Practical Beef Nutrition and Ration Formulation

1. Practical Beef Nutrition and Ration Formulation Dan Loy 301 Kildee dloy@iastate.edu

2. Basic Outline • Nutrient Requirements of Importance • Adjustments to Requirements (beef cows) • Heifer development • Adjustments to Requirements (feedlot) • Introduction to BRANDS • Common Nutritional “problems” (time permitting)

3. Nutrient Requirements of Importance • Energy • Protein • Major Minerals • Minor Minerals and Vitamins

4. PARTITIONING OF ENERGY Gross Energy (GE) Digestible Energy (DE) Metabolizable Energy (ME) Net Energy (NE) Digestion loss (fecal) Urine loss Combustible gases (CH4) Heat increment (HI) -heat of fermentation -heat of nutrient metabolism NEm -basal metabolism -activity at maintenance -sustaining body temp NEg -retained energy

5. Net Energy for Production • Weight Gain • Lean vs. Fat • Body Condition gain • Fetal Growth • Milk Production

6. Net Energy for Maintenance • Basal Metabolism • Environmental adjustments

7. Metabolizable Protein bypass CP UIP energy (TDN) MP DIP (ammonia) MCP

8. Effect of Weight and ADG on Protein Requirements

9. Major Minerals • Calcium • Required for milk production and growth • Grains are low in Ca, Forages are high in Ca • Phosphorous • Required for milk production and growth • Grains and corn coproducts are high in P, and low in Ca • Ca:P may be important in steers because of urinary calculi

10. Major Minerals cont’ • Magnesium • Low in lush spring grass—Grass Tetany is a common deficiency • Salt • Sodium requirement, most feeds are low in sodium • Potassium • High in forages, low in grains. • Sulfur • Needed when urea is added. Toxicity is concern

11. Trace Minerals and Vitamins • Trace Minerals for Beef Cattle • Co, Cu, I, Fe, Mn, Se, Zn • Should be part of sound mineral supplementation program • Regional differences • Vitamin Requirements • Vitamin A, D, E. Some B vitamins may be needed for stressed calves.

12. Adjustments to Requirements (cows) • Stage of Production • Environmental Adjustments • Cow size and breed • Body Condition Scoring

13. Seasonal Beef Cow Energy Requirements

14. Seasonal Beef Cow Protein Requirements

15. EFFECT OF ENVIRONMENT ON ENERGY REQUIREMENTS Lower Critical Temperature Upper Critical Temperature THERMONEUTRAL ZONE Cold stress Heat Stress Optimum for Performance and Health High Low EFFECTIVE AMBIENT TEMPERATURE

16. Lower Critical Temperature • Coat Description LCT • Summer or wet 59 • Fall 45 • Winter 32 • Heavy winter 18

17. Effective Temperature Temperature Wind Speed -10 0 10 20 30 Calm -10 0 10 20 30 5 -16 -6 3 13 23 15 -25 -15 -5 4 14 30 -46 -36 -26 -16 -6 *Maintenance Requirements increase .7% for each degree of cold stress.

18. Environmental Adjustments NRC • Added are: • Internal insulation factors (body condition or fatness) • Hide thickness • Heat production from feed

19. Effect of Breed on Energy Requirements

20. Effect of Lactation on Energy Requirements

21. Body Condition Scoring • Management tool for adjusting energy requirement of beef cows • Also used to evaluate previous nutrition of feeder cattle

22. Thin Cows • 1  Severely emaciated; starving and weak; no palpable fat detectable over back, hips or ribs; tailhead and individual ribs prominently visible; all skeletal structures are visible and sharp to the touch; animals are usually disease stricken. Under normal production systems cattle in this condition score are rare. • 2  Emaciated; similar to BCS 1, but not weakened; little visible muscle tissue; tailhead and ribs less prominent. • 3  Very thin; no fat over ribs or in brisket; backbone easily visible, slight increase in muscling over BCS 

23. Borderline and Optimum • borderline • 4  Borderline; individual ribs noticeable but overall fat cover is lacking; increased musculature through shoulders and hindquarters; hips and backbone slightly rounded versus sharp appearance of BCS 3. • optimum • 5  Moderate; increased fat cover over ribs, generally only 12th and 13th ribs are individually distinguishable; tailhead full, but not rounded. • 6  Good; back, ribs, and tailhead slightly rounded and spongy when palpated; slight fat deposition in brisket.

