e c t o f u s in g a commercial type creep p e l l e t c o n ta in in g Aureo- mycin a t 20 mg. p e r pound o f r a t i o n . A dd ition o f Aureomycin ap p a ren tly in c re a se d r a t e o f g a in d u rin g the f i r s t two weeks o f th e t r i a l . Lamhsl' on a whole g ra in r a t io n (w ithou t Aureomycin) had th e low est r a t e of. g a in and : feed consum ption p e r lamb during t h i s p e r io d . . At th e end o f t h e . f i f t y - d a y t r i a l , fe ed c o s t and fe e d c o s t p e r hundredw eight o f g a in were low est fo r th e whole g ra in group (w ithou t Aureomycin), and h ig h e s t f o r th e group on th e commercial ty p e p e l l e t (w ith Aureom ycin).. The lambs on the-w hole g ra in r a t io n appeared " p o t-b e ll ie d " which would have ad v e rse ly a f fe c te d c a rca ss g rad es , had th e lambs been m arketed th e n . The c o s t o f in c lu d in g Aureomycin a t 20 mg. p e r pound in an o a t-b e e t pu lp p e l l e t was more th a n re p a id th rough in c re a se d fe e d e f f ic ie n c y . Rate o f g a in was n o t a f fe c te d . In c id en ce o f sco u rs was approx im ate ly eq u al among th e fo u r g roups. Be­cause o f th e low occurrence o f sco u rs , th e v a lu e of Aureomycin i n c o n tro l­l in g scou rs could n o t be determ ined .

I I . I n th e second t r i a l , e leven l o t s o f th r e e w ether lambs each were hand -fed a g ra in and a l f a l f a hay r a t io n ; w eight ga ins were observed . V a riab le s in c lu d e d com binations o f th y ro p ro te in , t h io u r a c i l , o r s t i l b e s t r o l in a soybean meal c a r r i e r , and s t i l b e s t r o l p e l l e t s im plan ted subcutan­e o u s ly . Lambs showed a marked d is l ik e f o r th io u r a c i l when i t was in c lu d ed in th e r a t i o n . There was a h ig h ly s ig n i f ic a n t d if fe re n c e (P O .O l) in g a in s p e r lamb among l o t s . A 12 mg. s t i l b e s t r o l im plan t gave th e .h ig h ­e s t r a t e o f g a in (0 .60 pounds p e r d ay ), w h ile 0 .3 gm. th io u r a c i l o r a l ly ’ p e r head d a i ly gave th e lo w est (0 ,23 pounds p e r day). A dd ition o f 0 .3gm. th io u r a c i l o r a l l y p e r head d a ily to the r a t io n o f lambs a lre ad y im­p la n te d w ith a 12 mg. s t i l b e s t r o l p e l l e t low ered d a i ly g a in s by 0 . 0? pounds p e r day . Levels o f 0 ,3 , 1 . 0, and 2 . 0 . mg. s t i l b e s t r o l o r a l ly p e r head d a i ly r e s u l te d in r a t e o f g a in in c re a s e s o f O .lL , 0 , 08 , and 0.13 pounds p e r day r e s p e c t iv e ly over th e c o n tr o ls . Feed requ irem en t p e r hundred pounds o f g a in was improved by 99, 101, and 68 pounds, re s p e c tiv e ­l y . O ral in ta k e o f s t i l b e s t r o l w ith e i th e r th y ro p ro te in o r th io u r a c i l in c re a se d fe e d e f f ic ie n c y over th a t o f th e c o n tro ls b u t d id n o t a f f e c t r a t e o f g a in . C arcass grades o f one anim al from each l o t showed the lambs were no t f a t . The c o n tro l anim al graded average ch o ice , th e h ig h e s t o f a l l th e e lev en l o t s . The p i t u i t a r y , a d re n a l, and th y ro id g lands were removed and w eighed, a f t e r w hich th e g lands were p re se rv ed f o r fu tu re h i s to lo g ic a l study*

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INTRODUCTION

The most im p o rtan t feed f o r th e new-born lamb i s m ilk . A fte r two

Treeks o f age th e rumen becomes in c re a s in g ly fu n c tio n a l , and the lamb can

th en consume in c re a s in g amounts o f o th e r feeds, such as g ra in s - and hays.

P a s tu re p lu s a few pounds o f m ilk d a i ly p ro v id e an adequate source o f

n u t r i e n ts f o r p ro d u c tio n o f h e a lth y , norm al-grow ing lam bs.

Lambs born e a r ly in th e y e a r , b efo re green g ra ss i s a v a ila b le , b e n e f i t

by hav ing access to creep fe e d . This fe e d i s p la ce d in an ex c lo su re th a t

p e rm its sm all, lambs to e n te r , b u t excludes th e ewes.

In g re d ie n ts used in a lamb creep fe e d can vary w ide ly , b u t th e end

r e s u l t shou ld be a r a t io n th a t i s p a la ta b le to th e lam bs. Although good

r e s u l t s have been o b ta in ed on on ly o a ts o r co rn , a m ix ture o f sev e ra l• , ' ' (

feedp i s u s u a l ly recommended. The young lambs should be o f f e r e d 'a rough-

age such as good a l f a l f a hay as w ell- a s a c o n ce n tra te m ix tu re .- Choice

a l f a l f a hay can be chopped, mixed w ith th e c o n ce n tra te , and o ffe re d f re e

c h o ice . Another way i s to l im i t th e co n ce n tra te and feed th e hay. f r e e

cho ice i n rack s which th e ewes cannot re a c h . Feed o f fe re d lambs should

always be c lea n and f r e s h . Lambs' w i l l re fu se to e a t much feed th a t i s •

o ld , s p o ile d , o r con tam inated .

There i s a t re n d in Montana tow ard more farm f lo c k s o f sheep . Home-

grown g ra in s and o th e r fe e d s are a v a ila b le and cheap on fa rm s$ th e re fo re

lambs a re sometimes c re e p -fe d and so ld on th e e a r ly m arke t.

In th e p a s t s e v e ra l y e a r s , r e s e a rc h w orkers and commercial fe ed e rs

have o b ta in ed d e s ira b le e f f e c t s on non-rum inan ts, and to a l e s s e r e x te n t

on ru m in an ts , by in c lu d in g a n t ib io t i c s in th e r a t i o n . These e f f e c t s have

7 - .

in c lu d ed more ra p id grow th, b e t t e r fe e d u t i l i z a t i o n , and h e a l th ie r an im als»

The Montana A g r ic u ltu ra l Experim ent S ta t io n conducted a feed in g t r i a l V

during th e Spring o f 1 9 # in response to many re q u e s ts re c e iv e d fo r

s p e c i f ic in fo rm a tio n on th e v a lu e of a n t ib io t i c s in lamb creep r a t io n s »

Only tw in lambs were s e le c te d f o r th i s experim ent, as any p o te n t ia l bene­

f i t from th e a n t ib io t i c would be ex p ressed more r e a d i ly th an w ith .s in g le

lam bs.

— 8 *"»

REVIEW OF LITERATURE

A n tib io t ic s

A n tib io t ic s a re growth in h ib i to r s o r b a c te r ic id a l agerjts which are

form ed by l iv in g organism s, and which a re a c t iv e in v e ry low concentra­

tio n s e

D r. Fleming d isco v e red th e f i r s t r e a l l y e f f e c t iv e a n t ib io t ic in 1928,

when he s tu d ie d a v a r ia t io n o f S taphylococcus, a id found th a t around a

la rg e co lony o f a co n tam inating organism the Staphylococcus co lo n ie s b e ­

came tr a n s p a r e n t and underwent l y s i s . This work was ig n o red u n t i l 19^1.

Then th e demands o f World W a r 'l l s tim u la te d an in te r n a t io n a l p ro je c t to

i s o l a t e and p u r i f y th e a c t iv e m a te r ia l produced by F lem ing 's contam inating

organism . Today t h i s m a te r ia l i s known th e w orld over as. P e n ic i l l i n ,

■' S tu d ie s in th e a n t ib io t i c s f i e l d expanded g r e a t ly fo llo w in g su ccess­

f u l work .w ith P e n i c i l l i n . Duggar (191:8) and a s s o c ia te s o f th e L ederle

L a b o ra to rie s announced th e d isc o v e ry o f c h lo r te t r a c y c l in e a t a conference

h e ld by th e New York Academy' o f Sciences i n Ju ly , 19I4.8 , This a n t ib io t ic

i s produced by an A ctinom ycetes, S treptom yces a u re o fa c ie n s , which was

f i r s t i s o la te d from a sample o f s o i l c o l le c te d from a tim o th y f i e ld in ■

M isso u ri, During c e r ta in s ta g e s .o f growth th i s sp ec ie s i s c h a ra c te r iz e d

by a golden ye llow c o lo r , and th e i s o la te d a n t ib io t ic i s s im i la r ly c o lo re d .

The m anufacturing p ro cess f o r c h lo r te tr a c y c l in e i s p a te n te d by

L ed erle L a b o ra to r ie s , and th e p roduct i s so ld under th e t r a d e name of

Aureomyein, or Aurofac in " th e case o f l iv e s to c k supplem ents. L i t t l e has

been re p o r te d on th e ex ac t m anufacturing p rocedure u se d . Raper (1952),

in d ic a te s a fe rm e n ta tio n medium used i s composed as fo llo w s : Corn s teep

- 9 -

l iq u o r , I p e rc e n t; su c ro se , I p e rc e n t; (NH^)2HPOii , 0 .2 p e rc e n t; KH2POj4,

0 .2 p e rc e n t; MgSO^.THgO, 0 .025 p e rc e n t; OaCO^, 0 .1 p e rc e n t; p lu s s e v e ra l

o th e r c a t io n s .

F erm en ta tion i s conducted in la rg e (10,000 g a llo n ) a e ra te d tanks

•which a re a g i ta te d as i n th e m anufacture o f o th e r a n t ib io t ic d rugs. The

p u r i f ie d c r y s ta l l in e form i s o b ta in ed by p r e c ip i ta t in g th e c h lo r te tr a c y -

c l in e w ith calcium io n s , and th en in tro d u c in g HCl to form the s a l t known

as Aureomycin HCl.

Stephens e t a l . (1952), g ives the s t r u c tu r e o f c h lo r te tr a c y c l in e a s

shown in F igu re I .

F igu re I . S tru c tu re o f c h lo r te t r a c y c l in e .

Aureomycin i s h ig h ly a c t iv e a g a in s t gram -negative rods and d isp la y s

v e ry low to x i c i t y to h ig h e r an im a ls . I t i s ra p id ly absorbed , c i r c u la te d ,

and e x c re te d . Because o f th e s e f a c to r s i t can cause a lm ost complete

s t e r i l i z a t i o n o f th e i n t e s t i n e , a cco rd in g to Thimann, (1955)• In man,

b a c te r ia sometimes alm ost d isap p e a r from th e fe c e s . O ccas io n a lly the

s t e r i l i z e d fe c e s becomes in fe c te d w ith a pathogan ic y e a s t sp ec ie s which

causes s e r io u s secondary in f e c t io n s .

I h i l e the t r i a l re p o rte d in th i s th e s i s used Aureomycin as the a n t i ­

b i o t i c , o th e r a n t ib io t i c s a re a v a ila b le which a re r e la te d chem ica lly , and

which g ive somewhat s im ila r r e s u l t s in t h e i r e f f e c t on th e physio logy o f

- I G -

farm anim als* Terram ycin i s th e tr a d e name f o r o x y te tra c y c lin e , which i s

s im ila r to c h lo r te t r a c y c l in e , and i s w id e ly u sed . Many o th e r a n t ib io t i c s

have been d isco v e red , b u t on ly th e most p rom ising ones a re employed in

e x ten s iv e t r i a l s w ith l iv e s to c k . B esides th e two a lre a d y m entioned,

B a c itr a c in , S trep tom ycin , P roca ine p e n i c i l l i n , and a r e c e n t one, t e t r a ­

c y c lin e , a re th e more im p o rtan t ones used i n supplem enta tion o f commer­

c i a l feeds*

Aureongrcin in Ghiok R ations

Aureomycin was used e x c lu s iv e ly as human m ed ication u n t i l i t was in ­

d i r e c t l y found b e n e f ic ia l to farm anim als as w e l l . Animal n u t r i t i o n i s t s

by 19U8 had found a d e f in i te growth response in an im als, p a r t i c u la r ly

c h ic k s , from feed in g l i v e r e x t r a c t s , f i s h m eal, o r cow manure*■ Also some

substance in th e se m a te r ia ls was found e s s e n t ia l f o r h a t c h i b i l i t y o f hen

eg g s. This unknown substan ce was term ed "Animal P ro te in F a c to r ." C ry sta l'

l in e V itam in B^g was found to b e th e crude Animal P ro te in F a c to r substance

th a t gave such b e n e f ic ia l response in c h ic k s .

R icks e t a l . (Ipl)B) th en d isco v e red V itam in B^g a c t i v i t y in c u ltu re

b ro th s o f v a rio u s sm all b a c te r ia and A ctinom yeetes, in c lu d in g the s t r e p ­

tom ycin-producing organism . I t was shown also, t h a t V itam in B^g was p ro ­

duced in o th e r m ic ro b ia l fe rm e n ta tio n s . Aureomycin and o th e r c u ltu re f i l ­

t r a t e s fo rm erly d isp o sed o f as w astes were now co n ce n tra te d , and became

a c h ie f source of Vitamin B^g fo r c l i n i c a l u se , and in th e form o f A .P .F .

supplem ents were used to s a t i s f y th e sky ro ck e tin g demands o f feed manufac­

t u r e r s . E f fo r ts were s u c c e s s fu lly made to f in d s t r a in s of m icro-organism s

capable of g iv in g h igh y ie ld s o f V itam in B]_g.

- 11

S to k stad e t al« (l9ij.9), a t th e L ed erle L a b o ra to r ie s , fe d Aureomycin

fe rm e n ta tio n A .P .F . supplem ents and o b ta in ed a growth response w ith ch icks

t h a t was more th an cou ld be expected from Vitam in by i t s e l f e The .

supplem ents were known to c o n ta in Aureomycin re s id u e j th e in v e s t ig a to r s

th e re fo re th eo rized - t h a t th e e x tr a growth.was due to Aureomyoim*

S to k stad and Jukes (1950) fe d ch ick s a d ie t w ith adequate le v e ls o f

Vi t ami n . and when sm all amounts o f Aureomycin were added to th e r a t io n ,

a s ig n i f ic a n t e x tr a growth response was o b ta in e d . This proved conclu­

s iv e ly t h a t th e a n t ib io t i c i t s e l f had a b e n e f ic ia l e f f e c t on ch ick grow th.

W ith th e a n t i b i o t i c , th e amount o f V itam in B^g needed was o f te n found to

be reduced . T he. a d d itio n of V itam in B^g and a n t ib io t ic s to a r a t io n does

not a l t e r th e need fo r o th e r B-complex v ita m in s .

Coats e t a l . (193>l), L i l l i e e t . a l . (1953) and H i l l e t a l . (1953),

in d ic a te ch ick s re a re d in new or c lean q u a r te r showed no growth responses

when fe d a n t i b i o t i c s . H i l l and Larson (1955) s ta t e th a t w orkers a t the

Lobund I n s t i t u t e o f N otre Dame f i r s t re p o rte d germ -free ch ick s and p o u lts

f a i l t o show growth re sp o n ses when fe d a n t ib io t i c s , b u t . l a t e r work showed

sporadic, g ro w th -in c rea se s fo r b o th germ -free ch icks and p o u lts fe d a n t i ­

b i o t i c s .

Aureomycin in Swine■R atio n s

L asley e t aL. (195U), summarized work of s e v e ra l y e a rs from v a rio u s

s ta t io n s on th e response o f swine to d i f f e r e n t a n t ib io t i c s when b asa l

r a t io n s co n ta in ed p ro te in frcm p la n t o r p la n t and anim al so u rc e s .

The d a ta f o r norm al, h e a lth y p ig$ from w eanling to m arket w eights

showed c le a r ly t h a t a n t ib io t i c s were e f f e c t iv e in most t r i a l s w ith an

— 12 —

average in c re a s e (ij.8 t r i a l s ) o f about 17 p e rc e n t in d a i l y g a in s , 11 .£

p e rc e n t in d a i ly feed consum ption, and a sav ing o f 3 .9 p e rc e n t in amount

o f fe e d re q u ire d p e r u n i t o f g a in , compared to p ig s on th e b a sa l r a t io n s .

There was l i t t l e d if fe re n c e among Aureomycin, Terram ycin, P roca ine p e n ic i l ­

l i n , and S trep tom ycin in a b i l i t y to in c re a se average d a i ly g a in s and feed

consum ption. There was no c le a r - c u t evidence th a t any one a n t ib io t ic

t e s t e d was s u p e r io r to any o th e r one in in c re a s in g e f f ic ie n c y o f feed

u t i l i z a t i o n . ,

A n tib io t ic s seemed to be s l i g h t ly more e f f e c t iv e when added to an

a l l - p l a n t p r o te in r a t io n th an when added to one c o n ta in in g p ro te in s from

b o th p la n t and anim al so u rc e s . A le v e l o f about 5 m illig ram s a n t ib io t ic

p e r pound o f t o t a l r a t i o n , o r 20 to 25 m illig ram s p e r pound o f p ro te in

supplem ent seemed to g ive optimum re sp o n se from .normal, h e a lth y p ig s . I t

was suggested th a t h ig h e r l e v e l s would be b e n e f ic ia l when p ig s a re in fe c te d

w ith c e r ta in ty p es of pa thogen ic o rgan ism s.

A n tib io t ic s in p ig r a t io n s seem to be e f f e c t iv e in c o n tro l l in g c e r ta in

k in d s o f b a c te r ia lo c a te d i n th e d ig e s t iv e t r a c t which cause sco u rs . Many ■

r e p o r ts in d ic a te t h a t a n t ib io t i c s a re e f f e c t iv e in. c o n tr o l l in g c e r ta in

ty p e s o f sc o u rs . D ata a re p re se n te d concern ing u n th r i f ty p ig s , showing an

average o f 96.2 p e rc e n t in c re a s e over c o n tro ls in r a te o f g a in when a n t i ­

b io t i c s were fe d , and an average in c re a s e o f 22.9 p e rc e n t i n e f f ic ie n c y

in g a in s . The perform ance o f th e c o n tro l groups o f th e se u n th r i f ty p ig s

was, however, f a r below norm al.

One experim ent was review ed i n w hich a creep r a t io n c o n ta in in g one

p e rc e n t Aureomycin was o f fe re d su ck lin g p ig s , and 0*5 p e rc e n t Aureomycin

— 13

su p p lie d in th e sow r a t i o n . The ' average £6-d ay weaning w eigh t o f th e p ig s

was in c re a s e d 1 1 .pounds. The op in io n was t h a t th e a n t ib io t i c was no t

t r a n s f e r r e d th rough th e sows’ m ilk , b u t was tak en in adequate amounts v ia -

th e c reep feed*

L asley review ed an o th er t r i a l in which k3 l i t t e r s o f p ig s were used

to t e s t P roca ine p e n i c i l l i n a t le v e l s o f ^ mg. and 20 mg. p e r pound o f

p ig s t a r t e r . Feed consumption, and r a t e o f g a in o f the p ig s .b o th in c re a s e d .

Scours were no t e lim in a te d , b u t were m arkedly reduced . A le v e l o f 2 .5 mg.

p e r pound o f r a t io n showed no s ig n i f ic a n t e f f e c t on feed consumption o r

r a t e o f g a in .

Aureomycin was re p o r te d to have a sp arin g a c tio n on p ro te in r e q u ir e ­

ments o f g ro w in g -fa tten in g p ig s when ra t io n s c o n ta in in g Ih to 20 p e rc e n t

crude p r o te in were compared. In an o th er t r i a l u sing Terram ycin fe d w ith

d i f f e r e n t le v e l s o f p r o te in , p ig s re c e iv in g a 1$ p e rc en t p r o te in r a t io n

(reduced to 12 p e rc e n t a t 100 pounds) d id j u s t a s w e ll a s p ig s re c e iv in g .

an 18 p e rc e n t p ro te in r a t io n (reduced to 1$ p e rc e n t a t 100 pounds). I t

. was sugg ested th a t th e p re se n t s tan d a rd s f o r p ro te in fo r p ig s m aybe

,h ig h e r th a n n e ce ssa ry when r a t io n s in c lu d e adequate amount o f B v ita m in s .

High le v e l s o f B v itam in s i n a p ro te in supplem ent seem to in c re a se the ■

e f f ic ie n c y of p ro te in u t i l i z a t i o n .

Summarizing s e v e ra l r e p o r t s , L asley s ta te d th a t th e re seemed to be

l i t t l e o r no advantage from feed in g a n t ib io t i c s to brood sows during

g e s ta t io n , as m easured by l i t t e r s iz e , and s iz e and l i v e a b i l i t y o f new­

born p ig s .

Anreomycin i n Young; C alf R a tio n s

From abundant re s e a rc h evidence th a t has accum ulated du ring th e p a s t

s e v e ra l y e a r s , i t i s e v id e n t t h a t swine and p o u ltry respond fav o ra b ly Wien

a n t ib io t i c s a re in c lu d e d . in t h e i r r a t i o n s . The n u t r i t io n o f the v e ry

young rum inant can be expected to b e 's im i la r to th a t o f m ono-gastric

anim als because o f s im ila r p h y s io lo g ic a l fu n c tio n s . T h ere fo re i t would

be rea so n ab le to expect a fa v o ra b le r e a c t io n o f th e v e ry young rum inant '

to a n t i b i o t i c s . T h is has been b rough t o u t reg a rd in g th e work done w ith

young c a lv e s , most o f w hich were o f d a iry b re e d in g .

S tu d ie s by B a r tle y e t a l . (1950) (195k)» R usoff e t a l . (1951), Jacob­

son a t a l . (1951), Knodt and Ross (1952), EacKay e t a l . (1952), Bloom and

Khodt (1953) and o th e r s , u s in g Aureomycin on young d a iry ca lv e s have shown

b e n e f i ts th rough in c re a s in g growth r a t e s and d ecreasin g occurrence of

s c o u rs . Some W orkers--B ell et_ a l . ( I 9 5 l ) , H urley e t a l . (1952), R usoff

e t a l . (1953)—have found th a t use of a n t ib io t i c s r e s u l t s i n improved feed

e f f ic ie n c y . However, B a r tle y e t a l . (1950), B e ll e t a l . (1951), Jacobson

e t a l . (1951), L o o s li e t a l . (1951), H urley e t a l . (1952), and o th e rs found

no d if fe re n c e in th e amount, o f ■feed needed to produce a u n i t o f ga in in

body w e ig h t.

H urley e t a l . (1952), s ta te d Aureomycin fe d to c a lv e s r e s u l te d in no

e f f e c t on u t i l i z a t i o n o f d ry m a tte r , c a rb o h y d ra te s , n itro g e n , or ash .

