Olson T A, van Dijk A, Koger M, Hargrove D D, Franke D E
J Anim Sci. 1985 Nov;61(5):1121-31. doi: 10.2527/jas1985.6151121x.
Angus (A), Brown Swiss (S) and A X S reciprocal F1 (AS) dams were mated to A, S and AS (also reciprocal F1) sires resulting in nine breed groups of progeny with varying proportions of Angus and Brown Swiss breeding. Breed group of dam and of sire significantly influenced birth weight, preweaning daily gain, weaning weight, 205-d weight, condition score and frame size. The means for birth weight and weaning weight were 33 and 213 kg, respectively. Brown Swiss bulls sired calves with the heaviest birth and weaning weights. Calves produced by S dams likewise were heavier at birth and weaning. Pregnancy rates were influenced significantly by year, age and breed of dam and averaged 79, 95 and 92% for S, AS and A cows, respectively. Survival rate averaged 97% and was not influenced significantly by any of the effects examined. Because survival rates were similar for all breed groups, the results for weaning rate paralleled those for pregnancy rate. Genetic influences on preweaning growth traits and survival rate were partitioned into additive breed differences (B) and heterosis (H) effects for direct (d) and maternal (m) components. Pregnancy and weaning rates were examined using similar analyses except that genotype of service sire of dam replaced that of the offspring for the direct additive breed and direct heterosis components. The Bd values indicated that the Angus breed was inferior (P less than .01) to the Brown Swiss breed for all preweaning growth traits except for condition score, in which the Angus breed surpassed (P less than .01) the Brown Swiss. The Bm values also showed an advantage for the Brown Swiss breed for all preweaning growth traits. The additive maternal effect (the genotype of the females exposed), Bm, was important for pregnancy rate and weaning rate (P less than .001 and P less than .05) but not for survival rate (P greater than .10). The direct additive breed effect was not important for any reproductive trait. Direct heterosis did not affect any of the preweaning or reproduction traits; however, maternal heterosis (Hm) significantly affected all traits except birth weight, frame score and survival rate. The Hm estimates were 12.0 and 8.4 kg for weaning weight and 205-d weight, respectively. The Hm estimates for pregnancy rate, survival rate and weaning rate were 10, 2 and 13%, respectively.
将安格斯牛（A）、瑞士褐牛（S）以及A×S正反交F1代（AS）母牛与安格斯牛、瑞士褐牛和AS（也是正反交F1代）公牛交配，产生了九个后代品种组，其安格斯牛和瑞士褐牛的育种比例各不相同。母牛品种组和公牛品种组对出生体重、断奶前日增重、断奶体重、205日龄体重、体况评分和体格大小有显著影响。出生体重和断奶体重的平均值分别为33千克和213千克。瑞士褐牛公牛所生小牛的出生体重和断奶体重最重。由S母牛所生的小牛在出生和断奶时同样较重。受胎率受年份、母牛年龄和品种的显著影响，S、AS和A母牛的平均受胎率分别为79%、95%和92%。成活率平均为97%，不受所考察的任何因素的显著影响。由于所有品种组的成活率相似，断奶率的结果与受胎率的结果相似。对断奶前生长性状和成活率的遗传影响被划分为直接（d）和母体（m）成分的加性品种差异（B）和杂种优势（H）效应。对受胎率和断奶率进行了类似分析，只是在直接加性品种和直接杂种优势成分中，用母牛配种公牛的基因型代替了后代的基因型。Bd值表明，除体况评分外，安格斯品种在所有断奶前生长性状上均劣于瑞士褐牛品种（P小于0.01），而在体况评分上安格斯品种超过了瑞士褐牛品种（P小于0.01）。Bm值也表明瑞士褐牛品种在所有断奶前生长性状上具有优势。母体加性效应（所产雌性的基因型）Bm对受胎率和断奶率很重要（P小于0.001和P小于0.05），但对成活率不重要（P大于0.10）。直接加性品种效应对任何繁殖性状都不重要。直接杂种优势对任何断奶前或繁殖性状都没有影响；然而，母体杂种优势（Hm）显著影响除出生体重、体格评分和成活率之外的所有性状。断奶体重和205日龄体重的Hm估计值分别为12.0千克和8.4千克。受胎率、成活率和断奶率的Hm估计值分别为10%、2%和13%。
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