Vets Working With Beef Cattle Nutrition

1. Vets Working With Beef CattleNutrition Dgriffin@GPVEC.UNL.EDU http//gpvec.unl.edu

2. Health & Nutrition Go Hand-N-Hand • Understand • What they eat • Water intake • Feed intake • Growth requirements • Production requirements

3. Grass / Forage • Vegetative stage • All regrows • Reproductive stage • No regrowth • LEAVE HALF • Insures adequate CHO reserves • Improves root depth

4. Grass Types Cool Season Warm Season

5. Forage Intake • Grazing “Animal Unit” = 1,000 lbs. • Grazing Intake ~ 2.2 to 2.4% BW on DMB • 3 plant cell wall components … • Cellulose, Lignin & Hemicellulose • NDF includes all 3 components • NDF can be used to estimate “fill” • “Max” Intake adjustment = 120/NDF

6. Estimating Available Forage • An acre is ~ 70 yards square • Available forage … lbs. / acre • Select useable forage in ½ meter SQ • Length & Side of standard note book • Dry sample to 100% Dry Matter (DM) • 40 * grams DM ~ = lbs. / acre

7. What is the most important nutrient? • WATER • How much water does a herbivore need each day? • 10% of BW or 12 gal / AU • Double in heat stress

8. Polio AIP Urinary Calculi Water Intox. Intake related Overload Laminitis Ketosis Nutritional Diseases

9. Environmental Mud 4” = -14% Cold >0º F = 15% Heat Decrease intake Antagonistic Feeds Negative disassociative factor Occurs when rat feedstuffs require different bugs. Nutrient Loss

10. Environmental Mud 4” = -14% Cold >0º F = 15% Heat Decrease intake Antagonistic Feeds Negative disassociative factor Occurs when rat feedstuffs require different bugs. Nutrient Loss

11. Nut Terms • DMB = Dry Matter Basis • ADB = Air Dry Basis • (~90% DMB …used for additives) • AFB = As Fed Basis • Call (bunk call) = amount of AF ration to be delivered (usually daily) • Sometimes to indicate remaining feed • DMI = Dry Matter Intake • DOF = Days On Feed

12. Nut Terms • TDN = Total Digestible Nutrients • An energy term not used by real feedyard nuts • NEm = Net Energy for maintenance • NEg = Net Energy for gain • ~ 45 % the NEm of roughage • ~ 65 % the NEm of grains • DIP = Digestible Intake Protein • UIP = Undigestible Intake Protein

13. Forage Cellulose Cellulolytic Bugs (Slow dig rate) pH 6.2 – 6.8 Volatile Fatty Acids & Methane Glucose Concentrate Starch Amylolytic Bugs (fast dig rate) pH 5.5 – 6.6 Volatile Fatty Acids & Methane + Lactate Glucose Energy Digestion

14. Volatile Fatty Acid Production • 1° Ruminant Energy Source … Big “3” … (APB) Acetate, Propionate, Butyrate • Forage … 70:15:10 • Concentrate … 50:35:15

15. VITAMINS& MINERASLS

16. Mineral Function … More Details • Calcium (CA) … is required for healthy bones, teeth, transmission of nerve impulses & muscle contraction. • Ca blood levels are maintained relatively constant through a fantastic physiologic process involving Ca phosphorus & vitamin D. • Ca & phosphorus are stored in bone & mobilized into the blood & soft tissues (muscles & nerves) as needed. • Ca requirement for non-growing adults such as non-lactating pregnant cows is 15 to 20 grams per day (g/d) & doubles early in lactation & for rapidly growing cattle. • Little is known about the maximum tolerable level of Ca, but it is important to maintain a Ca to phosphorus (Ca:P) ratio of between 1.5:1 to 2.5 to 1.

17. Mineral Function … More Details • Phosphorus (P) … is also required for healthy bones, teeth. It also functions in DNA formation & cellular energy metabolism. • Phosphorus deficiency is frequently considered in grazing cattle. • Symptoms include decreased animal performance, including reduced weight gains, poor reproductive efficiency, & low milk production.

18. Mineral Function … More Details • Magnesium (MG) … is critical for normal function of several metabolic enzymes including glucose utilization & DNA formation. • Grass tetany (frequent urination, erratic behavior, & convulsions) is the most common symptom producer’s associate with a magnesium deficiency. • Magnesium levels decrease in association with the high water content of rapidly growing plants in the spring. • Five to ten grams of magnesium per day is usually adequate, however there are some grazing circumstances that would require these recommended levels to be doubled.