These c a lv e s re c e iv e d a r e s t r i c t e d d ie t o f n o n - fa t d ry m ilk s o l id s . Rate

o f gain was n o t a f f e c te d . K esle r and Knodt (1952), re p o r te d m icro-organ­

ism s from T erram ycin-fed ca lv e s d ig e s te d 2 2 .R p e rc en t l e s s c e l lu lo s e th an

th e c o n tro ls , a s determ ined by th e a r t i f i c i a l rumen m e th o d .. Raddison e t

a l . (1953)j u s in g th e a r t i f i c i a l rumen a ls o , found Aureomycin added to

rumen-samples from young ca lv e s decreased d ig e s t io n o f f i l t e r paper c e l lu ­

lo s e b u t had no e f f e c t on a l f a l f a hay d ig e s t io n .

L a s s i te r e t a l . (l9$3) found Aureomycin d id no t a f f e c t d ry m a tte r

d i g e s t i b i l i t y in d a iry s t e e r s , b u t d id s ig n i f ic a n t ly d ep ress d i g e s t i b i l i t y

o f th e crude f i b e r . L a s s i t e r e t a l . (1933), u sing new-born d a iry c a lv e s ,

re p o r te d a b o o st in g a in , improvement in fe e d e f f ic ie n c y , and lowered

in c id en ce o f scou rs w ith Aureomycin. There was no e f f e c t on d i g e s t i b i l i t y

o f feed n u t r i e n t s , d ig e s t io n o f crude f i b e r , and u rea n itro g e n blood

l e v e l s . Aureomycin d id appear to low er n o n -p ro te in n i tro g e n b lo o d .le v e ls

fo r th e f i r s t seven w e e k s ; ,th is d ep re ss io n corresponded c lo s e ly w ith

s t im u la t io n of growth th a t o ccu rred in t h i s p e r io d .

P r i tc h a rd , e t a l . (1933), u sing Aureomycin on young id e n t ic a l- tw in

male c a lv e s , r e p o r ts in c re a se d growth r a t e and improved feed e f f ic ie n c y

fo r th e f i r s t e ig h t weeks of age. A seven-day c o l le c t io n p e r io d a t the

end o f th e e ig h th week showed p r a c t i c a l l y no d if fe re n c e s i n d i g e s t i b i l i t y

o f d ry m a tte r , ash , p r o te in , curde f i b e r , n i tro g e n - f re e e x t r a c t , o r f a t ,

Mann e t a l . (1933), s tu d ie d th e changes in c o n c e n tra tio n o f Aureo-

mycin in th e d ig e s t iv e t r a c t s of calves o f in c re a s in g age, and a lso com­

p a red th e r e s p e c t iv e m ic ro f lo ra and m icrofauna o f s e v e ra l s e ts o f Aureo-

m ycin -fed and c o n tro l c a lv e s . Animals were a l l o f s im ila r-a g e and b reed ing

and were handled to s im u la te American p r a c t ic e s . Aureomycin HCl a t ij.0-60

mg, was fe d d a i ly in a g ru e l from about th e tw e l f th day o f age to about

th e 3 th , 8t h , and 12 th week of age. At th e se tim es anim als were k i l le d .1 '

to g e th e r w ith a c o n tro l an im al. The t r e a t e d anim als had l a r g e r and l e s s

- 16 -

a c id rumen c o n ten ts which reached a rumen pH of more th a n 6 .0 ( s u i ta b le

f o r in te n s iv e rumen b a c te r i a l a c tio n ) a t a much e a r l i e r age th an c o n tro ls .

Aureomycin was nev er d e te c te d in th e rumen o r th e caecum, o n ly tra c e s

were found in th e omasum, and i t was d e f in i t e ly found in th e abomasum,

u s u a lly a t 2-j? mg. p e r gram o f c o n te n ts . There was l i t t l e d if f e r e n c e in

f i n a l developm ent o f a ty p ic a l rum en-v iab le s tre p to c o c c a l p o p u la tio n .

These w orkers concluded th a t Aureomycin taken by mouth does n o t a c t d i r ­

e c t ly on rumen m icro-organ ism s, b u t p ro b ab ly does a f f e c t them by making

th e anim al a b e t t e r h o s t , Aureomycin was always found in th e abomasum

where b a c te r i a l a c tio n i s n i l , and. where th e a c id pH corresponds to th e

c o n d itio n a t which Aureomycin p o ssesses a maximum o f s t a b i l i t y . The s t a t e s

ment was made th a t a complete c i l i a t e m icrofauna was e s ta b lis h e d a t e ig h t '

weeks of age. I f th is i s always t r u e , th e b e n e f ic ia l e f f e c t s of a n t i ­

b io t i c s shou ld become e v id en t a t an e a r ly ag e .

H este r e t a l . (l95>lt) s tu d ie d a b so rp tio n , d i s t r ib u t io n , arid e x c re tio n

o f Aureomycin in th e body o f c a lv e s which re c e iv e d doses o f £0-90 mg,

d a i ly o r a l ly , or I4.OO mg. weekly by in je c t io r i . Compared to th e c o n tro ls ,

growth was in c re a se d 19 p e rc e n t in 16 weeks. A n tib io tic was found p re se n t

in b lood plasm a, b i l e , and u r in e . . The h ig h e s t c o n c e n tra tio n was found in

u r in e o f in je c te d c a lv e s , and th e lo w est le v e l s in b lood plasm a. L ivers

and k idneys of in je c te d anim als co n ta in m easurable amounts o f Aureomycin,

w h ile a t r a c e was found in th e l i v e r and k idney of one c a l f o r a l ly - f e d .

The sp lee n , thymus-, p i t u i t a r y , and muscle showed no a n t ib io t i c in any c a l f .

No- Aureomycin was found in th e rumen o f th e in je c te d c a lv e s . A d e f in i te

p a t te r n -of d i s t r ib u t io n was e s ta b lis h e d in th e in t e s t i n e s . A n tib io t ic in -

- 17 - •

c reased in c o n c e n tra tio n from th e upper end to th e low er p o r t io n o f the

sm all i n t e s t i n e , and decreased in c o n c e n tra tio n between th e low er sm all

i n t e s t in e and th e an a l end of th e la rg e i n t e s t i n e .

Aureomycin in S te e r Rumen S tu d ies

Work has a lso been perform ed on o ld e r c a t t l e . B e ll e t a l . (19^1),

fed Aureomycin to s te e r s and found a d e f in i te d ecrease in d i g e s t i b i l i t y

o f a l l n u t r i e n t s . Chance e t a l . (1953) s tu d ie d th e in f lu e n c e o f Aureo-

mycin on rumen d ig e s t io n and r a t e ,of passage o f n u t r ie n ts from th e rumen.

Two ru m e n -f is tu la te d s te e r s were u sed . Aureomycin was fe d a t 0*5 gm. p e r

day f o r 15 days, and th en 1 .0 gm. p e r day f o r th e nex t 15 days. The p e r ­

io d when no a n t ib io t i c was g iven was th e c o n tro l period* • Rum en.contents

were com pletely evacuated , w eighed, sam pled, and re p la c e d in the rumen b e ­

fo re fe e d in g (zero h o u r) , and ag a in a t s ix and tw elve hours a f t e r feeding*

R ate o f removal o f d ry m a t te r , crude f i b e r , crude p ro te in and n itro g en ^

f r e e e x tr a c t was h ig h e s t when 0*5 gm. le v e l was fed .. Accumulation o f d ry

m a tte r , crude p r o te in , and n i t ro g e n - f re e e x tr a c t in th e rumen occurred a t

th e zero hour when 1 .0 gm. le v e l was fe d , su g g es tin g a s l i g h t d ep ress io n '

in d i g e s t i b i l i t y o f the c o n s t i tu e n ts may have taken p la c e . There w as-a

d e f in i te accum ulation o f e th e r e x tr a c t in th e rumen a t th e zero hour when

e i th e r le v e l o f Aureomycin was fe d .-

Hungate e t a l . (1955) measured t o t a l .fe rm en ta tio n p ro d u c tio n of rumen

c o n ten ts of Aureomycin - f e d and c o n tro l s t e e r s , bo th in th e p resence and

absence o f a d d i t io n a l Aureomycin. I n h ib i t io n by added a n t ib io t i c was

g re a te r in th e c o n tro l an im als , in d ic a t in g th a t th e Aureomycin fe d f i r s t

a l t e r e d th e com position o f th e m ic ro b ia l p o p u la tio n . Methane p ro d u c tio n

- 18 -

was reduced by th e added Aureomycin , bu t th i s whs thought to be a secondary

r e s u l t from in h ib i t io n o f p ro d u c tio n of th e in te rm e d ia te s hydrogen and f o r ­

m ate . The m icro-organism s seemed to be more s e n s i t iv e to Aureomyciri than

to S trep tom ycin .

Aureomycin and P e n ic i l l in a t d i f f e r e n t le v e l s o f in ta k e were s tu d ie d

(Horn e t a l . 1 9 # ) i n d ig e s t io n and n itro g e n b a lan ce t r i a l s w ith s te e r s .

He found Aureomycin had a g re a te r d e p re ss in g e f f e c t th an P e n ic i l l in on th e

d i g e s t i b i l i t y o f p ro te in and crude f i b e r . The tiro a n t ib io t i c s had an

equal e f f e c t in d ec rea sin g n itro g e n r e te n t io n . . At th e l e v e l o f 100 mg. ■

p e r day, Aureomycin r e s u l te d in a l e s s d e s ir a b le rumen f l o r a l com position

f o r roughage d ig e s t io n , a s evidenced b y .a decreased a b i l i t y to d ig e s t f ib e r

in an a r t i f i c i a l rumen.

Aureomycin in Sheep F a tte n in g R ationsy .

Colby e t a l . (1950) fe d Aureomycin a t IQO mg, d a ily ,, o r a l ly by cap­

s u le , to f a t te n in g lam bs, and a lso th e same le v e l p lu s a l l known B v i t a ­

m ins. The t r e a te d groups w ent alm ost e r i t i r e ly o f f fe e d . P e n ic ill irp ja o d .

S trep tom ycin were g iven a t th e same le v e l s and by th e same methods... Those,

two compounds were l e s s sev e re in t h e i r e f f e c t s compared to Aureomycin,

W eight gains of a l l tre a tm e n ts were le s s , th a n t h a t o f the controls,* some

anim als (Aureomycin tre a tm e n t) l o s t w e ig h t.

At South D akota, Jordan (1952) fe d n a tiv e and w e s te rn f a t te n in g lambs

a r a t io n o f s h e l le d ye llow co rn , a l f a l f a hay and soybean m eal. Aureomycin

was added to th e soybean m eal and was f e d a t le v e ls o f 7 .2 m g,, 10 ,0 mg.,

and I Lu It mg. p e r lamb d a i ly . R esu lts o f fo u r se p a ra te t r i a l s showed th a t

lambs d id n o t go o f f feed or scour e x c e s s iv e ly . Feed consum ption was n o t

- 1 9 -

s tim u la te d , b u t in two t r i a l s th e lambs were more e a s i ly p u t on f u l l feed*

The lU«k mg. l e v e l reduced r a te o f g a in and feed e f f ic ie n c y in both t r i a l s

where i t was employed. Aureomycin d id n o t give complete p ro te c t io n from

e n te ro toxem ia, b u t d id reduce i t m a te r ia l ly in th e l a s t t r i a l . Gains were

improved in one t r i a l where u n th r i f ty lambs were. u sed .

Jordan and B e ll (l9E>l) conducted two t r i a l s u sing 21 and 16 lambs r e ­

s p e c t iv e ly in which th e y f u l l - f e d a s tan d a rd c o r n - a l f a l f a hay r a t io n p lu s ,

a n t i b i o t i c s . A c o n tro l group was in c lu d e d . In the f i r s t t r i a l , th e lambs

were supplem ented w ith 6 .0 mg. Aureomyein p e r lamb d a i ly and had an a v e r­

age g a in o f 0 . 14.9 pounds p e r lamb d a i ly , compared w ith 0 .39 pounds p e r

lamb d a i ly fo r th e c o n t r o l s . Also 22 p e rc e n t l e s s c o n c e n tra te s p e r 100

pounds o f g a in was re q u ire d . In th e second t r i a l , 10 .8 mg. Aureomycin p e r

lamb d a i ly was su p p lie d , and th e an im als gained O4I4O pounds p e r lamb d a i ly ,

compared to O.36 pounds p e r lamb d a i ly f o r .th e c o n tro ls . The t r e a te d

lambs in t h i s case re q u ire d 20 p e rc e n t l e s s fe e d .

T urner and H odgetts (19£2), in A u s tra l ia , fed s in g le 750 mg. doses

o f Aureomycin HCl o r a l ly to a d u l t Merino sheep . T h is dosage was e q u iv a len t

to 23 .6 -27 mg. p e r kg. o f body w e ig h t. Rumen f lo r a was reduced 75 p e rc e n t

w ith in two h o u rs . This reduced le v e l p e r s i s te d f o r two. days, and th e su r­

v iv in g b a c te r ia were p redom inan tly G pam -positive rods and c o c c i . O ther

e f f e c t s in c lu d e d marked d ep ress io n in rumen fe rm en ta tio n , re d u c tio n o f

o rg an ic a c id p ro d u c tio n , dep ressed a p p e t i te , and w eight l o s s . The anim als

responded fa v o ra b ly to a d m in is tra tio n o f rumen f lu i d and y e a s t e x t r a c t .

E l l i o t and E llsw o rth (1953) fe d f a t te n in g lambs Aureomycin a t 10 mg.

and 20 mg. p e r pound o f fe e d , and had th re e rough ag e-g ra in r a t i o s —80-20,

- 20 -

60-b0, and ij0-60» The 20 mg. le v e l o f Aureomycin showed, a s ig n i f ic a n t in ­

c re a se in g a in w ith th e h ig h e r le v e ls o f roughage, b u t showed a lo s s a t

th e h igh g ra in l e v e l . 'B rid g es e t a l . (1953) a t Texas fe d f a t te n in g lambs

Aureomycin a t 1 .1 mg. p e r pound of fe e d , 2 .2 m g., 3 .2 m g., U.3 m g., 5 .0

m g., and 15 mg. The b a sa l r a t io n was m ilo and a l f a l f a hay o r m ilo , co tto n ­

seed m eal, and a l f a l f a hay . The Aureomycin r e s u l te d in r e l a t i v e l y sm all

in c re a s e s in r a t e o f g a in , which were n o t s t a t i s t i c a l l y s ig n if ic a n ts . Feed

e f f ic ie n c y was a p p a re n tly improved a t th e 2 .2 and 5*0 mg. l e v e l s .

B otkin (1953) a t Wyoming fe d 30 mg. Aureomycin p e r lamb d a ily and

s tim u la te d g a in s to 28 days b u t produced no advantage over a c o n tro l group

when th e 117-day feed in g p e rio d ended. There was no ap p aren t d if fe re n c e

in c a rc a ss g ra d e s . D ressing p e rcen tag es were s l i g h t ly h ig h e r fo r the

supplem ented lam bs.

K eith and L eh ere r (195U) fed lambs in d iv id u a l ly , tw ice a day, a con­

c e n tr a te o f equal p a r t s b a r le y and o a ts w ith-tw o p e rc e n t s a l t , p lu s pure

c r y s ta l l in e Aureomycin HGl a t 10 mg. p e r pound o f t o t a l f e e d . Compared

to a c o n tro l group, th e lambs consumed from 12 to 30 p e rc e n t l e s s t o t a l

f e e d , made 36 to 53 p e rc e n t le s s average gain (0*17 to O.32 pounds p e r

d ay ), and re q u ire d 20 to 3)4 p e rc e n t more feed p e r u n i t p f g a in .

Thompson and G rainger (195W o f the U n iv e rs ity of Kentucky conducted

a s e r ie s o f th re e m etabolism t r i a l s c o n s is t in g o f th re e groups o f two

w ethers each ( I — C o n tro l; I I —b a sa l p lus 10 mg. pure c r y s t a l l i n e Aureo-

mycin HCl p e r pound o f r a t io n ; I I I - ^ b a s a l p lu s Aurofac to fu r n is h 10 mg.

Aureomycin HCl p e r pound of r a t i o n ) . The r a t i o n was composed o f 61t0 gm.

ground corn cobs; 116.88 gm. soybean m eal; 16 gm. a l f a l f a m eal; 16 gm.

- 2 1 -

m olassesj' p lu s m in e ra ls (Ca, P , . Na, C l, and Co) and cod l i v e r o i l , A

10-d ay p re lim in a ry p e r io d was fo llow ed by a 10-d ay c o l le c t io n p e rio d .

W ethers in Groups I I and I I I showed an o rex ia w ith in lj:8 to 72 hours a f t e r

a n t ib io t i c s were supplem ented. A p p e tite re tu rn e d to norm al a f t e r two or

th r e e d ay s . Average ap paren t d ig e s t io n c o e f f ic ie n ts f o r crude f ib e r were

71oIi.j 60,1]., and 59,7 f o r Groups I , I I , an d , I I I r e s p e c t iv e ly . These d i f ­

fe re n c e s were s t a t i s t i c a l l y s ig n i f i c a n t* ■ There was no d if fe re n c e in

n i tro g e n r e te n t io n among g roups.' A pparent d i g e s t i b i l i t y of d ry m a tte r ,

n i t r o g e n - f r e e e x t r a c t , and energy was low ered fo r th e t r e a t e d anim als,

b u t d if f e r e n c e s were n o t s ig n i f ic a n t ,

T illm an and MacVicar (X9$k) s tu d ie d th e e f f e c t o f 10 mg. c r y s ta l l in e

Aureomycin d a i ly on d i g e s t i b i l i t y o f r a t i o n components fe d w ether lam bs.

They found no s ig n i f ic a n t e f f e c t on th e amount p f n itro g e n re ta in e d or on

d i g e s t i b i l i t y of th e r a t i o n . •

H a tf ie ld e t a l . (1951].), a t I l l i n o i s , ran th re e t r i a l s u s in g w este rn

b lack faced w ether lambs fe d ground corn , soybean meal, and a l f a l f a , p lu s

Aureomycin as Aurofac o r Aureomycin HCl. L evels o f the a n t ib io t ic were

7 .2 mg. p e r pound o f fe e d .a n d 7 .6 mg. Combining r e s u l t s o f the th re e

t r i a l s , , average d a i ly gains' a r e 'h ig h e r by 0 .055 - O.Oli] pounds, average

feed e f f ic ie n c ie s were h ig h e r , and average ca rca ss g rades.w ere h ig h e r fo r

th e Aureomycin supplem ented g ro u p s . Aurofa c - fe d lambs n e a r ly p a r a l l e l l e d

average perform ance o f th e lambs re c e iv in g Aureomycin HCle • The au tho rs

tho u g h t a n t ib io t i c s have a p r a c t i c a l use in g ro w in g -fa tten in g ra t io n s fo r

lambs by im proving r a te and e f f ic ie n c y o f g a in s , and by red u c in g th e num­

b e r o f u n th r i f ty lam bs.

K ercher and Smith (1955)j . a t C o rn e ll, worked w ith lambs on c o b a lt -

d e f ic ie n t d i e t s . Aureomycin fed a t 10. mg. per. day seemed t o r e ta r d body

w eigh t lo s s e s and in c re a se d hay consumption s l i g h t ly . The Aureomycin ■

d e f in i t e ly cou ld n o t s u b s t i tu te f o r th e c o b a lt t h a t was absen t in the

d ie t , how ever. '

Jo rdan (1954) used fo u r lots", o f 12 lambs each end f e d fo u r d i f f e r e n t

r a t io n s —Lot I —lo n g a l f a l f a hay and co rn in equal p ro p o r tio n s j l o t I I —

ground a l f a l f a hay and co rn in eq u al p ro p o r tio n s mixed and p e l le te d , p lu s

0 .3 pounds lo n g a l f a l f a p e r lamb d a i ly ; Lot I I I — same a s Lot I I p lu s 10

mg. Aureomycin p e r pound o f p e l le te d r a t io n s ; Lot IV-—th re e pounds ground,

a l f a l f a hay and one pound ground co rn , p lu s 10 mg. Aureomycin p e r pound

o f m ix. This l a s t m ix tu re was p e l le te d and fe d 'along w ith lo n g a l f a l f a '

a t 0 .3 pounds p e r lamb d a i ly . Average d a i ly gains were—0 .5 1 , 0 .54 , 0 .6 0 ,

and 0 .57 pounds p e r lamb fo r Lots I , I I , I I I , and IV re s p e c t iv e ly .

P e l le t in g o r Aureomycin d id n o t in c re a s e feed consum ption. T o ta l feed

consum ption p e r lamb was h ig h e s t i n Lot IV, b u t com consumption was

lo w est h e re . P e l le t in g d id not in c re a s e fe e d e f f ic ie n c y , b u t d id in c re a se

fe e d c o s ts m a te r ia l ly . Lot I I I lambs (Aureomycin supplem ented) re q u ired

10 p e rc e n t l e s s fe e d p e r pound o f g a in th a n d id lambs i n Lot I I .

B otkin and P au les (1954) a t Wyoming fe d r a t i o s o f ro u g h ag e -to -

c o n c e n tra te o f 1 : 1 , '1 .5 : 1 , and 2 :1 . The co n cen tra te c o n s is te d o f b a r le y ,

d r ie d b e e t p u l p ,■and ground a l f a l f a hay . Response to Aureomycin was n o t

a f fe c te d by th e d i f f e r e n t r a t io n s . The c o n tro l group (l5 3 lam bs) averaged

0 . 28? pounds g a in p e r lamb d a i ly , and re q u ire d 7.50 pounds t o t a l d ig e s t­

i b l e n u t r i e n ts p e r pound o f g a in . Those lambs g e tt in g 10 mg. Aureomycin

- 22 -

- 23 -

p e r pound o f r a t io n gained O.3OJ4 pounds p e r day, and consumed 7$2ij. pounds

t o t a l d ig e s t ib le n u t r i e n t s p e r pound of g a in .

At Texas, Kunkel (195>1|.), hand -fed lambs a . complete r a t io n o f hay,

co tto n seed -m ea l, m ilo and m in e ra ls fo r $6 days-. - Xhe c o n tro l g ro ip had an

average d a i ly g a in o f 0 „lj5 pounds p e r day arid -requ ired 7 .it? pounds feed -

p e r pound o f g a in ; a group supplem ented m t h 5. m g.' Aureomycin- p e r pound-

o f fe e d gained O0IUt pounds' p e r lamb d a i ly and .consumed 7.17 pounds feed

p e r pound o f g a in , w hile a l o t r e c e iv in g 10 mg. Aureomycin p e r pound o f

r a t io n gained an average o f 0 og2 pounds d a i ly and took 7 . 2 6 .pounds 'o f '

feed p e r pound o f g a in . C arcass-g rad es were about equal among th e th re e

g roups.

