Abstract
Genetic and phenotypic parameters for body weight in Bunaji cattle at different ages were calculated, using data from 544 calves born at the Shika Research Station, Zaria, Nigeria, 1973-1983. Heritability estimates obtained from regression of offspring on dam were 0.33±0.16, 0.34±0.37, 0.11±0.19 and 0.16±0.27 for calf weights at birth and at 3, 6 and 12 months of age, respectively. Repeatability estimates for calf weights at birth and at 3 and 6 months of age, all considered as traits of the dam, were 0.12±0.09, -0.23±0.13, and -0.08±0.08, respectively. The correlation coefficient between birth and 3-month weight was estimated as 0.19. The correlation coefficients between weights at other ages were much higher, with estimates ranging 0.48-0.57. It is concluded that the proportion of additive genetic variance for body weight in this study was low, and genetic response to selection in these herds might therefore also be low.