19. Mineral Function … More Details • Cobalt (CO) … is required for vitamin B12 synthesis by ruminal bacteria. • Since vitamin B12 synthesis occurs in the rumen, cobalt must be consumed in the diet daily. • Cattle daily cobalt requirement is approximately one milligram per day. • Cobalt is typically abundant in most feed stuffs therefore additional supplementation is rarely required. • Deficiency symptoms for cobalt include loss of appetite, followed by muscle wasting & anemia.

20. Mineral Function … More Details • Copper (CU) … deficiencies seem to be the most widely discuss yet seldom observed mineral nutrition malady in the beef industry. • Cu deficiency symptoms include loss of hair color (reddish ting to black hair is often described … although low copper levels in the diet is not the only cause of hair bleaching) & unthriftiness, anemia. • One tenth gram (10 PPM) of Cu in the diet is adequate for beef cattle. • The molybdenum (MO), sulfur (S) & iron (FE) levels are as important as the copper level in the diet. • Molybdenum intakes greater than 1/20 gram (5 PPM), sulfur intakes greater than 40 grams (0.4%) &/or iron intakes 10 grams (1000 PPM) will tie up dietary Cu & necessitate increasing Cu supplementation. • BUT … Cu toxicity (symptoms include acute breakdown of red blood cells) in beef cattle does occur especially in heavy muscle breeds of cattle. It can occur with as little as 115 ppm copper in the diet. • Because Cu, molybdenum & iron are stored in the liver symptoms of deficiency or toxicity occur only after long term dietary insult.

21. Mineral Function … More Details • Selenium (SE) … it seems much of the U.S. has soils that are either talked about as deficient or excessive … Maybe not so. • Daily SE requirement is approximately one milligram / day (0.10 PPM). • SE status in cattle is difficult to evaluate. • The old thumb rule about SE deficiencies being associated with acid or sandy soils can be misleading. • Soils or forage analysis is a more reliable & less expensive for predicting cattle status than blood or hair samples. • Check with your area soils & forage testing laboratory for their opinion about the local SE levels. • SE & Vit. E utilization in the body is metabolically related. • Low levels of SE can be off set with Vit. E supplementation. • Conversely low levels of Vit. E can be off set with SE supplementation. • White muscle disease in young calves is the most common problem associated with a SE / Vit. E deficiency. • Retained placentas are commonly associated with SE / Vits. E deficiency BUT there are many other causes not related to minerals. • SE toxicity causes blindness & ataxia (blind-stagers). • It is also known as alkali disease & is mainly seen in western states.

22. Mineral Function … More Details • Zinc (ZN) … is required in the formation of enzymes needed for proper protein & carbohydrate metabolism, & in proper immune function. • Excessive calcium levels can interfere with zinc uptake & utilization. • Dietary requirement for zinc is approximately 1/3 gram (30 PPM) per day. • Deficiency symptoms include hair loss, dermatitis, scabby legs, slow wound healing, excessive salivation & unthriftiness. • Because zinc is abundant in most feedstuffs a deficiency is unlikely. • However supplementation could be considered in cattle on silage rations & if the calcium level in the diet is high.

23. Focus On Important Issues … But the Sky Probably Not Falling • In the Cow – Calf herd, reproduction is the most important production management issue. • While breeding soundness in not all nutrition, the body condition score (BCS), which is related to nutrition, plays a massive role in the fertility of cows, but BCS has virtually nothing to do with mineral nutrition. • BCS is simply related to ration energy intake. • Minerals have been associated with reproductive function such as open cows; cystic ovaries; retained placentas; misshapen ovaries; poor fertilization of eggs; erratic, weak, silent or no heat cycles, delayed conceptions, abortions, & poor quality semen. 

24. Mineral Interactions

25. Mineral Availability … • Sulfate forms are “Indexed as 100% Bioavailability” • Chelates are + 100% index bioavailability • Oxides have the lowest bioavailability • Differences are important but frequently over sold. • All mineral forms, other than Cu & Fe can be used by adjusting the amount add in the supplement. • Cattle are rarely deficient in Fe & excessive amounts adversely affect the immune system. • In fact, excessive amounts of any mineral should be considered immune suppressive.