In ..another S6-d ay t r i a l , K inkel .s e l f - f e d a .complete r a t io n of •

p e rc e n t c o tto n seed h u l l s , 37.-3 p e rc e n t m ilo , 7 .5 p e rc e n t co tto n seed mqal,

and 10 p e rc e n t m o lasses. Again th re e l o t s were employed3 Lot I was the

C o n tro lj L o t I I re c e iv e d the b a sa l r a t io n p lu s 7 .5 mg. Aureomycin p e r

pound o f feed ; Lot I I I go t th e .basa l r a t io n , p lu s 1 5 .0 mg. .Aureomydn- p e r .

pound o f fe e d . Average d a i ly gains were 0 .3 0 , 0 ,3 2 , and 0*36-pounds, and

fe e d re q u ire d p e r pound of g a in was 1 3 .1 , 1 1 .2 , and 12 .0 pounds fo r Lots

I , I I , and I I I , r e s p e c t iv e ly .

The most r e c e n t work from Texas ( Kunlcel and P a c k e tt , 1955) was w ith

20 lambs fe d 15 mg. Aureomycin p e r pound of. r a t io n a n d a c o n tro l group o f

20 lambs fe d th e same r a t i o n w ith o u t a n t i b i o t i c s . The supplem ented

group gained 0 .U6 pounds p e r head daily .-on 6 , 7b pounds' fe e d p e r pound - o f

g a in ; th e c o n tro ls gained O.I4.3 pounds d a i ly on 7.03 pounds feed p e r pound

o f g a in . The Aureomycin. group d re ssed o u t about one p e rcen tag e p o in t

— 2k "•

h ig h e rj th e re was no d if fe re n c e in ca rca ss g ra d e s .

P 'acke tt e t a l . (i9$5) summarized d ea th lo s se s in fo u r y ears o f the

Texas work. Aureomycin a t vary in g le v e l s g e n e ra lly showed a decrease in

en te ro to x em ia . Of 230 lambs in c o n tro l groups, 10 anim als d ied o f e n te ro -

toxem ia (k»3 p e rc e n t) , and 12 d ied from a l l causes (5*2 p e rc e n t) . During

t h i s game p e rio d 353 lambs were fe d r a t io n s in c lu d in g Aureomycin a t v a rio u s

l e v e l s . Here th e re were no d eath s from en tero toxem ia , and on ly s ix d eath s

(1 .7 p e rc e n t) from a l l c a u se s . Lambs fg d th e a n t ib io t i c o f te n s t a r t e d o f f

e a t in g l e s s , apd sco u rin g was less , in te n s e and. of- a s h o r te r d u ra tio n th an

w ith th e c o n t r o l s . I t was .suggested th a t th e g re a te s t value o f a n t ib io t ic s

i n fe e d e r lamb r a t io n s was a c o n d itio n e r allow ing g re a te r ease of

g e t t in g lambs on f u l l fe e d .

Three t r i a l s were re p o r te d by Bohiqan e t a l . (1955) in which lambs

were fe d 0 .0 , 5*0, 1 0 .0 , and 20.0 mg. le v e l s o f Aureomycin p e r pound,of

g ra in mix, w ith and w ithou t B-Vitamin supp lem enta tion . The h ig h e r a n t i ­

b io t i c le v e l s to g e th e r w ith p resence o f B-Vitamins were, s l i g h t l y more

fa v o ra b le th an th e c o n tro ls in r a te o f gain and fe e d e f f ic ie n c y , b u t

d if f e re n c e s were n o t s t a t i s t i c a l l y s ig n i f ic a n t . No adverse e f f e c t s - were

n o tic e d among th e t r e a t e d g roups. The a u th o rs suggested t h a t e i th e r a n t i ­

b io t i c s do n o t i n h i b i t a c t io n o f rumen piioro-organism s th a t norm ally

sy n th e s iz e B-V itam ins, or t h a t th e feeds used in th i s s tu d y meet the

B-Vitamin requ irem en ts o f the f a t te n in g lam bs, B-Vitamin co n ten t of th e

r a t io n s was n o t de term ined .

Anglem ier and O ld f ie ld (1955) a t Oregon found th a t h e a lth y ,lambs on

a s tan d a rd g ra in and legume hay r a t io n ap p a ren tly d id no t b e n e f i t from th e

- 25

a d d itio n in th e d i e t o f 10 mg.- Anrofac p e r pound o f t o t a l fe e d . In another

tir i& l} .. 'u n th rif ty lambs..on an o b v io u sly u n s a t i s f a c to ry d i e t .of g ra s s ,.s ila g e

p lu s e i th e r g ra in o r ammoniated m o la sse s .d id h o t respond to a n t ib io t ic s

a t th e same r a t e . Ih en g ra s s hay was s u b s t i tu te d f o r th e g r a s s .s i l a g e to

th e p o in t where th e lambs' gained i n w e ig h t, a s ig n i f ic a n t improvement in

r a t e o f g a in over th e c o n tro ls .w as e v id en t in a l l groups, fe d Aureomyci n .

I t was th e o r iz e d t h a t th e a n t ib io t i c a id ed in ,.some way in th e r e e s ta b l i s h ­

ment o f a d e s ir a b le rumen f lo r a a f t e r adverse feed ing c o n d itio n s have been

im proved. - '

B otkin and P au les (1955) fe d e ig h t l o t s o f 50 lambs each In a s tudy

o f p e l l e t in g and a n t i b i o t i c s . -Feeding p e l l e t s gave c o n sid e ra b ly f a s t e r

and.more e f f i c i e n t g a in s , bu t fe e d c o s ts p e r pound o f gain, were h ig h e s t

f o r th e p e l le te d r a t i o n s . Less la b o r was needed when p e l l e t s were used ,

and th e lambs reached m arket w eight 30 days e a r l i e r than lambs on a

s im ila r r a t i o n n o t .p e l le te d . A n tib io t ic s (Aureomycin' a t 19 mg. p e r day,

o r Terram ycin a t 18 m g."per day) r e s u l te d in s l i g h t l y f a s t e r and more

e f f i c i e n t g a in s , b u t th e fe e d p o st p e r pound o f gain-was s l i g h t l y h ig h e r

f o r lambs re c e iv in g a n t ib io t i c s . Lamb fe d r a t io n s c o n ta in in g b a r le y ,

e i th e r p e l le te d o r u n p e lle te d , made f a s t e r and more e f f i c i e n t -gains th an

lambs fe d r a t io n s c o n ta in in g c o m . The b a r le y r a t io n was a ls o cheaper.

Aureomycin i n S uck ling Lamb ■ R ations’

Colby e t a l . (1950) re p o r te d no b e n e f ic ia l , r e s u l t s when 0 . 5- 1 .0

p e rc e n t A .P .F ., supplem ent c o n ta in in g 0 .6 mg. V itam in and h.O mg.

Aureomycin p e r gm. was added to a r a t io n fo r su ck lin g lam bs.

Kinsman and R id d e ll (1953), d iv id ed k9 su ck lin g lambs in to f iv e

- 26 -

groups and fe d each group th e same b a sa l r a t io n o f corn , o a ts , b ran , and

l in s e e d meal f o r e ig h t weeks. F ive .a n t ib io t ic s were fe d a t . I ^ mg. p e r

pound o f C o n cen tra te -G ro u p I —Aureomycin^ I I —Terram ycinj I I I —P en ic illin ,*

IV— C o n tro l; and V—Terram ycin and V itam in There was no apparen t

d if fe re n c e in r a t e s o f d a i ly g a in , th e extrem es being 0®j?ll pounds f o r

Group I , and O.^li.6 pounds f o r Group V. Feed, consumption in pounds p e r

pound Of g a in was as fo llo w s : Group I —2 .83 ; I I —2 .8 8 ; I I I —3 . 48; IV—

3 .1 2 ; and V— 3 .1 7 . G enera lly speak ing , a l l groups were on a p a r in t h r i f t ­

in e s s and c o n d itio n .

Luce et_ a l , (1953) c re e p -fe d Hampshire lambs u s in g 10 mg. Aureomycin.

T reatm ents were as fo llo w s : Lot I —C o n tro l; I I —10 mg. Aureomycin p e r lamb

d a i ly i n th e c reep feed fo r 14 days; I I I — same a s I I b u t f o r 21 days; IV—

10 mg. from seven days o f age to weaning; V—LO mg. from th ree- weeks' of

age to w eaning. Lots. I , I I , and I I I made h ig h e r t o t a l gains than Lots IV

and V. There was no d if fe re n c e in s u rv iv a l r a te o r h e a lth o f lambs between

g roups.

H a tf ie ld e t al_. (1954) ra n two t r i a l s on c re e p -fe e d in g su ck lin g lambs*

The b a s a l r a t io n ( f i r s t t r i a l ) was 30 p e rc e n t c o m , 30 p e rc e n t o a ts , 30

p e rc e n t wheat b ra n , and 10 p e rc e n t soybean mealy Aureomycin a t 7.2 mg,

p e r pound o f r a t io n was added. A lf a lf a was f e d f r e e c h o ic e . In th e second

t r i a l th e r a t io n was composed o f 88*5 p e rc e n t corn-and-cob m eal; 10 p e rc e n t

soybean m eal; and 1 .5 p e rc e n t m in era l m ix tu re (bonemeal and tra c e -m in e ra l­

iz e d s a l t ) . Aureomycin was su p p lie d a t abou t 7*5 mg. p e r pound o f r a t io n ,

and a l f a l f a hay was ag ain o f fe re d f re e ch o ice . The a n tib io tic -su p p le m e n te d

r a t io n s gave sm all (n o n s ig n if ic a n t) b u t c o n s is te n t ly h ig h e r average d a i ly

- 27 -

r a te s o f g a in and fe e d e f f i c i e n c ie s . Also c a rc a ss g rades were h ig h e r th an

th e c o n t r o ls . The au th o rs th o u g h t t h a t a n t ib io t i c s may h e lp reduce th e

number o f u n th r i f ty and■poor-do ing la m b s .■

Another t r i a l , G aither e t a l . (195^), c o n s is te d o f s e lf - f e e d in g 2Q

lambs from two weeks of age to m arket age. The r a t io n was made up of 60

p e rc e n t co rn , 20 p e rc e n t f in e ly ground cob, 10 p e rc e n t a l f a l f a m eal, 10

p e rc e n t soybean m eal, and m in e ra ls . Anreomycin a t the ra te o f 7 .0 mg. p e r

pound o f r a t io n was supplem ented. S ig n i f ic a n t ly h ig h e r average d a ily

g a in s were reco rd ed ; however, feed e f f ic ie n c y was reduced s l i g h t ly .

Jordan and BeI l (195>U)> ra n two experim ents w ith su ck lin g lam bs. . The.

f i r s t experim ent c o n s is te d o f fo u r se p a ra te p a r t s in which Aureomycin was

fe d a t le v e ls o f 5 .0 mg. p e r lamb d a i ly , U..3 m g., U.S'mgo,,- an d .10.8 mg. -

f o r 33 to 5>0 days. In th re e ou t o f the fo u r t r i a l s , , r a t e o f gain was in ­

c re a sed (av . o f 0 .65 pounds p e r lamb d a i ly as compared to 0.59 pounds fo r

th e c o n tr o ls ) , and fe e d e f f ic ie n c y was a lso s l i g h t l y in c re a s e d . No

d ig e s t iv e d is tu rb a n c e s were re p o r te d . In t h e i r second experim en t, th e se

w orkers in je c te d 80 mg. Aureomycin HCl stibcu taneously n ear th e f o r e - r ib o f

h a l f th e lam bs. The f i r s t two t r i a l s of t h i s experim ent had s ix to n in e -

day o ld G o rried a le lam bs, and the th i r d t r i a l had o n e -d ay .o ld lam bs. No

c reep fe e d was u sed . The d if fe re n c e s in average d a i ly g a in are s l ig h t ,

b u t fa v o r th e c o n tro l groups in two ou t o f the th r e e t r i a ls * .

Bohman et_ a l . (1955) fe d 20 orphan lambs from two to fo u r weeks o f

age to m arket w e ig h t. Aurofac a t th e r a t e o f 10 mg. p e r pound o f concen­

t r a t e was su p p lie d . Some o f th e se lambs re c e iv e d Aureomycin in th e m ilk

i n a d d i t io n , a t th e r a t e o f 10 mg. d a i ly . Each lamb was han d -fed 0 .6

- 2 8 -

pounds o f m ilk tw ice d a i ly f o r th,e f i r s t $0 d ay s . A lfa lfa hay was o ffe re d

f r e e cho ice along w ith th e .c o n c e n tra te . The tre a tm e n ts d id n o t s i g n i f i ­

c a n tly improve r a t e o f g a in , d re s s in g p e rq e n tag e , o r c a rca ss g rad e . No

adverse e f f e c t s were n o tic e d th a t cou ld be a s so c ia te d Tifith th e tre a tm e n ts .

Beeson e t a l . (195k) im plan ted two-day o ld suck ling lambs subcutan­

eo u sly w ith th e fo llo w in g a n t ib io t i c s : Wi mg. B a c itra c in ; 88 mg. B ac it­

r a c in ; 22 mg. B a c itra c in and 9*k mg. P e n ic i l l in ; IiU mg. B a c itra c in and 18.8

mg. P e n ic i l l i n ; lUO mg. Aureomycin HCl; 132 mg. B a c itra c in .. None o f th ese

tre a tm e n ts had a s ig n i f ic a n t e f f e c t on growth r a t e ,

Madsen e t a l . (1955) ra n a one-week t r i a l in v o lv in g 63 su ck lin g lambsI

from UO R am bou ille t, Columbia, and Hampshire ewes. : A creep r a t io n o f r o l l ­

ed b a r le y , £0 p e rc e n t; r o l l e d o a ts , 30 p e rc e n t; d r ie d m olasses b e e t p u lp ,

10 p e rc e n t; and c o tto n se e d m eal, 10 p e rc e n t was o ffe re d f r e e ch o ice .

A lf a l f a hay was o f fe re d s e p a ra te ly . The ewes' re c e iv e d one pound b a r le y p e r

head d a i ly , p lu s a l f a l f a hay . Aurofac was su p p lied a t th e r a t e o f 10 mg.

Aureomycin p e r pound o f creep m ix ture to a p o r t io n o f th e lam bs. No

s ig n i f ic a n t e f f e c t was re p o r te d on growth r a te o r feed consum ption.

Summary: Aureomycin in R ations o f Farm Animals

The v a lu e o f a n t ib io t i c s to farm anim als can be summarized in g e n e ra l.

A d e f in i t e improvement i s observed i n r a t e o f g a in , feed e f f ic ie n c y , and

g e n e ra l h e a lth when a n t ib io t i c s a re a p p lie d to p o u ltry and swine r a t i o n s . •

The l e s s fa v o ra b le the environm ent i s from a h e a lth s ta n d p o in t, th e more

response can be expected from a n t i b i o t i c s .

D airy ca lv e s scour l e s s , which r e s u l t s in a low er m o r ta l i ty r a t e .

W hile r a t e o f ga in m aybe in c re a se d i n e a r ly l i f e , t h i s e f f e c t i s u s u a lly

— 29 —

l o s t a s th e anim al approaches m atu rity*

E a rly work w ith sheep and s t e e r s r e s u l te d in u n d e s ira b le r e s u l t s .

This was due a t l e a s t in p a r t to the h ig h le v e l s o f a n t ib io t i c s u sed .

Some b e n e f i ts a re re a liz e d - from use o f low (10 mg, p e r pound o f r a t io n )

l e v e l s o f a n t ib io t i c s in sheep f a t t e n in g r a t io n s , bu t. th e e f f e c t s a re

d e f in i t e ly l e s s s p e c ta c u la r th an w ith swine and p o u l tr y . W hile u s u a lly

n o t s t a t i s t i c a l l y s ig n i f i c a n t , r e s u l t s show a s l i g h t t re n d tow ard more

fa v o ra b le r a t e o f g a in , and b e t t e r f e e d e f f ic ie n c y . Perhaps th e b ig g e s t

advantages are th a t sheep go on fe e d w ith le s s t ro u b le , experience le s s

en te ro to x em ia , and ex p erien ce le s s sco u rin g , e s p e c ia l ly under commercial

f e e d - lo t c o n d itio n s where d ise a se may be an im portan t fa c to r*

— 30 — .

OBJECTIVES

T his experim ent was designed, to s tu d y th e e f f e c t s o f fo u r d i f f e r e n t

creep r a t io n s on r a t e o f g a in , fe e d e f f ic ie n c y , and gen era l h e a l th o f suck

l in g tw in lam bs. The o b je c tiv e 's o f th e t r i a l were ( l ) to determ ine, th e

e f f e c t o f p e l l e t i n g a sim ple o a t-b e e t pu lp r a t io n , (2) to de term ine th e

e f f e c t o f adding Aureomycin a t 20 mg. p e r pound o f r a t io n to a sim ple o a t -

b e e t pu lp creep p e l l e t , an d '( 3 ) to de term ine th e e f f e c t o f u s in g a commer­

c i a l ty p e creep p e l l e t c o n ta in in g Aureomycin h t 20 m g ..p e r pound o f r a t io n

- 31 -

■ PROCEDURE

T h irty -tw o ewes o f S u ffo lk , Hampshire, an d w h ite face b reed in g were

randomly d iv id e d by b reed in to , fo u r groups .o f e ig h t ewes p e r group* Each

ewe s e le c te d fo r th e t r i a l had two h e a lth y lam bs, v a cc in a ted fo r e n te ro -

toxem ia, a t h e r s id e .

During th e ex p erim en ta l p e r io d , a l l fo u r groups phared a d jo in in g

s e c t io n s o f a m eta l-co v ered frame shed t h a t w as.open to th e so u th . Each

group was con fined in a pen tw elve f e e t wide and. f i f t y - e i g h t f e e t lo n g ,

t h i r t y - f i v e f e e t o f which was under th e shed . Creeps, were b u i l t a t the

ends o f each pen under the sh ed . In each creep was p la c e d a feed tro u g h

m easuring tw elve in c h es w ide, n in e ty inph'es lo n g , and th re e in ch es deep.-.

To keep lambs from stan d in g in th e tro u g h and con tam inating th e creep

fe e d , a o n e -b y -s ix in ch board was c e n te re d and supported about e leven

in ch es above th e tro u g h f lo o r , runn ing th e le n g th o f th e tro u g h .

The creep fe e d form ulae and th e d e s ig n .o f th e experim ents a re given

i n Table I . R a tio n s I and 2 co n ta in ed equal.am ounts p f th e same in g re d i­

e n ts , th e on ly v a r ia b le b e in g t h a t R atio n I was in bu lk form and R ation 2

i n p e l l e t form . Sugapulp was in c lu d ed in -R a tio n I so the r a t io n would

c o n ta in th e e q u iv a le n t o f 10 p e rc e n t ' m o lasses. R ation 3 d i f f e r e d from

R atio n 2 o n ly by c o n ta in in g Aurofac 2A At a le v e l o f 20 mg. Aureomycin

p e r pound o f fe e d . . R atio n It co n ta in ed th e same c o n c e n tra tio n o f Aureo-

mycin as d id R atio n 3* bu t th e com position was p a tte rn e d a f t e r a commer­

c i a l feed p e l l e t , and was composed o f a la r g e r v a r ie ty o f in g re d ie n ts .

S u f f ic ie n t creep fe e d was weighed and d i s t r ib u te d each morning to

have feed a v a ila b le to th e lambs a t a l l tim es,. Feed n o t e a te n a f t e r

32

Table !«■ Experiqiental Design and Ration Composition.

R atio n No*"■

I . 2 3 ' h

Number o f Ewes: Hampshire h 5 5 . 5S u ffo lk ' 3 2 2 2W hite fa c e ■ I . I I I

■ T o ta l Ewes F F F F ■

Number o f Lambs 16 16 16 16

Feed Treatm ent ( lb s , p e r day p e r Ewe)A lfa lf a , F i r s t C u ttin g ad l i b . ad l i b . ad l i b . ad l i b .O ats, Whole I / 1 .5 . 1 .5 1 .5 ' 1 .5

Feed Treatm ent (Lambs)Whole G rain P e l le te d R ations

R atio n No * I 2 3 4

In g re d ie n ts (p e rc e n t) O ats, w h o le . 87.50O afs, p u lv e riz e d . 87.50 86.92 3040PB arley , p u lv e riz e d ——— ————— -W-W7I 25.00Wheat mixed feed . (m illru n ) ————— ——WW— 15.79Soybean O il Meal ————— ————— ————— 5.00Linseed O il Meal ■•wwi-ee— ————— ————— 5.00A lfa lf a Meal ■ — — —— — — —— 5 ,ooY east, a c t iv e d r ie d ————— 2.00Y east, i r r a d ia te d —— — — — — — — — — Wewwwweei7 0.01Aurofac 2A —'-T——• o ,55 .0.55Trace M inerals — — — — — — —— ....... 0*15D icalcium phosphate — —— —— 0.50S a l t ————— ————— —— — 1.00Beet p u lp , d r ie d m olasses we*-,™. 2.50 2 .50M olasses, b e e t ■ 1P..00 1.0,00 10,00Sugapulp, (80$ M olasses) 12.50 ————— •wen —

100*00 100.00 100,00 100,00

l / O ats .were fe d a t 1 ,0 lb s* p e r ewe d a i ly f o r the f i r s t two weeks.

two days was weighed back and n o t o f fe re d a g a in , Weighbacks o f uneaten

feed during the f i r s t p a r t of th e t r i a l c o n s is te d c h ie f ly o f f in e m a te r ia l

from p e l l e t s , Ag th e lambs in c re a se d in s iz e and a p p e t i te , t h i s f in e

m a te r ia l was e a te n more r e a d i ly .

The ewes were fe d o a ts a t the ra te , o f one pound p e r head p e r day fo r

th e f i r s t two w eeks, a t which tim e th e le v e l .was r a is e d to .one. and a h a l f

pounds p e r head d a i ly . F i r s t c u t t in g b a le d a l f a l f a hay was su p p lied ad

lib idum tw ice d a i ly in .s e l f - f e e d e r bunks*. Uneaten feed was com pletely

removed and weighed each m orning.

W ater from a w e ll was p rov ided in wash tu b s and made a v a i la b le to th e

lambs and ewes. G ranu la ted (n o n -io d ized ) s a l t was a v a ila b le in each pen

to bo th ewes and lam bs. S a l t consum ption fo r th e th ir ty - tw o ewes and

s ix ty - fo u r ' lambs was approx im ate ly one hundred pounds du ring the f i f t y day

feed in g t r i a l .

The sheep were fe d in d ry l o t f o r f i f t y days (A p ril 11 to May.31,

1935) a t th e F o rt E l l i s farm of th e Montana A g r ic u ltu ra l Experim ental

S ta t io n n e a r Bozeman, M ontana. During t h i s tim e , w eigh ts were taken each

week f o r b o th ewes and lam bs. Follow ing th e d ry l o t p e r io d , th ey were

k ep t on p a s tu re w ith o u t supplem ental fe e d . Lambs were weaned Ju ly 29,

1955j a t which tim e w eigh ts were o b ta in e d .

