Kress D D, Doornbos D E, Anderson D C
Dept. of Animal and Range Sci., Northern Agricultural Research Center, Havre, Montana 59501.
J Anim Sci. 1990 Jul;68(7):1910-21. doi: 10.2527/1990.6871910x.
Measures of maternal productivity and reproduction of Hereford (HH), Angus-Hereford (AH), 25% Simmental-75% Hereford (1S3H), 50% Simmental-50% Hereford (1S1H) and 75% Simmental-25% Hereford (3S1H) dams were studied. Half of each dam breed group was bred to Tartentaise and half to Charolais sires to produce 706 calves at weaning from 930 exposures to breeding in a Montana range environment. Data were analyzed according to a model that included the fixed effects of year, dam breed group, dam age, calf sex, calf sire breed, plus appropriate two-way interactions, linear partial regression on calf birth date and random effects of sire within dam breed group (maternal grandsire of the calf) and sire within calf sire breed. Calf sex interacted with calf sire breed for several traits, but interactions were due to changes of magnitude of differences between sexes. There were no significant interactions of dam breed group with other main effects for calf growth traits, except for the interaction with calf sire breed for some calf growth traits. This interaction was due to a change in magnitude; it suggested that larger sire breeds should be matched to larger dam breeds with greater potential for milk production. The only significant interaction for traits that included reproduction of the dam was dam breed group X age of dam. Ranking of dam breed groups depended on age at measurement. Differences among dam breed groups were significant for most traits. Calf weaning weights for HH, AH, 1S3H, 1S1H and 3S1H dams were 211, 223, 227, 237 and 243 kg, respectively; calf weaning weights per cow exposed were 157, 163, 179, 189 and 169 kg; calf weaning weights per unit of dam weight were .40, .41, .43, .44 and .42, respectively. Thus, dam breed groups that weaned the largest calves were not necessarily the most productive under Montana range conditions.
对赫里福德（HH）、安格斯 - 赫里福德（AH）、25%西门塔尔 - 75%赫里福德（1S3H）、50%西门塔尔 - 50%赫里福德（1S1H）和75%西门塔尔 - 25%赫里福德（3S1H）母畜的繁殖力和生殖指标进行了研究。每个母畜品种组的一半与塔尔坦泰斯公牛配种，另一半与夏洛莱公牛配种，在蒙大拿州的牧场环境中，经过930次配种，共产出706头断奶犊牛。数据根据一个模型进行分析，该模型包括年份、母畜品种组、母畜年龄、犊牛性别、犊牛父本品种的固定效应，以及适当的双向交互作用、犊牛出生日期的线性偏回归，还有母畜品种组内父本（犊牛的外祖父）和犊牛父本品种内父本的随机效应。犊牛性别与犊牛父本品种在几个性状上存在交互作用，但这些交互作用是由于性别间差异幅度的变化所致。对于犊牛生长性状，母畜品种组与其他主要效应之间没有显著的交互作用，只有在一些犊牛生长性状上与犊牛父本品种存在交互作用。这种交互作用是由于幅度的变化；这表明较大的父本品种应与具有更大产奶潜力的较大母本品种相匹配。对于包括母畜繁殖在内的性状，唯一显著的交互作用是母畜品种组×母畜年龄。母畜品种组的排名取决于测量时的年龄。母畜品种组之间在大多数性状上存在显著差异。HH、AH、1S3H、1S1H和3S1H母畜所产犊牛的断奶体重分别为211、223、227、237和243千克；每头参与配种的母牛所产犊牛的断奶体重分别为157、163、179、189和169千克；每单位母畜体重所产犊牛的断奶体重分别为0.40、0.41、0.43、0.44和0.42。因此，在蒙大拿州的牧场条件下，断奶犊牛体重最大的母畜品种组不一定是生产效率最高的。
