EFFECT OF SEASON ON RESUMPTION OF OVARIANANDESTROUSACTIVITY AFTER PARTURITIONINTHE EWE OULED DJELLAL

A BENYOUNES; F LAMRANI  F

A BENYOUNES Facultédes Sciences de la Nature et de la Vie et des Sciences de la Terre et de l’Univers, Université 8 Mai1945, Guelma -Algérie
F LAMRANI F Facultédes Sciences Biologiques, Université des Sciences et de la Technologie Houari Boumediene (USTHB), Alger –Algérie.

Keywords: ewesOuledDjellal, postpartumanoestrus, progesterone, Algeria

Abstract

The objective of the trial was to evaluate the effect of season on the resumption of ovarian and estrus activity after parturitionin ewesOuledDjellal. The study was conductedin the eastof Algeria-36° 28 'north latitude and 7° 28'east longitude-, about 41eweslambedin the spring (20) and autumn(21)and their lambswere weaned at45days ofage.Ovarian activity ofeweswas examinedbyanalysisof alternatingprogesterone levels,determined byradioimmunoassay, following blood tests carried out between 25-60 days post-partum. Daily estruses werecontrolled withramssince the 60thdaypostpartum.Whatever the season, the renewal ofovarian activity ofewes, very favorable forthe autumn (P < 0.001) was observed after theend 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 ofpostpartumanoestruswas obtained with autumn lambing(P < 0.001)