Genetic and Phenotypic Parameters of Reproductive Performance of Boujaâd and Sardi Ewes

Abstract

The analysis concerned 1264 and 811 reproduction records of Boujaâd and Sardi ewes, respectively. Data were collected from 1993-94 to 1999-2000 at Deroua Experimental Station of the Institut national de la recherche agronomique at Béni Mellal. The genetic parameters for reproductive traits were estimated by the REML estimation of variance and covariance components method. Repeatability estimates in Boujaâd ewes were 0.18 and 0.17 for litter size at birth and at weaning, 0.23 and 0.18 for litter weight at birth and at weaning, respectively, and 0.18 for length of pregnancy. Corresponding estimates in Sardi ewes were 0.21 and 0.18, 0.24 and 0.15, and 0.16. Heritability estimates of Boujaâd ewes were 0.18 and 0.11 for litter size at birth and at weaning, 0.18 and 0.11 for litter weight at birth and at weaning, respectively, and 0.04 for length of pregnancy. Corresponding estimates in Sardi ewes were 0.21 and 0.18, 0.24 and 0.15, and 0.16. Genetic and phenotypic correlations between these traits varied from 0.83 to 1.00 and from 0.27 to 0.93 in Boujaâd ewes, and from 0.06 to 0.96 and from 0.07 to 0.82 in Sardi ewes, respectively. It was concluded that these parameters could be used in selection programs to improve productivity in Boujaâd and Sardi ewes.