Use of melatonin treatment to improve reproductive performance of Tunisianewes.

150 Queue fine de l'Ouest and 150 Noire de Thibar sheeps (140 ewes and ten rams for each breed) were used in this study. The treated ewes received a subcutaneous implant of melatonin (Melovine R) 40 days before mating, on 17 March. The fertility of treated ewes was nor significantly different from that of control ewes, 95,7 vs 90 percent and 92,8 vs 88,5 percent, respectively for Queue fine de l'Ouest and Noire de Thibar ewes. The fecondity of treated ewes was significantly higher than that of control ewes, 1,19 vs 0,98 and 1,2 vs 0,97 lambs by ewe mated respective ly for Qu eue fine de l'Ouest and Noire de Thibar breeds (p < 0,05). The prolificity of treated ewes was significantly higher than that of contr ol ewes, 123,8 vs 109,5 and 129,2 vs 109,6 lambs percent ewes lambing, resp ectively for Queue fine de l'Ouest and Noire de Thibar breeds (p < 0,05).