Abstract
This study was carried out on Awassi sheep in two flocks: the first the flock of college of Agriculture and Forestry/ University of Mosul and the second flock of AL- Rashidia Animal Breeding for two years. A hundred and five ram lambs were used in this study , body weight and scrotal size were measured at 4 , 5 , 6 and 7 months of age. The results showed a non significant effect of year of birth on body weight, the ram lambs of AL-Rashidia flock were significant succeeded in their body weight, a significant differences were found in body weight of ram lambs at 4 months of age due to age of dam, and the single were better significantly than twins in body weight at 4 months of age only. There were a significant effect of year of birth on scrotal size at 5, 6 and 7 months of age , the effect of flock was a significant on scrotal size at all ages , s significant differences were found in scrotal size at 5 and 6 months of age due to age of dam , in other hand no significant effects was observed for type of birth on scrotal size at all ages. Heritabity estimates at 4 , 5 , 6 and 7 months of age were (0.58 , 0.64 , 0.52 and 0.44) for body weight and (0.30 , 0.22 , 0.21 and 0.31)for scrotal size respectively , all genetic and phenotypic correlations between the studied traits were positive and highly significant.
