Corso Di Fisiologia Della Nutrizion

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Farm Animal Nutrition

ANUT 221

2006

Study Guide

Internal students

Physiology and Animal Science,

School of Rural Science and Agriculture



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Table of Contents

Welcome from your lecturers 3

About ANUT 221 5

Resource material 6

Lecture and practical timetable 7

Assessment 8

Problem Solving Session 9

Anatomy and Digestion Practical Report 13

Salivary, Gastric and Intestinal Digestion 13

Digestive Tract Anatomy 17

Technique to measure glucose absorption (Demonstration) 20

Gas Formation by rumen microorganisms 23

Feed formulation practical 24

Poultry experiment procedure and assessment 27

Basic knowledge questions 34

Learning assistance (tutorial) questions 38

Major text resources 43

Example exam questions 44



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Animal Metabolism, Digestion and NutritionANUT 221

Welcome from your lecturers !

Professor John Nolan

E-mail: [email protected]

Phone: 02 6773 2605

Professor John Nolan has expertise in ruminant and monogastric animal nutrition and feeding behaviour.He held research contracts for the Australian Meat and Wool Research Corporations for a number of yearsafter gaining his PhD (studies of ruminant nutrition and metabolism). Since 1986 he has lectured toundergraduates in biochemistry, animal nutrition and animal production units and been supervisor of

many post-graduate students. His current research projects are in ruminant, poultry and pig nutrition andin feeding behaviour of farm animals.

Dr Ian Godwin

Phone: (02) 67 73 2488e-mail: [email protected]

Dr. Ian Godwin is Senior Lecturer in the Division of Physiology. His training as an animal nutritionist,closely linked with expertise in physiology provides the impetus to drive research programs in digestivephysiology. His interests include nutritional physiology of production animals, humans and animals asdiverse as yabbies and the black rhinoceros!

mailto:[email protected]





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Dr Roger Hegarty Phone: 02-6770 1806Email: [email protected]

Dr. Roger Hegarty’s major research areas include ruminal metabolism (rumen protozoa and methaneproduction in ruminants) and nutritional modification of fat and lean deposition in lambs. He developedmuch of this Unit in 1995 while working for UNE. He is presently employed as a Research Officer in theNSW Agriculture Beef Centre and can be contacted on (02) 67 70 1806e-mail: [email protected]

Course Coordinator: Dr. Darryl Savage

Phone (02) 6773 3623

E-mail: [email protected]

Darryl Savage has experience in education and research management in tropical animal nutrition.Previously, he managed on-farm research programs for commercial cooperators, including the world’slargest beef producing companies. He holds research contracts with many commercial organizationsand industry bodies such as Meat and Livestock Australia. He has worked in both the intensive and

extensive segments of the Australian beef industry and operates a family beef, wool and sheep meatproduction enterprise. He has involvement in the live export trade with a focus on improving thewelfare of sheep on arrival in the Middle East region.






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About ANUT221

This unit introduces basic concepts in digestion and metabolism and their integration through neural andendocrine function. There are sections on foods (or feeds) and principles of food analysis; the anatomy andphysiology of the digestive tract; the energy and protein requirements of ruminants and non-ruminants;

nutritional roles of carbohydrates, proteins, lipids; and minerals and vitamins. Diet formulation and therelationships between nutrition and animal production are also covered, and the practical work is mainlyfocussed on experimentation that elucidates principles of physiology or is directly related to animal production.

General Outcomes from the Unit

After completing this course you should have a clear working knowledge of the basic food ingredients that you(and simple-stomached animals, including pigs and poultry) need to meet requirements over a lifetime. Youshould understand how energy, protein, minerals, vitamins, water and atmospheric oxygen contribute tohealth, growth and (re)production. You should also understand the factors that determine an animal’s nutritionalrequirements that change as its physiological status changes during its lifetime and whether the animal will eatfeeds that meet its requirements. You should have learned how to formulate diets to meet an animal’s current

needs.

You will also learn about the fermentation processes in the forestomachs of ruminants that enable them toutilise the world’s vast resources of cellulosic foods (grazed forages, browse, agricultural by-products etc) They

can eat these feeds that have little direct nutritional value for human beings or other animals with simplestomachs) and, in conjunction with simple nitrogen sources such as urea, turn them into valuable commoditiessuch as milk, meat, wool and draught power from which humans benefit enormously.

What is ‘nutrition’?

Nutrition is not, strictly speaking, a “core discipline” - it is an amalgamation of other disciplines. ANUT221 depends on, and assumes, a basic knowledge of biochemistry, physiology and aspects of earlier course

work, and builds on these to provide an understanding of how animals obtain nutrients, and then process (digestand metabolise) them to form animal products. It also provides the basis for developing feeding managementstrategies that ensure farm animals are fed correctly and economically for their health and optimum production,

whilst avoiding toxicity.

Ingestion, digestion and metabolism

Nutrition - the supplying of energy substrates and nutrients to an animal’s body - ultimately is determined bythe animal’s physiology and behaviour. Feeding behaviour is important because, after all, a perfectly balanceddiet is of no use to an animal unless it eats it, and animals may simply not recognize that the food or supplementwe are offering is ‘food’, or they may avoid eating it because they do not recognize it, or they have learnt that itwas toxic when they ate some of it on a previous occasion! Aspects of physiology, on the other hand, impingedirectly on the level of food intake and its digestion, and on the flow of nutrients into various areas of ananimal’s body (providing the building units for synthesis of meat, wool, milk). Particular aspects covered indetail are the anatomy and functions of the digestive tract and certain parts of the endocrine system that regulatethe animal’s biochemical pathways and physiology. The delivery of nutrients to tissues depends on manyfactors, such as how well those nutrients are digested and absorbed by the gastrointestinal tract and howefficiently they are used by the tissues – the latter depending on the ‘balance of the nutrients’ supplied andendocrine and other factors. Feeding behaviour is dependent on the animal’s previous dietary history andexperience of different feeds, whether the animal is hungry or satiated and the animal’s physiological state

ANUT221 is offered jointly by Physiology and Animal Science staff in the School of Rural Science andA riculture and NSW A riculture.



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(pregnancy, lactation etc). Even the environment (both physical and mental) in which the animal lives may haveprofound effects on intake and the flow of nutrients into the body.

Although we teach in modules such as ‘gut physiology’, ‘energy’, ‘protein’, ‘minerals and vitamins’, ‘dietformulation’, you should not lose sight of the inter-relationships between these topics. For example, when wesupplement an animal with a protein-rich concentrate, the animal is provided not only with protein, but also withenergy, amino acids (that may be glucogenic), minerals, vitamins and water. Do you remember from BCHM210the basic biochemical structures of amino acids and the metabolism of carbohydrates, and the requirements of animals for vitamins? You will certainly need this information, and it is your responsibility to revisit it if youneed to.

Why study nutrition?

All of us need to have a working knowledge of nutrition for our own well-being, and to be able to respondknowledgeably when people ask us for nutritional advice. For farmers and their advisers, an understanding of nutrition is crucial. We hope that you will not only gain a basic understanding of nutrition but also enjoy thepractical components and exercises in the course that are designed to instill some of this expertise.

Enjoy your discovery of physiology, nutrition and feeding behaviour and best wishes for your studies!!

Resource material

This Study Guide provides information on how you should approach the problem of gaining anunderstanding of basic nutrition during this semester. The guide aims to assist you in the learning processand provide you with details of how your progress will be assessed during the term and at the end-of-semester exam. Exercises and likely exam questions are included. It also contains information relating tothe Practical Experiments and Practical Reports to be covered in the course -- and a justification of why we have structured the course in the way we have.

In addition to this Unit Guide, we have prepared lecture notes that contain the information you willneed for your studies in this Unit. The book contains 39 lectures, presented by the three lecturers,grouped into 7 major modules as follows:

1. Digestive physiology and anatomy

2. Feed composition and feeding systems3. Carbohydrate utilisation4. Lipid utilisation5. Protein utilisation6. Minerals and Other Nutrients7. Issues in Animal Nutrition and Production

Inevitably there will probably be more information in the book than you will need for a basicunderstanding of nutrition. However, we hope you will find all the information both interesting andhelpful. We suggest you use this resource as a textbook during your study and as a source of relevantinformation to assist with your assignments. Additional resource material and questions are providedbelow, and in the practical notes.

Lectures and practical sessions

All lectures and practical sessions are held on Tuesday, starting at 9am in the Wright Lecture Theatre.As the entire day is dedicated to this unit, the program for each Tuesday may be flexible to

accommodate lecture, tutorial and practical needs. Tuesday is nutrition day!



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Timing Dates Lecturer Assessable practical

Week 23Week 24Week 25Week 26

25th

JulyFree week 8

thAugust

15th

August

Dr Ian Godwin Topics 1. Physiology of the gastro tract2. The digestive tract3. The stomach4. Pancreatic and biliary secretion5. The small intestine6. The large intestine7. Physiology of the ruminant8. Forestomach function and development10. Digestive tract of the chicken

12. Pancreas and metabolic regulation 113. Pancreas and metabolic regulation 2

Assessable practical (value = 10% Due date: 8 th

August )“Problem solving session” Assessable practical (value = 10% Due date: 15

th August)

“Anatomy and Digestion”

Week 27 22 nd

August Dr Roger Hegarty Topics 14. Feed analysis systems15. Energy systems 116. Energy systems 217. Factors affecting feed digestibility

Week 28 29 th

August Prof John Nolan Topics 9. Rumen digestion11. Comparative digestion strategies18. Plant carbohydrates19. Carbohydrate digestion by monogastrics

Basic knowledge quiz – first attempt (3pm, 29

th August, Wright Lecture Theatre, value = 10%)

Week 29 5 th

September 3 rd

year tour

Week 30 12 th

September Prof John Nolan Topics 20. Rumen microorganisms21. Rumen metabolism22. When fermentation goes wrong23. Utilisation of products of carbohydrate digestion

Week 31 andWeek 32 Mid-semester break

Week 33Week 34

3 rd

October 10

th October

Prof John Nolan Topics 26. Protein27. Proteins in animal production28. Mammalian protein metabolism29. Feed protein evaluation30. Nitrogen dynamics – ruminant31. Managing protein nutrition

Assessable practical (value = 15% Due date: 10 th

October) “Poultry feeding experiment”

Week 35Week 36Week 37

17th

October24

thOctober

31st

October

Dr Darryl Savage Topics 24. Introduction to lipids25. Mammalian lipid metabolism32. Macro-minerals33. Trace minerals34. Vitamins35. Water and feed additives36. Regulation of feed intake37. Feeding behaviour: nutrient intake38. Efficiency of production39. Feeding standards for pigs, poultry and ruminants

Basic knowledge quiz – second attempt (if required) (3pm 10

th Oct, Wright Lecture Theatre, value = 10%)

Assessable practical (value = 15% Due date: 31st

October) “Formulation of a feedlot ration for cattle”

Week 38 Exam period begins



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Assessment

Assessment item Value

Basic knowledge quiz 10%End-semester exam 40%Practical reports and seminar 50%

TOTAL 100%

Overall marks of 50%, 65%, 75% and 85% in both theory and practical assessments are expected forgrades of ‘pass’, ‘credit’, ‘distinction’ and ‘high distinction’, respectively. A student must performsatisfactorily in all components of the unit to pass the unit: for all grades, a higher mark in certainassessments may not necessarily be deemed to counterbalance a relatively weaker achievement inother assessable tasks.