- 33 -

- 3h -

RESULTS MD DISCUSSION

The w eigh t g a in s and feed c o s ts o f tw in lambs f o r th e f i f ty - d a y feed ­

in g p e r io d a re summarized in Table 11 . The lambs in th e d i f f e r e n t groups

were o f approx im ate ly th e same age, averag ing s l i g h t ly over one month.

Each group contained s ix te en lambs of three, d if fe r e n t breed s. Average

i n i t i a l weight of the lambs .was approxim ately twenty-nine pounds.

A lfa lf a hay was a v a ila b le to th e ewes and lambs a t a l l tim e s . Hay

consum ption averaged lj.8,3 pounds p e r day f o r each pen o f e ig h t ewes and

s ix te e n lam bs. Weighback was about 17 p e rc e n t o f th e t o t a l hay o f fe re d .

During th e f i r s t p a r t o f th e t r i a l , a l l lambs e x h ib ite d a p re fe re n ce fo r

a l f a l f a le av e s t h a t c o l le c te d in th e bpttom s of. th e hay bunks, in s te a d

o f th e creep feed o ffe re d them . Hoirever, du rin g th e l a s t t e n days o f

th e t r i a l , lambs in Croup I a te th e creep fe e d in p re fe re n ce to th e a l ­

f a l f a le a v e s .

■ The o a t r a t io n fe d th e ewes was in c re a se d from one pound p e r head

p e r day, to one and a h a l f pounds, because th e ewes began lo s in g w e ig h t.

W eight lo s s was much l e s s ra p id when ewes were, fe d a t th e h ig h e r g ra in

l e v e l . A fte r f iv e weeks on th e h ig h e r c o n ce n tra te l e v e l , ewe w eights in

Group k le v e le d o f f , w h ile th e ewes in thp o th e r groups con tinued to lo s e

from o n e -h a lf to one and a h a l f pounds p e r week.

The lambs eager ly consumed a maximum o f th e oat ra tio n o ffered the

ewes. As the lambs became la rg er and stron ger, the grain consumed by

them in creased in to a considerab le amount. The strong a ttra c tio n the

lambs d isp layed fo r th e grain i s in te r e s t in g , in view o f th e fa c t th at

creep feed was always a v a ila b le to them. I t was noted th a t lambs in

Table I I . .Weight Gains and Costs o f Suckling Twin Lambs Fed Fopr

- 32 -

Creep Rations

R atio n No. IFeed Treatm ent Whole G rain

Aureomycin O

2 3 it '. - P e l le te d R ations . 0 X X

Average I n i t i a l Age o f Lambs (Days). . 3k 31 31 35

No. o f Lambs on Experim ent 16 16 ' ■ 16 16

F i r s t Two Weeks o f T r ia l : ' iAverage W eights ( l b s . )

I n i t i a l 3 0 .L 28.9 29.3 29.3F in a l 3 5 .2 35.8 . 36 .it . 36.3D aily Gain 0.3L 0.19 • 0 .71 0 ,7.1 ■

Feed Consumption p e r Laiqb ( l b s , ) 5 .3 ■„ 6 .1 6 .1 5.9Feed Consumption p e r Cwt. Gain 110.5 ' 88.it . 85.9 8it,3Feed Cost p e r Cwt♦ I2.LU $3.12 #3.33 #3.47Feed Cost p e r Cwt* Gain #2.69 #2.76 #2.86 $2,93

F i r s t ■T h ir ty - f iv e ' Days o f T r ia l : Average W eights ( l b s . )

■ I n i t i a l : 30.L 28.9 . 29.3 29,3F in d l lt9 .9 Lt9.1 it8.9 51.1 "D a ily Gain 0 ,56 0.58 0 .56 0.63

Feed Consumption p e r Lamb ( lb s . ) 35.8 32 .it 29.8 3it.ltFeed Consumption p e r Cwt, Gain . 132.3 ; . 160 ,i t , ,1 5 2 .0 . .157.8

. Feed Cost p e r Cwt. ■ $2 . LtLt .# 3 .1 2 #3.33 #3.47Feed Cost p e r Cwt. Gain #3.22 $5.oo #5.05 #5.48

R e su lts o f Complete T r ia l : Average W eights ( l b s . )

I n i t i a l ' 30.lt 28.9 29,3 29.3F in a l 60,6 59.3 60 .5 64.2D aily Gain 0 .60 0.61 0.62 0.70 ■D aily Feed Consumption ( lb s , ) I 0.96 1.21 1 .08 1.36

Feed Consumption p e r Lamb ( l b s . ) Lt8,l 60.it 5U.2 68.0Feed Consumption p e r Cwt. Gain 159.2 ■198.7 .1 7 3 .7 194*6Feed Cost p e r Cwt, #2. Ltlt • #3.12 #3.33 #3.47'Feed Cost p e r Cwt, Gain #3.88 ■#6.20' #5.78 #6.75Feed Cost p e r Lamb #1.17 $1.88 $1.80 #2.36

36 —

Group I on a creep feed o f sev en -e ig h th s whole o a ts e x h ib ite d l e s s d e s ir e

to consume t h e i r dams' g ra in r a t io n th an .d id - lambs having c reep feed

a v a ila b le in p e l l e t form..

Lambs on th e oat-Sugapulp r a t io n (Group l ) tended a t f i r s t to e a t

a l l th e Sugapulp and leav e sm all amounts, o f o a ts from day to day. How­

e v e r , th e o a t re s id u e d id no t accum ulate e x c e ss iv e ly . Toward th e l a t t e r -

p a r t o f th e t r i a l , bo th Sugapulp and o a ts were even ly consumed each day.

Comparison o f P e l le te d and Whole Gyain R ations

P e l le t in g th e fe e d , r a th e r than fe e d in g a whole g ra in r a t io n , in ­

c re a sed fe e d consum ption du ring the f i r s t two--week p e rio d , a s w e ll 'as ■

du rin g the e n t i r e t r i a l . The in c re a se d fe e d consumption was r e f le c te d

by a d if fe re n c e in g a in o f O.lj? pounds p e r day fo r th e f i r s t two weeks,

in fa v o r o f th e group g e tt in g p e l l e t s . Lambs o f Group I , on whole g ra in ,

averaged as heavy a t th e end of f i f t y days a s d id th e -pe lle t- fe d lambs

o f Group 2, and consumed 12 .3 pounds le s s fe e d p e r lamb, o r 39 .5 pounds

l e s s feed p e r hundredw eight o f g a in , ' Cost o f feed p e r hundredw eight'

fav o red Group I,. which to g e th e r w ith th e g re a te r fe e d e f f ic ie n c y r e s u l te d

in a d if f e re n c e o f $2.32 i n feed co st p e r hundredw eight o f gain in favo r

o f Group I . F in a l ly , th e re was a d if fe re n c e in feed c o s t p e r .lamb o f

$0.71 in fav o r o f Group I .

During th e l a s t p a r t of t h e - t r i a l , Jambs in Group I had a " p o t-b e ll ie d "

appearance . I t was tho u g h t t h a t c a rca ss sco res o f t h i s group would be

low ered somewhat because o f t h i s c o n d itio n .

Comparison o f P e l le te d R ations With and W ithout Aureomycin Supplem entation

Lambs in Groups 2 and 3 bo th re c e iv e d a r a t io n s im i la r i n com position

■ 37 -

to lambs o f Group I , but in p e lle te d form. Rations 2 and. 3 d iffered only

in th a t Ration 3 contained Aureomycin at th e r a te o f 20 mg, per pound o f

feed , w h ile Ration 2 contained no Aureomycin . I t i s q u ite apparent th at

Aureomycin had an e f f e c t on ra te o f gain duping the f i r s t two weeks o f the

t r i a l , as there was a d ifferen ce in d a ily ga in o f 0,22 pounds in favor o f •

the Aureomycin group. Feed consumption probably had no e f f e c t on the

d ifferen ces in ra te o f g a in , as lambs o f Gpoups 2 'and 3 both consumed an

average o f 6 .1 pounds o f fe e d . . .Although Aureomycin increased the rate o f

gain considerab ly during the f i r s t two-week period , the increased feed

c o s t , due to in c lu s io n o f Aureomycin, more than o f f s e t th is advantage.

The end r e s u lt for the f i r s t two-week period was a d ifferen ce o f $0.10 in

feed c o st per'hundredweight o f gain favorin g lambs o f Group 2 .

At the end o f th e f i r s t t h ir t y - f iv e days, the d a ily ra te s o f gain were

almost equal. The d ifferen ce in feed c o s t per hundredweight o f gain be­

tween the two groups had been reduced by h a lf , .

At the end o f f i f t y days, the d a i ly ra te s o f gain were v ir tu a l ly

the same for the two groups o f lambs. Feed consumption per lamb and feed

consumption per hundredweight o f gain were somewhat lower, fo r the Aureo­

mycin supplemented anim als. This advantage more than o f f s e t the higher

ra tio n c o s t , r e su lt in g in a f in a l d ifferen ce o f $0.08 in to ta l feed cost

per lamb, favorin g the Aureomycin group.

Comparison o f Simple and Complex P e lle te d Rations Both Containing

Aureomycin

lambs in Groups 3 and k both rece iv ed p e lle te d creep rations contain­

ing 20 mg. Aureomycin per pound of feed . The ra tio n s d iffe re d on ly in

- 38 -

th a t Ration 3 was composed o f o a ts , b ee t p u lp ,. and beet m olasses, whilp

Ration k contained a larger v a r ie ty o f in g red ien ts . Table I in d ica tes .

th e com position o f each ra tio n .

During, th e f i r s t two-week p e r io d , d a i ly r a te s o f g a in were id e n t ic a l

f o r lambs in Groups 3 and Iw There was s l i g h t l y l e s s fe e d consumption in

Group U, b u t t h i s advantage was o f f s e t by th e h ig h e r feed c o s t p e r hundred­

w e ig h t. The d if fe re n c e in feed . Cbpt p e r hundredw eight o f g a in was $D.07

in fa v o r o f Group 3»

By the end o f the f i r s t t h ir t y - f iv e days, d a ily ra tes o f gain favored

.lambs fed th e complex r a tio n . This in creased gain i s a t l e a s t p a r t ia l ly

exp la in ab le by the increased feed consumption o f lambs in Group Iw How­

ever, i t s t i l l took le s s . f e e d per hundredweight o f gain for.lam bs in Group

3, and th is f a c t , p lu s the lower feed p r ic e , made a d ifferen ce o f $0.1j3 in '

feed co st per hundredweight o f gain in favor o f Group 3«

R e su lts fo r th e whole f i f ty - d a y t r i a l show lambs in Group h con tinued

to ga in a t a f a s t e r r a t e th an th o se in Group 3« Feed e f f ic ie n c y con tinued

to fa v o r Group 3 lam bs. There was a f i n a l d if fe re n c e o f $0.97 in feed

c o s t p e r hundredw eight o f g a in , in d ic a t in g R atio n 3 d e f in i t e ly made cheaper

g a in s th an R a tio n If. F in a l fe e d c o s t p e r lamb was $2.36 f o r R ation 1|,

compared to $1,80 fo r R atio n 3» I t should be no ted , however, th a t lambs

o f Group h were approx im ate ly fo u r pounds h e a v ie r th an th o se o f Group 3»

O y e r-a ll Comparison o f th e Four R ations a t the End o f the Feeding T r ial.

During th e f i r s t two weeks Aureomycin ap p a ren tly in c re a s e d r a te o f

g a in i n lambs o f Groups 3 and U, compared to th o se in Groups I and 2.

Feed consum ption du ring th i s p e r io d was approx im ate ly equal f o r a l l groups

g e t t in g p e l l e t s . Lambs on the whole g ra in r a t io n (Group l ) had th e low est

r a t e o f g a in and fe e d consumption o f th e fo u r groups su g g es tin g r a te o f

g a in was in f lu e n c e d by feed consum ption, and in d i r e c t ly by fe e d p a la t -

a b i l i t y . Feed c o s t p e r hundredw eight o f g a in was lo w est f o r Group I .

By th e end o f f iv e weeks th e re was a d e f in i te d if fe re n c e between

groups in bo th fe e d consum ption and r a t e o f g a in . Lambs' in Group I had th e

low est consum ption and th o se in Group It th e h ig h e s t . R ate o f ga in was ■

n e a r ly th e same fo r lambs in Groups I , 2 , and 3, b u t d e f in i t e ly h ig h er fo r

lambs o f Group I4. Feed c o s t p e r hundredw eight o f ga in co n tin u ed to be •

lo w est f o r Group I and h ig h e s t for.G roup I*.

The f i n a l v a lu e s f o r d a i ly gains show Qroups I , 2 , and 3 were v i r ­

t u a l l y th e same,- w h ile th e value f o r Group L was d e f in i t e ly h ig h e r . Feed

consum ption p e r lamb was lo w est f o r Group I , and h ig h e s t f o r Group U,

w h ile Groups 2 and 3' were in te rm e d ia te . Lambs from Group I gave th e .b e s t ,

fe e d e f f ic ie n c y , w h ile th o se from Group 2 gave th e p o o re s t .

Feed c o s t was lo w est f o r Group I because no p e l l e t in g charge was in ­

v o lv ed . The p e l l e t fe d lambs- o f Group 3 was s l ig h t ly more expensive than

th e p e l l e t f o r lambs in Group 2 because o f th e added Aureomycin. The Group

h p e l l e t was th e most c o s t ly , due to p e l l e t in g ch arg e , added Aureomycin,

and more expensive in g re d ie n ts .

Group I lambs made the ch eapest g a in s , due to th e low fe e d co st and

most fa v o ra b le feed e f f ic ie n c y . However, th e le s s fa v o ra b le conform ation

o f th e la m b s -d e tra c te d from t h i s o th e rw ise d e s ir a b le r a t i o n .

Feed c o s t p e r lamb was low est fo r Group I , and h ig h e s t f o r Group I+.

A dd ition o f Aureomycin to a p e l l e t reduced feed c o s ts $0.08 p e r lamb in

- 39 -

t h i s t r i a l

The h e a l th o f the anim als used in th i s t r i a l was good. One lamb in

Group I (no Aureomycin) had scours duping th e second and t h i r d weeks, and

an o th e r lamb had a case during th e t h i r d week o n ly . Group 2 (no Aureo­

mycin) had one case o f scou rs du rin g th e second, t h i r d , and fo u r th weeks.

There was one d e f in i te case and. one b o rd e r lin e case in Group 3 (A u reo -.

mycin supplem ented)j bo th cases occufped du rin g th e fo u r th week,

■The in c id en ce o f scou rs fo llow ed no d e f in i te , p a t te r n between g ro u p s.

The e f f e c t o f Aureomycin on sco u rs wag n o t e s ta b lis h e d due to th e low

in c id en ce o f scou rs in t h i s t r i a l .

E a rly i n th e t r i a l th re e S u ffo lk ewes-became lame, each in a r e a r ’ '

f o o t . S u lfa p i l l s g iven o r a l ly had l i t t l e e f f e c t ; however, l i b e r a l a p p li­

c a t io n o f s u l f a powder on th e open wound and bandaging gave good r e s u l t s

in two o u t o f th e th re e c a s e s .

P a s tu re P e rio d Follow ing th e Feeding T r ia l

Follow ing th e co n c lu sio n o f th e creep feed in g p e r io d , a l l groups were

combined and ru n f i f t y - e i g h t days on p a s tu re w ith no a d d it io n a l fe e d .

Table I I I g ives r a t e o f gain and weaning w eight d a ta f o r th e lam bs.I

Lambs' from a l l fo u r groups gained a t approxim ately th e same r a te when

on p a s tu r e . Lambs in Group I gained th e s lo w est (0 .31 pounds p e r day),

lambs in Groups 3 and I4. were in te rm e d ia te (O.3I4 pounds p e r day), and Group

2 lambs gained the f a s t e s t (O.36 pounds p e r day). The lambs th a t re c e iv e d

th e whole g ra in r a t io n gained th e slow est on p a s tu re , su g g es tin g th ey w e re ■

a t a s l ig h t d isadvan tage compared to lambs th a t g o t feed in p e l l e t form .

Creep feed consumption was h ig h e r f o r a l l lambs on p e l l e t s th a n on whole

- I l l -

Table I I I . . R e su lts o f 58-d ay P a s tu re P e rio d Follow ing Creep Feeding

R a tio n N o.. I 2 3 ■ UFeed. Treatm ent • Whole G rain P e l le te d R ations

Aureomycin ■ Q 0 X . ' X

F if ty - e ig h t Days on P a s tu re : '

Average W eights ( l b s . )

S ta r t o f P a s tu re P e rio d • 60 .6 #.3 6 0 .3 ' 6U.2 'End o f P a s tu re P e rio d 78.£ 80.0 80 .0 . 8U.0D aily Gain on Pasture.. D a ily Gain S ince B egin-

' 0 .31 . O.36 0.3U . 0.3Uhing o f Experim ent .(109 days) Ochh O.U 7 0.U6 0.30

g ra in , and t h i s p o s s ib ly had some e f f e c t .

The Group I). lambs continued to hold th e ir weight advantage, as they

weighed o f f pasture severa l pounds heavier than did lambs o f the other

groups,.

F ig u re s ' f o r o v e r - a l l r a t e o f g a in p e r lamb a re g iven , which in c lu d e

b o th the £0-day feed in g p e rio d and th e 58-day in te r v a l on p a s tu r e . Lambs

on th e w hole. g ra in r a t io n (Group l ) gaiped th e slow est pounds p e r

day), and Group It'lam bs .gained th e f a s t e s t (0 ,50 pounds p e r day). This

d if f e re n c e p ro b ab ly r e f l e c t s the e f f e c t o f t o t a l poynds o f fe e d consumed

w h ile th e lam bs.w ere on creep f e e d , ,a s Group I. lambs .consumed th e l e a s t

( l t8 ,l pounds p e r lamb) and Group it lambs consumed the most (68 .0 pounds

p e r lam b). The f i n a l r a te o f ga in v a lu es f o r lambs' o f Groups 2 and 3 were

a lm ost id e n t i c a l , in d ic a t in g Aureomycin in t h i s t r i a l had l i t t l e , o v e r - a l l

e f f e c t on g a in in g r a t e .

*- b-3 —

SUMMARY

T h irty -tw o S u ffo lk , Hampshire-and w h ite fa ce ewes, a l l w ith tw in ■

lam bs, were randomly d iv id ed by b reed in to fo u r equal g roups, and fed -

1 .5 pounds whole o a ts d a i ly p lu s a l f a l f a hay f re e ch o ice . Four d i f f e r e n t

creep feeds were su p p lie d th e m onth-old lambs f r e e c h o ice . R ation I con­

ta in e d seven p a r ts whole o a ts to one p a r t ' "Sugapulp. V .R ation 2 con tained

th e same in g re d ie n ts a s R atio n I , b u t in p e l le t , form . R ation 3 was a

p e l l e t s im ila r to R a tio n 2 , b u t supplem ented w ith 20 mg, Aureomycin p e r

pound. R atio n I; was designed to s im u la te a com m ercial-type creep p e l l e t ,

supplem ented w ith 20 mg. Aureomycin p e r pound.

Rate o f gain , feed e f f ic ie n c y , and general h ea lth o f the lambs were

compared.

During the f i r s t two weeks o f the seven-week t r i a l , Aureomycin

apparently in creased ra te o f ga in . Group I lambs fed the whole grain ra­

t io n (no Aureomycin) had the low est ra te o f gain and feed consumption per

lamb fo r t h is p er iod .

At the end o f f iv e weeks, lambs' op th e whole grain r a tio n were con­

suming the le a s t feed per lamb, and lambs on th e commercial type p e l le t

w ith Aureomycin (Group U were consuming the most feed per lamb. Rate o f

gain was h ig h est fo r lambs fed the commercial p e l le t and were equal for

the other th ree groups. This same feed consumption and r a te o f gain re ­

la tio n sh ip between groups e x is ted at the end of the t r i a l .

Feed c o st and feed c o st per hundredweight o f gain were low est fo r

Group I on whole grain . These lambs appeared " p ot-b ellied " which was

thought would be r e f le c te d in a sm aller dressing percentage and lower

- l i . i i . -r '

c a rca ss grade compared w ith lambs from th e o th e r th re e groups®

Feed c o s t and f e e d .c o s t p e r hundredw eight o f g a in was h ig h e s t fo r '

Group U on th e commercial type p e l l e t p l u s ' Aureomycin .

The c o s t o f in c lu d in g Aureomycin a t 20 mg. p e r pound in an o a t-b e e t

pu lp p e l l e t was more th a n re p a id th rough in c re a se d feed e f f ic ie n c y .

G eneral h e a lth o f th e ewe's and lambs was good. In c id en ce o f scours

among th e lambs was d iv id ed alm ost e q u a lly among the fo u r g roups. Because

o f th e low in c id en ce o f scou rs in t h i s t r i a l , th e v a lu e o f Aureomycin in

c o n tro l l in g scou rs was no t de term ined .

At th e end o f a f i f t y - e i g h t day p a s tu re p e r io d fo llo w in g the feed ing

t r i a l , o v e r - a l l d a i ly gains were s m a lle s t (O9Iii* pounds p e r day) fo r the

whole g ra in group, and h ig h e s t (0 .50 pounds p e r day) fo r th e commercial

p e l l e t group. P e l le t in g th e creep r a t io n ten d ed to in c re a s e g a in s s l i g h t ­

l y , b u t a d d itio n o f Aureomycin to th e o a t-b e e t pulp p e l l e t had no e f f e c t

on subsequent r a t e o f ga in o f lambs on p a s tu r e .

Anglem ierj ■ A» F . and J . E. O ld fie ld * 1955® Responses to AureomyeinSupplem entation by Lambs Under D if f e re n t Feeding C o n d itio n s . Amer.Soc. Anim*. P ro d . 6 :1 8 ? .

B a r tle y j -E. E ., F . C. F o u n ta in e j and F . W. A tkeson. 1950. The E ffe c t of an A .P .F . C oncen trate C ontain ing -Aureomycin on th e Growth and W ell­b e ing o f Young C alves. Jo u r. Anim. S c i . 9 :6^6 .

B a r tle y j E. Eej F . W. A tkesonj H. C. F ray e rj and F . C. F o u n ta in s . 195L*A n tib io t ic s in D airy C a t t le N u tr i t io n , I I I . E f fe c ts o f D if fe re n t L evels o f Aureomycin In ta k e Upon th e Growth and W ell-being, o f D airy C alves, and th e A sso c ia tio n o f D iffe ren ces With Changes in ' Environ­m ent. Jo u r . Anim. S c i . 37:259..

Beeson, W. M., T. W.- P e rry , W., A. S t i t t , and J . B. O uthouse. 195^. A n ti­b io t i c P e l l e t Im plan ts fo r S uck ling Lambs. Jo u r. Anim. S c i . l3 :2U 2. .

