McAllister A J, Lee A J, Batra T R, Lin C Y, Roy G L, Vesely J A, Wauthy J M, Winter K A
Centre for Food and Animal Research, Agriculture Canada, Ottawa, ON.
J Dairy Sci. 1994 Aug;77(8):2400-14. doi: 10.3168/jds.S0022-0302(94)77183-6.
Additive and nonadditive genetic effects on lifetime yields of milk and milk components and lifetime profitability were estimated from 5070 cattle in a Holstein pureline, an Ayrshire-based pureline, and 10 crossbred groups of these purelines. Lifetime yields of milk, fat, protein, and lactose and lifetime milk value and annualized discounted net returns were analyzed. Lifetime yields, lifetime milk value, and annualized discounted net returns of the Holstein x Ayrshire-based line F1 and an F1 x (F1 x F1) cross were not significantly different from those for the Holstein pureline. Net reproductive rate for F1 females was 9% greater than that of contemporary Holsteins. The Holstein pureline was superior to the Ayrshire-based pureline for direct additive genetic merit for all traits. Heterosis for the lifetime traits ranged from 16.6% for lifetime milk yield to 20.6% for annualized discounted net returns. Cytoplasmic maternal effect on annualized discounted net return was significant and favored the Ayrshire-based line. Potential economic benefit may derive from development of a crossbred cow that is superior to Holsteins. Maximum exploitation of additive and nonadditive genetic effects on lifetime yields and profitability appears to favor a rotational crossbreeding system with two breeds.
对荷斯坦纯系、艾尔夏纯系以及这两个纯系的10个杂交组中的5070头牛，估计了牛奶和牛奶成分终生产量以及终生盈利能力的加性和非加性遗传效应。分析了牛奶、脂肪、蛋白质和乳糖的终生产量以及终生牛奶价值和年化贴现净收益。荷斯坦×艾尔夏系F1以及F1×(F1×F1)杂交种的终生产量、终生牛奶价值和年化贴现净收益与荷斯坦纯系的这些指标没有显著差异。F1雌性的净繁殖率比当代荷斯坦牛高9%。在所有性状的直接加性遗传优点方面，荷斯坦纯系优于艾尔夏纯系。终生性状的杂种优势范围从终生牛奶产量的16.6%到年化贴现净收益的20.6%。细胞质母体效应在年化贴现净收益方面显著，且有利于艾尔夏系。潜在的经济效益可能来自培育出优于荷斯坦牛的杂交母牛。对终生产量和盈利能力的加性和非加性遗传效应进行最大程度的利用，似乎有利于采用两个品种的轮回杂交系统。