Basic knowledge questions (value = 10%)

There will be 15 “basic knowledge” questions relating to animal nutrition you will be required to

answer. To achieve the full 10% value for this component of the assessment, you will be required toanswer at least 14 of the questions correctly. If only 13 questions or less are answered correctly, aresult of zero will be awarded for this component of the unit’s assessment. A list of basic knowledgequestions are provided in a later section of this study guide for your information. The 15 questions thatwill appear in the quiz, will be taken from this list. All students will be offered two attempts at thisquiz. If you do not achieve a mark of 14 or better in the first quiz, you can have a second attempt.

The 15 questions that appear in the exam are considered essential basic knowledge for any animalnutrition student.

The basic knowledge quiz (first attempt) will be held on Tuesday 29 th August at 3pm in the WrightLecture Theatre. The second attempt (for those students that did not achieve 14 marks or better in thefirst attempt) at the Basic Knowledge Quiz will be held on Tuesday 10 th October at 3pm in the WrightLecture Theatre. The duration of the Basic Knowledge Quiz will be 20 minutes.

End-semester exam (value = 40%)

The end-semester exam will be held during the exam period in November. The exam will be 2 hours induration and will cover material from all topics and practical sessions. Copies of previous year’sexams can be found on the UNE website athttps://secure.une.edu.au/pls/erez/ELE_GATEWAY?EREZ_Option=EXAM

Practical reports and seminar (value = 50%)

The Practical component of this unit is designed to link closely with and to complement the lecturematerial and to provide you with hands-on experience of laboratory experiments, feed formulation andpractical feeding of farm animals. A description of each practical session is provided below.

Practical Due date Value Problem solving session 8th August 10%Anatomy and digestion practical report 15th August 10%

Poultry feeding experiment report 17th October 15%Feedlot ration formulation seminar 31st October 15%

TOTAL 50%

https://secure.une.edu.au/pls/erez/ELE_GATEWAY?EREZ_Option=EXAM

https://secure.une.edu.au/pls/erez/ELE_GATEWAY?EREZ_Option=EXAM



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Problem solving session

(Value = 10%, Due date: 8th

August)

You will be allocated into pairs and will be asked to present your answer to a hypothetical problem.The problems are listed below and you will be allocated one of them. Each group will have 10minutes to present their solution to the problem to the rest of the class. It is recommended that you usePowerpoint to deliver your presentation. You will be graded on both your research into the solution of

the problem and your presentation. Much of the background material for your problem solving can begained from the course notes. We want you to think laterally with these problems. If you can see asolution with future technology (eg. gene manipulation) – let us (the audience) know. Also alert us asto any future research that is needed.

The problems to be solved. 1) A new treatment for autism, a psychiatric disorder, has been recently suggested. This treatmentinvolves intravenous infusion of the hormone secretin, with a view to counteracting other peptidehormones in the brain. As the local gastrointestinal physiologist, you are asked to comment on thefollowing, prior to the commencement of some animal trials.1. Can we simplify the treatment by giving the hormone orally?

2. What side effects are likely to result from the use of this treatment?

2) High blood cholesterol levels are known to be linked with a high incidence of cardiovasculardisease in humans. As a feedmilling nutritionist for Uncle Bill's pet foods, you are asked to makesuitable rations for geriatric cats, dogs, pigs, sheep, turkey's etc. “The major thrust”, say the marketingwing of the company, “is to sell the concept of lowering your pet's cholesterol in old age, so they livelong and fulfilling lives. We'll make zillions with this concept, how can we do it?" What dietary factorsare important for controlling cholesterol levels in the blood and what are your comments to the boardof directors about the proposal?

3) Cimetidine is an antihistamine (H2-blocker), widely used to treat gastric ulcers in humans. The

drug has been tested on pigs and has also been shown to prevent the formation of ulcers in this species.As part of a trial to treat the high incidence of gastric ulcers in housed sows, sows were given foodcontaining cimetidine, throughout pregnancy and lactation. After farrowing it was noted that as thepigs approached weaning age many were found to be anaemic (a megaloblastic anaemia) and showedpolyneuropathological symptoms. After weaning the problem appeared to correct itself. What is alikely cause of the disorder in the piglets and how could it be treated?

4) Whilst eating her lunch, Ingrid notices that her lower jaw begins to swell rapidly on one side.It is not particularly painful, but is obviously rather disconcerting. The swelling dissipates over thenext hour or so. Later on that afternoon she accepts some chewing gum from a friend and her friendexclaims, "What is wrong with your jaw it is all swollen up"? Again the swelling subsides, but laterthat night when she is hungry and is waiting for her dinner to cook, her friends eat a beautifully richsmelling pizza in her presence. Again her under jaw area swells and she finally consults a doctor.What do you think the diagnosis may be and how would you explain the symptoms to her?

5) A gastroenterologist wants to examine the colon of patients using a new colonoscopic technique.Unfortunately this cannot be done whilst faecal material remains in the large intestine, because theview is blocked. The colon needs to be completely empty of opaque material and ideally filled withclear fluid? "Patients object to being given enemas, so how can this be achieved", asks thegastroenterologist. What is your advice?

6) A new nematode parasite has been discovered in the New England area. It appears to live withinthe abomasum of the sheep and cattle and the stomach of pigs. Virtually nothing is known about thisworm (its appearance has coincided with the landing of something from outerspace into the Guyra



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reservoir), but some cytochemistry reveals that large quantities of gastrin granules appear to bereleased into the blood stream when the worm feeds from the gastric mucosa. You are asked tospeculate on the effects this may have on the host, the conditions that the worm may prefer and whythe worm may release this substance at feeding.

7) After years of eating an unhealthy diet Ingrid has decided to do something about it. She is going toundergo a whole lifestyle change and believes a good start would be to undergo a colon hydrotherapysession to rid her body of the accumulated wastes. She is a little concerned about the cost $80 persession (totals of 10 sessions). She asks your opinion and gives you the attached material supplied by

http://www.shanti.com.au/colonic/colonic1.htm.

8) The attached material (http://chetday.com/fcprins.html ) was obtained from the internet by a parentof a child who has had chronic diarrhoea for some time. They think this may be the answer to theirchild’s problems and seek your opinion of Dr Shelton’s dietary suggestions.

9) A farmer (Harry) wishes to mix his own pig ration from home grown constituents. He bases hisration on wheat and soybeans with appropriate mineral/vitamin mixes to provide a balanced diet usingthe same amounts of ingredients exactly as his local feedmill. The farmer simply mixes his ingredients,hammermills and feeds his pigs. His pigs grow exceptionally poorly. The following data is providedfrom the local abattoir where his pigs were killed. The abattoir is monitoring pancreatic enzyme

activities with a view to commercial sale. What is happening and what is your advice to the farmer?

Pancreatic Enzyme Activities

(units/mg protein)

Normal Harry's Hogs*Trypsin 12 7Chymotrypsin 10 6Amylase 39 12

*Note each value is considered significantly lower.

10) Bart, steals an endoscope from the physiology building and decides to examine his own colon. Henotes that he has many out-pouchings from his large intestine. He reads in the lecture notes that heborrowed from his friend who actually attends lectures that this condition is called diverticulitis. Heimmediately changes his diet to reduce the roughage component and blends all his food in a blender togive his colon the least work possible. Is Bart an idiot or not?

11) You are working for Care-Australia in a remote refugee camp in central Africa. The water supplyhas been contaminated with faecal effluent and cholera has broken out among the population. Thediarrhoea is extremely severe and people are dieing by the dozen. You are concerned about potentiallythousands of deaths. How are you going to treat these people?

12) You are working for Care-Australia in central Africa and notice that many of the children haveKwashiorkor with swollen bellies. You decide to give them a protein supplement. A quick readthrough your nutrition notes shows that the best quality protein is casein, the protein found in milk.You order large quantities of milk powder as this has good keeping qualities and should provide themuch needed protein for the kids. What is a likely scenario and how could you prevent it?

13) A milk replacer diet for early weaned dairy calves is being developed. Meat meal can no longer beused since the Mad Cow Disease problem, Fish meal is unprocurable because new methods of catchingfish means far less wastage and hence less fishmeal and soybean meal has become too expensive. Aprotein source being trialled is saltbush protein ( Atriplex spp). The protein specifications look ideal,

but the extract contains high levels of oxalate. You are asked to comment on what problems are likelyto occur because of this oxalate and how they may be overcome.



