Gregory K E, Cundiff L V, Koch R M, Dikeman M E, Koohmaraie M
Roman L. Hruska U.S. Meat Animal Research Center, USDA, Clay Center, NE 68933.
J Anim Sci. 1994 Apr;72(4):833-50. doi: 10.2527/1994.724833x.
Retained heterosis for growth, carcass, and meat traits was estimated in F3 generation castrate male progeny in three composite populations finished on two levels of dietary energy density (2.82 Mcal of ME and 3.07 Mcal of ME and 11.50% CP) and serially slaughtered at four end points at intervals of 20 to 22 d. Breed effects were evaluated in nine parental breeds (Red Poll [R], Hereford [H], Angus [A], Limousin [L], Braunvieh [B], Pinzgauer [P], Gelbvieh [G], Simmental [S], and Charolais [C] that contributed to the three composite populations (MARC I = 1/4 B, 1/4 C, 1/4 L, 1/8 H, 1/8 A; MARC II = 1/4 G, 1/4 S, 1/4 H, 1/4 A; and MARC III = 1/4 R, 1/4 P, 1/4 H, and 1/4 A). Breed effects were important (P < .01) for carcass weight, dressing percentage, fat thickness, and marbling score; for retail product, fat trim and bone percentages and weights at two levels of fat trim (8 and 0 mm); and for carcass lean, fat, and bone percentages and weights. Mean slaughter weight was 54.7 kg greater for the Simmental, Gelbvieh, and Charolais breeds than for the Limousin but did not differ (P > .05) from Limousin in retail product weight or carcass lean weight because of higher dressing percentage, lower fat trim percentage, and lower bone percentage of Limousin. The effects of dietary energy density were important (P < .01) for most traits. The interaction of breed group x dietary energy density generally was not important. Retained heterosis generally was significant for each composite population for weight of retail product, fat trim, bone, and carcass lean, fat, and bone. For percentage of retail product, fat trim, carcass lean, carcass fat, and chemical fat in the 9-10-11th rib cut, generally, heterosis was significant for composites MARC II and MARC III but not for composite MARC I (i.e., composites MARC II and MARC III had a lower percentage of retail product and carcass lean and a higher percentage of fat trim, carcass fat, and chemical fat in the 9-10-11th rib cut than the mean of contributing purebreds).
在三个复合群体的F3代去势雄性后代中，对生长、胴体和肉质性状的杂种优势保留情况进行了评估。这些群体在两种日粮能量密度水平（2.82兆卡代谢能和3.07兆卡代谢能以及11.50%粗蛋白）下育肥，并在四个终点以20至22天的间隔连续屠宰。对九个亲本品种（红波尔牛[R]、赫里福德牛[H]、安格斯牛[A]、利木赞牛[L]、西门塔尔牛[B]、平茨高尔牛[P]、德国黄牛[G]、西门塔尔牛[S]和夏洛莱牛[C]）的品种效应进行了评估，这九个品种构成了三个复合群体（MARC I = 1/4 B、1/4 C、1/4 L、1/8 H、1/8 A；MARC II = 1/4 G、1/4 S、1/4 H、1/4 A；MARC III = 1/4 R、1/4 P、1/4 H和1/4 A）。品种效应在胴体重、屠宰率、脂肪厚度和大理石花纹评分方面很重要（P < 0.01）；在零售产品、两种脂肪修整水平（8毫米和0毫米）下的脂肪修整和骨百分比及重量方面也很重要；在胴体瘦肉、脂肪和骨百分比及重量方面同样重要。西门塔尔牛、德国黄牛和夏洛莱牛品种的平均屠宰体重比利木赞牛重54.7千克，但由于利木赞牛的屠宰率较高、脂肪修整百分比较低和骨百分比较低，其零售产品重量或胴体瘦肉重量与利木赞牛没有差异（P > 0.05）。日粮能量密度对大多数性状的影响很重要（P < 0.01）。品种组×日粮能量密度的交互作用通常不重要。对于零售产品、脂肪修整、骨以及胴体瘦肉、脂肪和骨的重量，每个复合群体的杂种优势保留情况一般都很显著。对于零售产品百分比、脂肪修整、胴体瘦肉、胴体脂肪以及第9 - 10 - 11肋切块中的化学脂肪百分比，一般来说，MARC II和MARC III复合群体的杂种优势显著，而MARC I复合群体则不显著（即MARC II和MARC III复合群体在零售产品和胴体瘦肉百分比方面较低，而在第9 - 10 - 11肋切块中的脂肪修整、胴体脂肪和化学脂肪百分比方面高于亲本纯种的平均值）。