B e l l , M. C ., C. K. W hitehair and W. D. G allup . 1951» The E f fe c t o f Aureo- mycin on D ig estio n in S te e r s . Jo u r. Anim. S c i . 10:1039.

Bloom, S. and C. B. Knodt.. 1953« Aureomycin Supplem entation o f R ations f o r D airy C alves. Jo u r . D airy S c i . 36:633»

BohmaPf V. R ., J . E. Hunter, and LeGyand Walker. 1955» A n tib io tic s and B-Vitamins fo r Lambs. Jour. Anim. S c i . 1^:111.

Botkin, M. P . and Leon P au les. Control o f Death Loss and D ig estiv e D istur­bances in Feeder Lambs. Univ. o f Wyo. Agric« Exp. S ta . Mimeo. C ir.No. 33.

B o tk in , M. P . and Leon P a u le s . 195U» E f fe c t o f Aureomycin in Various R a tio s o f Roughage to C oncen trate f o r Feeder Lambs. Univ. o f Wyo.• A gric . Exp. S ta . Mimeo. C ir . No. Wi.

B o tk in , M. P , and Leon P a u le s . 1955» The E f fe c ts o f P e l le t in g and o fA n tib io t ic s in Lamb F a tte n in g R a tio n s . Amer. Soc. Anim. P rod . 6 :163 .

B rid g es, J , H ., J . C . M il le r , W. G. Kammlade, J r . , and H, 0 . K inke l.1953» E f fe c ts o f V arious LeVels o f Aureomycin in F a tte n in g Lambs. Jo u r . Anim. S c i . 12:660*

Chance, C. M., C. F . Huffman, and C. W. Duncan. 1953» A n tib io t ic s inRumen D ig estio n and S y n th e s is . I . The E ffe c t o f Aureomycin on Rumen D ig es tio n and th e Passage o f N u tr ie n ts from th e Rumen During S p e c if ic I n te r v a l s A fte r F e e d in g ., Jo u r . D airy S c i . 36:253.

C oats, M. E ., C. D* D ick inson , G. F . H a rriso n , S. K. Kon, S. H., Cummins, and W. F. J . C u thbertson . 1951» Mode o f A ction o f A n tib io t ic s in S tim u la tin g Growth o f Chicks, N ature 168:332.

Colby, R. W., F. A. Rau, and F. A.' Couch, 1950» E f fe c t o f Feeding an "Animal P ro te in F ac to r" C o n ce n tra te ■to- Young Lambs. Jo u r , P h y s io l. 163: l t l6 .

Colby,' R. W., F* A. Rau, and J . C. M il le r . 1950« The E f fe c t o f Aureo-r mycin and Type o f R atio n on F a tte n in g Lambs. Jo u r . Anim. S c i .9 :652 .

Dugger, B. M. 19US. Aureomycin—A P roduct o f th e C ontinuing Search f o r New A n t ib io t ic s . Annals o f - th e New York Acadamey o f S c ien ces .51:177» '

E l l i o t , R. F . and S. A. E llsw o rth , .1953« The E f fe c t o f Aureomycin and Type o f R ation on F a tte p in g Lambs. Jo u r . Anim. S c i . 12:9!U .

G a ith e r , W. E ., E. H a tf ie ld , and U. S . G a rrig u s . 195b. Hhat About HighO il Corn f o r Lamb Feeding? Univ. 111. A gric . Exp. S ta . Mimeo.

. ASb02a.

H a tf ie ld , E. E ., U. S. G a rrig u s , and H. W. •N orton. 195b. A n tib io tic• Supplements in R ations f o r Growing and F a tte n in g Lambs. . Jo u r. Anim.

S c i . 13:715.

H e ste r , H. H ., F . T. Landagora, and L, L, R u so ff , 195b. The D is tr ib u ­t io n o f Aureomycin in th e Body o f D airy Calves Showing a Growth Response When th e A n tib io t ic i s A dm inistered O ra lly o r Intram uscu­l a r l y . Jo u r . Anim. S c i , 13:988.

H i l l , D. C ., H. D. Bran ion , S. J f S lingeP j and G. W. Anderson. 1953« In f lu e n c e o f Environment on the Growth Response o f Chicks to P en i­c i l l i n , P o u ltry S c i . 32:b62.

H i l l , Eldon G ., and Nora L. L arson . 1955. E f fe c t o f C h lo r te tra c y c lin e S upplem entation on Growth and Feed U t i l i z a t io n o f Unsuckled Baby P ig s O btained by H ysterectom y. Jo u r . Anim, S c i . I b : l l l 6 .

Horn, L. H. J r . , R. R. Snapp, and L. 5 . G a ll. 1955« The E f fe c t o f A n ti­b io t i c s Upon.th e D ig estio n o f Feed N u tr ie n ts by Y earlin g S te e rs , ' With B a c te r io lo g ic a l D ata . Jo u r . Anim. S c i . Ib:2b3«

Hungate, R. E ., D. W. F le tc h e r , and I . A. Dyer. 1955» E f fe c ts o f C hlor- t e t r a c y c l in e Feeding on Bovine Rumen M icro-organism s. Jo u r , Anim.S c i . lb :997«

Jacobson, N. L ,, L. G. K a ffen tzak is and W,,R. H urley , 1951* Response o f Rum inating D airy Calves to Aureomycin Feed ing . (A b s tra c t) Jo u r . Anim S c i . 10:1050.

- It7 -

Jo rdan , R. M. 1952. Aurecmycin Supplements in Lamb F a tte n in g R a tio n s . Jo u r . Anim. S c i . 11 :566.

Jo rdan , R. M. 1951t. Lamb Responses to A n tib io t ic s and P e l le te d R a tio n s . (A b s tra c t) Jo u r . Anim. S c i . 13:1009.

Jo rdan , R.. M, and D. T, B e l l . 1951. E f fe c t o f Aureomycin on Growing- a n d ' F a tte n in g Lambs. (A b s tra c t) Jo u r . Anim. S c i. 10:1051.

Jo rdan , R* M, and D, T-. B e l l . 195b. E f fe c t o f Aureomypin Supplements bn S uck ling Lambs. Jo u r . Anim, S c i. 13:lt50 , '

Kammlade, W. G. 19b7. Sheep Science.. J . B .. L ip p in co tt C o., KT. Y ., N. Y ., 53b p p .-

K e ith , T. B. and W. P . L eh rer, J r . 195b. Growth Response o f Lambs Fed Three L evels o f Roughage and Pure C ry s ta l l in e Aurebmycin HCl. P ro c . Amer. Soc. Anim. P rod . ( ¥ .3 . ) 5:117*

K eroher, C. J . and S. E. Sm ith. 1955« The Response o f C o b a lt-d e f ic ie n t lambs to - Levovorin and C h lo r te tra c y c lin e ,. Jo u r , Anim. S c i. lb:878»

K e sle r , E. M, and C, B. Knodt. 1952. E f fe c t of Terram ycin on Growth andand Rumen Function in H o ls te in C alves. Jo u r . Apim. S c i . 11:768. ■

Kinsman, D. M, and W. H. R id d e l l . 1953• A n tib io tic in Creep R ations o fS uck ling Lambs. Jo u r . Anim.. S c i. 11 :769 .

Knodt, C. B. and E. B. R oss. 1952. The Value o f V arious Levels o f Aureo- mycin i n H l k Replacem ents fo r D airy C alves. Jo u r. D airy S c i.35?b93. :

Kunkel, H. 0 . 195b. Taken from a Pam phlet by E l l i o t t , R. F, and H. M. Haddock. 1955. The Continuous Feeding o f Aureomycin to Lambs. American Cyanamid C o., 30 R o c k e fe lle r P la z a , N. Y. 20, N. Y. .

KunkeI , H. 0 . and L. 0 . P a c k e tt , J r . 1955. Taken from a Pamphlet byE l l i o t t ,• R. F . and H. M, Haddock. 1955» The Continuous Feeding o f ' Aureomycin to Lambs. American Cyanamid C o,, 30 R o c k e fe lle r P laza ,N. Y. 20, N. Y. ' ■

L a s ley , J . F . , L. F . T r ib b le , and A. G. Hogan. 195b. Value o f A n tib io tic s in Swine R a tio n s . M issouri A gr. Exp. S ta . Res. B ui. 5b3.

L a s s i t e r , C. A ., T. W. Dpnto n , and G. I . B a s tin . 1953« The Value ofC e r ta in S u r fa c ta n ts as Growth S tim u lan ts When Fed to C av les . J o u r . D airy S c i . 36 :592 .

L a s s i t e r , C, A ., T. W. D en to n ,' and J . W. R u s t. 1955- The E f fe c t o f C hlor- te t r a c y c l in e and Ethomid C /l£ on Growfch, Apparent D ig e s t i b i l i ty , and Blood L evels o f Urea and T o ta l N on-pro tein n itrp g e n in Young D airy C alves. Jo u r . Anim. S c i . ll|.:760e

L i l l i e , R. J . , J . R. Sizem ore, and H, R. B ind. 195>3* Environment andStim ulation o f Growth o f Chicks by A n tib io t ic s . P ou ltry S c i, 32:^66 . •

L o o s li , J , K ., R. H. Wasserman, and L. S. G a ll. 19!?1» A n tib io t ic S tu d ies With D airy C alves. . J o u r . D airy S c i , 31;:£00»

Luce, L. C . , B . H . S chn ider, E. D. Tayson, and E. E. Goodwin, 1933. A n tib io t ic s f o r Lambs. N a tio n a l Wool Grower. 143:17.

' MacEay, A. M., W. H. R id d e ll , and R. Fitzsim m ons. 1932. Feed Supplement C ontain ing Aureomycin and V itam in Bip f o r D airy C alves. Jo u r. Anini. S c i , l l : 3 l a .

Madsen, M. A ., D. J . Matthews, and R. E. Taylor. 1933* . The E ffec t o f ■ Aureomycin in th e Creep Ration o f Suckling. Lambs. Amer. Soc. Anim. Prod. 6:139 .

Mann, S. O ., F rances M» Masson, and A. E. O xford. 193U* E f fe c t o f Feeding Aureomycin to I Calves upon th e E stab lish m en t o f T h e ir Normal Rumpn M ic ro flo ra and M icrofauna.' " B r i t , . Jo u r. N u tr i t io n . 8 :2^6 .

Murley, W. R ., N. L. Jacobson, and R. S. A lle n . 1932. E ffe q t o f Aureo- mycin S upplem entation on Growth and Feed U t i l iz a t io n o f Young D airy C a l v e s J o u r . D airy S c i . 33 :8^6 .

P a c k e tt , L. V. J r . , J . H. B ridges, Marcus H oelcher, and H. 0 . E ih k e l.1933* The Use o f A n tib io t ic s in S e lf - fe e d in g Lambs, (A b s trac t) ■Jo u r . Anim. S c i . 114:1219.

Pritchard, G. 1«, J . A. Newlander and W. H. R id d e ll. 1933* AureomycinE f fe c ts : Growth and D ig e s t i b i l i ty S tu d ie s With I d e n t ic a l Twin C alves.Jo u r . Anim. S c i. 1^:336*

R ahdison, J . J . , E. E, B a r tle y , F . C. F o u n ta in s , and F., W. A tkeson. 1933.E ffe c t o f Aureomycin an d /o r Grass Ju ice C oncen trate on C ellu lo se D ig es tio n in an A r t i f i c i a l Rumen as In f lu en ced by D if f e re n t Sources o f N u tr ie n ts . Jo u r . Anim. S c i. 12:929.

R aper, K. B. 1932. A Decade o f A n tib io t ic s in America. M ycologia.U lt( I ) :! .

R icks, E. Lf , N. G* Brink, F. R. Koniuszy, T. R. Wood, and K. Folkers.19U8. Comparative Data on Vitamin B^g from Liver and a New Source, Streptomyces G riseus. S cien ce. 1Q8:63U*'

- 1*9 -

Ru1SSGff, L. L ., ' J . ' A. A lfo rd , .and C. E. Hyde. 19^3. E f fe c t o f Type ofP ro te in on th e Response o f Young D airy Calves to Aureomycin With Data on th e I n t e s t i n a l M ic ro flo ra . Jo u r . D airy S c i . 36;IjJ?.

R u sso ffji L. L . , A. V. D avis, and J . A. A lfo rd . 19^1. Growth PromotingE f fe c t o f Auredmycin oh Young Calves Weaned from M ilk .a t an E arly Age. Jo u r. N u tr i t io n . 1*5j289.

Stephens, C. R ., L. H. Conover, F-. A. H ochste in , P . P . Regna, F . J . .P ilg r im , K. j . B runings, and R. B. Woodward. 1952. Jo u r . Amer. Chem. Soc. 75:1*976..

S to c k s ta d , E. L. R ,, and T. H. Ju k es . 1950. F u tu re O bservations on the Animal P ro te in F a c to r . P ro c . Soc. Exper. B io l, and Med.- 73:523.

S to ck s tad , E, L. R ., T. H. Jukes, J . V. P ie rc e , A. C. Page, J r . , and A. L,. ' F h an k lin . 191*9. The M u ltip le N ature o f th e Animal P ro te in F a c to r.Jo u r , B io l . Chem. 180:61*7.

Thimann, K, V. ■ 1955. The Life- of B a c te r ia . The M acm illian C o., N. Y. ■773 Pi?.

Thompson, C. M., and R. B. G ra in g er♦ 1951*. E ffe c t o f Aureomyein on Diges­t io n o f Low Q u a lity Roughage by Sheep. (A b strac t) Jo u r . Anim, S c i. 13:1002. . . .

Turner, A. W., and V. E. H odgetts. 1952. Depression o f Ruminal D igestion■ in Adult. Sheep by -Aureomycin. Jour. Dairy S c i. 36(3):A 39.

INTRODUGTXON

The endocrine glands, are important in reg u la tin g p h y sio lo g ica l fun­

c tio n s o f th e body* Of th ese endocripe gland s, thp sex glands are.

c lo s e ly a sso c ia ted -with animal growth and f in a l adult s i z e , as w e ll as

l ib id o , reproduction, and secondary sex c h a r a c te r is t ic s . Recent work

has shown th a t some chemical substances p o ssess sex hormone a c t iv i ty

which a lte r the growing and fa t te n in g •c h a r a c te r is t ic s o f farm animals

and are thereby b e n e f ic ia l fo r animal production.

The sy n th etic compound d ie th y ls t i l b e s t r o l , commonly referred to in

animal production journals a s s t i lb e s t r o l , p o ssesses a c t iv i t y sim ilar

to the fem ale sex hormones and i s severa l tim es as p oten t a s estron e,

S t i lb e s t r o l i s cheaper to manufacture than the natural female sex hormones

and i s e f f e c t iv e when given o r a lly , "Whether the s t i lb e s t r o l molecule

i s changed in to the stru ctu re o f one o f th e female sex hormones or

whether th e compound i s effective" in i t s o r ig in a l form i s unknown.

S t i lb e s t r o l has been in v e s tig a te d and accepted as having a favor­

able in flu en ce on rate and e f f ic ie n c y o f production o f c er ta in c la s s e s -

o f anim als. More inform ation i s needed on how s t i lb e s t r o l in ter a c ts

w ith c la s s , breed, age, and sex o f farm anim als. The in te r e s t in g e f fe c t

o f s t i lb e s t r o l and other drugs on animal production also warrants

in v e s t ig a t io n .

That the thyroid gland i s involved in the reg u la tio n of general

body metabolism* as w e ll as growth and development, i s now w e ll estab­

l is h e d . U n til recen t years, study o f th e fu n ction s o f th is gland was

lim ite d to the use o f expensive glandular ex tracts or su rg ica l a lte r a tio n

o f the gland* The thyroid' i s the o n ly gland in which in tern a l secretion s

can now be e n t ir e ly co n tro lled by use o f chemical compounds which are

inexpensive and r e a d ily a v a ila b le to th e research er. Varying degrees o f

hyperthyroidism can be produced.in animals by feed in g iod in a ted casein ,

or thyroprotein* The hypothyroid con d ition can be induced by feeding

sy n th etic goitrogens such a s th io u r a c il, th iou rea , and th io b a r b ita l.

S t i lb e s t r o l , th io u r a c il , and thyroprotein a s.th e patented product

VProtamone" were, used in variou s combinations in th is experiment to study

th e ir e f f e c t s o n .ra te o f ga in , feed e f f ic ie n c y , and carcass q u a lity o f

whether lambs

E E V im OF LITERAT UEE

E f fe c t o f F eeding S t l l b e s t r o l t6 Farm Animals

A d m in is tra tio n o f s t l l b e s t r o l to b r o i l e r s r e s u l t s i n in c re a se d

gro-mth r a t e , improved c a rc a s s q u a l i ty , and more f a t d e p o s it io n (Lorenz,

19b$S Thayer, Jaap , and P e n q u ite , 19h5s and Andrews and Bohren, 19U7)..

D inusson e t a l . (1950), in two d i f f e r e n t ex perim en ts, im planted

i;2 mg. o f s t l l b e s t r o l subcu taneously i n th e shou lder re g io n o f b eef

h e i f e r s . In th e f i r s t experim ent, c o n tro ls ga in ed 2.07 pounds p e r head

d a i ly , compared to 2*32 pounds f o r th e t r e a t e d group. In the second ex -■■ ■ ■

p erim en t, c o n tro ls gained 1 .72 pounds p e r head d a i ly , w h ile th e s t i Ib e s -

t r o l - t r e a t e d group ga ined 2 .00 pounds d a ily* The t r e a te d h e i f e r s a te

more and had g re a te r fe ed e f f ic ie n c y th a n th e c o n tro ls . ' T rea ted anim als

had. a more p rom inent mammary developm entj however, th is , mammary develop­

ment d id n o t make a s ig n i f ic a n t d if fe re n c e in c a rc a s s g rades o r d re ss in g

p e rc e n ta g e . S t l l b e s t r o l tended to low er th e e ry th ro c y te co u n t, b u t had

n o 'e f f e c t on blood l i p i d , c h o le s te ro l , o r calcium c o n te n t.

Andrews e t a l . (l9j?0) gave y e a r l in g s te e r s 60 mg. and 120 mg*

im p lan ts o f s t l l b e s t r o l . The c o n tro l groups gained 2 ,2 ^ ,pounds p e r

head d a i ly . Animals t r e a te d w ith tbe 60 mg. dose gained 2.1+7 pounds,

and th o se g iven 120 mg. dose gained 2.68 pounds p e r head d a i ly . The

t r e a te d anim als a te more and u t i l i z e d t h e i r fe e d more e f f i c i e n t l y th an

th e c o n tro l groups. Some mammary development was n o tic e d . D ressing

p e rcen tag e and c a rc a s s grades were s im ila r fo r th e c o n tro l and t r e a te d

g roups, a lthough some of th e c a rc a sse s o f th e t r e a te d group were d esc rib ed

as "hooky".

— 52 —

“ 53 “*

In g e n e ra l, c a t t l e t r e a te d w ith s t i l b e s t r o l im p lan ts show c e r ta in

u n d e s ira b le c h a r a c t e r i s t i c s , in c lu d in g r a is e d t a i l heads and mammary

developm ent„ D r. Wise Burroughs o f Iowa S ta te C ollege was in s tru m en ta l

in develop ing th e te ch n iq u e o f g iv in g s t i l b e s t r o l a t low le v e l s in th e

d a i ly r a t i o n . The Iowa S ta te C ollege R esearch Foundation , I n c . has now ■

lic e n s e d The E l i L i l l y Co. to m anufacture a. prem ix p re p a ra t io n c o n ta in in g

s t i l b e s t r o l . Soybean meal i s used as a c a r r i e r . f o r th e d rug . The

p ro d u c t i s so ld under th e tr a d e name lrS t i lb o s o l l' and i s a v a ila b le on ly

to feed m anufactu rers ' f o r in c o rp o ra tio n in feed supplem ents.

The a p p lica tio n o f s t i lb e s t r o l as a minute percentage o f the ra tion

r e s u lt s in a minimum o f undesirable sid e e f f e c t s . D ressing.percentages

and fed era l carcass grades o f c a t t le fed the drug o r a lly are very sim ilar

to th a t o f con tro l groups. There i s no d if fe r e n c e .in amounts o f fa t ,

lea n , bone, or m oisture in r ib -ey e sec tio n s in control and supplemented -

b eef anim als.

The E li L i l l y Co* (1955) has summarized r e s u l t s o f fe e d in g s t i l b e s ­

t r o l to c a t t l e a t a g r i c u l tu r a l experim ent s t a t io n s , in C olorado, Iowa,

M ichigan, N ebraska, Ohio, In d ia n a , Tennessee, G eorgia, Texas, Colorado,

and K ansas. T h e ir summary in d ic a te s t h a t s t i l b e s t r o l fe d to c a t t l e r e ­

s u l t s i n in c re a s e d d a i ly gains and red u ced fe e d c o s ts . T h e ir recommended

l e v e l of s t i l b e s t r o l , fe d o r a l ly , i s 10 mg. d a i ly . D ata from tw en ty -s ix

s e p a ra te experim ents u s in g s t i l b e s t r o l a t t h i s le v e l in c a t t l e and c a l f

r a t io n s show in c re a se d average d a i ly g a in s i n tw en ty -fiv e o f th e ex p e ri­

m ents. Animals w eighing over s ix hundred pounds gained on th e average '

16 p e rc e n t f a s t e r than c o n tro ls on h ig h -en e rg y o r h igh-roughage r a t i o n s .

C alves (under s ix hundred pounds) gained an average o f 12 p e rc e n t f a s t e r

on h ig h -en e rg y r a t io n s th a n d id c o n t r o l s . In c re ase d fe e d e f f ic ie n c y was

e v id en t in a l l tw e n ty -s ix experim en ts. M ature c a t t l e on h ig h -en erg y

r a t io n s r e q u ire an average o f 13 p e rc e n t Ie sp feed p e r pound o f g a in .

When on high-roughage r a t io n s , an average o f 17 p e rc en t l e s s feed p er

pound o f g a in was needed. Calves on h ig h -en e rg y ra t io n s showed 10 p e r­

c e n t in c re a s e i n feed e f f ic ie n c y , w hile c a lv e s on h igh-roughage ra t io n s

showed a sav ing o f 3 p e rq e n t.

D ata f o r s t i l b e s t r o l - t r e a t e d anim als on p a s tu re a re more lim ite d

th a n f o r c a t t l e ,te s te d in d ry l o t . Clegg and Cole (195k) r e p o r t th a t

s te e r s sub cu tan eo u sly im plan ted w ith 120 mg. o f s t i l b e s t r o l and run on

p a s tu re where supplem ental fe e d was a v a ila b le made g r e a te r g a in s than

s t i lb e s t r o l - im p la n te d s te e r s on p a s tu re a lo n e . T rea ted h e i f e r s on

p a s tu re showed no in c re a se in g a in over th e c o n tro l g roups. Feed con­

sum ption was in c re a se d s l i g h t ly and economy o f feed u t i l i z a t i o n was

in c re a se d m arkedly f o r a l l t r e a te d an im als. A g re a te r p e rcen tag e o f th e

h ig h e r c a rc a ss g rades was c o n s is te n t ly found i n th e u n tre a te d anim als in

b o th s t e e r and h e i f e r g roups. The au th o rs gave s e v e ra l re a so n s fo r th e

f a i l u r e o f t r e a te d c a rc a sse s to reach th e sqme grade a s th e c o n tro ls .

