INTRODUCTION TO ANIMAL SCIENCE 320

COURSE OUTCOMES1. Identify and explain methods of laboratory analysis of feed nutrients. 2. Identify and explain in vivo methods for the measurement of the nutritional value of

feedstuffs. 3. Assemble and interpret feed composition measurements from laboratory analyses,

NRC publications, or scientific literature to be used in diet formulation and problem-solving.

4. Interpret commercial feed labels. 5. Identify the nutritional and physical characteristics and production of available

feedstuffs used in livestock, poultry and companion animal diets. 6. Identify feeds by both gross and microscopic techniques 7. Recall and evaluate the suitability and limitations of specific feedstuffs in the

preparation of diets for different species and production classes of animals. 8. Identify the effects of cropping, harvest, storage, and processing practices on the

nutritional and physical characteristics of feedstuffs. 9. Use manual calculation techniques to balance rations for animals. 10. Understand and use computer ration balancing software for specific classes of

animals. 11. Evaluate diets for nutritional adequacy and practicality within the limitations of

preparation, transport, storage, feeding, and economic feasibility. 12. Understand the mechanisms of action and appropriate use of feed additives and

implants in animal feeding programs. 13. Develop feeding systems appropriate for different animal classes entering different

phases of production or life. 14. Understand and evaluate diet mixing and delivery systems.

SCHEDULEDate Lecture/Lab Topic Instructor1/9 Lecture 1 Introduction. Reviewing nutrient digestion in nonruminant and ruminant

animalsJ Russell

1/9 Lecture 2 Chemical analysis of feedstuffs J Russell

1/11 Lab Calculating the composition of feedstuffs and diets J Russell

1/18 Lecture 1 Determining the digestibility of feedstuffs J Russell

1/18 Lecture 2 Energy systems for feedstuffs J Russell

1/18 Lab Use of energy systems for calculating feed intake or animal production J Russell

1/23 Lecture 1 Energy feedstuffs L Baumgard

1/23 Lecture 2 Protein supplements L Baumgard

1/25 Lab Quiz 1. Feedstuff identification L Baumgard

1/30 Lecture 1 Protein supplements L Baumgard

1/30 Lecture 2 By-product feedstuffs L Baumgard

2/1 Lab Exam 1

2/6 Lecture 1 Forage species and quality J Russell

2/6 Lecture 2 Grazing systems J Russell

2/8 Lab Calculating feed inventories J Russell

2/13 Lecture 1 Harvested forages (Hay) J Russell

2/13 Lecture 2 Harvested forages (Silages) J Russell

2/15 Lab Quiz 2. Basic ration formulation methods J Russell

2/20 Lecture 1 Mineral and vitamin supplements L Baumgard

2/20 Lecture 2 Feed processing and mixing L Baumgard

2/22 Lab Formulating premixes L Baumgard

2/27 Lecture 1 Feed additives L Baumgard

2/27 Lecture 2 Interpreting feed tags L Baumgard

2/29 Lab Exam 2

3/5 Lecture 1 Feeding companion animals (Dogs) L Baumgard

3/5 Lecture 2 Feeding companion animals (Cats) L Baumgard

3/7 Lab Diet preparation for Dogs and Cats L Baumgard

3/19 Lecture 1 Feeding beef cattle (Breeding herd) J Russell

3/19 Lecture 2 Feeding beef cattle (Growing-finishing cattle) J Russell

3/21 Lab Balancing rations for beef cattle (Beef Brands) J Russell

3/26 Lecture 1 Feeding swine (Breeding herd) J Patience

3/26 Lecture 2 Feeding swine (Growing-finishing pigs) J Patience

3/28 Lab Quiz 3. Balancing rations for swine (National Swine Nutrition Guide) J Patience

4/2 Lecture 1 Feeding calves L Baumgard

4/2 Lecture 2 Feeding developing heifers L Baumgard

4/4 Lab Exam 3

4/9 Lecture 1 Feeding dairy cattle (Lactating herd) L Baumgard

4/9 Lecture 2 Feeding dairy cattle (Dry and transition cattle) L Baumgard

4/11 Lab Balancing rations for dairy cattle (CNCPS) L Baumgard

4/16 Lecture 1 Feeding Poultry (Layers) M Persia

4/16 Lecture 2 Feeding Poultry (Meat birds) M Persia

4/18 Lab Quiz 4. Balancing rations for poultry M Persia

4/23 Lecture 1 Feeding sheep D Morrical

4/23 Lecture 2 Feeding horse P Miller-Auwerda

4/25 Lab Balancing rations for sheep/ horses (Sheep & Horse Brands D Morrical/P. Miller-Auwerda

Final Exam

Exam 4

EVALUATION AND GRADE SCALE

Item Number Points each Total pointsProblem sets 12 25 300Quizzes 4 25 100Exams 4 100 400

Drop lowest total quiz or exam score (No make-up quizzes or exams will be given)