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14) Following a major earthquake epicentred on Guyra, much of the local potato crop was ruined.However, many potatoes near harvest were lifted from the ground by the earthquake and the tubersexposed to the sun for several weeks. Many of these were harvested and although noticeably green incolour, were fed to the population at the Guyra Lamb and Potato Festival barbecue. You have alsoheard that the lamb was lotfed and that poultry manure was included in the sheep ration. Many of thepeople who ate at the BBQ suffered severe diarrhoea, excessive salivation and muscle tremor shortlyafter eating at the BBQ. As an agronomist/nutritionist, you are asked to comment about a letter writtento the editor of the Armidale Distress. The letter states "that the feeding of poultry manure to sheep isdisgustingly gross, cruel and unethical and that many people at the festival needlessly suffered as a

result of this inhumane practice. The lotfeeders should be sued!"

15) As part of their research, Air Antarctica are testing the effects of high altitude without pressurecompensation, on the human body in the event that the cabin pressure of an aircraft suddenly drops inmid flight. To do this research a pilot trial ( pun intended ) using sheep in a decompression chamber isset up. The air is removed from the chamber, but the partial pressure of oxygen is maintained, to suchan extent that it simulates flying unpressurized at 9000m, while breathing in an oxygen mask. The airin the chamber is constantly exchanged, monitored and analysed and it is noted that at thecommencement (control period) of the experiment that considerable methane and CO2 are present inthe chamber air. With the drop in pressure the levels of methane and CO2 drop dramatically and theanimals appear to go into circulatory shock and collapse, several die. In an earlier study, QANTAS

used captured hijackers for their research in a similar protocol with no untoward effects. Theresearchers ask your opinion as to what is going on!

16) A computer model has been developed to simulate the movements of phosphate in a farmingecosystem in a very environmentally sensitive area in the Snowy Mountains. The model follows Pmovement from soil to plant to animal and back to soil with all the appropriate inputs. It is designed toallow for the kinetics of phosphate transfer between the different P pools. It assumes that P in faeces isslowly released into the soil as the faecal pellet must first degrade. This assumes effects of climaticvariables etc. P in urine is assumed to enter the soluble soil pool very rapidly. The model worksbeautifully for sheep in a grazing system. During one very severe drought the farmer is forced tosupplementary feed his animals with wheat grain. The computer model is given the same data inputsfor the animal and the soil, but the food phosphate intake is simply adjusted to allow for the slightincrease in P intake. Some time later after it has rained, major problems with blue-green algaecontamination of waterways emerge. You are asked to comment in the land and environment court onthe possible shortcomings of the computer model.

17) Your friend in the Animal Psychology department has developed a chewing gum for cattle. Theanimals appear to enjoy chewing away at this inert substance and it appears to prevent boredom andsome stereotypic behaviours. She asks you whether it may be of use in bored feedlot cattle.

18) Following a dairy deregulation protest, an irate protestor has managed to contaminate 1000 tonnes

of dried milk powder with some feedlot effluent at the Tamworth Acme plant. Analysis confirms thecontamination and the E. coli count is deemed too high for the milk to be used for humanconsumption. However it is deemed quite OK for animal consumption. You are approached by AcmeDairy Products about the possibility of using this material for animal consumption. The Tamworth areais quite diverse in animal species that are fed high protein supplements. Pigs, poultry and beef lotfeeding together with dairying are the major industries. Which industry would you recommend themilk powder be used with, and how could any possible problems be overcome?



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Anatomy and digestion practical report


August)

SALIVARY, GASTRIC AND INTESTINAL DIGESTION

AIM: This practical class is designed to give you some understanding of the chemistry associated

with enzymatic digestion, buffers and emulsification of fats.

NOTE: This practical must be handed to the demonstrator at the end of the practical session.

INTRODUCTION:

Digestion of food begins in the mouth. Simple physical breakdown of food into smallerparticles occurs because of mastication and further down the tract by the movements of the variousorgans.

The chemical digestion of food results from the action of the many enzymes secreted into thegastrointestinal tract.

The determination of the buffering power of whey (from milk).

a) Pipette 10mL of whey into a small beaker and measure its pH using the pH meter.

b) Pipette 0.5mL of 0.1N HCl into the beaker containing the whey, gently stir andmeasure the pH again.

c) Repeat steps b), until the pH approximates 4 (the pH of chyme entering theduodenum).

d) Repeat steps a), b) and c) using water instead of whey.

e) Complete the following table

Cumulative Acid Added (mL) pH of Whey pH of Water

0.0

0.5

1.0

1.52.0

2.5

3.0

3.5

4.0

4.5

5.0

Did the whey show any buffering against the acid?______________________________________________________________________________________________________________________________________________________



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Why are patients with peptic ulcers or dyspepsia advised to eat regularly, preferably many smallmeals, rather than fewer big meals?____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

The emulsification of fat by bile.

a) Set up two tubes in a test tube rack.

b) Pipette 5mL of water into the first tube and 5mL of diluted bile into the other tube.

c) Add 1 drop of vegetable oil to each tube.

d) Shake vigorously and let stand.

e) Interpret the result.

______________________________________________________________________________________________________________________________________________________

___________________________________________________________________________The action of pepsin on congo red fibrin (stained protein).

a) Set up 4 test tubes in a rack (A, B, C and D).

b) Add the following to these tubes:

A- 3mL of pepsin solution, 3mL of 0.1N HCl, mix.B- 3mL of pepsin solution, 3mL of water, mix.C- 3mL of water, 3mL of 0.1N HCl, mix.D- 3mL of pepsin solution, boil under a bunsen flame, 3mL of 0.1N HCl, mix.

c) Place a small piece of fibrin in each tube.

d) Incubate in a water bath at 37˚C for 15 minutes, shaking occasionally.

e) The release of dye from the stained fibrin indicates enzymatic digestion of the protein.

Results:Tube A_____________________________________________________________________Tube B_____________________________________________________________________

Tube C_____________________________________________________________________Tube D_____________________________________________________________________

What does boiling do to the pepsin?________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Is HCl necessary for the action of pepsin?__________________________________________________________________________________

______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________



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The effect of pH on trypsin activity.

a) Set up two tubes in a rack.b) Pipette 2mL of pH 4 buffer in Tube A and 2mL of pH 8 buffer into Tube B.c) Add a small piece of Congo red fibrin to each tube.d) Add 0.5mL of trypsin to each tube.e) Incubate in a water bath at 37oC for 15 minutes, shaking occasionally.f) Observe for digestion of fibrin.

At what pH was the trypsin more active? How does this pH correspond to the pH of the smallintestine?_________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

What neutralises the acid secreted into the stomach further down the gastrointestinal tract?__________________________________________________________________________________

_______________________________________________________________________________________________________________________________________________

The clotting of milk by rennin.

a) Set up four test tubes in a rack (A, B, C and D).

A 5mL of fresh milk.B 5mL of fresh milk + 2mL of rennin solution.C 5mL of fresh milk + 2mL of boiled rennin solution. (Boil the rennin under a Bunsen in a

separate tube and then add to the milk).D 5mL of fresh milk + 10 drops of saturated ammonium oxalate solution + 2mL of rennin

solution; in that order.

b) Incubate the tubes at 37˚C and test every 5 minutes for coagulation by tilting the tubes (notshaking).

What does ammonium oxalate do to render rennin ineffective?____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

What is the importance of milk coagulation to the neonate?____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Mixed saliva of humans

1) Take 40 mL of 0.25% starch solution in a 100 mL conical flask. Incubate at 37˚C. Leave inincubator until required.

2) Set up six 10 mL test tubes containing 5 mL of Benedict's solution. Labelled A-F

3) Set up six 10mL test tubes; add 2ml of iodine solution to each tube. Labelled A-F



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4) Add 1 mL 0.25% starch solution to the first Benedict tube (A) and also to the first iodine tube(A) only. The iodine solution gives a blue/black colour indicating presence of starch. Place theBenedict's tube in a boiling water bath and leave there for at least twenty minutes. Cool in airand inspect for precipitate which appears as a fine reddish suspension and/or a pale greenemulsion. A precipitate indicates the presence of a reducing sugar. This should not be presentin your tube A.

5) Expectorate into your flask containing 0.25% starch.

6) Place the flask in the water bath at 37oC and pipette off a 1 mL sample every 2 minutes and testfor starch (iodine tubes) and reducing sugar (Benedict's tubes), using the procedure outlined in4) above except use tubes labelled B at 2 minutes, C at 4 minutes etc.

7) Finish the experiment when the iodine tubes show no colouration. Record this time. Whatdoes this mean?_____________________________________________________________________

8) Record also the time of appearance of erythrodextrin (reddish purple with the iodine solution).(This may not occur).

9) Record the time of first appearance of reducing sugar in the Benedict's tubes.

i) What is meant by mixed saliva?______________________________________________________________________________________________________________________________________________________

ii) What is the action of ptyalin (amylase)?______________________________________________________________________________________________________________________________________________________



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Digestive Tract AnatomyYou will be shown a video of a dissection of a sheep digestive tract. You will also have demonstrateda dissection of the gastrointestinal tract of a chicken and a rat.

The digestive system of the sheep.

Describe the epithelial surface of the rumen ____________________________________________reticulum__________________________________________omasum___________________________________________abomasum_________________________________________

What are rumen pillars?______________________________________________________________________________________________________________________________________________________________________________________________________ What is the function of the oesophageal groove?______________________________________________________________________________________________________________________________________________________________________________________________________

What is the consistency of the digesta in the rumen, omasum and abomasum?

______________________________________________________________________________________________________________________________________________________________________________________________________

Why is the oesophagus a different colour to rest of the tract? ______________________________________________________________________________________________________________________________________________________________________________________________________

Describe the musculature of the chicken gizzard.______________________________________________________________________________________________________________________________________________________________________________________________________

What is Meckel’s diverticulum?___________________________________________________________________________________________________

___________________________________________________________________________________________________



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Draw a table of the digestive processes occurring in each of the major segments of the GI tract of the sheep, chicken andthe rat. Explain what happens to cellulose and to protein in each of these segments.



