Strategically Feeding Protein and Energy During Winter and Managing Cow Condition

1. Strategically Feeding Protein and Energy During Winter and Managing Cow Condition Don C. Adams dadams1@unl.edu

2. Nutrient Requirements of the Cow

3. Net Energy (NE) Requirements for a 1200 lb March Calving Cow with 23 lbs/day Peak Milk Production NRC (1996)

4. Crude Protein in Cattle Diets on Sandhills Range Crude Protein, % OM APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB • Month

6. Forage Organic Matter Intake and Particulate Passage Observed Using Steers Grazing Sandhills Meadow or Range Organic Matter Intake g/kg BW Particulate Passage %/hr

7. Rumen Volume and Dry Matter Fill of Steers Grazing Sandhills Meadow and Range g/kg BW

8. Amount of Milk Produced by the Cow .

9. 25 20 15 10 Milk Production by Cows With High and Low Production During Summer Grazing • 5 High Daily milk production, lb Low June 18 Sept 14 May 28 Aug 1 Adams et al. 1993

10. 1 0.5 0 (0.5) Body Condition Score Change for Cows With High or Low Milk Production During Summer Grazing • (1) Low Body condition score change High April 10 On grass June 19 Beginning breeding Aug 5 End breeding Sept 20 Weaning

11. 18 16 14 12 10 CRUDEPROTEIN, % 8 6 4 2 0 APR MAY JUN JUL AUG SEP OCT NOV DEC JAN Crude Protein in Cattle Diets on Northern Great Plains Rangeland

12. Date of Weaning

13. Weaning Dates • 8 weaning dates: • August 18, 1999 to November 24, 1999 • August 16, 2000 to November 22, 2000 (140 to 240 days after calving)

14. Effect of Weaning Date on Change in Cow Body Condition Score R2 = .95

15. Average Weaning and Supplement Effects on Cow Body Condition Score From September to December Condition Score Change

16. Weaning and Supplement Treatments for March Calving Cows • August weaning • 1. No protein supplement during winter grazing • 2. Protein supplement during winter grazing • November weaning • 1. No protein supplement during winter grazing • 2. Protein supplement during winter grazing

17. Pregnancy 95.1% 94.2% Effect of Weaning Date on Cow Body Condition Score P<.0001

18. Pregnancy 93.8% 95.5% Effect of Protein Supplementation on Cow Body Condition Score P<.0001

19. No Protein Supplement November Wean August Wean Protein Supplement

20. November Wean, with Winter Supplement November Wean, No Winter Supplement November Wean, with Winter Supplement November Wean, No Winter Supplement

21. August November 432 518 Calf Weaning Weight, lb

22. Protein No Protein 397 382 Calf Weaning Weight, lb

23. Costs for Items That Differ and Net Revenues at Weaning August November Supp. No Supp.Supp. No Supp. Cow costs, $/hd Fall grazing 54.26 52.91 75.16 73.37 Supplement 15.77 15.77 Total Cost 70.03 52.91 90.93 73.37

24. Costs for Items That Differ and Net Revenues at Weaning August November Supp. No Supp.Supp. No Supp. Cow costs, $/hd Fall grazing 54.26 52.91 75.16 73.37 Supplement 15.77 15.77 Total Cost 70.03 52.91 90.93 73.37 Revenue, $/hd Gn/loss, culls -11.66 -5.39 -22.82 -16.06 Calves 374.70 395.47 426.66 421.93 Net/cow exp. 293.01 337.17 312.91 332.50

25. Feedlot Performance Weaning Protein Supp. Early LateSupp. No Supp. In wt, lb 432 518 487 463 Days on feed 244 194 Interactions ES ENS LS LNS Out wt, lb 1274 1259 1314 1213 Daily gain, lb 3.4 3.4 4.0 3.7 HCW, lb 796 780 816 754

26. Costs and Net Revenues After Finishing August Wean November Wean Supp. No Supp.Supp. No Supp. Costs, $/hd Calf 471 449 474 451 Feed 326 301 269 249 Yardage 74 74 59 59 Trucking 2 2 3 3 Processing 25 25 25 25 Total Cost 898 851 830 787 Revenue, $/hd Steer 872 858 877 810 Net/cow exp -9 3 22 11

27. Wintering June Calving Cows and June Born Calves

28. Cost of Winter Grazing (Jan – Mar) and Supplement for June Calving Cows

29. End of Summer Costs and Breakevens for Calves Wintered in Drylot or On Range

30. Finishing Costs and Breakevens for Calves Wintered in Drylot or On Range

31. Wintering Pregnant Heifers

32. Crude (CP), Escape (UIP) and Degradable Protein (DIP) in Cattle Diets on Sandhills Range Protein, %OM APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB Month

33. Composition of Supplements Fed to Heifers Grazing Nebraska Sandhills Range

34. Pregnancy Rate of Heifers Supplemented to Meet MP Requirements or CP Requirements

35. Cost of Supplements Fed and Net Present Value (NPV) of Bred Heifers