ANIMAL SCIENCE 320
Instructors
Dr. Cheryl L. Morris
201D Kildee Hall
clmorris@iastate.edu
Graduate TA:
Olivia Genther
333 Kildee Hall
genthero@iastate.edu
Dr. Jim Russell
313 Kildee Hall
jrussell@iastate.edu
Graduate TA:
Matt O’Neil
337C Kildee Hall
maoneil@iastate.edu
Meeting Times and Locations
Monday and Wednesday Lectures:
8:00 – 8:50 AM
Kildee 108
Wednesday Labs:
2:10 – 4:00 PM
Kildee 203
Computer Labs:
SCHEDULE
Date
1/14
Lecture/Lab
Lecture
Topic
Introduction. Reviewing nutrient digestion in nonruminant and ruminant
animals
Chemical analysis of feedstuffs
Instructor
C.Morris
1/16
Lecture
1/16
Lab
Calculating the composition of feedstuffs and diets
C.Morris
1/21
Lecture
Determining the digestibility of feedstuffs
C. Morris
1/23
Lecture
Energy systems for feedstuffs
C. Morris
1/23
Lab
Use of energy systems for calculating feed intake or animal production
C. Morris
1/28
Lecture
Energy feedstuffs
J. Russell
1/30
Lab
Quiz 1. Feedstuff identification
J. Russell
2/4
Lecture
Protein supplements
J. Russell
2/6
Lecture
By-product feedstuffs
J. Russell
2/6
Lab
Basic Ration Formulation
J. Russell
2/11
Lecture
Forage species and quality
J. Russell
2/13
Lecture
Grazing systems
J. Russell
2/13
Lab
2/18
Lecture
Harvested forages (Hay)
J Russell
2/20
Lecture
Harvested forages (Silages)
J Russell
2/20
Lab
Multiple Ingredient Ration Formulation
J Russell
2/25
Lecture
Mineral and vitamin supplements
C. Morris
2/27
Lecture
Feed additives
C. Morris
2/27
Lab
Formulating premixes
C. Morris
3/4
Lecture
Feed processing and mixing
C. Morris
C.Morris
Exam 1
SCHEDULE
Date
3/6
Lecture/Lab
Lecture
3/6
Lab
3/11
Topic
Feed processing and mixing
Instructor
C. Morris
Quiz 2. Interpreting feed tags and regulations
C. Morris
Lecture
Companion Animals
C. Morris
3/13
Lecture
Companion Animals
C. Morris
3/13
Lab
Companion Animals
C. Morris
3/25
Lecture
Poultry
M. Persia
3/27
Lecture
Poultry
M. Persia
3/27
Lab
Poultry
M. Persia
4/1
Lecture
Horses
C. Morris
4/3
Lecture
Horses
C. Morris
4/3
Lab
Exam 2
C. Morris
4/8
Lecture
Swine
J. Patience
4/10
Lecture
Swine
J. Patience
4/10
Lab
Swine
J. Patience
4/15
Lecture
Beef Cattle
J. Russell
4/17
Lecture
Beef Cattle
J. Russell
4/17
Lab
Beef Cattle
J. Russell
4/22
Lecture
Dairy Cattle
J. Russell
4/24
Lecture
Dairy Cattle
J.Russell
4/24
Lab
Quiz 3 & Dairy Cattle
J. Russell
4/29
Lecture
Small Ruminants (Goats/Sheep)
D. Morrical
SCHEDULE
Date
5/1
Lecture/Lab
Lecture
5/1
Lab
Topic
Small Ruminants (Goats/Sheep)
Exotics
Final Exam (Exam #3)
Instructor
D. Morrical
C. Morris
EVALUATION AND GRADE SCALE
Grading:
Item
Number
Points each
Total points
Problem sets
12
25
300
Quizzes
3
33.3
100
Exams
3
100
300
-100
-100
Drop lowest total quiz or exam score
Total
Grades
600
%
A
93-100
A-
90-93
B+
87-90
B
83-87
B-
80-83
C+
77-80
C
73-77
C-
70-73
D+
67-70
D
63-67
D-
60-63
F
<60
DIGESTIVE SYSTEMS REVIEW
Pages 63-78
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
• Importance and size dependent on diet
REVIEW OF NUTRIENT DIGESTION IN NONRUMINANTS
Nutrient
Mouth
Starch
Amylase
initiates
digestion
to
maltose
Disaccharides
Structural
carbohydrates
Stomach
Small intestine
Large
intestine
Pancreatic
amylase &
intestinal
maltase to
glucose
Intestinal
disaccharidases
to
monosacharides
Fermented
to volatile
fatty acids
REVIEW OF NUTRIENT DIGESTION IN NONRUMINANTS
Nutrient
Protein
Mouth
Stomach
Small intestine
HCL and
pepsin
initiates
digestion
to
peptides
Pancreatic
proteases &
intestinal
dipeptidases
to amino acids
Lipids
(Including fatsoluble
vitamins)
Bile salts &
pancreatic
lipase to
monoglycerides,
fatty acids, and
fat-soluble
vitamins
Water soluble
vitamins
Absorption
Large
intestine
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
• Nutrient composition of nonruminant animal
products resemble the nutrient composition of
the diet
• Nonruminant nutrient requirements must be
met directly from the diet
– Essential Amino acids
a.
b.
c.
d.
e.
Which of the following is not an
amino acid that is essential in
nonruminant diets?
Glutamic acid
Phenylalanine
Lysine
Tryptophan
None of the above
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 (Ventriculus)
– Grinds feed
• Small intestine
– No lactase
• Large intestine (Ceca)
– 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
Fermented
Volatile fatty acids (VFA)
Liver & peripheral tissues
Energy and fat synthesis
Small intestine
(Digestion similar to NR)
What is the primary volatile fatty acid
produced in the rumen fed a high
forage diet?
1.
2.
3.
4.
5.
Acetic acid
Butyric acid
Lactic acid
Conjugated linoleic acid
Propionic acid
PROTEIN DIGESTION IN RUMINANTS
True protein
NPN
Undegraded
Small intestine
Metabolizable
protein
Degraded
Recycled via
saliva
(20% of dietary N)
NH3
Microbial
protein
NH3
Liver
Urea
Kidney
Excreted
LIPID DIGESTION IN RUMINANTS
Fat
Undegraded
Degraded
Glycerol
VFA Long chain FA
Liver & peripheral tissues
Energy and fat synthesis
Saturated FA
Small intestine
(Digestion similar to NR)
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)