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Oesophagus

Stomach

Caecum

Colon

Small

Intestine

Rat

(Rattus norvegicus)

Diet - Omnivorous

largely grain

Oesophagus

Omasum

Abomasum

Colon

Caecum

Small

IntestineReticulo-rumen Sheep

(Ovis aries)

Diet - Herbivorous

Crop

Proventriculus

Isthmus

Gizzard

Pyloric

Sphincter

Caeca

Small

Intestine

Pancreas

Gall Bladder

Liver

Large

Intestine

Cloaca

Chicken(Gallus gallus)

Diet - Omnivorous



19

Demonstration of a technique to measure glucose absorption

Aim: To show that glucose is absorbed in from the small intestine of a rat as a representative mammal.

IntroductionThe small intestine is the major site of absorption of nutrients in virtually all mammals. In the non-ruminant it absorbs sugars, peptides, amino acids, fats, vitamins and minerals. The ruminant is somewhatdifferent as much of the energy substrates are absorbed prior to the small intestine as volatile fatty acids.However, the small intestine is still the major site for absorption of peptides, amino acids, fats andvitamins and minerals.

Glucose and amino acids are transported against a concentration gradient, indicating the presence of anactive transport mechanism. They are dependent on the concomitant absorption of sodium. For glucosethe transporter is the sodium-dependent hexose transporter, known more formally as SGLT-1.

(Johnson LR, ed. Physiology of the Gastrointestinal Tract. Raven Press, NY, 1994. pp. 1751-1772)

Many methods, both in vitro and in vivo, have been used to study simple sugar absorption, eg. in vitro –perfusion, everted sacs, rings of intestine and isolated mucosal cells in vivo – perfusion using multiple

lumen tubes or circulating pumps, and ligated, washed out loops in anaesthetized animals. We shall beusing the last method. The disappearance of the substance under study (it need not necessarily beglucose) is taken as an index of absorption.

Procedure

1. Weigh the rat (adult fasted for 24 hours).2. Anaesthetise the rat with sodium pentabarbitone at the rate of 5mg/100g body weight byintraperitoneal injection. Maintain surgical anaesthesia throughout the experiment.

Intraperitoneal Injection of a Rat (http://www.urmc.rochester.edu/ucar/images/2fig8.gif) 3. Make a mid-line incision in the abdominal wall about 2cm long from the pelvic region cranially.Do not make the incision too cranially as you may cut the diaphragm.4. Locate the caecum. Follow the small intestine cranially from the caecum for at least 30cm and

ligate with cotton. Do not tie off any mesenteric blood vessels.



20

Segment of rat small intestine showing the mesentery and blood vessels

5. Using a 26G needle inject saline at 39oC into the lumen of the intestine caudal to the ligation to washthe loop. Carefully force the saline along towards the caecum and ligate the intestine forming about a 10cm loop.

6. Form a second loop in the same way starting about 1cm from the previous one.7. Fill one 2 ml syringe with about 1.5mL of warm Krebs-Ringer-Bicarbonate without glucose(A). Fill a second syringe with 1.5mL of glucose solution (B) (6g/L glucose in Krebs-Ringer-Bicarbonate).8. Inject the most cranial loop from syringe A until the loop is just turgid.9. Inject the most caudal loop from syringe B until the loop is just turgid.

a) Note the time loop B is half filled and b) note the exact amount of glucose solution (B) injected.10. Close the laparotomy with 3 pairs of Allis forceps.11. After 10 mins, remove the loops from the body as quickly as possible and place them inbeakers after wiping off any blood with surgical gauze.12. Give the rat an overdose of anaesthetic and cut the diaphragm.13. Wash out the loop contents with 9g/L saline into small measuring cylinders and make up to 3mL with saline.14. Filter the loop contents and determine the glucose concentration.15. Remove the rest of the small intestine and note the relative location of the removed loops andthe overall length of the small intestine.16. Calculate the glucose absorbed per cm of small intestine per hour.

i. calculate apparent glucose absorbed from loop B.ie. (volume injected x conc. injected) – ( volume recovered x conc. recovered)adjust to give value in mg/cm/hr

ii. calculate residual glucose + glucose secreted into loop A.ie. (volume recovered x conc. recovered) mg/cm/hr

iii. True absorption = step i) – step ii) in mg/cm/hr.

Data

Volume injected into loop A __________________________________________Volume injected into loop B __________________________________________Glucose concentration injected into loop A_______________________________

Glucose concentration injected into loop B_______________________________Length of loop A___________________________________________________Length of loop B___________________________________________________Volume recovered from loop A________________________________________ Volume recovered from loop B________________________________________Glucose concentration recovered from loop A ____________________________Glucose concentration recovered from loop B____________________________Absorption time ___________________________________________________

Questions

What would you need to control for in order to obtain repeatable results with this technique?________________________________________________________________________________________________________________________________________________________________________



21

________________________________________________________________________________________________________________________________________________________________________What are some of the limitations of this technique?____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

How else could you measure glucose absorption from the small intestine?____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

How are each of the following carbohydrates absorbed from the small intestine?

Glucose_________________________________________________________________________________________________________________________________________________________________

Fructose_________________________________________________________________________________________________________________________________________________________________Galactose________________________________________________________________________________________________________________________________________________________________Sucrose_________________________________________________________________________________________________________________________________________________________________Lactose_________________________________________________________________________________________________________________________________________________________________Maltose_________________________________________________________________________________________________________________________________________________________________Starch___________________________________________________________________________________________________________________________________________________________________Cellulose________________________________________________________________________________________________________________________________________________________________

What is the fate of carbohydrate that is not absorbed from the small intestine?____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________



22

Gas Formation by Rumen Microorganisms

Introduction

The main gases found in the forestomach of sheep are carbon dioxide and methane. The rumen ishighly anaerobic ie. low in oxygen and it is kept this way by the gases produced from the fermentationof food by the rumen microorganisms. The volumes of gas produced vary remarkably with diet andcan be quite large. A cow consuming 8 kg of lucerne in 4 hours produces about 125 litres.

The gases come mostly from the fermentation of sugars and other carbohydrates in the feed. Thevolume and rates of gas production are important in the aetiology of bloat, but they are NOT the onlyfactors.

MethodsA manometer and water bath at 38oC filled with coloured water is provided.

Rumen contents are removed from the fistula of the sheep and 20 mL is added to the main body of thereaction flask.

Half of the class will add 2 mL of glucose solution to their rumen fluid flask before measuring the gasproduction.

Attach the stopper and manometer tube to the flask.

Take a zero time reading from the manometer and a further reading at 5 minutes.

Calculate the rate of gas production for your rumen fluid/hour and for that of the whole sheep over 24hours.

CalculationsFor the rumen fluid the rate of gas production in mL/mL/hour equals:

Manometer reading (in mLs) x 12 (5mins x 12=1 hour)20 (Volume of flask in mLs)

For the sheep over 24 hours multiply the above value by 24 (hours in a day) and by 4000 (number of mLs in sheep rumen).

What is the fate of this gas?

How does methane production relate to ruminant nutrition?

Methane is a flammable gas. Design a simple methane generator that could be used to run a Bunsenburner. http://www.wioa.org.au/conf_papers/05/paper14.htm



23

Poultry feeding experiment report


October)

Background Information on Diet Formulation for Australian Broilers

In Australia, the Poultry Industry has available a wide variety of feeds from which to formulate well-balanced, economic diets. These feeds are produced under widely different conditions, and are fed tobirds in a range of different environments.

The large broiler producers in Australia mix their own feeds. Some smaller operators buy in feed fromstockfeed companies. The large producers and the Stockfeed companies use specialist nutritionists andcomputer-based diet formulations to meet requirements as outlined in the Practical notes.

ENERGY REQUIREMENTS

Energy requirements for poultry birds vary depending on the type of bird, its stage of production, and

environmental factors. Requirements are largely met from a range of cereal grains that normallycomprise 50-70% of the diet. The choice of grain depends on apparent ME (AME), amino acid contentand price.

These grains and typical ME values (MJ/kg) include:

Sorghum 14.0Maize 14.0Triticale 13.0Wheat 13.0 (range 11-15)Barley 12.0

Oats 11.6

Provided the sorghum is a low-tannin variety, there is no limit to its inclusion in poultry diets.

Maize can also be used in any quantity for layers but, because it produces yellow fat colour, should notexceed 30% of the grain fraction of broiler diets.

Wheat is widely used, with no limitation on the level of dietary inclusion; energy and amino acidcontent can however, vary widely! Barley has a lower energy content because it contains poorly

digested β-glucans (fibre); it should not be more than 20% of the grain component of diets for youngbirds.

Triticale (wheat/rye cross) can also be used at up to 40% of the grain component, but contains severalanti-nutritional substances. Oats contains high levels of fibre but when ground it can be included inpoultry diets.

By-products such as rice pollard (high oil content), wheat bran and pollard (millrun) and molasses(max. 5%, because of high minerals, especially K) can also be used.

PROTEIN

Meat meals are used in all States, but are variable products. Their high Ca and P contents normallylimit their inclusion in diets as a source of protein.

Blood meal (especially ring-dried) is an excellent source of essential amino acids but is ratherunpalatable and should not exceed 5% of the diet.

Soyabean meal is an excellent source of the essential amino acids (but beware trypsin-inhibitor insome varieties, and in legumes in general)..



24

Lupins (sweet varieties) and peas are used in South Australia and Western Australia but are relativelyhigh in fibre and low in sulphur amino acids (bitter varieties contain alkaloids that adversely affectperformance of growing birds).

Fishmeal, poultry offal meal, blood meal, peanut meal, sunflower meal, copra meal, lucerne meal(because of saponins, max.5%) and cottonseed meal (because of gossypol, max. 10%) are also usedoccasionally. Protein sources are blended to achieve a balance in the supply of essential amino acids.It is unusual for any protein concentrate to exceed 20% of the diet. A mix of sources is more likely togive a balanced amino acid profile.

Birds are normally given a ‘starter’ formulation for the first 21 days, and then changed to a ‘grower’diet . The protein content, especially of the starter diet may affect carcass composition at slaughter(even of birds of the same slaughter weight).

