ESTIMATE OF GENETIC AND PHENOTYPIC PARAMETERS FOR LITTER SIZE AND WEANING WEIGHT IN YANKASA SHEEP

Résumé

Data on 964 and 1150 weaning weight and litter size records respectively, collected over a 10years period on Yankasa Sheep breeding project at the National Animal Production Research Institute (N.A.P.R.I), Zaria, were used in the 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 of 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 of 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