The muscle f ib e r s were l a r g e r , had a more co arse appearance, and were

d a rk e r re d in c o lo r th an th e meat o f th e c o n t r o ls . E x ten t o f m arbling

was d i s t i n c t l y lo w er. The amount o f bo th i n te r n a l and e x te r n a l f a t

d e p o s it io n among t r e a te d anim als was c o n s id e ra b ly low er. Shoulders and

rounds were h e a v ie r , b u t th e lo in s were l i g h t e r th an th a t o f th e con­

t r o l s . Conform ation was a ty p ic a l . C arcasses appeared s im ila r to those

- 5 5 - -

o f s ta g s . There was no d if fe re n c e in d re s s in g p e rcen tag es o r in the p e r­

cen tage o f sh rin k between ho t and c o ld c a rc a ss w eigh ts o f t r e a te d o r con­

t r o l an im als .

0 1Hary and C u lliso n (1956), a t G eorgia, re p o rte d on two experim ents

in v o lv in g a t o t a l o f t h i r t y - s i x head o f y e a r l in g and tw o -y ea r-o ld s te e r s

ru n on mixed g ra s s and legume p a s tu r e s . P a s tu re was adequate a l l during

th e experim en ts, and no supplem ental feed was g iv en . Treatm ent o f h a l f

th e anim als w ith 2k mg. o f s t i l b e s t r o l r e s u l te d i n a d a i ly g a in o f 0.69

pounds p e r s te e r over c o n tro l groups in Experiment I . In Experim ent I I ,

th e same tre a tm e n t showed a h ig h ly s ig n i f ic a n t d a i ly in c re a s e in gain o f

0 .58 pounds.

Dinusson e t a l . (1951) in v e s t ig a te d th e e f f e c t o f s t i l b e s t r o l im­

p la n ts on g ro w in g -fa tten in g sw ine. No c o n s is te n t s tim u lu s to r a t e o f

g a in was a p p a re n t. Response was somewhat h ig h e r a t w eigh ts o f n in e ty to

one hundred pounds th an a t l ig h te r .w e ig h ts , b u t th e d if fe re n c e s were n o t

g r e a t . C on tro ls re q u ire d 5 .2 to 13 .7 p e rc e n t more feed p e r pound o f

g a in . G il ts responded more th an b arro w s. In two t r i a l s , 12 mg. p e l l e t s

were im p lan ted subcu taneously in the e a r j t h i s lo c a t io n r e s u l te d in

c y s t ic en cap su lin g d f th e p e l l e t . In th e t h i r d t r i a l , 2k mg. o f p e l l e t s

were p la ce d in th e s c r o ta l sac o f the barrow s and in th e d o rs a l reg io n

o f th e necks in g i l t s . P r a c t i c a l swine r a t io n s were fe d . Out o f e leven

g i l t s t r e a te d w ith s t i l b e s t r o l , fo u r s u f fe re d p ro lap se o f th e u te ru s .

About th re e days a f t e r im p la n ta tio n , a l l g i l t s showed extrem e sw ellin g

o f th e e x te rn a l g e n i ta l i a which never re tu rn e d to normal a n e s tru s condi­

t io n du rin g the t r i a l . A ll g i l t s and barrow s showed mammary development

— ^6 —

and t e a t grow th, b u t th e e f f e c t was g re a te r w ith the g i l t s . Renewed sex-

d e s ire and a b i l i t y f o r e re c tio n was e v id e n t in th e barrow s, ^ sp e c ia lly

th o se im p lan ted i n the s c r o ta l c a v ity .

Woehling e t a l . (195>1) im plan ted 12 mg. s t i l b e s t r o l p e l l e t s in to

th e r e a r f la n k o f w eanling p ig s , and re p e a te d th e p ro cess tw elve weeks

l a t e r . - No s ig n i f ic a n t d if f e re n c e s were found f o r average d a i ly g a in ,

fe e d e f f ic ie n c y , fe ed consum ption, d re s s in g p e rcen tag e , eye muscle

measurement, o r back f a t th ic k n e s s . There was a h ig h ly s ig n if ic a n t

d if f e r e n c e in seed in ess o f the f re s h b e l ly , compared to th e c o n tro l

g roups. R eproductive organs showed d e f in i te evidence o f hormonal stim u­

l a t i o n .

Pearson e t a l . (19!?2) conducted two experim ents to de term ine e f f e c t s

o f s t i l b e s t r o l im p lan ts on c e r ta in c h a r a c te r i s t i c s o f sw ine. In Experi­

ment I , l a s t i n g 10? days, 25 mg. p e l l e t s were in je c te d a t th e beginning

and end o f th e f i r p t month. At th e end' o f two months, two more 25 mg.

p e l l e t s were im p lan ted . In Experim ent I I , a 50 mg. p e l l e t was im planted

a t th e beginning o f th e t r i a l * Im plan ts d id n o t m a te r ia l ly a f f e c t g a in s

o f g i l t s o r barrow s, b u t a p p a re n tly cau sed a g row th -dep ressing a c tio n

upon young b o a rs . Feed e f f ic ie n c y was u n a ffe c te d , as were d re ss in g p e r ­

cen tag e , th ic k n e ss o f back f a t , c a rca ss g rad e , and te n d e rn ess o f m eat.

E a tin g q u a l i t i e s o f meat from boars were n o t improved*

Andrews e t a l . (I9h9 a and b) f i r s t re p o r te d r e s u l t s o f s t i l b e s ­

t r o l fe ed in g on w ether lam bs. C ontro l and t r e a t e d groups go t th e same

amount o f fe e d . Lambs t r e a te d w ith 12 o r 2k mg. o f s t i l b e s t r o l gained

0 .50 pounds p e r head d a i ly , w h ile the c o n tro ls gained 0*35 pounds p e r

— 57 —

head. Treated animals required 31 percent le g s corn per hundred pounds

o f ga in . Carcass grades were somewhat higher in the co n tro l groups.

Rope e t a l . (1950) o b ta in ed h ig h ly s ig n i f ic a n t d if fe re n c e s in r a te o f

g a in in fa v o r o f lambs im plan ted w ith one 15 mg. p e l l e t p e r lamb.

Jordan (1950) implanted 12 mg. p e l le t s in both four and e ig h t

month old- feed er lambs. There was a s ig n if ic a n t in crease in rate of

gain fo r each t r i a l . Feed per 100 pounds o f gain was reduced 16 and 21

percent r e sp e c t iv e ly . There was l i t t l e d ifferen ce in d a ily feed consumed,

but trea ted lambs were ea sier to keep on fu ll , .fe e d than were the c o n tr o ls .

There was no s ig n if ic a n t d ifferen ce in carcass grades between treated

and con tro l lambs o f four months age, but trea ted lambs e igh t, months o f

age were' o f a lower grade than th e corresponding groups.

R e su lts o f l a t e r work u s in g s 't i l b e s t r o l im p lan ts on fe e d e r lambs

ag ree w ith th e ev idence a lre a d y p re s e n te d . Mean e t a l . (1953)J .Andrews

and Beeson (1953)3 Jordan and BeI l (1952)3 and O1Mary e t a l . (1952)

o b ta in ed s ig n i f i c a n t ly in c re a se d r a t e o f g a in and s ig n i f i c a n t ly in c re ase d

feed e f f ic ie n c y . C arcass q u a l i ty f o r t r e a te d anim als was low ered . S t i l -

b e s t r o l low ered fe e d c o s ts and s l i g h t l y low ered s e l l in g p r ic e in some

c a se s , b u t a g r e a te r p r o f i t p e r lamb was r e a l iz e d .

B e ll e t a l . .(19514-) showed th a t no b e n e f i t was d e riv ed from a second

15 mg. im p lan t made 70 days a f t e r an o r ig in a l im plant on fe e d e r lambs in

a commercial f e e d lo t . Of 517 lambs on experim ent, tw elve lambs were l o s t

from p ro la p se o f th e rectum and from excess sw e llin g and inflam m ation

in th e r e c t a l o r p e r in e a l re g io n s . A ll th e se anim als had re c e iv e d two

im plan ted p e l l e t s . The c o n d itio n resem bled symptoms o f u r in a ry c a lc u l i .

— 58 —

I t was tho u g h t th a t th e h igh in c id en ce o f p ro lap se was due to s t r a in in g

r e s u l t in g from d i f f i c u l t y o f u r in a t io n ,

Clegg e t a l , (1955) found anim als w eighing from 20 to 60 pounds

responded th e same to s t i l b e s t r o l im p la n ts . R ate o f ga in was in c reased

s ig n i f i c a n t ly in a l l c a s e s . E f fe c ts were th e game when 12 mg. o r 36 mg.

p e l l e t s were employed. Range groups on n a tiv e range g ra ss o r i r r i g a t e d

la d in o c lo v e r and mixed g ra s s p a s tu re d id as w e ll as groups on g ra in and

h ig h q u a l i ty roughage.

. S ev e ra l re c e n t t r i a l s have in v e s t ig a te d th e m e rits o f fe ed in g s t i l ­

b e s t r o l in the r a t io n , as opposed to th e im p lan t m e th o d .■ Hale e t a l .

(195U) used le v e l s o f - s t i l b e s t r o l from 0 ,5 to 1200 meg. p e r pound o f

r a t io n in s ix in d iv id u a l feed in g t r i a l s . I n f iv e o f th e s ix t r i a l s a

response i n w eigh t g a in was o b ta in ed a t ox n e a r th e 2 .0 meg. l e v e l . For

a l l s ix t r i a l s , th e response was 19 p e rc e n t over th e c o n t r o l s . At

l e v e l s between 3 ,0 meg. and 600 meg., no c o n s is te n t response was no ted ,

b u t q u ite o f te n a d ep re ss in g a c tio n was found. The 600 meg. and 1200

meg. le v e l s in c re a se d w eigh t g a in s 20 p e rc e n t and 28 p e rc e n t re sp ec tiv e ly -

over th e c o n tro ls , b u t th e se r e s u l t s were n o t v e r i f i e d in two group

feed in g t r i a l s . In th e se t r i a l s , s t i l b e s t r o l fed o r a l ly d id n o t appear

to have an a p p re c ia b le e f f e c t on c a rc a s s q u a l i ty . Measurement o f c e r ta in

secondary sex organs o f w e thers and u te r in e measurement on a lim ite d

number o f ewe lambs showed th a t the s t i l b e s t r o l ex e rted p h y s io lo g ic a l

a c t i v i t y .1

Jo rdan e t a l , -(1955) fe d s t i l b e s t r o l o r a l ly a t 0ol m g., 0 .5 mg.,

and 1 .5 mg. p e r lamb d a i ly , w ith no s ig n i f i c a n t e f f e c t on r a t e o f g a in .

- 59 -

Lambs fed the 0*1 mg. and 0 .5 mg. le v e ls produced carcasses th a t graded

higher than th e co n tr o ls , Trhile lambs on the 1 .5 mg. le v e l produced

carcasses equal to that' o f the c o n tr o ls . . Other lambs given s t i lb e s t r o l

im plants gained s ig n if ic a n t ly fa s te r than th e con tro ls but produced

lower y ie ld in g or grading ca rca sses.

H a le ■e t a l . (1955) fe d s t i l b e s t r o l to w ether lambs a t app rox i­

m a te ly 2 .0 mg. p e r head d a i ly in a f a t te n in g r a t io n . Rate o f gain wast

increased 22 percent over a con tro l group. Feed consumption was not

'■-consistently, in creased , and carcass q u a lity was a ffec te d on ly s l ig h t ly .

S t i lb e s t r o l fed a t 3 .6 mg. per head d a ily f a i le d to g ive as sa t is fa c to r y

ra te o f gain as did s t i lb e s t r o l fed a t the lower le v e l s . . Close examina- '

t io n o f the animals showed c er ta in changes in extern al appearance sim ilar

to those n o ticed w ith s tilb e str o l-im p la n ted lambs, in clu d in g enlarged

prepuce, mammary development, .and edema o f the anal area.

Summary ■

Research data compiled during the la s t decade by experiment s ta tio n s'

and commercial feed ers throughout the United S ta tes have shown that s t i l ­

b e s tr o l i s e f f e c t iv e in obtain ing c e r ta in d esired e f f e c t s when used in

l iv e s to c k r a tio n s or when applied subcutaneously in p e l le t form. In

p ou ltry s t i lb e s t r o l i s gen era lly used in implant form and r e s u lt s in

increased growth ra te and a b e tter q u a lity carca ss. In f in ish in g beef

c a t t le , s t i lb e s t r o l i s used very e x te n s iv e ly a t low le v e l s in the d a ily ■

r a tio n . Gains and feed e f f ic ie n c y are improved, and carcass ch aracteris­

t i c s are not adversely a ffe c te d . The drug i s probably more e f fe c t iv e

upon fa tten in g c a t t le than upon animals on pasture a lon e.

I

- 60 -

S t i lb e s t r o l work w ith swine has not produced s a t is fa c to r y r e s u lt s .

Rate o f gain and feed e f f ic ie n c y are not increased s ig n if ic a n tly ,; Un­

d esira b le carcass c h a r a c te r is t ic s and.unfavorable sid e e f f e c t s such as

prolapse o f th e uterus may r e s u lt from the use o f s t i lb e s t r o l on swine,

S t i lb e s t r o l was f i r s t used on sheep in th e p e l le t im plant form.

In almost a l l experim ents, r a te o f gain and feed e f f ic ie n c y are improved.

Feed consumption i s not u su a lly a f fe c te d . Carcass q u a lity i s d e f in ite ly

lowered, p a r t ly because o f a lack o f s u f f ic ie n t fa t covering over the

shou ld ers. On a commercial f e e d - lo t b a s is , prolapse o f the uterus and

rectum o f ewe and wether lambs r e sp e c t iv e ly have occurred-. More recent

work using s t i lb e s t r o l in sm all d a ily do’bes in the ra tio n in d ica te s

th is method o f s t i lb e s t r o l supplementation may increase ra te o f g a in '

and feed e f f ic ie n c y without unfavorably a ffe c t in g carcass q u a lity .

** Si. •*

E f fe c t o f Feeding T h io n ra c il and T hyrop ro te in to Farm Animaip

S e c re to ry a c t i v i t y o f th e th y ro id g land I s re g u la te d by an i n t e r ­

a c t io n and b a lan ce between th e th y ro id hormone and th y ro tro p h in from the

a n te r io r p i t u i t a r y . There a re s e v e ra l chem ical compounds known th a t can

cause a hypo thyro id c o n d itio n in man and an im als . The most p o te n t o f

th e se g o itro g e n ic compounds i s t h io u r a c i l , In some unknown way, th e se

compounds i n t e r f e r e w ith th e sy n th e s is or u t i l i z a t i o n o f th e th y ro id

hormone, io d o th y ro g lo b u lin . A ccording to Turner (191$), evidence fav o rs

th e th e o ry th a t normal sy n th e s is o f iodo thy ro g lo b u lin i s low ered , causing

.an in c re a se d o u tp u t o f th y ro tro p h in from th e " a n te r io r p i t u i t a r y , Thyro­

tro p h in s tim u la te s growth o f s e c re to ry ep ith e liu m o f th e th y ro id g land ,

and m o b iliz e s io d o th y ro g lo b u lin s to re d in th e th y ro id g la n d . • As th i s

supp ly i s exhausted , th e m etabo lic r a te o f th e anim al d e c l in e s .

V arious degrees o f hyperthy ro id ism can a lso be produced by in t r o ­

ducing in to an anim al sm all amounts o f an io d in a te d c a se in o r io d in a te d

p r o te in p ro d u c t. A ccording to B la x te r (±9k9) io d in a te d c a se in was p re ­

p a red f i r s t i n Germany s h o r t ly b e fo re th e s t a r t o f World War I I . The

p ro d u c t was found to .co n ta in v a r ia b le amounts o f the same compound sec re ­

te d by th e th y ro id g lan d . American and B r i t i s h w orkers improved the

io d in a t io n p ro cess so t h a t th e th y ro id a l p o ten cy o f io d in a te d case in i s

many tim es th a t o f d r ie d th y ro id g lan d . O ther p ro te in s such a s serum

g lo b u lin , serum album in, and egg albumin have been s u c c e s s fu lly sub­

s t i t u t e d f o r c a se in as a s t a r t i n g m a te r ia l . Io d in a te d c a se in i s p ro ­

duced com m ercially in th e U nited S ta te s and so ld under th e r e g is te r e d

tr a d e name uProtam one. u This p roduct w i l l w ith s ta n d th e r a th e r h igh

— 62 —

tem p e ra tu res o f cubing encoun tered in fe e d p re p a ra t io n and does not lo s e .I ■ '

i t s p o ten cy du rin g s to ra g e . P a l a t a b i l i t y of feeds i s u n a ffe c te d by th e

a d d it io n o f "Protamo'ne."

Much o f th e e a r ly work u sin g th io u r a c i l was done on r a t s . When '

t h io u r a c i l i s ad m in is te red to growing r a t s , Astwood (I9h3)t MacKenzie and

MacKenzie (19^3), growth i s reduced . S e c re tio n o f the th y ro id gland i s .

in h ib i te d and b a s a l m etabo lic r a t e i s low ered . •

Kempster and Turner ( I 9I4.5D fe d c h ick s a r a t io n c o n ta in in g 0 ,2 p e r­

c e n t th io u r a c i l f o r s ix te e n days b eg inn ing a t te n weeks o f ag e . The

growth r a t e , as t h e i r work shows, i s n o t a f fe c te d bu t m arket grade i s

im proved. When th e same l e v e l i s fed f o r t h i r t y - s i x days, fe e d re q u ire ­

ment p e r pound o f gain i s in c re a se d , growth r a t e d ecreased , and m arket

grade g r e a t ly im proved. Andrews and S c h n e tz le r (19I4.6 ) fe d th io u r a c i l a t

s im ila r l e v e l s to ch ick s betw een s ix and fo u r te e n weeks o f ag e . Growth

r a t e was reduced s l i g h t ly , bu t m arket grade and f a t d e p o s it io n were

s ig n i f i c a n t ly in c re a s e d . "

D etw iler and Andrews (1930) fe d b r o i l e r s th io u r a c i l as 0 .1 3 p e rc e n t '

o f th e r a t io n to b r o i l e r s and in a d d itio n im plan ted a 6 m g .•s t i l b e s t r o l

p e l l e t subcu taneously i n th e neck from th e n in th through th e tw e lf th

week o f age. This tre a tm e n t r e s u l te d in maximum g a in s , fe e d e f f ic ie n c y ,

and m arket q u a l i ty . T h io u ra c il o r s t i l b e s t r o l fe d alone c o n s is te n t ly

improves c a rc a ss q u a l i ty , b u t th e com bination o f th e two i s su p e r io r to

e i th e r a lo n e . F a t d e p o s it io n and d re s s in g p ercen tag e were in c re a se d in

a l l t re a tm e n ts . D e tw iler and Andrews (1930) suggest t h a t th e le n g th o f

tre a tm e n t and dosage le v e l s p robab ly cou ld be red u ced . -

- 6 3 -

Evidence o f th e e f f e c t s o f th io iy ra c il and r e la t e d compounds in feed

e f f ic ie n c y by hogs i s c o n tra d ic to ry . Van Der N ott e t a l . (I9k7)>

McMillen d t a l . (19L7), and Muhrer e t a l . (±9h7) found th io u r a c i l in ­

c re ased fe e d e f f ic ie n c y of sw ine. Beeson e t a l . (l9li-7) and Acevedo e t

a l . (I9l|.8) re p o r te d o p p o s ite r e s u l t s . The p e rio d o f growth o f the

anim al when supp lem enta tion i s perform ed appears to be an im p o rtan t

f a c to r , Ih en th e drug i s g iven on ly du rin g th e l a s t few weeks o f the

fe e d in g p e rio d i n sw ine, th e re i s u s u a lly a s ig n i f i c a n t ly improved

economy o f g a in .

Johnston e t a l . (19l|.6) o f th e U nited S ta te s Department o f A g ricu l- .

t u r e , s tu d ie d th e in te r a c t io n o f tem pera tu re and th io u r a c i l upon ca rca ss

c h a r a c t e r i s t i c s , r a t e o f g a in , and feed e f f ic ie n c y o f hogs. At teim-

p e ra tu re s n ear £0° F , tre a tm e n t w ith t h io u r a c i l r e s u l te d in decreased ,

th ic k n e s s o f back f a t and in c re a se d p e rcen tag e o f p ro te in i n th e hams.

L iv e rs and th y ro id s were la r g e r i n anim als t r e a te d a t 90° F. and 5>0° F.

th a n in th e c o n tro l anim als,, b u t d if f e re n c e s in th e s iz e o f th e se organs

was g re a te r a t th e .lower te m p e ra tu re . R ate o f ga in was in c re a se d a t the

low er te m p e ra tu re , b u t no t a t the h ig h e r tem p e ra tu re . D iffe re n c es in

economy o f fe e d u t i l i z a t i o n appeared to be g re a te r between t r e a te d

p ig s and th e c o n tro ls a t £0° F . th an betw een t r e a t e d anim als and c o n tro ls

a t 90° F .

E f fe c ts o f hyperth y ro id ism in r e la t io n to l a c t a t io n in d a iry c a t t l e

and o th e r phases o f anim al p ro d u c tio n has been com prehensively review ed

by B la x te r e t a l . (19U9). He r e p o r ts t h a t w ith in a l im i te d range the

p e rcen tag e in c re a s e in m ilk y ie ld i s rough ly p ro p o r tio n a l to th e dosage

- 6h -

o f thyroprdteinj fa t percentage in creases a ls o , the in crease usually-

appearing a t lower dosage le v e l s than th e in crease in m ilk y ie ld . Milk

from cows fed iod in ated p ro te in i s sa fe and n u tr it ip n a lly adequate. ■

Because thyroprotein supplem entation in creases th e b asa l metabolic

r a te , n u tr ien t intake must be increased to avoid rather severe lo s se s in

body w eigh t. Some experiments show th at a higher intake o f n u trien ts

w ithout supplemental thyroprotein in crea ses m ilk production as much as

does a higher n u tr ien t intake p lu s the th yrop rotein .

I t i s g en era lly thought th a t iod in ated p ro te in can be p ro fita b ly

used on ly during periods o f m ilk s c a r c ity , and then on ly fo r a period o f

approxim ately two months.. and on ly in commercial herds. Use o f iod inated

p ro te in i s not considered d esirab le in pure bred breeding herds.