Imported synthetic amino acids, especially DL-methionine and L-lysine monohydrochloride are usedto overcome amino acid imbalances. These are normally racemic mixtures of D- and L-isomers, butexcept for DL-methionine, the L-isomer only has nutritional value for the bird. One study showed that,on an equi-molar basis, methionine hydroxy analogue had 70% of the potency of DL-methionine.

LIPIDS

Ingredients such as tallow, maize oil, sunflower oil and safflower oil are useful for increasing energydensity of the diet and as sources of essential fatty acids including linoleic acid. They increasepalatability and ME, and reduce dustiness and wear in pelleting machinery. Up to 10% lipid can beincluded in diets. Canola (Rape) and sunflower seed are sources of omega-3 fatty acids which may beincorporated into meat and are thought to be beneficial to human health. Rancid fats and oils shouldnot be used in diets.

CALCIUM AND PHOSPHORUS

Limestone, shell grit and marble are used to increase Ca concentration. These are available aspulverized powder and can be mixed with other ingredients before pelletting. Phosphorus is often

obtained from meat and bone meals, or from dicalcium phosphate or rock phosphates. Phytatephosphorus (of plant origin) is only about 30% available, but availability can be increased by theinclusion of phytase and/or vitamin D3 in the diet. Calcium and P requirements increase as the dietaryconcentration of vitamin D3 decreases. There is an interaction between these three nutrients and an

inappropriate dietary ratio may lead to tibial dyschondroplasia (weak leg bones) which has become aserious problem in modern broiler production.

MINERALSNa, Mn and Zn are the minerals usually most likely to need special attention when formulating diets.Broilers show signs of toxicity with more than 100 ppm of chlorine in the water supply.

VITAMINS

These are usually imported and are made into vitamin mixes. Vitamins are generally assumed to beabsent from normal feed ingredients, although green feeds can be useful sources of vitamins. Dietaryrecommendations are currently in need of updating. Vitamins and minerals are usually mixed togetherto make a premix.

ANTIBIOTICS/GROWTH PROMOTANTSThese are prohibited except on veterinary prescription. Nicarbazin is used to prevent coccidiosis.

Flavomycin, Roxalin and Zinc Bacitracin are classified as growth promotants and are used by someproducers and do not pose hazards for the consumer.



25

FEED INTAKE AND DIET FORMULATION

Although diet formulations are often expressed in terms of “nutrient/kg” or “% of nutrient”, the actualintake of any nutrient will depend on the quantity of feed consumed. The amount of energy andnutrients consumed each day is the important issue.

Birds tend to consume more feed as energy density in the diet decreases. They also eat more in coolweather, and less in hot weather - probably largely in response to varying energy requirements. Inthese situations, the requirements for protein, calcium and other nutrients remain largely unchangedand therefore the concentration of nutrients in the feed mix should be altered to take account of thechanging intake. In other words, it is important to think of energy:nutrient ratios. Some producers usedifferent feed formulations in hot and cool weather. Feed restriction in early life has been tried as ameans of reducing abdominal fat.

CHOICE FEEDINGAnother approach to the problem of feeding birds when environmental conditions are subject to dailyfluctuations is to allow the birds to choice feed. Birds can be given a choice of whole grain, aconcentrate containing protein, minerals and vitamins, and allowed to choose a balance suitable fortheir individual needs.

Finally, it is worth noting that feed formulations that give best biological performance are notnecessarily the most profitable.



26

Poultry experiment procedure and assessment

AIM.The aim of the study is to test the nutritional value of each of 6 diets when given to broiler chickens inthe first 4 weeks of life (the experimental period will be 3 weeks).

MATERIALS and METHODS.

Two hundred and fifty birds will be raised from day-old in brooders to 7 days of age. The largest andsmallest birds will be identified by weighing and removed from the experiment. This is to remove‘runts’ in particular, as these can bias the results by abnormal growth or untimely death (to leave thesein would necessitate using about 10 times the number of birds to minimise unbalancing effects on theexperiment). The remaining birds (216) will be stratified into weight classes and allocated at random to6 dietary treatment groups (6 birds * 6 treatments* 6 replicates = 216 birds):

Nutritional treatments1. ‘Commercial diet. This diet will be a commercial layer mash manufactured by Ridley

Agri-products in Tamworth and bought ‘off the shelf’. It will provide a commercial‘yardstick’ against which the diets we formulate here at UNE can be judged. This mash

will be pelleted at UNE to closely resemble the other diets we will formulate and pellethere at UNE.

2. 'Simple' diet. This diet will be formulated to meet as closely as possible, according tocurrent industry practice, all the nutritional requirements of the birds for optimal growthand general welfare, using a minimum of ingredients to provide ME, crude protein, mineraland vitamin, but will be relatively inadequate in available phosphate. This will mimic asmallholder or homemade diet.

3. 'Augmented simple' diet (Dicalcium phosphate). This diet will also have the sametheoretical specifications as the ‘simple’ diet. However, one additional ingredient, foodgrade dicalcium phosphate, will be added.

4. 'Augmented simple' diet (phytase). This diet will also have the same theoreticalspecifications as the ‘simple’ diet but an additional ingredient, phytase enzyme (AlltechAssociates), will be added. This is current “world best practice” both to make boundphosphate available to the birds and to minimise environmental phosphate which promotesalgal blooms in runoff.

5. ‘Supreme diet’. This diet

6. Diluted diet. This diet will have the same specifications as Diet 4, except that it will bediluted by the addition of a non-digestible material (celite). Birds will theoretically need toeat more of this diet than of Diet 4 to obtain the same intake of digestible energy andnutrients.

The birds will be fed the test diets for 3-4 weeks. The birds will be monitored daily by MrThomson. Weight gain and total feed intake will be recorded by the students. Theexperimental results will be processed and reported as a scientific paper by the class.

The important measurements for birds on each of the 6 dietary treatments over the experimental periodwill be:

total feed intake (g/bird per day)total live-weight gain (g/bird per day)

feed conversion ratio.



27

Daily tasks for internal students.

1. Check for dead or sick birds in each cage. Make a note of what you have seen (e.g. ‘allhealthy’; ‘one bird in cage 18 looks poorly’; one bird dead in cage 3’ –weight of dead bird was300 g; combined weight of remaining 5 birds was 1545g’). Remove any dead birds.

2. Weigh back the feed containers from the left (b) and right (a) side of each cage. Tare thebalance to zero with nothing on the pan, then record the weight of the container plus feed. Top

up (don’t overfill !!) the container with the appropriate feed and re-weigh the feed+container.The cage and diet details are on the recording sheet and the diet details correspond with thelabeling on the bags of feed.

3. Clean watering containers if necessary and top up water

4. On designated days, Wednesdays and Saturday, weigh the birds in each cage as a group. Tarethe container empty, and record the combined net weight of all birds in the group. Handle the

birds gently during the catching and weighing process.

The Scientific Report of the Feeding Trial

Writing a scientific report

Scientific reports of research experiments are usually written up using the following headings:-

1) Abstract

2) Introduction3) Materials and Methods (incl. Statistical Methods)4) Results5) Discussion6) References

Following is a brief description of the individual sections.

(1) Abstract

This should provide a concise overview of the report (usually about 5% of the full report). It should

briefly describe the experiment and its aims, and then explain what was discovered and the relevanceof the findings.

(2) Introduction

Give a brief history of what is already known from other research of relevance the topic. Develop athesis. State briefly and specifically what you wish to determine and the importance of thisinformation.

(3) Materials and Methods

Describe what was done and how, e.g. the experiment design, experimental materials used, what was

measured and the methods used, and details of the methods of statistical assessment of the results. Thedetail should be sufficient to enable another scientist to repeat the experiment and duplicate theexperimental conditions.



28

(4) Results

Summarise all data arising from the experiment and highlight the important (usually statisticallysignificant) findings. Use summary tables or figures that summarise the data and their statistical

significance, don’t present the raw data. (The fewer and simpler the Tables and Figures the better:avoid presenting the same data in both Tables and Figures). Use SD when describing observations, SEwhen the objective is estimation or when testing a hypothesis. Often the use of a CV at a specifiedlevel of significance is more informative than a single ‘P’ value. Ensure the reader has sufficientinformation to verify the main conclusions. It often seems difficult to avoid discussing results in the“Results’ section, but many journals are strict on this point - avoid discussion of the results in theResults section - restrict yourself to simply highlighting the important differences in your datasummary.

For assistance conducting a statistical analysis of the data, we recommend using the tools

available on the following website:

http://faculty.vassar.edu/lowry/VassarStats.html

(5) DiscussionDiscuss the implications of your results in relation to current knowledge of the subject (from previoussimilar studies). It is important also to relate the results to the objective of your experiment – was theaim achieved satisfactorily? If not, explain why. Discuss any ‘aberrant’ results (and your reasons notincluding them in averages if you excluded any data). Highlight the main findings. Discuss practicalimplications of the study and suggest how knowledge of the topic might be further advanced by furtherresearch.

(6) References NB. Any statement that you make, that is not your own idea, should be followed by a cited reference,or other acknowledgement. You must indicate how the reader can gain access to the source of information you have referred to.

Citations in a scientific report should be acknowledged in an accepted (and consistent) manner,e.g.Scott, M.L., Nesheim, M.C. and Young, R.J. (1976). Nutrition of the Chicken, 2nd edition, M.L. Scottand Associates, Ithaca, New York.NRC (1977). Nutrient Requirements of Domestic Animals. No. 1. Nutrient Requirements of Poultry,7th revised edition. The National Research Council, National Academy of Sciences, USA.Wyatt, R.D. Tung, H.T., Donaldson, W.E. and Hamilton, P.B. (1973). A new description of riboflavindeficiency syndrome in chickens. Poultry Science, 52, 237-242.RIRDC (1999). ‘Five year plan. Rural Industries Research and Development Corporation

http://www.rirdc.gov.au/pub/chick5yr.htm (web site accessed July, 2001).

Some General Reference Sources

AGRICULTURAL RESEARCH COUNCIL (1975). The Nutrient Requirements of Farm

Livestock. No. 1 Poultry. London, Agricultural Research Council.

