Estimates of Genetic parameters for Growth Traits of local Hamra breed threatened with extinction in southwestern arid Rangeland of Algeria

Abstract

The data base for body weights and growths of 411 Hamra lambs were used to estimate genetic parameters. These lambs were obtained from 31 rams and 493 ewes between 2012 and 2017. Traits analysed were weights at birth (B W), 30 days (W 30), 90 days (W 90) of age, and average daily gains from 10 to 30 (ADG 10-30) and30-90 (ADG 30-90) days. REML estimates of variance and covariance components were obtained assuming animal models that included the fixed effects for year-type of birth (2012 single, 2012 twin,. ., 2017 single, 2017 twin), sex (male, female), and ewes age at lambing (54 months). Heritabilities were 0.12, 0.06 and 0.11 respectively for B W , W 3O and W 90 and the average daily gains were 0.05 and 0.17 for ADG 0-30 and ADG 30-90. The estimates of genetic correlations showed no genetic antagonisms among the growth traits. The genetic correlations estimated were positive and medium to high, except those between ADG 30-90 and ADG 0-30 and between ADG 30-90 and W 30 which were slightly negative. Phenotypic correlations were positive and ranged from 0.12 to 0.85. They were high between adjacent weights and between ADG and their corresponding weights.

Keywords

• Heritability
• Genetic correlation
• Growth Traits
• Sheep