The Libyan Barbary Sheep I. Reproductive Traits

Abstract

A total of 180 Libyan Barbary ewes were divided into six groups of 30 ewes each and mated with rams at two monthly intervals throughout the yeart to identify the breeding and lambing season and to study some other reproductive traits. The results indicated that maximum fertility following mating was obtained in the period of May-June (94%), July-August (88%), September-October (80%) and January-February (46%). Lower fertility was obtained in the periods of November-December (22%) and March-April (22.7%). Lambing rate followed the same trend of fertility and there were no differences in prolificacy. Considering the performance of the breed in other government farms with the result of this study, it is concluded that the Libyan Barbary breed may be reported a non-seasonal in its breeding and this phenomenon can be exploited both biologically and economically in this breed. However, other studies such as ram fertility in relation to the time of mating and the ovulatory activities of ewes using other means should be considered. Lambing periods had significant effects upon lambing difficulty (LD) and lamb vigor (LV) scores but had no effect on survival of lambs to weaning. Lambs born in the period of October-November had better LD and LV scores while those born in the period of April-May and June-July had the worst scores.

There were no differences in lamb survival to weaning in relation to lambing period. However, the results of lamb survival need to be combined with those of growth rates to assess relative importance of lambing season. The effect of age of ewe on the reproductive traits and the effects of sex, type of birth and age of ewe on LD. LV and survival of Iambs were also studied.