Data used in this study were from test-day milk production records of Canadian Holsteins from 1998 to 1999 for first parity on 10130 cows.
本文使用的数据来源于1998到1999年加拿大10130头荷斯坦奶牛第一胎次的测定日记录。
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However, more Jerseys were needed to produce this milk, compared to the number of Holsteins, with the total body mass of the Jerseys 26 per cent smaller.
Genetic engineering is precisely what cattle breeders do when they select better strains of Holsteins, only bioengineers employ more precise and powerful control.