Estimate of genetic and phenotypic parameters for litter size and weaning weight in Yankasa sheep.

Abstract

Data on 964 and 1150 weaning weight and litter size records respectively, collected over a 10-year period on Yankasa Sheep breeding project at the National Animal Production Research Institute (N.A.P.R.I.), Zaria, were used in this study. The analysis was for estimation of genetic and phenotypic parameters for litter size and weaning weight in Yankasa sheep. Estimates of heritability for litter size and weaning weight were obtained from paternal half sib intraclass correlation. The genetic and phenotypic relationship between the litter size and weaning weight were estimated from the covariance and variance components or the two traits. Least squares means of 1.18±0.02 and 10.67 ±0.11 were obtained for litter size and weaning weight, respectively. Heritability (h²) estimates or 0.18±0.07 and 0.63±.0.01 were obtained, respectively for litter size and weaning weight. Genetic and phenotypic correlations of -0.83±0.052 and 0.23±0.094 respectively, were obtained, between weaning weight and litter size.

Key words: Genetic, Phenotypic, correlations, litter size, weaning weight heritability