24. Fat Condition • 7  Fat; cow appears fleshy and carries fat over the back, tailhead, and brisket; ribs are not visible; area of vulva and external rectum contain moderate fat deposits; may have slight fat in udder. • 8  Very fat; squared appearance due to excess fat over back, tailhead, and hindquarters; extreme fat deposition in brisket and throughout ribs; excessive fat around vulva and rectum, and within udder; mobility may begin to be restricted. • 9  Obese; similar to BCS 8, but to a greater degree; majority of fat deposited in udder limits effective lactation. Under normal production systems cattle in this condition score are rare.

25. Condition Scoring Examples • Condition Score 3 • Condition Score 6 • Condition Score 8 Pictures from NDSU factsheet AS-1026

26. Condition Scoring of Cows • Optimum is condition 5-6 at calving • Each condition score it 80 to 150 pounds depending on cow size • It is best to condition score cows in the fall to allow sufficient time for condition score gain

27. Heifer Development • Target Weight Concept • Heifers should be 60% of mature weight at breeding and 85% of mature weight at calving • Sets target weights and rate of gain • 1400 mature size should weigh: 840 at breeding and 1190 at calving. If fall weight is 500 lb., in November (210 days before breeding), then ADG needs to be 1.6 to breeding.

28. Adjustments to Requirements (feedlot) • Frame size • Implants • Feed additives • Step up programs • Bunk Management/Monitoring

29. Frame Size

30. Weight at 28% Body Fat

31. The Normal Growth Curve Management for more rapid growth changes the shape

32. Muscle Growth

33. Fat Growth

34. Methods of Increasing Grain Ration Step Concentrate Intake % Concentrate Feed Intake X = Days Days Days Increasing Grain Feed Intake Concentrate Intake X % Concentrate = Days Days Days

35. Feed Additives for Feedlot Cattle • Ionophores • MGA • Optaflexx • Broad spectrum antibiotics • Coccidiostats

36. Adapting cattle to grain • Two parts • Manage feed consumption • Adjust rumen microbes to new substrate • Each may take 2-3 weeks with calves • May only take 4 weeks with previously adapted yearlings • Thumb rule for initial grain consumption • .5 to 1% of bodyweight

37. Developing a Starting Program (some examples) • determine expected intake • determine eventual ration • determine beginning concentrate levels

38. Sample starting program - Long hauled calves ( 400 lb.)

39. Sample starting program - precon or low stress calves (400 lb.)

40. Sample starting program - Backgrounded yearlings (800 lb.)

41. Goal of Feedbunk Management • Deliver a consistent, nutritious, fresh ration in a manner that maximizes feed intake and minimizes waste and spoilage.

42. Pen Number Lot Number Head Count In Weight Current Weight Days on Feed Days on Ration Indication of Slick Bunks Indication of When Bunks Last Cleaned Amount of Feed Fed Last 5-7 Days Some Items a Good Bunk Sheet Should Contain From Horton (1990)

43. SDSU Bunk Scoring System • Developed to improve feed deliveries in a University Research Feedlot • Improved efficiency • Uses a 4-Point Bunk Scoring System From Pritchard (1993)

44. SDSU 4-Point Bunk Scoring System

45. Bunk Score 0 to 1/2

46. Bunk score 1 and 2

47. Example Bunk Sheet

48. Making Feed Calls • Cattle Aggressiveness • 25-50-25 Rule • Weather • Heat • Mud • Rain • Cold • Storm Rations?

49. Other Bunk Mgmt Factors • Feed presentation • Mixing • Processing (particle size) • Fines (conditioners) • Nutritional Adequacy

50. Bunk Management Philosophy