26. MGA estrus control ADG + 10 % FE – 5 to 6 % +/- Carcass Quality Rumensin intake control ADG +/- 0 % FE – 7 to 10 % (roughage) +/- Carcass Quality Bovatec ADG +6 to 7 % FE – 7 to 10 % CTC & Aureo-S-700 - sickness ADG +20 %, FE – 15 % … all short term (28 days) Decrease sickness 10 to 35 Can feed 10mg/lb/d – 5 days WD = 10 days Tylan / OTC - Liver abscess A+ livers: ADG - 3 to 5 %, FE - 7 % Feed Additives … (all added on “air dry basis” ADB & No ELDU)

27. AMDUCA’ Scope • ELDU permitted only when animal’s health is threatened or animal is suffering … Therapeutic only. • ELDU is not allowed for production • Implants … reproductive … etc. • ELDU is not allowed for feed additives

28. Acidosis • Biochemical & physiological stresses caused by rapid & excessive production & absorption of organic acids & endotoxins when an animal over consumes a meal of readily fermentable carbohydrates, usually grains. • The severity of the acidosis insult determines the symptoms observed … subacute (ph <5.6) to  acute (ph <5.0)

29. Acidosis Factors • Grain Source & Processing • Rate & extent of ruminal digestion • Roughage Source & Processing • Additives (ionophore, buffer, etc) • Rat Step Up Management • Sudden Intake Change • Environmental Change

30. Grain & Processing Ranked by Ruminal Starch Digestion  Fast • Wheat • Barley • High Moisture Corn (ground) • Steam Flaked Corn & High Moisture Corn (whole) • Dry Rolled Corn – Steam Flaked Grain Sorghum • Dry Whole Corn • Dry Rolled Grain Sorghum  Slow

31. Typical pH – Feed Response

32. Acute Visible Diet Transition Intake Regulation Forage = fill Grain = chem mech SDS, PEM, Liv Abs Wall damage Reduce absorb Reduce gain & FE Founder (previous >45) Subacute Difficult to observe Reduced intake Pen conditions Individual reduction masked by pen average Erratic feed intake patterns Intake  pH Acidosis Symptoms

33. Subclinical Acidosis

34. pH  intake All cattle affected Bunk consistency Multiple deliveries Proper processing Roughage (3-10%) Grain adaptation (14-28D) Don’t change two things at once Bunk mgnt flex Ionophore Monitor records Consistency Habit Acidosis Control

35. Water … • The most important nutrient … right? • Know what other nutrients are in the water … SO4 • Requirement … 8 to 10 % BW • 1000 critter needs + 10 gallons a day • UNLESS … its hot • Heat (>82º F) … double water need • Hide color affects water needs in the heat • RESERVE CAPACITY IS EVERYTHING • Days water needs in 2 hrs when it is hot • Measure when system is stressed (2 hrs post feeding)

36. The Ear Is A Busy Place

37. Buller Syndrome … an enigma • *PHYTOESTROGEN (Plant ESTROGEN) • Also molds … including bunk molds • Not associated with DOF • Weather (Hot & Dry) … yes, but • Bunk Management … yes, but • Association with Implants “burst” • Peak release following implanting • Implant location (middle 1/3) … maybe • Crushed pellets … I doubt it.

38. Sick signs • Depression • Appetite / Fill: shape & texture • Loose feces • Respiration / Cough / Rate • Rectal Temperature ??? • Don’t let a thermometer do your thinking’

39. How Sick Cattle Eat • Pull any new calf that is slow to come to the bunkLook for sick cattle shortly after putting out feed.

40. Sick: Intake vs. Temp

41. Feeding Sick Calves • Get a good nutritionist • High quality feedstuffs • Formulate for low intakes • Bunk management • Intake is everything

42. Rat Balancing … Pearson Square

43. Problem … Sick Weaned Feeder • 600 lb … Intake ~ 1.1 % BW (DMB) … intake = 6.6 lbs DM • Protein Requirement = 1.9 lbs CP • Receiving Ration = 13.2% CP … 600 x 2.5% BW = 15 lb x 13.2% = 2 lb CP • Soy Bean Meal (SBM) = 48% • How much SBM must be added to meet the sick calf’s requirements?

44. Answer … Sick Weaned Feeder • Intake 6.6 lbs (DM) … Needs 1.9 lb CP • 1.9 / 6.6 = 28.8 % CP • R-Rat = 13.2 CP – 28.8 = 15.6 parts SBM • SBM = 48.0 CP – 28.8 = 19.2 parts R-Rat • Total … 34.8 parts • R-Rat = 55.2 % , SBM = 44.8 %

46. Implants … & humans No Withdrawal Time Required • Lets look at sources of estrogens …

47. Implants & Growth