Boyd G W, Kiser T E, Lowrey R S
J Anim Sci. 1987 Jun;64(6):1703-9. doi: 10.2527/jas1987.6461703x.
At 50 d prior to predicted calving, 37 multiparous Angus cows were grouped by sire of mating, age and weight of cow and placed on either a high energy (HE, n = 19) diet or a moderate energy (ME, n = 18) diet. Objectives were to determine the effect of prepartum nutrition on: prepartum serum concentrations of estrone (E1), estrone sulfate (E1SO4) and progesterone (P4); pre- and postpartum cow body weight changes; calf birth weight and cow and calf postpartum performance. The ME cows were group-fed Coastal bermudagrass hay ad libitum and dormant pasture; HE cows were group-fed 2.7 kg ground corn X head-1 X d-1 in addition to the ME treatment. Both groups were combined and fed identically after calving. Cows fed HE were heavier (P less than .01) than cows fed ME at d 10 prepartum and their calves were heavier (P less than .05) at birth and weaning than calves from cows fed ME. Serum E1 concentrations were not significantly different between groups, but serum E1SO4 was higher (P less than .01) at d 10 prepartum in ME cows compared with HE cows. Serum P4 concentrations of ME cows were higher (P less than .05) than those of HE cows. Cow body weights were greater (P less than .01) for the HE group than for the ME group during the first 6 mo postpartum. Cow rebreeding performance was identical for both groups.
在预计产犊前50天，将37头经产安格斯母牛按交配公牛、母牛年龄和体重进行分组，分别给予高能量（HE，n = 19）日粮或中等能量（ME，n = 18）日粮。目的是确定产前营养对以下方面的影响：产前血清雌酮（E1）、硫酸雌酮（E1SO4）和孕酮（P4）的浓度；产前和产后母牛体重变化；犊牛出生体重以及母牛和犊牛产后性能。ME组母牛自由采食海岸百慕大草干草和休耕地牧草；HE组母牛除采用ME组的处理外，还每头每天补饲2.7千克粉碎玉米。两组母牛在产犊后合并饲养，日粮相同。产前10天，采食HE日粮的母牛比采食ME日粮的母牛体重更重（P < 0.01），其犊牛在出生和断奶时比采食ME日粮的母牛所产犊牛体重更重（P < 0.05）。两组之间血清E1浓度无显著差异，但产前10天，ME组母牛血清E1SO4浓度高于HE组母牛（P < 0.01）。ME组母牛血清P4浓度高于HE组母牛（P < 0.05）。产后前6个月，HE组母牛体重比ME组母牛更重（P < 0.01）。两组母牛的再繁殖性能相同。