LIENER, I.E. (1980). (Ed.). Toxic Constituents of Plant Foodstuffs. 2nd

Ed. New York. Academic

Press.

McDONALD, P., EDWARDS, R.A. and GREENHALGH, J.F.D. Animal Nutrition .

NATIONAL RESEARCH COUNCIL (1966). Nutrient Requirements of Poultry. 5th

Washington,

National Academy of Science - National Research Council.

SCA (Standing Committee on Agriculture) (1989). The Nutrient Requirements of Poultry. CSIRO

Publishing, Melbourne.



http://www.rirdc.gov.au/pub/chick5yr.htm






29

SCOTT, M.L., NESHEIM, M.C. and YOUNG, R.J. (1976). Nutrition of the Chicken. 2nd

Ed.

Ithaca, New York. M.L. Scott and Associates.

UNDERWOOD, E.J. (1971). Trace Elements in Human and Animal Nutrition. 3rd

Ed. New York.

Academic Press.

Some JOURNALS British Poultry Science, Nutrition Abstracts and Reviews, Poultry Abstracts, Poultry Science,

Proceedings of the Australian Poultry Science Foundation

A final piece of advice …

Before you attempt to write your report, please read some scientific articles (e.g., in British Poultry

Science or Poultry Science) to get a ‘feel’ for the style that is required. It does no harm to copy thestyle of a report; it is plagiarism only if you copy its content.



30

Feedlot ration formulation seminar

(Value = 15%, Due date: 31st October)

The aim of this practical exercise is to develop a feedlot ration and feeding program for “Tullimba”

feedlot and present your proposed program and its justification in a seminar.

It is most important that your seminar addresses the key issues in developing a feedlot feedingprogram. It is even more important that your recommendations for the feeding program are justified byusing published research data that demonstrates the specific production benefits of your suggestedstrategies. The assessment criteria for this exercise are describe at the bottom of this section.

Description of Tullimba feedlot

“Tullimba” is a 740 hectare property, 50 kilometers west of Armidale, owned by The University of New England. It was developed specifically to provide a valuable feedlot site for the Beef CRC

research programs. The property is 720 to 780 metres above sea level with summer-dominated annualrainfall of 800 mm. Its main feature is a 1200 megalitre water reservoir constructed in 1982, with anirrigation licence for 450 hectares.

The feedlot is situated 100 km from the reliable grain growing regions of Inverell and Warialda and150 km from the large hay producing areas around Tamworth. The feedlot experiences mean monthlymaximum temperatures of up to 28°C in January and mean monthly minimum temperatures below 0°Cin July. The area receives an average of 15 frosts per month during July and August with averagemonthly wind speeds of 8.5 km/h in late spring and early summer.

The feedlot facility has a 2000 head capacity. There are 40 pens constructed to hold 15 animals per

pen, with the remaining capacity comprising pens with 50 to 100 head capacity.

The feedmilling capacity at Tullimba is provided by a roller mill for grain processing and a tub grinderfor roughage preparation. The feedmill shed is designed in a “cafeteria” style to allow a range of feedstuffs to be easily stored and accessed for feeding. Grain storage capacity is through four 113-tonne grain silos. Protein meal storage capacity is through two 40-tonne silos and a 22,500 litre tank for liquid supplement (eg. Molafos) is situated adjacent to the feedmill shed. Feed ingredients aremixed in a tractor-drawn four-tonne RMH mixer wagon capable of accurately weighing one kilogramincrements.

The cattle you are required to develop a feeding program for will be lot-fed for 80 days and sold for

slaughter to the domestic market – Woolworths supermarket specifications.

Description of cattle and market destination

For the purposes of this practical exercise, the description of the cattle your feeding program will bedesigned for is:

• Bos indicus cross Bos taurus steers

• Average entry liveweight = 360kg

• Average exit liveweight = 470 kg

• Feeding period: 70 to 90 days

• Target market: domestic (Woolworths) supermarket trade• All animals have been treated with HGP on arrival at feedlot



31

Preparation for the practical sessionTo prepare you for the practical session, you will visit Tullimba feedlot and conduct an inspection of the facilities. This will provide you with an understanding of the constraints limiting to feedingmanagement. You feeding management program should reflect these constraints.

You will also have the opportunity to use two ration formulation software packages available throughUNE, Grazfeed® and GrassGro®. You will be provided some training and instruction on the use of

these packages. There are many software packages available for ration formulation. For those thatchoose to use a software package for developing their rations, this training will be most beneficialpreparation.

Tasks

You are required to design a feedlot feeding program for the cattle described above at Tullimbafeedlot. As a suggestion, some suitable steps in undertaking this exercise would be:

1. Identify suitable feedstuffs and additives2. Determine the availability of these feedstuffs and additives3. Formulate three least-cost rations*:

a) Starter rationb) Grower rationc) Finisher ration

4. Design the feeding program for each of these rations. This task could include:a) Describing the duration each ration is fed for across the 70 to 90 day periodb) Describing how much feed is delivered daily (kg/head/day) and what the split between

morning and afternoon feeding would be.

5. Justification for the feeding program. This is the most important component of the exercise.This component is your opportunity to demonstrate your understanding of the nutritionalprinciples underpinning your feeding program. You are encouraged to use published researchdata to support your

* For designing least-cost rations, you are encouraged to use a software package to assist. While this isnot compulsory, almost all commercial feedlots and commercial feedlot nutritionists rely on softwaresupport when developing rations. There are many commercially produced least-cost ration softwarepackages available all around the world. There are also many ration formulation software packagesavailable at no cost on the internet. As an enrolled student at UNE, you have free access to some

software packages including Grazfeed®

and GrassGro®

. These packages can be very useful fordesigning your rations. The packages available through UNE can be found at the following website:

http://www.ed-serve.une.edu.au/

You will need your UNE username and password to access the software packages through thiswebpage.






32

Assessment

Every seminar will be assessed according to the assessment sheet displayed below. This sheetdemonstrates the relative importance of various aspects of your seminar in terms of assessment. Oncemarks have been compiled, you will receive the assessment sheet from each examiner. This willprovide you with useful feedback on the strengths of your seminar and identify areas with opportunityfor improvement.

Assessment item Comments Value Mark

Clarity and use of visual aids(Were the main points of theseminar logically presented anddiscussed? Was the presentationwell organized and professional?)

10%

Applicability of recommendations(Are the recommendationsappropriate for application atTullimba?)

10%

Identification and discussion of key feeding management issues.(Were all of the key issues raisedand discussed in a manner thatdemonstrates understanding?)

20%

Appraisal of ration design (Do therations satisfy nutrient/productionrequirements?)

15%

Justification for the feedingprogram design (Is there use of

published research data todemonstrate the production andfinancial benefits of therecommended program? Was thedata appropriately cited and froma reliable source?)

30%

Answers to questions (Do theanswers demonstrate a depth of understanding rather than surfaceknowledge?)

15%

Total 100%



33

Basic knowledge questions

(The 15 questions that will appear in the Basic KnowledgeQuiz will be drawn from this list of questions)

1. What atoms make up carbohydrates?

2. How many grams in 2 kilograms?

3. How many milligrams in 0.5 grams?

4. Define ‘mole’.

5. What is a ‘hexose’?

6. What is ‘cytoplasm’?

7. What does ‘ATP’ stand for?

8. Give a common word that means ‘lysis’.

9. What is a ‘neuron’?

10. What is the principal characteristic of all oxidizing agents? (Hint: electron).

11. What differs between ‘saturated’ and ‘unsaturated’ fatty acids?

12. What is an endergonic chemical reaction?

13. Name a hormone involved in the maintenance of normal blood glucose concentrations inmammals.

14. What are the two components of the autonomic nervous system?

15. (i) Give one example of an exocrine gland.

(ii) Give one example of an endocrine gland.

16. What does ‘gastric’ mean?

17. What is a neurotransmitter? Give an example.

18. Give an example of a steroid hormone.

19. What is meant by a ‘second messenger’ (in endocrinology)?

20. Name two organs in the thoracic cavity.

21. Bile is secreted by which organ?

22. Gastric juices are found in which organ?

23. Where would you find your soft palate?

24. What is an afferent nerve?

25. What is an efferent nerve?



34

26. The pH of the gastric stomach is high or low?

27. A peptide consists of multiples of which chemical unit bonded bypeptide bonds

28. Name one fat-soluble and one water-soluble vitamin.

29. What is a villus?

30. What is a simple (every-day) name for a triglyceride (triacylglycerol)?

31. Write the chemical formula for a ferric ion.

32. What is a common name for the reticulum?

33. Name two gases produced during rumen fermentation.

34. Give an example of a rumen volatile fatty acid.

35. What is meant by the biological half life of a compound in the body?

36. Where would you find the cloaca of a chicken?

37. What is coprophagy?

38. Where would you find your parotid glands.

39. What, in chemistry, is meant by a buffer?

40. What separates the thoracic and abdominal cavities?

41. Name one thing required for active transport of a substance across a membrane.

42. What is one main difference between smooth muscle and skeletal muscle?

43. What are the ultimate end-products in living cells when glucose is completely oxidized?

44. On the diagram below, circle the amino group.

45. What do the prefixes, ‘mono’ and ‘poly’ mean?

46. What is a polysaccharide chain?

47. What are the primary building units (monomers) of plant starch?

48. What class of compounds would a nutritionist expect to find in an ‘ether extract’ of plantmaterial?

49. What does the ‘ash’ component in a feedstuff mean to nutritionists?

50. What is the role of lipase?

CH NH2

R

COOH

CH NH2

R

COOH



35

51. Label the diagram below with the terms anterior , posterior , dorsal , ventral

52. Label the diagram below putting terms at the end of each bar, cf . ‘Diaphragm’.

53. Why do small animals usually have a basal heat production (expressed as kilojoules/kg liveweight) that is higher than that of larger animals?

54. What is the difference between lactose and lactate?

55. What are the simple building units (monomers) used in formation of cellulose?

56. What is meant by lipogenesis?

57. What is meant by lipolysis?

58. What is meant by gluconeogenesis?

59. How is ‘crude protein’ concentration in a feed ingredient calculated from knowledge of its totalnitrogen concentration?

