Abstract: In this study, the data of Birth Weight (BW), Weaning Weight (WW) and Daily Gain from birth to weaning (DG) of Arabi lambs were used to estimate of environmental effects, heritability, phenotypic and genetic correlations among these traits. The effect of age of dam on BW was highly significant (p<0.01). The BW of lambs born to 2-year-old ewes in comparison to other lambs born to 3-6 year-old was significantly lighter. The male lambs as compared to the female ones had a heavier BW, WW and DG significantly (p<0.01). A comparison between born single (4.12, 26.21 and 0.252 kg, respectively) and twin lambs (3.55, 23.88 and 0.201 kg, respectively) indicated that the BW, WW and DG of born single lambs were significantly higher (p<0.01). Lambing year had a highly significant effect on the pre-weaning traits (p<0.01). Heritability of BW, WW and DG were 0.121±0.073, 0.095±0.072 and 0.096±0.079, respectively. Phenotypic and genetic correlations between BW-WW, BW-DG and WW-DG were (0.229 and 0.489), (0.119 and 0.429) and (0.987 and 0.999), respectively.
H. Roshanfekr, M. Mamouei, K. Mohammadi and E. Rahmatnejad, 2009. Estimation of Genetic and Environmental Parameters Affected Pre-Weaning Traits of Arabi Lambs. Journal of Animal and Veterinary Advances, 8: 2590-2593.