Production performance of Barbados blackbelly sheep in Tobago, West Indies

Data on 298 lambs from 161 ewes of the Barbados Blackbelly breed from 1982 to 1985 at the Blenheim Sheep Station in Tobago were studied to determine t he influence of lambing season-year, sex and type of birth on body weights of lambs at birth, at 56 days (weaning) and 6 months of age, preweaning dai ly gain and mortality. The effect of the lambing season-year on litter size (total number of lambs born, born alive and weaned per ewe lambing) and to tal lamb weight at weaning were examined. The flock averages for body weigh ts of lambs at birth, at 56 days and 6 months of age, preweaning daily gain and mortality were 2.75. 10.8, 19.2, 0.152 kg, and 18.3%, respectively. Av erages for total number of lambs born, born alive and weaned were 1.92. 1.8 8, 1.51, respectively, and total lamb weight at weaning was 16.7 kg. The la mbing season-year effect was apparent for all traits studied except for lit ter size and lamb mortality, Sex of lamb was not a significant source of va riation. Type of birth had significant effect on lamb growth traits and tot al lamb weight at weaning. Single born lambs were heavier than those born a s twins or more, Ewes with triplets or more weaned 21 kg lamb weight compar ed to 18 and 12 kg for twins and singles, respectively. Lamb mortality was 27.8% for those with below average birth weight and 8.8% for those with abo ve average birth weight (P < 0.05). (C) 2001 Elsevier Science B.V. All righ ts reserved.