Weaning and the ram-effect on fertility, serum luteinizing hormone and prolactin levels in spring rebreeding of postpartum Awassi ewes

Abstract

Spring rebreeding activity was investigated in 44 multiparous Awassi ewes allocated to one of three treatments. The first treatment entailed ewes suckling lambs for 45 days and then continuously exposed to fertile rams (Group 1); ewes of the second group were weaned at 14 days of age and then were either exposed continuously (Group 2) or intermittently (Group 3) to rams. Time of weaning and type of exposure to the ram did not influence the reproductive performance in terms of fertility and prolificacy in postpartum Awassi ewes. Time of weaning did not influence serum LH concentrations monitored at 3 h intervals in Groups 1 and 2. However, serum prolactin (PRL) concentrations were significantly higher in Group 1, compared to Group 2 of ewes. Serum LH levels at weaning were significantly higher in ewes that conceived and lambed, compared to ewes that did not. It was concluded that spring rebreeding of postpartum Awassi ewes did not respond to ram presence and/or early weaning in terms of improved reproductive performance. The lack of reproductive response was further reflected in LH and PRL profiles.