ISSN: 0041-3216

ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 62 Number 1
Research Papers
Breed and environmental factors that influence lamb loss in Shika
and
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.
Keywords: Sheep; Environment; Mortality; Lambs