Marston T T, Lusby K S, Wettemann R P, Purvis H T
Department of Animal Science, Oklahoma State University, Stillwater 74078, USA.
J Anim Sci. 1995 Mar;73(3):657-64. doi: 10.2527/1995.733657x.
In three consecutive years, spring-calving Hereford and Hereford x Angus cows (n = 348) were used to determine effects of level of supplemental energy or protein before and after calving on cowherd performance. Beginning on November 1, cows were individually fed 1.22 kg/d of a 40% CP (PROTEIN) or 2.44 kg/d of a 20% CP supplement (ENERGY) until calving. After calving, cows remained on the same supplement, were switched to the other supplement, or were fed 2.44 kg/d of a 40% CP supplement (HI PROT). Supplementation ended on April 20, the start of a 65-d breeding season. Cows fed ENERGY during gestation had greater BW gains (9 kg) at calving than PROTEIN-fed cows (P < .01). Calf weaning weight was not affected by supplementation. Cows fed ENERGY before calving had an 11% greater pregnancy rate than the cows fed PROTEIN (P < .002). Cows fed PROTEIN or ENERGY after calving had similar BW gains but cows fed HI PROT after calving lost less BW during supplementation (P < .002). Pregnancy rates were not influenced by treatments fed for a short period after calving. In conclusion, conception rates were significantly improved by feeding greater levels of supplemental energy prepartum but not postpartum. Energy supplements can affect reproduction with minimal effects on BW or condition.
连续三年，使用春季产犊的赫里福德牛以及赫里福德牛与安格斯牛的杂交母牛（n = 348）来确定产犊前后补充能量或蛋白质水平对牛群生产性能的影响。从11月1日开始，母牛分别每天饲喂1.22千克含40%粗蛋白（蛋白质）的补充料或2.44千克含20%粗蛋白的补充料（能量）直至产犊。产犊后，母牛继续饲喂相同的补充料、换喂另一种补充料，或每天饲喂2.44千克含40%粗蛋白的补充料（高蛋白质）。补充饲喂在4月20日结束，此时开始为期65天的繁殖季节。妊娠期饲喂能量补充料的母牛在产犊时的体重增加量（9千克）高于饲喂蛋白质补充料的母牛（P < 0.01）。犊牛断奶体重不受补充饲喂的影响。产犊前饲喂能量补充料的母牛的怀孕率比饲喂蛋白质补充料的母牛高11%（P < 0.002）。产犊后饲喂蛋白质或能量补充料的母牛体重增加量相似，但产犊后饲喂高蛋白质补充料的母牛在补充饲喂期间体重损失较少（P < 0.002）。产犊后短期饲喂的处理方式对怀孕率没有影响。总之，产前饲喂较高水平的补充能量可显著提高受孕率，产后则不然。能量补充料可影响繁殖，对体重或体况的影响最小。
