Koch R M, Cundiff L V, Gregory K E
J Anim Sci. 1982 Dec;55(6):1310-8. doi: 10.2527/jas1982.5561310x.
Heritability and phenotypic environmental and genetic correlations of postweaning gains for intervals of 28 to 224 d were calculated from data on 2,410 crossbred steers and 3,088 Hereford bulls. Gains were essentially linear for the 224-d interval. As the length of the performance interval increased from 28 to 224 d, heritability of gain increased from .12 to .55 among the crossbred steers and from .09 to .24 among the Hereford bulls. There was no tendency for heritability to be larger or smaller for intervals of like duration initiated early or late in the 224-d interval. Heritability of individual animal regressions of weight on days was evaluated as an alternative measure of gain/d. Heritabilities were not different between daily gain and regressions when measured over the same intervals. Genetic correlations were generally positive and much larger than the environmental or phenotypic correlations, indicating that genetic influences tended to persist from one interval to another. Genetic correlations between intervals tended to become smaller as the number of days separating the intervals increased.
根据2410头杂交阉牛和3088头赫里福德公牛的数据，计算了28至224天间隔断奶后增重的遗传力、表型环境相关性和遗传相关性。在224天的间隔内，增重基本呈线性。随着生产性能间隔长度从28天增加到224天，杂交阉牛增重的遗传力从0.12增加到0.55，赫里福德公牛增重的遗传力从0.09增加到0.24。在224天间隔的早期或晚期开始的相同持续时间间隔内，遗传力没有变大或变小的趋势。个体动物体重对天数的回归遗传力被评估为日增重的替代指标。在相同间隔测量时，日增重和回归的遗传力没有差异。遗传相关性一般为正，且远大于环境或表型相关性，表明遗传影响倾向于从一个间隔持续到另一个间隔。随着间隔天数增加，间隔之间的遗传相关性趋于变小。
