Myers S E, Faulkner D B, Ireland F A, Berger L L, Parrett D F
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
J Anim Sci. 1999 Feb;77(2):300-10. doi: 10.2527/1999.772300x.
A 2-yr study was conducted to determine the effects of three weaning management systems on cow and steer performance. Cow-calf pairs were randomly assigned to one of three treatments, in which the steer calves were 1) early-weaned (yr 1, 177 +/- 9 d; yr 2, 158 +/- 21 d of age) and placed on a finishing diet (EW), 2) supplemented with grain for 55 d on pasture (yr 1, 177 to 231 d; yr 2, 158 to 213 d of age) while nursing their dams and then placed on a finishing diet (NWC), and 3) on pasture for 55 d while nursing their dams (yr 1, 177 to 231 d; yr 2, 158 to 213 d of age) and then placed on a finishing diet (NW). In yr 2, potential breed differences were evaluated using steers of three breed types: 1) Angus x Hereford (BRI); 2) Angus x Simmental (CON); and 3) Angus x Wagyu (WAG). In yr 1, EW steers gained 100% faster (P = .0001) than the average of NWC and NW steers, and NWC steers gained 32% faster (P = .02) than NW steers before weaning. In the feedlot, EW steers had lower intakes (7.70 vs 8.16 kg/d, P = .008) and better feed conversions (.170 vs .153, P = .002) than the average of NWC and NW steers. Marbling score was improved for EW steers compared with the average of NWC and NW steers (P = .003). In yr 2, EW steers had higher gains (P = .0006) during the entire study than the average of NWC and NW steers, and NWC steers had higher gains (P = .003) than NW steers. The EW steers had lower intakes (7.29 vs 7.68 kg/d, P = .0008) and better feed conversions (.160 vs .141, P = .0001) than the average of NWC and NW steers. The CON steers were heavier at slaughter than BRI steers (P = .01), and BRI steers were heavier than WAG steers (P =.0004). Early weaning improved the percentage of steers grading Average Choice or higher by 40%. The percentage of BRI steers grading Choice or greater was 21% higher and percentage of steers grading Average Choice or greater was 33% higher than CON. Cows with EW steers had higher ADG than cows with NW steers (.38 vs -.17 kg/d, P = .0001) before weaning. Cows with EW steers gained in body condition score (.23 vs .00, P = .04), and cows with NW steers did not change. Early weaning improved feed efficiency and quality grades of beef steers.
开展了一项为期2年的研究，以确定三种断奶管理系统对母牛和公牛生长性能的影响。母牛犊对被随机分配到三种处理方式之一，其中公牛犊1）早期断奶（第1年，177±9天；第2年，158±21天龄）并开始育肥日粮（EW），2）在牧场随母牛哺乳时补饲谷物55天（第1年，177至231天；第2年，158至213天龄），之后开始育肥日粮（NWC），3）在牧场随母牛哺乳55天（第1年，177至231天；第2年，158至213天龄），之后开始育肥日粮（NW）。在第2年，使用三种品种类型的公牛评估潜在的品种差异：1）安格斯×赫里福德（BRI）；2）安格斯×西门塔尔（CON）；3）安格斯×和牛（WAG）。在第1年，EW公牛在断奶前比NWC和NW公牛的平均生长速度快100%（P = 0.0001），NWC公牛比NW公牛快32%（P = 0.02）。在饲养场中，EW公牛的采食量低于NWC和NW公牛的平均水平（7.70对8.16千克/天，P = 0.008），饲料转化率更好（0.170对0.153，P = 0.002）。与NWC和NW公牛的平均水平相比，EW公牛的大理石花纹评分有所提高（P = 0.003）。在第2年，EW公牛在整个研究期间的生长速度高于NWC和NW公牛的平均水平（P = 0.0006），NWC公牛高于NW公牛（P = 0.003）。EW公牛的采食量低于NWC和NW公牛的平均水平（7.29对7.68千克/天，P = 0.0008），饲料转化率更好（0.160对0.141，P = 0.0001）。CON公牛在屠宰时比BRI公牛重（P = 0.01），BRI公牛比WAG公牛重（P = 0.0004）。早期断奶使等级达到精选级或更高的公牛比例提高了40%。BRI公牛达到特选级或更高等级的比例比CON公牛高21%，达到精选级或更高等级的公牛比例比CON公牛高33%。在断奶前，携带EW公牛的母牛比携带NW公牛的母牛具有更高的平均日增重（0.38对-0.17千克/天，P = 0.0001）。携带EW公牛的母牛体况评分增加（0.23对0.00，P = 0.04），而携带NW公牛的母牛没有变化。早期断奶提高了肉牛的饲料效率和品质等级。
