Effects of pre- and postpartum nutrition on reproduction in spring calving cows and calf feedlot performance1

L. A. Stalker, D. C. Adams, T. J. Klopfenstein, D. M. Feuz, R. N. Funston
2006 Journal of Animal Science  
Crossbred, spring-calving cows (yr 1, n = 136; yr 2, n = 113; yr 3, n = 113) were used in a 3yr experiment to evaluate the influence of supplemental protein prepartum and grazing subirrigated meadow postpartum on pregnancy rates and calf feedlot performance. A 2 × 2 factorial arrangement of treatments was used in a switchback design. From December 1 to February 28, cows grazed dormant upland range in 8 pastures (32 ± 2 ha each). The equivalent of 0.45 kg of supplement/cow per d (42% CP) was
more » ... d (42% CP) was provided to half of the cows on a pasture basis 3 d/wk. For 30 d before the beginning of breeding (May 1 to May 31), half of the cows grazed a common subirrigated meadow (58 ha), and the remainder was fed grass hay in a drylot. Cow BW and BCS were monitored throughout the year, and steer calf performance was determined until slaughter. Feeding supplement prepartum improved (P = 0.01 to P < 0.001) BCS precalving (5.1 vs. 4.7) and prebreeding (5.1 vs. 4.9) and increased (P = 0.02) the percentage of live calves at weaning (98.5 vs. 93.6%) but did not affect (P = 0.46) pregnancy rate (93 vs. 90%).
doi:10.2527/jas.2005-640 pmid:16908664 fatcat:3sehiwecqbcsxcbm2d4pmlmleu