Environmental and Genetic Effects on Early Growth Traits in Moghani Sheep Breeds

The effects of environmental factors on early growth traits (birth weight, weaning weight, body weight at 6 months of age and daily gain from birth to weaning and weaning to 6 months of age) using 10432 records in Moghani sheep breed were studied and Genetic and Environmental variance component were estimated using 8468 records of Jafarabad Animal Breeding Station from 1999 to 2004. Birth year on all traits and dam age had significant effect only for birth and weaning weight. Sex of lambs and birth type had no significant effect only daily gain from weaning to 6 months of age. Additive genetic direct variance, maternal environmental variance and heritability were estimate by REML fitting two different Animal models. The estimate of maternal environment variance was higher than additive genetic direct variance in some traits. Estimates of direct heritability for all traits were low.