EFFET DE LA SAISON SUR LA REPRISE DES ACTIVITES OVARIENNE ET OESTRALE APRES LE PART CHEZ LA BREBIS OULED DJELLAL

Abstract

The objective of the trial was to evaluate the effect of season on the resumption of ovarian and estrus activity after parturition in ewes Ouled Djellal. The study was conducted in the east of Algeria -36 ° 28 'north latitude and 7 ° 28' east longitude-, about 41 ewes lambed in the spring (20) and autumn (21) and their lambs were weaned at 45 days of age. Ovarian activity of ewes was examined by analysis of alternating progesterone levels, determined by radioimmunoassay, following blood tests carried out between 25-60 days post-partum. Daily estruses were controlled with rams since the 60th day postpartum. Whatever the season, the renewal of ovarian activity of ewes, very favorable for the autumn (P < 0.001) was observed after the end of exclusive suckling time (day 30). Indeed, the recovery of spontaneous cyclical ewes after parturition was related to their lambing season. Thus, the shortest duration of postpartum anoestrus was obtained with autumn lambing (P < 0.001).