Carvalheira J G, Blake R W, Pollak E J, Van Soest P J
Cornell University, Ithaca, NY 14853, USA.
J Anim Sci. 1995 Dec;73(12):3519-26. doi: 10.2527/1995.73123519x.
The growth performance of Landim and Africander breeds was compared using data collected from 1968 to 1981 at the Chobela Research Station in Mozambique. Animals from both breeds were managed together in groups by age and sex, except when separated for breeding. Growth traits were body weights at birth, weaning at 7 mo, 18 mo, and first calving, and pre- and postweaning daily growth rates. These traits were analyzed using a mixed-effects least squares model containing breed, year-season of birth, sex, the nested effect of parity within breed, a linear regression on dam's age, and the random effect of sire within breed. Africander calves were 16, 9, and 7% heavier (P < .01) than Landim calves at birth, weaning, and 18 mo (18 +/- 6 kg heavier than the 237-kg Landim average). However, there was no detectable difference for age-adjusted weight at first calving and postweaning daily growth rate. Diminishing weight and growth differences with advancing age may indicate adaptation by the Landim to the prevailing environmental limitations in southern Mozambique, especially through younger ages at puberty and at first calving.
利用1968年至1981年在莫桑比克乔贝拉研究站收集的数据，对兰迪姆牛和非洲瘤牛品种的生长性能进行了比较。除繁殖时分栏外，两个品种的动物按年龄和性别混群饲养。生长性状包括出生体重、7月龄、18月龄和首次产犊时的体重，以及断奶前后的日生长率。使用混合效应最小二乘模型对这些性状进行分析，该模型包含品种、出生年份季节、性别、品种内胎次的嵌套效应、对母牛年龄的线性回归以及品种内公牛的随机效应。非洲瘤牛犊在出生、断奶和18月龄时比兰迪姆牛犊分别重16%、9%和7%（P <.01）（比兰迪姆牛犊平均体重237 kg重18±6 kg）。然而，首次产犊时经年龄调整后的体重和断奶后日生长率没有显著差异。随着年龄增长，体重和生长差异逐渐减小，这可能表明兰迪姆牛适应了莫桑比克南部的主要环境限制，特别是通过青春期和首次产犊时的较年轻年龄。
