Myers S E, Faulkner D B, Nash T G, Berger L L, Parrett D F, McKeith F K
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
J Anim Sci. 1999 Feb;77(2):311-22. doi: 10.2527/1999.772311x.
A 2-yr study was conducted to evaluate 1) steers fed ad libitum high concentrate after weaning (CONC), or 2) steers grown on pasture for 82 d, followed by high-concentrate finishing (PAST), on the performance and carcass traits of 74 early-weaned (117 d of age) steers. Potential breed differences were evaluated using crossbred steers of three types: 1) 3/4 Angus x 1/4 Simmental (BRI), 2) 3/4 Simmental x 1/4 Angus (CON), and 3) 1/2 Wagyu x 1/4 Angus x 1/4 Simmental (WAG). Steers were randomly assigned within breed to the two treatments. There was no interactions (P > .10), so the data were pooled over years. The CONC steers had an ADG that was .17 kg/d higher (P = .0001), intake 1.09 kg/d lower (P = .0001), and gain:feed ratio .013 unit better (.190 vs .177, P = .008) than PAST steers overall. Growing treatment did not affect total concentrate consumed (P = .97). The BRI steers required 31 d less than did CON steers (P = .008), and 23 d less than WAG steers (P = .05) when fed to a constant fat end point (1.1 cm). The BRI steers exhibited an ADG .16 kg/d higher (P = .0003), tended (P = .07) to have an ADG intake .49 kg/d higher, and exhibited gain:feed .01 unit better (.189 vs 180) than WAG steers. When compared with CON steers, BRI steers consumed 310 kg less total concentrate (P = .0003). No differences (P > .38) were observed between growing treatments for carcass characteristics or sensory attributes except that CONC steers tended (P = .11) to improve percentage of steers grading Average Choice or higher by 47% over PAST steers. The WAG steers had a 76-unit higher marbling score (1,000 = Small00, 1,100 = Modest00) (P = .006) than BRI steers, resulting in 19% more (P = .09) steers grading > or = Choice and 82% more (P = .03) grading > or = Average Choice. Liver (P = .15) and rumen (P = .01) weights as a percentage of hot carcass weight were reduced for CONC steers. The CONC steers had higher gain, lower intake, better efficiency, reduced liver and rumen weights, and consumed the same amount of total concentrate when compared with PAST steers. The BRI steers had less finishing days and lower daily intake compared with CON steers. The WAG steers had more days finishing, lower gain, lower intake, more undesirable efficiencies, consumed the same amount of total concentrate, and improved quality grades compared with BRI steers.
开展了一项为期2年的研究，以评估以下两种情况对74头早期断奶（117日龄）公牛的生长性能和胴体性状的影响：1）断奶后自由采食高能量日粮的公牛（CONC）；2）在牧场饲养82天，随后进行高能量日粮育肥的公牛（PAST）。使用三种杂交公牛评估潜在的品种差异：1）3/4安格斯×1/4西门塔尔（BRI）；2）3/4西门塔尔×1/4安格斯（CON）；3）1/2和牛×1/4安格斯×1/4西门塔尔（WAG）。公牛在品种内随机分配到两种处理组。不存在交互作用（P>.10），因此数据按年份合并。总体而言，CONC组公牛的平均日增重（ADG）比PAST组高 .17 kg/d（P = .0001），采食量低1.09 kg/d（P = .0001），料重比高 .013单位（.190对.177，P = .008）。生长处理对总精料采食量无影响（P = .97）。当育肥至恒定脂肪终点（1.1厘米）时，BRI组公牛比CON组公牛所需天数少31天（P = .008），比WAG组公牛少23天（P = .05）。BRI组公牛的ADG比WAG组高 .16 kg/d（P = .0003），采食量倾向于高 .49 kg/d（P = .07），料重比高 .01单位（.189对180）。与CON组公牛相比，BRI组公牛的总精料采食量少310千克（P = .0003）。除CONC组公牛的上等选择级或更高级别等级的公牛比例比PAST组公牛高47%（P = .11）外，生长处理对胴体特征或感官特性无差异（P>.38）。WAG组公牛的大理石花纹评分比BRI组高76分（1000 = 少量，1100 = 适度）（P = .006），导致等级为≥选择级的公牛多19%（P = .09），等级为≥上等选择级的公牛多82%（P = .03）。CONC组公牛肝脏（P = .15）和瘤胃（P = .01）重量占热胴体重的百分比降低。与PAST组公牛相比，CONC组公牛生长速度更快、采食量更低、效率更高、肝脏和瘤胃重量减轻，总精料采食量相同。与CON组公牛相比BRI组公牛育肥天数更少、日采食量更低。与BRI组公牛相比，WAG组公牛育肥天数更多、生长速度更低、采食量更低、效率更低、总精料采食量相同、胴体质量等级更高。
