Abstract
Lamb losses in three Nigerian breeds of sheep, Yankasa, Uda and Balami and their crosses with exotic breeds were evaluated. The mean mortalities of lambs during 0—90 days, 91-365 and 366—1095 days were 15, 25 and 9%, respectively. The crossbred lamb survived significantly (P ? 0.05) better during the pre-weaning stage (0-90 days) than Uda and Balami, but had the poorest survival after weaning. Except at 91-365 days, Balami had the lowest survival rate at all other stages of growth. Season of birth significantly (P ?0. 05) influenced post-weaning and overall survival rate. Type of birth had a marked effect on lamb survival before and after weaning. Multiparous ewes significantly (P ? 0.05) reared more lambs in the pre-weaning stages than primiparous ewes; after weaning the latter were better than the former. Birth weight was linearly related to survival at the pre-weaning stage.