60. What is an ‘essential amino acid’?

61. Give the names of two essential amino acids.



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62. Name a trace mineral.

63. Name a ruminally produced volatile fatty acid (VFA) that is glucogenic in liver tissue.

64. Name three different classes of microorganisms found in the rumen.

65. Name two products arising when urea is degraded.

66. For protein synthesis, in addition to C, H, O and N, what other substance is required?

67. What is a ‘redox’ reaction?

68. What are the units used to describe the energy concentration in feed ingredients?

69. Name one major role of calcium in farm animals.

70. Name one major role of iron in mammals.

71. What is neophobia?

72. What do ‘in vitro’ and ‘in vivo’ refer to?

73. What is ketosis?

74. What is homeostasis?

75. What is meant by ‘denaturation of proteins’?

76. What is the process by which carbon dioxide in the atmosphere is converted to plantcarbohydrates?

77. What is the major source of amino acids that are absorbed from the small intestine ofruminants?



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Learning assistance

Lectures 1-13 (Dr Ian Godwin)

We recommend that you prepare brief written answers for each of the questions given below as an adjunct toyour on-going study (many only require a line or two) and bring them along to your tutorials where they will be discussed.Work through these questions as the material is covered in lectures. (Don't leave it until just before the exams, becausethat simply defeats their purpose and will win no help from the staff involved! If you still have difficulty after consultingtextbooks etc., don't hesitate to contact the lecturers concerned.)

TEXTBOOKS

Much of the material on monogastric physiology is covered quite well in your Physiology 210 text, i.e.Silverthorh D.V. 2004 Human Physiology, 3rd ed. Prentice-Hall, New Jersey.

(Chapter 20 covers Digestive Physiology and Chapter 21 covers the Pancreas and Metabolic Regulation.)

GENERAL GASTROINTESTINAL PHYSIOLOGY

1. Draw and label a diagram of a typical transverse section of the digestive tract.2. Why is secretion into the digestive tract considered to be exocrine?3. What is the peritoneum and what are its functions?4. What is the fatty apron?

5. Why does the peritoneal cavity contain large numbers of macrophages and lymphatic tissue?6. Describe the role of the hypothalamus in the control of food intake.

SALIVA

1. Describe the location of the salivary glands.2. Describe the composition of saliva.3. What is the function of saliva?4. Describe the control of salivary secretion.

DEGLUTITION, THE OESOPHAGUS AND VOMITING

1. Discuss the events associated with deglutition.2. Describe the muscle layers in the oesophagus.

3. What is hiatus hernia?4. What secretions are produced by the oesophagus?5. Describe the process of vomiting.

THE STOMACH

1 Draw a diagram of the stomach and label with greater and lesser curvature, fundus, antrum, pylorus, cardia andbody.

2. Name four types of cell in the gastric mucosa and their secretory products.3. What are rugae?4. Why doesn't the stomach digest itself?5. What is the function of intrinsic factor?6. What is required to make pepsin active?

7. Describe the chemical events associated with the secretion of HCl.8. List the stimulatory and inhibitory factors involved in regulating gastric secretion.

THE SMALL INTESTINE

1. List the divisions of the small intestine in proximal to distal order.2. What neutralises gastric acid in the small intestine?3. How is the surface area of the small intestine greatly enhanced?4. Describe the structure of a villus.5. Describe the processes of rhythmic segmentation and peristalsis6. List the enzymes of the intestinal brush border.7. What would happen if a patient with lactase deficiency had a large drink of milk?8. Describe the mechanisms of monosaccharide absorption.

9. Discuss the digestion and absorption of lipids.10. Describe the absorption of amino acids.

11. Describe the absorption of Ca2+

and Fe2+

.



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THE PANCREATIC AND BILIARY SECRETIONS

1. Draw a labelled diagram of the different conduits involved in biliary and pancreatic secretions.2. Describe the composition of bile.3. What is the function of bile salts?4. What is the purpose of bilirubin?5. Describe the arterial and venous connections to the liver.6. What are the roles of secretin and cholecystokinin in biliary secretion?7. What is the function of the gall bladder?8. What is the entero-hepatic recirculation of bile salt?9. Describe the composition of the exocrine pancreatic secretion.

10. Tabulate the pancreatic enzymes, their substrates and products.11. Why are most enzymes secreted in an inactive form?12. What activates trypsinogen?13. Describe the control of pancreatic secretion.

THE LARGE INTESTINE

1. What separates the small intestine from the large intestine?2. Draw a diagram of the large intestine, labelling the major sections.3. What is the role of the taenia coli?4. Describe haustral churning.5. What gives faeces its characteristic colour and odour?6. Why does the ingestion of oligosaccharides such as in baked beans cause flatulence?

7. Describe the events associated with defaecation.8. What is mass movement?

Two excellent references on reticulo-rumen motility are as follows.

Constable, P.D., Hoffsis, G.F. and Rings, D.M. (1990) The reticulorumen: Normal and abnormal motor function.Part 1 The Compendium 12, 1008-1014. Part 2 The Compendium 12, 1169-1174

Copies of these articles will be available for short-term loan from the School of Rural Science and NaturalResources Administrative Assistant (Woolshed) or from the Special Shelf in Dixson Library.

RUMINANT DIGESTION

1. What feature characterises a ruminant?

2. Describe the development of the ruminant forestomachs.3. Discuss the function and the physiology of the oesophageal groove.4. Describe the mixing movements of the reticulo-rumen.5. Describe the mechanisms involved in the eructation of gas.6. What is rumination? Describe the mechanisms involved.7. Contrast the functions of saliva in ruminants and non-ruminants.8. What is the function of the omasum?9. Why are there differences in the rates of passage of particles and fluids from the reticulo-rumen? How would you

measure these differences?10. Discuss the fate of dietary nitrogen in the ruminant.11. Discuss the fate of dietary carbohydrate in the ruminant.12. Why is the sudden introduction of grain to pasture fed ruminants likely to result in catastrophic losses?13. How would you determine the intake of crude protein by an animal freely grazing at pasture with some degree of

accuracy?

DIGESTION IN THE CHICKEN

1. Draw a simple labelled diagram of the digestive tract of a chicken.2. Why does a chicken have to raise its head when drinking?3. What is the function of the crop?4. What is the function of the proventriculus?5. Describe the structure and function of the gizzard?6. What is the major difference in the absorption of lipids between birds and mammals?7. Discuss the role of the caeca in water and electrolyte homeostasis.9. Why is fowl urine semi-solid?

COMPARATIVE DIGESTIVE PHYSIOLOGY

1. Discuss the value and mechanisms of coprophagy in the various species which exhibit this attribute.2. Contrast the different digestive strategies found in marsupials.



39

3. Why does the administration of oral antibiotics to most species often result in gastrointestinal disturbances?4. What are the major diffences found between the digestive tracts of carnivores, omnivores and herbivores?

PANCREAS AND METABOLIC REGULATION

1. Distinguish between glucose, glycogen, glycogenesis, glycolysis, glycogenolysis and gluconeogenesis.2. Name three hormones secreted by the pancreas.3. Briefly describe lipolysis, lipogenesis and ketogenesis.4. What is meant by absorptive state and postabsorptive state?5. Describe the metabolic actions of insulin.6. Describe the control of insulin secretion.

7. Compare Type I and Type II diabetes mellitus.8. Contrast the metabolic effects of glucagon and insulin.9. Discuss the role of glucocorticoids, adrenalin and growth hormone on metabolic regulation.10. How is blood glucose controlled upon ingestion of a high protein meal?

Lectures 14-19 (Dr Roger Hegarty and Professor John Nolan)

1. List important groups of nutrients found in feeds.2. List feed fractions that are included in a proximate analysis of a feed.3. In the Van Soest system of feed analysis, what feed components would you expect to be present in the Neutral

Detergent solubles, and in the NDF?4. Use a simple diagram to show the relationship between Gross Energy and Metabolisable Energy concentration of a

feed.5. What is the relationship between the TDN and ME concentration of a feed?6. Define maintenance energy requirement (MEm) of an animal and give a simple equation that will predict MEm across a

range of large and small animals. 7. Why is straw a useful feed for ruminants but not humans?8. Give an approx. value for the ME concentrations of wheat grain when fed to (a) sheep or (b) pigs.9. Does rate of intake affect the digestibility of a feed for ruminants? What is the effect of particle size?10. How does plant digestibility change as plants mature? What causes these changes?11. How might the digestibility of straw to be fed to ruminants be increased?12. What are the chemical differences between starch and cellulose? What are the implications of these chemical

differences for digestibility of starchy or cellulosic feeds for pigs?13. What are NSPs? What are the implications of NSPs in diets for chickens, pigs and cattle?

Lectures 20 –24 (Professor John Nolan)

1. What characteristics of the rumen make it an ideal environment for the growth of anaerobic microbes?2. Give one basis on which different types of rumen bacteria can be classified.3. What is one major difference between protozoa and bacteria?4. Why are anaerobic fungi thought to be important in the process of straw digestion?5. Fermentation could be defined as …………??6. What do rumen microorganisms achieve by degrading organic matter in the rumen?7. How does a ruminant animal itself benefit from the presence of anaerobic microbes in the rumen?8. What are VFAs and why are they so named?9. When ATP is converted to ADP in rumen bacteria, how is the ATP-energy dissipated?

10. Why is rumen propionate often considered separately from acetate and butyrate?11. Why is the microbial biomass produced in the rumen of benefit to the ruminant itself?12. How is the efficiency of growth by rumen microbes often described?13. What are the major contributing causes of the problem of lactic acidosis?14. How can lactic acidosis be minimised or prevented?15. What is the physiological reason for the onset of bloat?16. Name one close intermediate of the central biochemical pathways formed by metabolism of (a) acetate, (b)

propionate (c) butyrate (d) lactate (e) glucose (see BCHM210)17. Why is acetate considered to be non-glucogenic and propionate glucogenic?

18. How are butyrate and ketone bodies related?19. What is meant by ketonaemia?20. What is the difference between lactate and lactose?

