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

Abstract

Crossbred, spring-calving cows (yr 1, n = 136; yr 2, n = 113; yr 3, n = 113) were used in a 3-yr 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 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%).

Prenatal and pre-weaning growth and nutrition of cattle: long-term consequences for beef production

“…When compared at equivalent feedlot entry live weights, differences in feed intake due to birth weight were no longer apparent, consistent with findings in twin cattle, which tended to consume less feed in feedlot than singletons, due primarily to their lower live weight (De Rose and Wilton, 1991). Similarly, provision of supplement to cows for 3 months pre-partum had no significant post-weaning effects on ADG, feed intake and feed efficiency in steers (Stalker et al, 2006) or heifers (Martin et al, 2007) that were individually fed following weaning, although the heifers of supplemented cows tended to have greater absolute and residual feed intakes during individual feeding for 84 days post-weaning.…”

“…Consistent with these findings, when variation in live weight that contributed to differences in energy requirements for maintenance and growth were accounted for, low pre-weaning growth rates did not influence measures of efficiency in the feedlot of cattle of equivalent age compared with those grown more rapidly prior to weaning (Hennessy and Arthur, 2004). Furthermore, effects of early post partum nutrition on growth, intake and efficiency of steers (Stalker et al, 2006) and heifers (Martin et al, 2007) in the feedlot soon after weaning were not evident. These results are consistent with earlier findings, reviewed by Berge (1991), that feed conversion efficiency is little affected in the long term by nutrition prior to weaning.…”

“…Similar to our findings, gross compositional differences were not evident in the whole body or in the carcass of Hereford steers or heifers grown to 370 to 400 kg live weight following restricted or adequate nutrition of their dams from 180 days of pregnancy to parturition with a resultant 22% or 6.8 kg difference in calf birth weight . Furthermore, pre-partum supplementation of cows had no effects on the carcass composition of offspring following feedlotting for 222 days post weaning (Stalker et al, 2006).…”

“…Similarly, variable protein supply of the diet during the third trimester may or may not (Anthony et al, 1986a;Holland and Odde, 1992) alter birth weight of calves, while restricted or supplemental dietary protein during early or mid-pregnancy had little effect on birth weights (Perry et al, 1999 and. Furthermore, supplementation of grazing cows for 3 months pre-partum with 0.45 kg/day of 42% crude protein supplement did not affect calf birth weights (Stalker et al, 2006). However, more chronic nutritional restriction of energy and/or protein of heifers from weaning until parturition resulted in birth weight differences of up to 10 kg due to energy supply and up to 7.3 kg due to protein supply (Wiltbank et al, 1965).…”

“…The net effects of maternal nutrition during pregnancy on the calf remain of practical significance to livestock producers, and influences of nutrition during mid-and late pregnancy or late pregnancy only on calf weaning weight have been consistently shown (e.g. Hight, 1966 and1968a;Cafe et al, 2006b;Stalker et al, 2006), irrespective of effects on foetal growth.…”