Ruminant Nutrition for the Practicing Veterinarian Kathy Whitman

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 • • • Water Protein Carbohydrates Fats Vitamins Minerals http: //www. nap. edu/read/19014/chapter/1

Nutrition Acronyms • • 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? • • • 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 Grazing Supplement?

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 -77 F

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/condition 1 a. 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/condition 1 a. shtml • Feed analysis • Rumen contents – p. H – Microbial activity • Blood analysis – Acute disease – Validity for deficiencies/toxicities? – NEFAs, ketones (BHB is best) • Tissue analysis – Liver biopsy: https: //youtu. be/3 Zhezywr. N 8 U – Fetal tissues

Nutrition Resources Feed analysis: https: //youtu. be/t 4 sg. XS 8 H 53 k

A Word on Different Ruminants… • Cattle – Cow-calf – Feedlot – Dairy • Sheep/Goats – Pasture – Feedlot