Comerford J W, Benyshek L L, Bertrand J K, Johnson M H
Anim. and Dairy Sci. Dept., University of Georgia, Athens 30602.
J Anim Sci. 1988 Feb;66(2):306-16. doi: 10.2527/jas1988.662306x.
Evaluations of steer and heifer progeny from a diallel mating design of Simmental, Limousin, Polled Hereford and Brahman beef cattle over 5 yr are presented. Traits evaluated included final weight, hot carcass weight, ribeye area, 12th rib fat thickness, marbling score, yield grade, dressing percentage and percentage of kidney, pelvic and heart fat. Progeny of Simmental sires were heavier at slaughter than those with Brahman sires (P less than .05), but no differences were found for carcass weight. Dressing percentage was higher for Limousin crosses compared with progeny of other sire breeds (P less than .05). Similar results were found for dam breeds, except that progeny of Limousin dams had heavier carcasses with a higher dressing percentage (P less than .05) than Brahman crosses. Crosses of Limousin and Simmental had larger ribeye areas (P less than .05) compared with calves of the other breeds. Progeny of Polled Hereford dams had higher marbling scores and were fatter than progeny of dams of other breeds (P less than .05). Heterosis estimates were significant for all Brahman crosses for final weight, carcass weight and ribeye area, but these contrasts were negligible for other traits. Estimates of general combining ability were positive and significant for Simmental for final weight, carcass weight, ribeye area and marbling score and were significant and negative for Limousin for final weight, fat thickness and yield grade. Maternal values were generally small.
本文展示了西门塔尔牛、利木赞牛、无角海福特牛和婆罗门牛5年双列杂交设计中公牛和母牛后代的评估结果。评估的性状包括最终体重、热胴体重、眼肌面积、第12肋骨处脂肪厚度、大理石花纹评分、产肉等级、屠宰率以及肾、盆腔和心脏脂肪百分比。西门塔尔公牛的后代屠宰时体重比婆罗门公牛的后代重（P小于0.05），但胴体重没有差异。与其他父本品种的后代相比，利木赞杂交后代的屠宰率更高（P小于0.05）。母本品种也有类似结果，不过利木赞母牛的后代胴体更重，屠宰率高于婆罗门杂交后代（P小于0.05）。与其他品种的犊牛相比，利木赞和西门塔尔的杂交后代眼肌面积更大（P小于0.05）。无角海福特母牛的后代大理石花纹评分更高，比其他品种母牛的后代更肥（P小于0.05）。所有婆罗门杂交后代在最终体重、胴体重和眼肌面积方面杂种优势估计显著，但其他性状的这些差异可忽略不计。西门塔尔在最终体重、胴体重、眼肌面积和大理石花纹评分方面的一般配合力估计为正且显著，而利木赞在最终体重、脂肪厚度和产肉等级方面为负且显著。母本效应值通常较小。
