Heritability estimates of post-weaning performance traits in Hissardale sheep in Pakistan

Abstract

Data obtained from 5260 birth records of 1179 Hissardale sheep maintained at the Livestock Experiment Station, Jahangirabad, in the district of Khanewal during 1978-1995 were analyzed. The objective was to evaluate the performance and to estimate the heritability of Hissardale sheep in Pakistan. Mean 180-day, 270-day, and yearling weights were 23.5 ± 3.31 kg, 25.7 ± 3.49 kg, and 30.7 ± 3.83 kg, respectively. Mean greasy fleece weight was 3.6 ± 0.57 kg. Post-weaning mean daily weight gain was 45 ± 0.02 g. Mean weight at first service was 38.9 ± 4.9 kg. The number of services per conception averaged 1.23 ± 0.40. The sire model using PROC MIXED in SAS was used to estimate heritability. Heritability estimates for 180-day, 270-day, and yearling weights were 0.09 ± 0.03, 0.17 ± 0.04, and 0.15 ± 0.04, respectively. The heritability estimate of post-weaning average daily gain was low (0.06 ± 0.03). The heritability for greasy fleece weight was also very low (0.02 ± 0.02). Low estimates of heritability indicated the presence of less additive genetic variance and large environmental variance. Hence, improvement in the traits through selection may be limited.