Use o f th io u r a c il and thyroprotein on b eef c a t t le has been lim ited

to a few s tu d ie s . Andrews and Bullard (l9l|.0) p a r t ia l ly thyrodectomized

b eef s te e r s and found ra te o f gain was increased g rea tly during the f i r s t

s ix to e ig h t p ostop erative weeks. The ra te o f gain gradually decreased

to normal a f te r 10 to 12 weeks. I t was unknown how much o f the increased

ra te o f gain was due to removal o f the gland and how much was due simply

to regain o f weight l o s t during the op eration . Some o f the increase was

a ttr ib u ted to absence of the th yro id .

Beeson e t a l . (iplj.?) fed th io u r a c il to y earlin g s te e r s at 2 .0 :gm., '

U.O ;gm., and 6*0 gm. per s te e r d a ily . Rate o f gain was increased s l ig h t ly

at the two lower l e v e l s . Dressing percentage and amount o f carcass f in is h

was improved, but not s ig n if ic a n t ly .

Kline e t a l . (1914.9) fed. th io u r a c il to s te er s a t 0 ,2 percent o f the

— 6^ —

g ra in r a t i o n . Thig le v e l caused a decrease in consumption of g ra in mix­

tu r e and an in c re a s e in roughage consum ption. Feed e f f ic ie n c y was in ­

c re ased and fe e d c o s ts were low ered. R ate o f gain was n o t s ig n i f ic a n t ly

a f f e c te d . C arcass q u a l i ty was no t a f fe c te d over a long feed in g p e rio d ,

b u t c a rc a ss g rades o f tw o -y ea r-o ld h e i f e r s appeared to be s l i g h t ly im­

proved d u rin g a s h o r t fe ed in g p e r io d .

Some -work.has been done on r a t e o f in ta k e o f g o itro g e n ic compounds

in to th e body» ,ELi e t a l . (I9ij,8) s tu d ie d ab so rp tio n and e lim in a tio n of

th io u r a c i l i n ca lv es and g o a ts fo llo w in g o ra l and subcutaneous a d m in is tra ­

t io n s . Maximum b lood plasm a th io u r a c i l c o n ce n tra tio n s o ccu rred in b to

8 hours a f t e r o r a l a d m in is tra tio n o f 0 .1 gm. an d .0 .2 gm.. p e r kg, o f body

w eigh t and a f t e r 2 to !(.'hours’ fo llo w in g subcutaneous a d m in is tra tio n .

These r e s u l t s in d ic a te slow er r a te s o f a b so rp tio n th an w ith nonrum inants.

Maximum b lood plasm a le v e l s in th e ch icken may be reached w ith in 30

m inutes a f t e r a d m in is tra tio n o f t h io u r a c i l . In the goat and c a l f , plasm a

le v e l s were approx im ate ly p ro p o r tio n a l to dosage l e v e l s . S in g le doses

g iven subcu taneously r e s u l te d in approx im ate ly tw ice th e plasm a th io u r a c i l

c o n c e n tra tio n s as th e same dosage given o r a l ly . E s s e n t ia l ly uniform

b lood plasm a th io u r a c i l le v e l s were m ain ta in ed w ith a d m in is tra tio n s made

a t 12 hour i n t e r v a l s . The drug was p r a c t i c a l l y e lim in a te d th rough th e

u r in e w ith in 2li hours a f t e r c e s s a tio n o f a d m in is tra tio n .

S ev era l w orkers have t e s t e d th e e f f e c t s of th io u r a c i l on the more

im p o rtan t economic c h a ra c te rs in sheep . Andrews e t a l . (I9b7) t r e a te d

lambs w ith le v e l s o f 0.18 gm,, 0.33 gm., and 0.5L gm. o f th io u r a c i l p e r

lamb d a i ly . There was no s ig n i f ic a n t e f f e c t on t o t a l g a in in w eigh t, a l ­

— 66 —

though r a te o f ga in was s l i g h t l y l e s s in a l l l o t s re c e iv in g th e d ru g . At

1*1$ gm. p e r head d a ily , th e lambs showed .s ig n if ic a n t ly red u ced feed con­

sum ption and r a te o f g a in . At l e v e l s o f 0 .18 gm. an d .0 .33 gm. th e c a rca ss

q u a l i ty improvement approached s ig n if ic a n c e . F a t d e te rm in a tio n s o f th e

e n t i r e c a rc a sse s were n o t made, b u t i t was apparen t th a t cod and in te r n a l

f a t d e p o s it io n were in c re a se d . A .s im ila r in c re a se in f a t d e p o s itio n

occurs i n t r e a te d p o u l t r y . T h io u ra c il and th io u re a a t a l l le v e ls fed

produced h ig h ly s ig n i f ic a n t in c r e a s e s 'in th y ro id w e ig h ts . Feed re q u ire ­

ments p e r pound o f ga in were n o t a f fe c te d by th io u r a c i l u n t i l in ta k e ex­

ceeded th e 0 .33 gm. l e v e l , b u t th e re was a tendency fo r th e gross

e f f ic ie n c y to be reduced as le v e l s o f t h io u r a c i l and th io u re a were in -

c re a se d .

B arrick e t a l . (±9h9) ad m in is te red th io u r a c i l in th e fe e d a t 0 .21

gm. and 0 .39 gm. p e r lamb d a i ly du rin g th e w in te r f a t te n in g p e rio d o f

19k6-k7, and a t. th e r a t e o f 0 Jj.2 gm. and 0 .63 gm. during th e fo llow ing

w in te r . T h e ir r e s u l t s showed no s ig n if ic a n t e f f e c t on t o t a l g a in , feed

• e f f ic ie n c y , ca rca ss y ie ld , o r c a rc a s s g rad e . P ro p y lth io u ra c i l was given

i n th e fe e d a t 0 .03 gm. p e r iamb d a i ly d u rin g th e f i r s t w in te r . Again no

s ig n i f ic a n t e f f e c t s were rec o rd ed . T h y ro p ro te in was given, in th e feed

du rin g the second w in te r a t th e r a t e o f 0.£2 gm. and I . OL gm. p e r lamb

d a i ly w ith no s ig n i f ic a n t e f f e c t . Feed consum ption was reduced somewhat

by th io u r a c i l a t th e 0 .39 gm. to 0.63 gm. l e v e l s and was s tim u la te d some­

what by th y ro p ro te in a t b o th th e Oa$2 gm, and l.O L gm. l e v e l s . • Thyroid

g lands from th e th y ro p ro te in t r e a te d anim als were found to b e in a c t iv e *

Thyroid g lands from lambs fe d 0 .21 to 0 ,63 gm. o f t h io u r a c i l , and 0,03

- 6 ? -

gm. o f p ro p y l th io u r a c i l showed no more evidence o f s t im u la t io n th an those

from c o n tro l anim als and were n o t in c re a se d i p s iz e . The au thors con­

c luded from th e r e s u l t s o f t h i s experim ent th a t th e re was no advantage

in u s in g th io u r a c i l o r th y ro p n o te in f o r f a t te n in g w este rn fe e d e r lam bs. ■

B arrick e t a l . (l95>0) s tu d ie d th e p h y s io lo g ic a l e f f e c t o f th io u r a c i l

and o th e r drugs on w e th e r 'Ian b s . T h io u ra c il p u t in th e r a t io n s o f fe e d e r

.lambs a t le v e l s below 1 .0 gm. p e r lamb p e r day r e s u l te d in marked s tim u la ­

t io n o f th e th y ro id g land du rin g o n ly one o u t o f th re e y e a r s . 'In th e one

e f f e c t iv e t r i a l , th y ro id s o f lambs re c e iv in g as l i t t l e as 0.18 gm.

th io u r a c i l p e r lamb d a i ly were ,five tim es h e a v ie r th an c o n tro l lambs and

showed d e f in i te h i s to lo g ic a l evidence o f s t im u la t io n . T h iourea a lso

caused d e f in i te s tim u la tio n q f th e th y ro id s '. In two o f th e th re e y e a rs ,

th e th y ro id g lands from lambs g e t t in g 0*2 to 0 .6 gm. th io u r a c i l d a ily

were sm a lle r than th o se from c o n tro l lam bs, and h i s to lo g ic a l ly th e glands

from t r e a t e d and c o n tro l anim als were v e ry s im ila r . T h io u ra c il given

o r a l l y by cap su le o r t a b l e t a t le v e ls up to 1 .0 gm. p e r lamb d a i ly fo r

HO days produced v e ry l i t t l e e f f e c t . At th e 3 .0 gm. l e v e l th e glands

en la rg ed in s iz e and showed d e f in i t e h i s to lo g ic a l ev idence o f s t im u la tio n .

O ra l a d m in is tra tio n o f 1*0 gm. th io u re a t a b l e t s p e r lamb d a i ly caused

marked s t im u la t io n o f th e g land and . s e r io u s ly l im ite d feed consumption

and r a t e o f grow th.

P ropy l t h io u r a c i l g iven o r a l ly in t a b l e t form a t 0 .1 gm. d a i ly d id

n o t s ig n i f ic a n t ly , a f f e c t the th y ro id g lan d . The gland was s tim u la te d ,

however, when 1 .0 gm. p e r head d a i ly was g iven f o r th r e e w eeks.

Thyroid g lands o f lambs re c e iv in g 0*5 gm. to 1 ,0 gm. th y ro p ro te in

- 68 -

p e r head d a i ly were l a r g e r than th y ro id s from c o n tro l lambs o r th io u ra c .il

t r e a te d lam bs. ■ H is to lo g ic a l ly , the g lands were e a s i ly d e te c te d by t h e i r

g e n e ra l appearance o f i n a c t i v i t y i, '

Blood plasm a c h o le s te ro l was in c re a se d 30 p e rc e n t to h.0 p e rc en t as

a r e s u l t o f ad m in is te r in g th io u r a c i l o r th io u re a a t r a t e s as low a s 0 .6

gm. p e r head d a i ly . A marked in c re a se in c h o le s te ro l l e v e l was n o tic e d

when th e lambs were lo s in g w eigh t, re g a rd le s s o f the th io u r a c i l t r e a t ­

m ent.

V itam in A le v e l s in b lood plasm a o f lambs in dry l o t w ere no t

a f fe c te d by t h i o u r a c i l . . In one experim ent, in -mhich lambs t r e a te d w ith

th io u r a c i l were p u t on g reen p a s tu re fo llo w in g a d ry l o t fe ed in g t r i a l ,

th e in c re a s e in blood plasm a V itam in A. le v e l s was s ig n i f i c a n t ly l e s s th an

th e in c re a s e which o c c u r re d .in the c o n tro l an im als , At th io u r a c i l le v e ls

to 3 .0 gm. p e r head d a i ly , hem oglobin, e ry th ro c y te c o u n ts , and leukocyte

counts were n o t a f f e c te d .

L abarthe e t a l . (±9h9) fe d R am bouillet ewes a l f a l f a hay, ground

o a ts , and c o tto n se e d meal p lu s "Protamone" a t 0 .3 gm., 1 ,0 gm., and 1 .3

gm. p e r ewe d a i ly . Wool p b se rv a tio n s were made. A ll sheep produced more

wool under c o n tro l le d experim en ta l c o n d itio n s th an during th e p rev ious

y e a r on a ra n c h . Animals on th e two h ig h e s t le v e ls o f th y ro p ro te in p ro ­

duced 13 p e rc e n t and 10l|. p e rc e n t more wpol re s p e c t iv e ly th a n d id th e

c o n tro l l o t . Ewes on th e lo w est le v e l o f drug produced 16 p e rc e n t le s s

wool th an d id th e c o n tro l ewes. There was no a p p re c ia b le d if fe re n c e in

f ib e r le n g th , d iam e ter, o r g re a se p e rc en ta g e .

A s tudy o f th e pathway ta k e n by th y ro p ro te in in to th e body was made

— 6 9 —

by Campbell e t a l« (1950).. R ad io ac tiv e th y ro p ro te in uras ad m in is te red i n '

s o lu t io n , in tra v e n o u s ly , o r a l ly , and th rough rum en,' sm all i n t e s t i n e , and

c e c a l f i s t u l a s . When given in tra v e n o u s ly in sheep , n e a r ly a l l ra d io ­

a c t i v i t y had d isap p eared from the blood w ith in seven h o u rs , H ighest

le v e l s o f b lood r a d io a c t iv i ty were o b ta in ed fo llo w in g o r a l or.rum en

a d m in is tra tio n about 10 hours fo llo w in g tre a tm e n t. A c t iv i ty was le s s

when a d m in is tra tio n was made i n th e sm all i n t e s t i n e ; th e re was p r a c t i c a l ly

no a b so rp tio n from th e cecum. Follow ing ab so rp tio n in to th e b lood stream ,

p a r t o f th e th y ro p ro te in was in th e form o f r a d io a c tiv e th y ro x in e and p a r t

was p re s e n t as d i io do ty ro s in e and o th e r io d in e -c o n ta in in g compounds.

Summary

T h io u ra c il and o th e r s im ila r compounds w i l l i n h ib i t hormone p ro ­

d u c tio n o f th e th y ro id g lan d . When g iv en to p o u ltry and swine du rin g

on ly th e l a s t few weeks o f th e f a t te n in g p e r io d , th e re i s u s u a lly a

s ig n i f ic a n t improvement in economy o f g a in . . in c re a se d f a t d e p o s it io n

u s u a lly occurs in p o u l tr y .

R e su lts w ith b e e f c a t t l e and sheep have been in c o n s i s te n t . Some

w orkers b e lie v e th a t when op tim al c o n d itio n s fo r a d m in is tra tio n o f the

drug have been e s ta b l is h e d , i t s use may have some m erit upon th e se two

an im als .

T h y ro p ro te in compounds have been used e x te n s iv e ly i n d a i r y c a t t l e ,

to in c re a s e m ilk and m ilk - f a t p ro d u c tio n . The compounds are e f f e c t iv e

i n accom plish ing th e se g o a ls , b u t u n d e s ira b le s id e e f f e c t s th a t accompany

th e use o f th y ro p ro te in compounds may s e v e re ly l im i t t h e i r a p p lic a t io n .

In p o u l tr y , th y ro p ro te in c o n s is te n t ly r e s u l t s in a c c e le r a te d fe a th e r

- 70 -

growth o f c h ic k s . I t s e f f e c t on body grow th , egg p ro d u c tio n , and o th e r

f a c to r s i s v a r ia b le and no t c o n c lu s iv e .

When th y ro p ro te in i s given a t c e r ta in le v e l s to sheep , wool p ro ­

d u c tio n i s s t im u la te d .

- 71 -

OBJECTIVES

The purpose o f th i s experim ent was to s tu d y the e f f e c t s o f c e r ta in

drugs on th e r a t e o f g a in , fe e d e f f ic ie n c y , and c a rc a ss q u a l i ty o f wether,

lambs fe d a f a t te n in g r a t i o n . T reatm ents in c lu d ed com binations o f thyro-r

p r o te in o r th io u r a c i l w ith s t i l b e s t r o l ' g iven o r a l ly in the r a t i o n , and

s t i l b e s t r o l g iven subcu taneously as q p e l l e t im p lan t.

72 -

PROCEDURE

T h ir ty - th r e e w h ite f ace lambs o f R em bouille t, Columbia, and Targhee

b reed in g were random ized by b reed and w eigh t in to e leven lo t s o f th re e

anim als each . Average w eight fo r th e e n t i r e group vuas 80 .pounds, w ith a

range o f £8 to 97 pounds.

The lambs were k e p t in th e pens f o r app rox im ate ly one week before

th e t r i a l began . On Depember 13, th e i n i t i a l w eights were ta k en , and

anim als in pens seven , e ig h t , and n ine were g iven s t i l b e s t r o l p e l l e t s

subcu tan eo u sly below th e l e f t e a r .

A fte r December 13, each pen o f th re e anim als was fe d 0 of> pounds o f

soybean meal d a i ly s p r in k le d over th e g r a in m ix tu re . The m eal f o r some

pens se rv ed as a c a r r i e r f o r the t h io u r a c i l , th y ro p ro te in , and s t i l b e s ­

t r o l as w e ll as fu rn ish in g some p ro te in . The d esig n of the experim ent

i s shown in Table I .

A c o n ce n tra te m ix ture o f o n e - th ird whole o a ts , o n e - th ird whole b a r­

le y , and o n e - th ird d r ie d m olasses b e e t p u lp was o ffe re d each day in

amounts which th e lambs would c lean up. A lfa lfa hay was su p p lied ad

l ib i tu m to each pen o f sheep . S a l t was a v a i la b le I n each pen a t a l l

tim e s .

Lambs i n each pen were su p p lie d w a te r i n a wash tu b . T his method

was s a t i s f a c to r y excep t du rin g p e rio d s o f ex trem ely co ld w eather, a t

w hich tim es th e w a ter was fro ze n excep t fo r a few hours each day im­

m e d ia te ly fo llo w in g a d d it io n o f more w a te r ,. Row ev er, th e la c k of w ater

du ring c e r ta in p e r io d s o f th e day a p p a ren tly had no e f f e c t on the lam bs.

There was some v a r ia t io n in pen s fz e among the e leven l o t s . Lots

- 73 -

I th rough .6 had id e n t ic a l pen s iz e s ,, a l l b e in g lo c a te d in th e same wing

o f the sheep b a rn . Lots 7 th rough 11 were a l l fe d in a d i f f e r e n t w ing.

The s iz e o f th e se pens v a r ie d , b u t, I n g e n e ra l, th e pens were la r g e r .than

th o se o f th e f i r s t s ix l o t s ,

At th e end o f th e t r i a l , one lamb from each l o t was s la u g h te re d .

Each lamb k i l l e d was in te rm e d ia te in w eaning.w eight f o r i t s re s p e c tiv e

l o t ; c a rc a sse s o f th e s la u g h te re d lambs were graded,- The th y ro id , p i t u i ­

t a r y , and a d re n a l g lands were removed, and t h e i r re s p e c tiv e s iz e s and

volumes determ ined

Table I . Experim ental D esign, Weight G ains, and G rain Consumption Data o f Lamb F a tte n in g T r ia l .

S t i l b e s t r o l I mg. (o ra l)

S t i l b e s t r o l (o ra l) 0.5> mg. I mg. 2 mg. 12

Im plan t - • mg. 18 mg.

C ontrol

Lot and R ation No. I 2 3 I 3 6 7 8 9 10 11

T hy ro p ro te in , .0 .5 gm. d a i ly T h io u ra c il , .0.5) gm. d a i ly T h io u ra c il ,

I gm. d a i ly

X

X

%

X X X

Average Weigh ts ( l b s . )

I n i t i a l 77.0 78.0 82.3 78.3 79.0 79.0 80.3 82.7 82.7 81.3 79.3F in a l 102.3 103.0 103.3 111.3 107.0 112.7 123.3 120.0 115.3 99.3 102.3 1

Gain p e r lamb 23 ,3 27.0 23.0 33.0 28.0 33.7 1*2 .6 37.3 33 .6 18.0 23.0D aily Gain 4 .3 6 0 .38 0 .32 0 . 1*6 0 . 1*0 0.1*7 0 .60 0.33 0 .30 0 .23 . 0 .32 . 1

Feed Consumption p e r lamb

H it . 3 113.3 131.3 166.0 11*0.3 170.3 176.3 167.3 133.0 132.0 138 .3

Feed Consumption . p e r Cwt. Gain

1*32 .6 U27.0 370.9 303.0 301.0 33U.1 1*11*.3 . 1*1*9.1 1*33.1* 733.3 602.2

- 7f> ~

RESULTS MD DISCUSSION

Very soon a f t e r th e t r i a l began, i t became obvious t h a t c e r ta in

drug supplem ents w ere u n p a la ta b le to th e lam bs. In g e n e ra l, th e l o t s

re c e iv in g th io u r a c i l a te as l i t t l e o f th e supplem ent a s p o s s ib le . I tft

was. im p o ssib le to a c c u ra te ly weigh back the re fu se d supplem ent a s i t

was alw ays mixed w ith f in e b e e t pu lp m a te r ia l . I t was e s tim a te d th a t

lambs in Lot 3 a te about o n e -h a lf th e supplem ent o f fe re d , w hile those

i n Lots 2 , 8, 9, and 10 a te somewhat m ore. This f a c to r d id n o t a f f e c t

consum ption o f th e c o n c e n tra te , however, as the lambs v e ry e f f e c t iv e ly

s o r te d o u t the g ra in k e rn e ls and th e la r g e r b e e t pu lp p a r t i c l e s . Some .

g ra in was w asted i n the* th io u p a c i l - f e d l o t s . This lo s s was estim ated and

compensated f o r in computing feed e f f ic ie n c y f ig u r e s .

Hay consum ption averaged app ro x im ate ly l . b pounds p e r head d a i ly ,

n o t in c lu d in g w eighback. Hay consum ption between tre a tm e n ts d id no t

v a ry g r e a t ly . The c o n tro l 'la m b s (Lot .11) a te th e l e a s t .

The ex p erim en ta l d esig n , feed consum ption, and w eigh t g a in s o f th e

f a t te n in g lambs a re shown in Table I , The lambs weighed an average o f

80 pounds a t th e s t a r t and HO pounds a t th e end of the seven ty -one day

feed in g p e r io d . ' Gains o f th e lambs du rin g th e t r i a l were su b jec ted to

a n a ly s is o f v a ria n ce Snedecor (I9 lt6 ), There was a h ig h ly s ig n if ic a n t

(PO.Ol) d if f e re n c e among tre a tm e n t g a in s . Lambs in Lot 7 (12 mg, s t i l -

b e s t r o l im p lan t) ga ined th e f a s t e s t (0 ,60 pounds per d a y ). Lambs in

Lot 10 ( l.O gm. th io u r a c i l p e r head d a i ly ) ga ined th e s lo w est (0 ,25

pounds p e r head d a i ly ) .

Lambs i n Lot I re c e iv e d 0 ,5 gm. th y ro p ro te in and I 6O mg. s t i l b e s t r o l

- 76 -

d a i ly in th e r a t i o n . Lambs o f Lot 2 re c e iv e d 0 .5 gm. th io u r a c i l and 1 .0

gm. s t i l b e s t r o l in th e same way. A lthough th e re was a s l i g h t d i f f e r e n c e '

in r a t e o f g a in and feed e f f ic ie n c y betw een anim als o f L ots I and 2, t h i s

d if fe re n c e m ight be due to ch an ce . I t i s a lso p o s s ib le t h a t th e s t i l ­

b e s t r o l may have had an in te r a c t in g e f f e c t , masking the d if fe re n c e th a t

would have r e s u l te d i f th y ro p ro te in and th io u r a c i l had been compared

a lo n e .

The e f f e c t s o f 0 .5 and 1 .0 gm. o f th io u r a c i l p e r head d a i ly , when

b o th tre a tm e n ts co n ta in ed 1 .0 mg. s t i l b e s t r o l p e r head d a i ly , were com­

p a re d in L ots 2 and 3 . R e su lts fa v o re d th e low er le v e l o f th io u r a c i l fo r

feed e f f ic ie n c y , b u t d if f e re n c e s were sm a ll.

