Authors : Mourad Rekik , Narjess Lassoued , Lotfi S?adoun , Mahjoub Arous and Mohsen Ben Sassi
Abstract: The efficiency of the ram effect to synchronise Barbarine ewes prior to artificial insemination was examined in two trials conducted to (i) compare, in the first trial, conception rates after fixed-time artificial insemination of ewes synchronised with intravaginal sponges impregnated with progestagen followed by the introduction of rams or the administration of equine Chorionic Gonadotrophin (eCG) and (ii) establish, in the second trial, the level of lambing rate when ewes are inseminated 24 hours after oestrus, at the second ovulation following ram introduction and progesterone (20 mg i.m.) administration. Fresh, diluted semen at 400 x 106 sperm / ewe was used in both trials. The first trial involved 380 ewes in two flocks (A and B) and the second 155 ewes. In the first trial, the lambing rates obtained in ewes induced with eCG or the ram effect were respectively 58 and 55.5%. Flock had a significant effect (P<0.05) on the proportion of ewes conceiving to insemination after using the ram effect: 38 vs. 73% for A and B flocks respectively. In the second trial, 71 ewes (46%) exhibited oestrus between days 19-21 after ram introduction and progesterone injection and artificial insemination of these ewes yielded a lambing rate of 61%. It is concluded that under natural semi-arid conditions, substituting eCG by the ram effect when synchronising Barbarine ewes prior to artificial insemination could lead to satisfactory lambing rates.
Mourad Rekik , Narjess Lassoued , Lotfi S?adoun , Mahjoub Arous and Mohsen Ben Sassi , 2003. Using the Ram Effect as an Alternative to Ecg Before Artificial Insemination of Barbarine Ewes. Journal of Animal and Veterinary Advances, 2: 225-230.