Ovulation rate, litter size and prenatal losses in hair sheep of the French West Indies.

Abstract

Ovulation rate (OR) and litter size (LS) were recorded in local hair sheep of Martinique and in local x Lacaune-viande crossbreeds, in order to assess prenatal losses. Local hair sheep LS and OR were 1.91 and 2.41, respectively. Prenatal losses increased with OR, from 0.22 (OR = 2) up to 1.50 (OR > 3). The ewes (69.7%) with LS = 1 had actually lost at least one ovum, against 25.9% of the ewes with LS > 1. Ewes grazing Cynodon nlemfuensis (Stargrass) had lower LS than those grazing Digitaria decumbens (Pangola), in relation with a lower nutritional level and, maybe, more parasitism effects. No seasonal or age at lambing effect was shown. The OR and LS were dramatically decreased on local x Lacaune-viande crossbred ewes (minus 1.32 and 0.67 unit, respectively, P < 0.05). This suggests a possible negative effect of the tropical environment on the crossbreeds' reproductive function.