-100 -100

Total 700 Grades %A 93-100A- 90-93B+ 87-90B 83-87B- 80-83C+ 77-80C 73-77C- 70-73D+ 67-70D 63-67D- 60-63F <60

DIGESTIVE SYSTEMS REVIEWPages 68-82

Nonruminant Digestive Tract

FUNCTIONS OF PARTS OF THE NONRUMINANT DIGESTIVE TRACT

• Mouth– Chewing – Taste– Secretion of saliva

• Amylase?• Stomach

– Secretions• Hydrochloric acid • Protease

– Pepsinogen → Pepsin• Hormone

– Gastrin

• Small intestine– Secretions

• Pancreas– Proteases

» Trypsinogen → Trypsin» Chymotrypsinogen → Chymotrypsin» Procarboxypeptidase → Carboxypeptidase

– Carbohydrase» Amylase

– Lipase» Lipase

• Liver– Bile salts

• Intestinal mucosa– Carbohydrases

» Maltase» Lactase» Sucrase

– Peptidases– Gut hormones

» Secretin» Cholecystokinin

– Absorption• Large intestine

– Structural carbohydrate fermentation

REVIEW OF NUTRIENT DIGESTION IN NONRUMINANTS

Nutrient Mouth Stomach Small intestine Large intestine

Starch Amylase initiates

digestion to

maltase

Pancreatic amylase & intestinal

maltase to glucose

Disacharides Intestinal disacharidases

to monosacharides

Structural carbohydrates

Fermented to volatile fatty acids

REVIEW OF NUTRIENT DIGESTION IN NONRUMINANTS

Nutrient Mouth Stomach Small intestine Large intestine

Protein HCL and pepsin initiates

digestion to

peptides

Pancreatic proteases &

intestinal dipeptidases

to amino acids

Lipids (Including fat-

soluble vitamins)

Bile salts & pancreatic lipase to

monoglycerides, fatty acids, and

fat-soluble vitamins

Water soluble vitamins

Absorption Produced during

fermentation

SIGNIFICANCE OF NONRUMINANT DIGESTION• Endproducts of nonruminant digestion are

the simple nutrients derived directly from the complex nutrients in the diet– Implications

• Nonruminant nutrient requirements must be met directly from the diet

– Essential Amino acids» Phenylalanine» Valine» Tryptophan» Threonine» Isoleucine» Methionine» Histidine» Arginine» Leucine» Lysine

• Nutrient composition of nonruminant animal products resemble the nutrient composition of the diet

AVIAN DIGESTIVE TRACT

DIFFERENCES BETWEEN AVIAN AND NONRUMINANT MAMMALIAN DIGESTIVE TRACTS

• Mouth– No teeth– No amylase

• Esophagus– Has crop for feed storage

• Stomach– Proventriculus before feed is ground

• Gizzard (Venticulus)– Grinds feed

• Small intestine– No lactase

• Large intestine– Small in most species

• Cloaca– Organ where feces mixed with urinary waste products

RUMINANT DIGESTIVE TRACT

FUNCTIONS OF PARTS OF THE RUMINANT DIGESTIVE TRACT

• Mouth– Prehension of feed

• Lips and tongue– Chewing

• Eating and Rumination– Taste

• Avoidance– Secretion of saliva

• Secretion of buffers– NaHCO3 and NaH2PO4

– Maintain rumen pH• Recycling of N, Na, P, and water to rumen• Bloat prevention

• Esophagus– Involved in rumination and eructation

• Stomach– Reticulum, rumen & omasum

• Fermentation• Absorption of fermentation endproducts

– Abomasum• Secretion of hydrochloric acid and pepsinogen

• Small intestine– Similar to nonruminant– No sucrase

• Large intestine– Similar to nonruminant– More important in browsing species

CARBOHYDRATE DIGESTION IN RUMINANTS

Starch Structural CHO

Methane Undegraded Small intestine (Digestion similar to NR) Fermented

Volatile fatty acids (VFA)

Liver & peripheral tissues

Energy and fat synthesis

PROTEIN DIGESTION IN RUMINANTS

True protein NPN

Undegraded Small intestine Metabolizable Degraded proteinRecycled viasaliva (20% of dietary N) NH3 Microbial protein

NH3

Liver

Urea Kidney Excreted

LIPID DIGESTION IN RUMINANTS

Fat

Undegraded Small intestine (Digestion similar to NR) Degraded

Glycerol

VFA Long chain FA Saturated FA

Liver & peripheral tissues

Energy and fat synthesis

SIGNIFICANCE OF RUMINANT DIGESTION• Greater digestion of plant fiber than nonruminants• Major endproducts of carbohydrates are the VFAs

– High forage diets→More acetate (C2)→More milk fat– High grain diets→More propionate (C3)→Greater body weight

• Low amounts of glucose absorbed– High producing dairy cows subject to ketosis

• Protein requirement is primarily met by rumen degradable N– Rumen undegradable protein needed by high producing dairy

cows or growing cattle– No requirement for essential amino acids

• Ruminant animal products (meat and milk) contain high concentrations of saturated fatty acids (and CLA)