S t i l b e s t r o l in th e feed a t 0 .5 , 1 .0 and 2 .0 mg. p e r head d a i ly was

g iven to L ots U, 5> and 6 re s p e c t iv e ly . R esu lts a re n o t c o n s is te n t ,

p ro b ab ly due to in d iv id u a l v a r ia t io n and th e sm all number o f anim als in .

each tre a tm e n t. However, a l l th e lambs given s t i l b e s t r o l o r a l ly had

h ig h e r r a t e s o f g a in th a n th e c o n tro l lam bs.

Lambs in b o th Lots '8 and 9 re c e iv e d 0 .5 gm. th io u r a c i l p e r head

d a i ly , b u t Lot 9 lambs re c e iv e d an 18 mg, s t i l b e s t r o l im p lan t, compared

to a 12 mg. im p lan t in Lot 8 . In r a te o f g a in th e re was o n ly a very

s l ig h t d if f e r e n c e , which could e a s i ly have been due to chance . Feed

e f f ic ie n c y d a ta in d ic a te d somewhat g re a te r d if f e re n c e s , su g g es tin g th a t

th e 12 mg. im p lan t o f s t i l b e s t r o l was more d e s ir a b le th a n th e 18 mg.

im p la n t.

Animals in bo th Lots 9 and 10 re c e iv e d 0 .5 gm. o f th io u r a c i l p e r

head p e r day, b u t th o s e . in Lot 10 d id n o t re c e iv e the 18 mg, s t i l b e s t r o l

- 77 -

im p la n to I t i s q u ite ev id en t t h a t th e 18 mg. s t i l b e s t r o l p e l l e t a f fe c te d

r a t e o f g a in . Lambs o f Lot 9 gained e x a c tly tw ice as f a s t as d id th ose

in Lot 10 . Feed e f f ic ie n c y was a lso more fa v o ra b le when th e s t i l b e s t r o l

p e l l e t was added.

Lambs i n Lot 11 (c o n tro ls ) gained an av erage o f 0 .32 pounds p e r day,

and consumed 602 pounds o f feed p e r hundredw eight o f g a in . -Lambs in L ots

I and 2 had a v e ry s im ila r r a t e o f g a in , b u t consumed h$3 and L|27 pounds

o f fe e d p e r hundredw eight o f g a in r e s p e c t iv e ly . Lambs o f Lot 3 were

s l i g h t l y b e t t e r in feed e f f ic ie n c y th an th e c o n tro l lam bs. Lambs i n Lots

U, £ , and 6 a p p a re n tly b e n e f i te d from o ra l in ta k e o f s t i l b e s t r o l . R ates

o f g a in fo r lambs i n th e se th r e e l o t s were 0 .^6 ,. O.UO, and 0.1*7 pounds p e r

day, and feed consumption p e r hundredw eight o f g a in was S03, £01, and

pounds r e s p e c t iv e ly . Lot 7 anim als re c e iv e d o n ly a 12 mg. s t i l b e s t r o l

im plan t and had the h ig h e s t r a t e o f ga in (0»60 pounds p e r day) and fe e d

e f f ic ie n c y (Ull* pounds o f feed p e r hundredw eight o f g a in ) o f a l l t r e a t ­

ments in th e experim en t. A dd ition o f t h io u r a c i l (Lot 8 ) , o r a d d itio n o f

t h i o u r a c i l .and a l a r g e r s t i l b e s t r o l im p lan t (Lot 9 ) , r e s u l te d in a lower

r a t e o f g a in (0 .53 and 0.50 r e s p e c tiv e ly ) th an th e low er l e v e l o f

s t i l b e s t r o l p e l l e t a lo n e .

Lambs i n Lot .10 ( th io u r a c i l on ly ) were the only an im als whose p e r­

formance was d e f i n i t e l y i n f e r i o r to the c o n tro l lambs. R ate o f g a in was

0 .07 pounds p e r day l e s s and feed consum ption p e r hundredw eight o f gain

was 131 pounds more than fo r th e c o n tro l group.

One lamb from each l o t was s la u g h te re d a t the end o f th e t r i a l .

The in s p e c tin g v e te r in a r ia n condemned th e c a rc a s s o f th e lamb from Lot 7

- 78 -

because o f inflam m ation o f th e i n t e s t i n e s . The abnorm al co n d itio n o f th e

condemned lamb a p p a ren tly was n o t caused by the drug given i n th e feed in g

t r i a l . The rem ain ing c a rc a sse s were graded by a two-man com m ittee.

I t was n o tic e d t h a t th e p e l t s were u n u su a lly d i f f i c u l t to remove from

lambs re c e iv in g th e s t i l b e s t r o l im plan t tre a tm e n ts .

D ata w ere reco rd ed on w eights and s iz e s o f th e p i t u i t a r y , th y ro id ,

and a d re n a l g la n d s . These d a ta and th e c a rc a ss , g rades a re p re sen te d in

Table I I , In g en e ra l th e lambs were n o t e x c e s s iv e ly f a t . A p a r t i a l

e x p la n a tio n o f t h i s c o n d itio n m ight be t h a t th e lambs were q u ite mature

when th e t r i a l began . Also th e t r i a l was somewhat b r i e f , • I t should be

no ted th a t th e lamb s la u g h te re d from th e c o n tro l l o t graded average

ch o ice , which was th e h ig h e s t grade g iven any c a rc a s s . Because o f only

one c a rc a ss o b se rv a tio n p e r l o t , i t would be unwise to a t t a c h too much

s ig n if ic a n c e to th e c a rc a s s grades o b ta in e d .

In exam ining th e d a ta o f t h i s t r i a l , i t should be remembered th a t

on ly th re e anim als w ere .u sed w ith each tre a tm e n t. T h e re fo re , i t i s

conce ivab le t h a t r e s u l t s o b ta in ed in t h i s t r i a l may v a ry co n sid e rab le in

com parison t o r e s u l t s o f an experim ent in which la r g e r numbers of anim als

a re u sed . In a fu tu re t r i a l o f th i s n a tu re i t would be d e s ira b le to

supp ly th e th io u r a c i l i n a d i f f e r e n t form th an was used in t h i s e x p e ri­

m ent. A 't h i o u r a c i l - f i l l e d cap su le g iven d a i ly would in s u re th e in ta k e

o f a known amount o f th e d ru g . In d iv id u a l fe ed in g o f a n im a ls , o r e lse

u s in g more anim als p e r pen would in c re a s e accu racy . Using anim als o f

more uniform s iz e , and feed in g them fo r a lo n g e r p e r io d th an was used

in t h i s t r i a l would be d e s i r a b le .

Table I I , S lau g h te r D ata o f Lambs (One Animal p e r L o t) ,

S t i l b e s t r o l S t i l b e s t r o l .. ( o r a l ) Impla nt. C ontrolI . mg. (o ra l) 0 .5 mg. I mg. 2 mg. 12 mg 18 mg.

l o t and R atio n Nb. I - 2 3 U 5 6 7 8 9 10 . 11

T h y ro p ro te in j 0 .5 gm.XT h io u ra c ilj 0 .5 gm. X X X XT h io u ra c il j I gm. X

C arcass Grade (One av . low ' av . h igh h igh av. con- av . low av . av .... Lamb p e r L o t) good, choice. good good good good demned good good good choice

Endocrine GlandsP i t u i t a r y

W eight, gms. 0 .60 0 .70 0.68 0 .76 0 .65 0 .7 5 0.92 1 .07 1.19 0.62 0 .81Volume, c c . 0 .5 o . u O . U 1 .0 o .5 0 .7 1 .0 1 .0 1 .2 0 .9 0 .8

Thyroid ( r ig h t ) -. W eight, gm s., 1 .2 1 .2 1 ,5 1 .5 1 .3 1 .7 l o s t l o s t 0 .7 l o s t 1 .8

Volume, c c . 1 .1 1 .1 I . U 1 .7 1 .6 1 .7 l o s t l o s t 1 .0 l o s t . 1 .8

Thyroid ( l e f t ) " ■. W eight, gms. 1 .5 1 .6 1 .7 l . l 0 .7 l o s t l o s t l o s t 1 .7 l o s t 1 .5Volume, cc . i . U 1 .9 1 .7 l . l 0 .6 l o s t l o s t l o s t 1 .0 l o s t 2 .0

A drenal ( r ig h t )W eight, gm s.^ 1 .2 1 .5 1 .3 1 .5 - 1 .7 1 .8 l o s t i . U 1 .7 1 .9 I . UVolume, c c . 1 .1 1 .2 1 .5 1 .5 1 .2 1 .9 l o s t 1 .7 I . U 1 .9 I . U

A d ren a l' ( l e f t )W eight, gms. i . U 1 .3 1 .6 1 .3 i . U 1 .9 ■ 2 .1 . . 2 .0 1 .9 1 .7 l o s tVolume, c c . i . U . 1 .3 . 1 .5 1 .5 1 .2 2.-0 2 .5 1 .8 2 .0 2 .0 lo s t

8 0 -

SUMMARY

Eleven l o t s o f th re e w ether lambs each w ere hand f e d , accord ing to

a p p e t i te , a r a t io n o f equal- p a r t s whole o a ts , whole b a r le y , and d ried

m olasses b e e t p u lp , p lu s a l f a l f a hay. V a ria b le s in c lu d ed com binations

o f th y ro p ro te in , th io u r a c i l , o r s t i l b e s t r o l in c o rp o ra te d in soybean

m eal, and s t i l b e s t r o l p e l l e t s im planted subqu taneously .

Soybean meal contain ing- th io u r a c i l a lo n e , o r soybean meal co n ta in in g

th io u r a c i l in com bination w ith s t i l b e s t r o l was n o t r e a d i ly consumed,

a p p a re n tly because p a l a t a b i l i t y was a f f e c te d .

There was a h ig h ly s ig n i f ic a n t d if f e re n c e (P<e0 l) in ga ins p e r lamb

among l o t s . D a ily g a in s p e r lam b 'ranged from 0 o2fp to 0 ,60 pounds p e r

day,

A 12 mg. s t i l b e s t r o l p e l l e t im p lan t gave the h ig h e s t r a t e o f g a in

and b e s t fe e d e f f ic ie n c y o f any tre a tm e n t te s te d . The same s iz e im plant

p lu s th io u r a c i l g iven o r a l ly le sse n ed d a i ly g a in s by 0.07 pounds p e r day.

Three d i f f e r e n t l e v e l s o f s t i l b e s t r o l g iven o r a l ly r e s u l te d in

in c re a s e s o f 0,11;, 0 .0 8 , and 0 »15> pounds p e r day r e s p e c t iv e ly in r a te o f

g a in . Feed e f f ic ie n c y was improved 99# 101, and 68 pounds re s p e c t iv e ly

p e r hundred pounds o f g a in .

O ral in ta k e o f s t i l b e s t r o l w ith e i th e r th y ro p ro te in o r th io u r a c i l

in c re a se d feed e f f ic ie n c y , b u t d id n o t a f f e c t r a t e o f g a in .

The on ly tre a tm e n t d e f in i t e ly i n f e r i o r to the c o n tro l group was

th io u r a c i l by i t s e l f i n th e g ra in m ix tu re .

C arcass grades were o b ta in e d on one anim al from each l o t . The c a r ­

casses were n o t f a t . The c o n tro l anim al graded average c h o ice , th e

81 -

h ig h e s t o f a l l e lev en lo ts *

The p i t u i t a r y , a d re n a l, and th y ro id g lands were removed. A fte r

w eight and volume d a ta were reco rd ed , th e g lands were p re se rv e d fo r fu tu re

h i s to lo g ic a l s tu d ie s .

- 82 -

LITERATURE CITED

Acevedo, Ramon, B. S. S chw eigert, P . B. P earson , and F. I . D a h lb e rt. 19U9.E f fe c t o f Feeding T h io u ra c il to Swine on th e Rate o f Gain and Weight o f th e Thyroid Gland. Jo u r . Anim. S c i . 7:21iu

Andrews, F . N. and- W.-M. Beeson. 1953• The E f fe c ts o f Hormones on th e Growth and F a tte n in g o f Lambs. Jo u r . Anim. S c i. 12 :176 .

Andrews, F . N ., W. M. Beesorj, E. R. B a rr ic k , and Claude H arper. 1917, The In f lu en c e o f T h io u ra e il and Thiourea on th e Growth and F a tte n in g o f Lambs. Jo u r . Anim. S c i . 6 :3 .

Andrews, F. N ., W. M. Beeson, and Claude H arper. 19ii9« The E f fe c t o f S t i l b e s t r o l and T es to ste ro n e on the Growth and F a tte n in g o f Lambs. Jo u r . Anim. S c i . 8:578»

Andrews, F . N ., W. I .- Beeson, and F. D. Johnson. 1950. The E ffe c t o f Hormones on th e Growth and F a tte n in g o f Y earling S te e r s . (A b strac t) Jo u r . Anim. S c i . 9 :677 ,

Andrews, F . N. and B. B. Bohren. 19b7. In f lu en c e o f T h io u ra c il andS t i l b e s t r o l on Growth, F a tte n in g and Feed E ff ic ie n c y in B ro i le r s . P o u ltry S c i . 26:^47«

Andrews, F . H«, and J , F . B u lla rd . 19liOi The E ffe c t o f P a r t i a l Thyro­idectom y on th e F a tte n in g o f S te e r s . Amer. Soc. Anim. P rod . P roce 3 : 112 . .

; Astwood, E. B. 19U3. The Treatm ent o f I^rperthyroidism w ith Thiourea and T h io u ra c il . J o u r . Amer. Med. A ssoc, 122 :78 ,

B a rric k , E. R ., F . N. Andrews, and W, M. Beeson, 1950» P h y s io lo g ic a l E f fe c ts o f T h io u ra c il and S im ila r Drugs on Sheep. Jo u r . Anim. S c i» 9 :387 .

B a rr ic k , E. R ,, W. M. Beeson, F . N. Andrew?, and Claude H arper. 19^8.The In f lu en c e o f T h io u ra c il , P ro p y l th io u ra c i l , and T hyropro te in on th e Growth and F a tte n in g o f Lamb's. Jo u r . Anim. S c i . 7 :2^3 .

Beeson, W. M., F. N, Andrews, and P . T. Brown. 19h7» The E ffe c t of Thio­u r a c i l on th e Growth and F a tte n in g o f S te e rs . J o u r . Anim. S c i. 6 :1 6 .

Beeson, W. M., F.. W. Andrews, H. L. W itz, and T. W. P e r ry , 19k7. TheE f fe c t o f T h y rop ro te in and T h io u ra c il on th e Growth and F a tte n in g o f Swine, Jo u r . Anim. S c i. 6 :^8 2 .

B e ll , T. D ., W. A. Sm ith, and A. B. E rh a r t . ' 195k» The E f fe c t o f S t i l -b e s t r o l Upon Lamb Perform ance i n th e F e e d lo t. J o u r . 'Anim. S c i. 13:125.

- 83 -

B la s te r , K. L ., E. P . ReIn ik e , E. W. Cr amp to n , and W. E. P e te rs e n . 19k9. The Role o f T hyro idal M a te r ia ls and o f S y n th e tic G oitrogens in Animal P ro d u c tio n and an A p p ra isa l o f t h e i r P r a c t iq a l Use. Jo u r . Anim. S c i . 8 :307 .

Campbell, D. J . , F . N, Andrews, and J . E. C h r is t ia n . 1950. A bsorption o f R ad io ac tiv e T hyropro te in i n Sheep and C a t t l e . (A b s tra c t) Jo u r. Anim. S c i . 9 :638 .

Clegg, M. T.', Reuben Albaugh,: Joseph Lucas, and W. C. W eir. 1955. A Comparison o f th e E f fe c t o f S t i l b e s t r o l on th e Growth Response o f - Lambs o f D if f e re n t Age and Sex. Joun. Anim. S c i . 1U:178.

C legg, M. T. and H, H« C ole. 195L. The A ction o f S t i l b e s t r o l on the Growth Response o f Rum inants. J o u r . Anim. Sci.. 13 :108 .

D e tw ile r, R. W. and F. N. Andrews. 1950« In flu en ce o f T h io u ra c il and S t i l b e s t r o l on B ro ile r Q u a lity . P o u ltry S c i . 29:513•

D inusson, W. E ., F . W. Andrews, and W. M. Beeson. 1950. The E ffe c ts o f S t i lb e s t r o l , T e s to s te ro n e , Thyroid A lte rn a tio n , and Spaying on th e Growth and F a tte n in g o f Beef H e ife rs . Join?. Anim. S c i . 9 :321.

D inusson, W. E ., E a rle W. K losterm an, and M. L. Buchanan. 1951. S t i l - b e s t r o l , E f fe c t o f Subcutaneous Im p lan ta tio n on G row ing-Fattening Swine. Jo u r . Anim. S c i . 10 :885 .

E l i L i l l y Co. 1955. Feeding D ie th y l s t i lb e s t r o l to Beef C a t t le . Terre Haute, In d ia n a .

E l i , R. E . , K. J . O lson, and E. P . R eineke. 1914.8» A bsorption and E lim in­a t io n o f T h io u ra c il i n Rum inants. J p u r . Anim. S c i . 7:208®

H ale, W. H ., P . G. Homeyer, C. C. C u lb ertso n , and Wise B urroughs. 1955. Response o f Lambs Fed V aried Levels o f D ie th y ls t i l b e s t r o l . Jo u r.Anim. S c i . 1^ :909 .

■Hale, W. H ,, C. D. S to ry , C. G. C u lb ertso n , and Wisp B urroughs. 195U. Response o f Lambs Fed V aried Levels o f D ie th y ls t iT b e s t ro l . Jo u r.Anim. S c i . 13:985.

Jo rdan , P . S . , R. M. Jo rdan , and H. G. Groom. 1955. E f fe c t o f S t i lb e s t r o l , P ro g e s te ro n e -e s tra d io l Im plan ts and O ral A d m in is tra tio n o f S t i lb e s t r o l on F a tte n in g Lambs. Jo u r. Anim. S c i . 1^:936 .

Jo rdan , R. M. 1950. E f fe c t o f S t i l b e s t r o l on F a tte n in g Lambs. Jo u r.Anim. S c i . 9 :383 .

— 81). —

Jo rdan , R. M. and T. D. B e l l . 195>2. E ffe c t o f S t i l b e s t r o l on Carcags Q u a lity and Shrinkage and N itrogen R e ten tio n by Lam bs., (A b s tra c t) Jo u r. Anim. S c i . 11:795» ■

Kem pster, H, L. and C. W. T urner. 19L5* The E f fe c t o f Feeding T hioura- c i l on th e F in ish in g o f New Hampshire B ro i le r s . P o u ltry S c i . 2kt9h-

K lin e , E. A ., M. E. Ensminger, T. J . Cunha, W. W. Heinemann, and'W. E.Ham. 19l|.9. E f fe c t o f Adding Drugs to th e R ation o f F a tte n in g C a t t le . Jo u r . Anim. S c i. 8 :^09 .

L ab a rth e , Pedro , Eugene B ertone, and L. E9 Washburn. 191:9. The E f fe c t o f T h y ro p ro te in on Wool P ro d u c tio n . J o u r9 Anim9 S c i. 8 :6 2 4 .

Lorenz, F. W. 1945 a . The F a tte n in g A ction o f O ra lly A dm inistered, Syn­th e t i c E strogens a s Compared w ith D ie th y ls t i lb e s t r o l P e l l e t Im p lan ts . P o u ltry S c i. 24 :91 .

Lorenz, F , W. 1945 b . The In f lu en c e o f D ie th y ls t i lb e s t r o l on F a t De­p o s i t io n and-Meat Q u a lity in Chickens. P o u ltry S c i. 24:128.

M ackenzie, C. G. and J . B. MacKenzie. 1943. E f fe c t o f Sulfonam ides andT hioureas on th e Thyroid Gland and B asal M etabolism . . Endocrin .32:185.

McMillen, W. N ., E. P . R ein ik e , L. J . B r a tz le r , and M. J . F ra n c is . 1947. The E f fe c t o f T h io u ra c il on E ff ic ie n c y o f Gains and C arcass Q u a lity in Swine. Jo u r . Anim. S c i. 6 :305 .

Means, T. M., F , N. Andrews, and W. M. Beeson. 1953. The E f fe c t of Hormones on th e Growth and F a tte n in g o f Lambs. Jo u r . Anim. S c i. 12:176.

Muhrer, M. E ., D. R. W arner, Z. Palm er, and A. G. Hogan. 1947. The E ffe c t o f T h io u ra c il and Protamone on Growing Swine. J o u r . . Anim. S c i. 6 :489 .

O'Mary, C. C. and 'A . E. C u lliso n . 1956. E f fe c ts o f Low Level Im planta­t io n o f S t i l b e s t r o l in S te e rs on P a s tu re . Jo u r. Anim. S c i. 15 :48 .

O'Mary, C. C ., A. L9 Pope, G. D. W ilson, R. W. Bray, and L9 E. C assida . 1952. E ffe c ts o f D ie th y ls t i lb e s t r o l and P ro g este ro n e on Growth and. F a tte n in g and C e rta in C arcass C h a r a c te r is t ic s o f W estern Lambs.Jo u r. Anim. S c i. 11 :656 .

P earson , A. M., G. E. Combs, J r . , H. D. W allace, R. B. S le e th , J . W. Stroud, ■ J . M. Shepherd, and Marvin Koger, 1952. ' The E f fe c ts o f S t i lb e s t r o l

Im plan ts on Swine o f D if fe re n t Sexes. Jo u r . Anim. SGi. 11:251.

P e rry , T. W1 M. Beeson, and F, M. Andrews. 191*8. The E ffe c t o f Thyro- p r o te in on Growing, F a tten in g ,-: and C arcass . Q u a lity in Swine. Jo u r . Anim. S c i . 7:531»

Pope, A. L ., C. C. O1 Mary, W. E. B atterm an, R. W. Bray, and I . E. C assida, 1950. The E f fe c t o f C e rta in S te ro id Hormopes o n ,th e Growth, Fattens... in g , and C arcass Q u a lity o f Heavy Lambs. (A b s tra c t) Jo u r . Anim.S c i . 9 :6 8 0 . ' . • .

Thayer, R. H ., R. G. Jaap , and R. P en q u ite . 191*5» F a tte n in g Chickens by ■ Feeding E stro g en s . P o u ltry S c i . 2l*:l*83.

T urner, C. D. 191*8, G eneral E ndocrinology. W. B.. Saunders Co. P h ila ­d e lp h ia , Penn.

Vander Hoot, C, ¥ . , Rv R. Reece, and W, C. S k e lle y . 19l*7» The E ffe c t o fT h io u ra c il in th e R ation o f Growing Swinev Jo u r. Anim. S c i. 6 :12 .

W oehling, J . L ,, G. D. W ilson, R. H. Grummer, R. W. Bray, and L. E. C asida. 1951* E f fe c ts o f S t i l b e s t r o l and T es to ste ro n e P e l le t s Im planted in to Growing F a tte n in g P ig s . Jo u r . Anim. S c i. 10 :889.

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