Lectures 24-25 (Dr. Darryl Savage)

1. Why are lipids so classified? (Give a definition of lipid )



40

2. List several roles of lipids in individual cells, and in the body in general.3. Define essential fatty acid . 4. Are lipids degraded by rumen micro-organisms?5. Describe the roles of micelles and chylomicrons and lymph in the transfer of lipids from the gut to tissues.6. Why is margarine easier to spread on bread than butter? Could ruminants produce margarine?7. What do you consider upper limits for lipid inclusion in diets for chickens and ruminants?8. What are the major precursors of lipid synthesis in (a) ruminants (b) chickens?9. Indicate some sources of, and the significance of, omega polyunsaturated fatty acids?

Lectures 26-31 (Dr Darryl Savage)

1. Give a short definition of protein.

2. How is crude protein determined, and what are two limitations of this description of the protein content of afood?

3. List some of the forms in which proteins are found in the bodies of animals.4. Why do nutritionists often use dietary nitrogen and dietary protein almost interchangeably?5. What is the quantitative relationship between total N and protein and what is the origin of this relationship?6. What are the limitations of a protein analysis of a feed expressed as crude protein? How is this analysis done?7. Draw a chemical diagram showing the characteristic structure of an amino acid.

8. Define essential amino acid and name 3 of the essential acids of nutritional importance. How do ruminantsobtain essential amino acids?

9. What determines the quality of protein in a feed? How can protein quality be assessed?

10. In tissue cells of the body, what determines which of the thousands of possible proteins will be formed at anytime?

11. What happens to the amino acids released when unwanted tissue proteins are degraded within cells?12. What happens to excess amino acids circulating in the blood?13. What feeds contain high concentrations of true protein? In plants, how does protein content change with age?14. What is the significance of NPN? What diets contain NPN?15. Is urea a ‘protein supplement’? Explain your response.16. Define biological value of a protein source and indicate how BV can be determined using the animal that is to be

fed this protein source.17. In addition to knowing the protein content of a potential protein concentrate, what other information would you

like to have when assessing the economic value of that food.18. What is meant by tissue protein turnover ?19. How are protein turnover , protein synthesis and protein deposition related?

20. How can an estimate of the minimum protein requirement of an animal be determined? What additionalinformation is required to estimate the minimum dietary requirement?

21. In the rumen, what are the steps involved in protein degradation that give rise to ammonia?22. What is the nutritional significance of ammonia in rumen fluid?

23. What determines rumen ammonia concentration in the rumen throughout the day?24. What factors affect the rate of ammonia absorption across the rumen wall?25. What is the fate of absorbed ammonia after it crosses the gut wall and enters the bloodstream?26. Explain the term urea recycling. 27. Could dairy cows give birth to calves and produce milk on a diet which contained absolutely no protein or amino

acids?28. What are the special protein requirements associated with wool growth?29. Would you expect the Protein:Energy (P:E) requirements of animals to remain constant throughout their lifetime?

Give reasons for you answer.

30. How might the optimal requirements for dietary methionine be determined experimentally for meat-producingchickens?

Lectures 32-34 (Dr. Darryl Savage)

1. List 3 roles that minerals fulfill in cells.2. Give two reasons for animals not having sufficient minerals in cells to meet essential purposes.3. List 3 macro-minerals and 3 trace minerals of concern to nutritionists when formulating diets.4. In what forms of animal production do you consider calcium requires special consideration?5. What conditions are commonly associated with iodine deficiency and selenium deficiency?6. Define vitamin, and indicate some roles of vitamins in cells. 7. Why are vitamins considered to be essential components of the diet?

8. Give 3 examples of where vitamins are necessary co-factors for biochemical reactions to take place.9. Which are the fat-soluble and which are the water-soluble vitamins?

10. Is vitamin A ever likely to be deficient in ruminants, and if so, under what conditions?11. With what minerals do you associate vitamin D and Vitamin B12? Why?



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Lecture 35 (Dr. Darryl Savage)

1. What determines the total amount of water available to animal?2. What are the major routes of loss of water from animals?

3. Define obligated urinary water and free water. 4. Water intake, feed quality and feed intake are sometimes related. How?

Lectures 36 and 37 (Dr. Darryl Savage)

1. Contrast actual intake and potential intake and indicate what factors determine each.

2. List animal/physiological factors that affect requirements for energy and nutrients.3. List environmental factors that affect energy requirements, and show with a diagram the nature of the change in

requirements with changing ambient temperature.4. What dietary factors are most likely to limit intake of pigs and chickens?5. What are the dietary factors most likely to limit feed intake of grazing ruminants ?6. What factors affect rumen emptying?7. How do animals distinguish between food and non-food ?8. Do animals distinguish between different foods when there is choice?9. Do grazing animals exhibit a preference for some foods when they have choices, or is selection a random process?10. Why do ruminants often avoid supplements that we know are likely to be of nutritional benefit to them?

Conversely, why do they sometimes chew bones, lick soil and old batteries that we consider to be inappropriate asfoods?

11. What is conditioned aversion?

12. What senses do animals use to identify feeds?13. How might you train animals to avoid eating orange trees in an orchard?

Lectures 38 and 39 (Dr. Darryl Savage)

1. List some management strategies that may lead to higher rumen efficiency2. Define feed conversion efficiency (FCE) and feed conversion ratio (FCR). What are the limitations associated

with these indices of efficiency?3. Whole flock/herd efficiency may be expressed as the ratio of saleable product to feed intake, or whole farm feed

supply. Have these expressions any practical uses?4. What is the potential for controlling or eliminating protozoa in the rumen as a means of increasing ruminant

production?5. What is Standard Reference Weight and how is it used?6. What is meant by potential feed intake and relative (actual feed intake)?7. What is the ‘supplement substitution’ effect?

8. What is ‘compensatory growth’?9. What factors are included in the ‘maintenance energy requirement’ used in GrazFeed and GrassGro?10. Why does GrazFeed request information about the slope of the land?11. Why is the prediction of rumen microbial yield prediction in GrazFeed dependent on latitude and season?12. Why does GrazFeed need information on the fraction of legume in the pasture?13. Is selective grazing taken into account in GrazFeed ? How?



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Major text resources

The Lecture Book, prepared for use by ANUT221 External students, provides most of the information you are likely toneed to meet the learning objectives of this unit.

There are a number of other excellent text-books that you might also find useful. These include:

Animal Nutrition (McDonald, Edwards, Greenhaugh and Morgan) 5th edition. Longman (1995).

Nutritional Ecology of the Ruminant. (P. Van Soest). O & B Books, Inc.,New York.

Basic Animal Nutrition and Feeding (W.G. Pond, D.C. Church and K.R. Pond). 4th Edition.Dixson library: 636.0852 P798b (1995).

Trace Animals in Human and Animal Nutrition. 3rd edition. (E.J Underwood). Academic Press, New York (1971).

Applied Animal Nutrition, Feeds and Feeding , 4th Ed. Cheeke, P. and Shapiro, L.S. 4th Ed. (2001). Prentice hall, New York.

Human Physiology. 3rd Ed. Silverthorn, D.V. 2004. Prentice-Hall, New Jersey.



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End-of-Semester Exam (Example exam Questions)

Different types of questions might ask you to: tick correct answers in a list of possible answers to aquestion, list important points, write brief notes on, use a simple diagram to show …(a concept),describe in detail, or write an essay on …. Some questions will test your understanding of basicnutritional or physiological information, others will test your ability to use this information tointegrate, synthesise and answer more applied questions. You may be offered a choice within aquestion. The number of minutes (in brackets) provides an indication of the amount of time you shouldallocate to each question. Some examples are given below.

Tick the correct answer(s) (2 min allowed)

Salivary secretion is

a) stimulated by parasympathetic discharge

b) stimulated by sympathetic dischargec) controlled mostly by the actions of the salivary hormonesd) greatest during the gastric and intestinal phases of digestione) both a) and c) of the above

(5min)Write short notes on the oesophageal groove reflex

Write notes on 5 only of the following 7 topics with respect to their roles in animal nutrition andmetabolism:-

1. Regulation of voluntary feed intake in sheep2. Requirements in the rumen for efficient microbial growth3. Limestone4. Water5. One of the B vitamins, indicating its role in metabolism6. Lipid digestion, transport and deposition in tissues

7. Crude fibre

QUESTION (20 marks)

Write notes on 5 only of the following 7 topics with respect to their roles in animal nutrition and metaboism:-

1. Regulation of voluntary feed intake in sheep2. Requirements in the rumen for efficient microbial growth3. Limestone4. Water5. Name one of one of the B vitamins and indicate its role in metabolism

6. Lipid digestion, transport and deposition in tissues7. Crude fibre



QUESTION (20 marks)

a) In a six-week growth study, broiler growth was compared on two diets formulated to the same specifications from different ingredients (using dietary information from standard feeding tables). Analyse the results given in the Table(treatment means) and suggest reasons for the differences in bird performance.

Diet A Diet B

Liveweight

(g)

Cumulative

FCR(g feed/g gain)

Liveweight

(g)

Cumulative FCR

(g feed/g gain)

Start 47 - 51 -Week 2 450 1.41 475 1.37Week 4 1125 1.65 1150 1.70Week 6 2175 1.82 1902 1.93

b) If the live weight at 6 weeks of age had been very similar in both groups, what factors might explain significantdifferences in FCR?

QUESTION (20 marks)

Explain “digestible energy intake” and “metabolizable energy intake”. Indicate how these could be estimated in:-a) pigsb) sheep.

QUESTION (20 marks)

a) What are the major substrates oxidised to provide energy in tissues of:-

i) ruminants andii) pigs.

b) What effect does the type of substrate oxidised have on the efficiency of feed utilization by an animal?

c) Explain why a ruminant eating a dry, mature, low protein roughage may have low digestible energy intake.

d) What adjustments to a diet formulation, designed for animals housed in a thermo-neutral environment, are likelyto be needed for the same animals housed under very cold conditions.

Corso Di Fisiologia Della Nutrizion

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