Transcript Ruminant Nutrition for the Practicing Veterinarian

Ruminant Nutrition for the
Practicing Veterinarian
Kathy Whitman, DVM, MS
Nutrition:
All processes in the collection and
utilization of feedstuffs for maintaining
life or production of a product. Involves
behavior, digestions, absorption,
metabolism, and excretion.
Question 1
• What percentage of beef cow production cost
is related to nutrition?
A.
B.
C.
D.
15%
25%
50%
65%
Nutrient Requirements
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Water
Protein
Carbohydrates
Fats
Vitamins
Minerals
http://www.nap.edu/read/19014/chapter/1
Nutrition Acronyms
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DMI
AFB
NDF/ADF
CP, DIP, UIP
TDN
NEm, NEg, Nel
VFAs
DOF
Question 2
• When reading a feed label, what is “ash?”
A. The amount of fine particles after sifting
B. The mineral content
C. The vitamin content
D. The dry matter percentage
Reading a feed label
www.aafco.org
Reading Feed Analysis
Near Infrared Reflectance Spectroscopy (NIRS) Analysis
As Fed
100% Dry Matter
Moisture, %
7.3
Dry Matter, %
92.7
Crude Protein, % CP
19.5
21.0
Acid Detergent Fiber, % ADF
26.6
28.7
Neutral Detergent Fiber, % NDF
35.4
38.2
Total Digestible Nutrients, % TDN 65.3
70.4
Net Energy, Maint, Mcal/lb
0.70
0.75
Net Energy, Gain, Mcal/lb
0.44
0.47
Net Energy, Lact, Mcal/lb
0.68
0.73
Digestible Energy, Mcal/lb
1.31
1.41
Met. Energy, Beef, Mcal/lb
1.07
1.16
Relative Feed Value, (RFV)
162
Calcium, % Ca
1.18
1.28
Phosphorus, % P
0.27
0.29
Magnesium, % Mg
0.25
0.27
Potassium, % K
2.93
3.16
What is a ruminant?
• Fermentation!
– Ruminants digest 50-70% cellulose; monogastrics 3-5%
• Feeding bugs
Question 3
• How many stomach compartments does a
camelid have?
A. 2
B. 3
C. 4
D. 5
Important Species Differences
• Cu in sheep vs. other ruminant species
• Monensin (Rumensin) max dose: 360 vs 40
mg/hd/day
What determines requirements?
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Age?
Stage of production?
Body condition?
Environment?
Feedstuffs available?
Producer goals?
Changes in requirement
What is the Focus?
• Major balancers
– Protein: 8% Cows, 13-14% Heifers (MINIMUMS!!)
– Energy: TDN, NEm, NEg, NEl
– Ca:P ratio-what is appropriate?
• Adjustments
– Supplementation??
Rules of thumb
• Water intake: 8-16% BW
• Feed intake (Dry Matter): 1.5-2.2% BW
• Nutrient requirements
– Protein: 0.15-0.2% BW
– Energy (TDN): 1-1.8% BW
– Ca:P: 2-3:1 Ratio, 0.2-0.3%:0.1-0.15% BW
Feed sources
• Forage
• Concentrates
Question
In the traditional spring calving cattle cycle, how
much time does a bovine that will be fed for human
consumption spend on pasture?
A. Never, it goes right to a feedlot
B. Allowed to graze until weaned at 2 months, then
confined and put on a grain diet
C. Allowed to graze until weaned at 6 months, then
confined and put on a grain diet
D. It grazes until right before harvest with no
confinement
Pasture Management
Lactation
1ST
3RD
2ND
Grazing
JAN
FEB
MAR
APR
MAY
JUN
Supplement?
JUL
AUG
SEP OCT
NOV
DEC
Confined feeding
• “Dry lot”
• Less available land space
• Advantages?
• Disadvantages?
http://beef.unl.edu/cattleproduction/drylotting
beefcows
Protein
• Function
• Ruminant metabolism
– AA contruction
– Fiber utilization
– Why is it unnecessary to supplement daily?
• General requirements
– 0.15-0.2% BW
Question 5
• In general, there are 10 essential amino acids.
What additional amino acid is required by
cats?
A. Taurine
B. Leucine
C. Methionine
D. Tryptophan
Energy
• How do we measure energy in rations?
– TDN
– NE
– NDF/ADF
– Non-structural: Starches/sugars
• Where do ruminants derive energy?
– VFAs
– Non-structural carbs
Question 4
True or False?
The energy demand of a cow at maintenance is
higher when the temperature is 80F vs. 20F
Thermo-neutral Zone: 32-77F
Vitamins and Minerals
Vitamins and Minerals
Feed Additives
• Nutrient supplementation
– Salt block
– Lick tubs
– Fly controls
• Ionophores
– Monensin
• Antibiotics
– CTC
– Tylan
• Hormones
– MGA
Veterinary Feed Directives
• Prohibits use of antimicrobials for production
• Affects feed grade antimicrobials
– Not water or parenteral
• ELDU not applicable
• Prescription required
• Limits availability, esp. for small ruminants
Question
True or False?
Ionophores are considered antibiotics
Nutritional Disease
• Deficiencies
• Toxicities
• Interactions
Obvious…
…Sub-clinical
How do we know?
• Tools to evaluate nutritional status
– Body Condition Scoring
• https://beef.unl.edu/learning/condition1a.shtml
– Behavior?
• Health issues
– Increases is morbidity or mortality
– Unthrifty
– Ineffective preventatives, treatments
• Performance issues
– Reproductive deficiencies
– Poor growth
Diagnostics
• Body condition scoring
– https://beef.unl.edu/learning/condition1a.shtml
• Feed analysis
• Rumen contents
– pH
– Microbial activity
• Blood analysis
– Acute disease
– Validity for deficiencies/toxicities?
– NEFAs, ketones (BHB is best)
• Tissue analysis
– Liver biopsy: https://youtu.be/3ZhezywrN8U
– Fetal tissues
Nutrition Resources
Feed analysis:
https://youtu.be/t4sgXS8H53k
A Word on Different Ruminants…
• Cattle
– Cow-calf
– Feedlot
– Dairy
• Sheep/Goats
– Pasture
– Feedlot