SEASONAL VARIATIONS OF THE REPRODUCTIVE ACTIVITY IN LOCAL BREED’S EWES RAISED IN THE SOUTH-WEST OF ALGERIA

The objective of this study was to determine the characteristics of variations in sexual activity of ewes taken in a saharian environment in the southwest of Algeria. Two experiments were conducted in this study. In the first one, a monthly monitoring was carried out on a population of 1430 ewes dominated by the Ouled Djellal breed, aged between 1 and 7 years, and belonging to 12 livestock farms distributed in different zones of the study area. In the second experiment, 63 healthy Ouled Djellal ewes, assumed non-pregnant and aged from 1 to 5 years, were involved to determine the hormonal profiles of progesterone, oestradiol, FSH, and LH during the four seasons (autumn, winter, spring, and summer). Hormonal assays were measured by using the chemiluminescent immunoenzymatic technique (CLIA). The monthly distribution of lambing in ewes has allowed us to deduce that sexual activity is continuous throughout the year with a maximum of lambing in autumn. The results of the hormone assays also revealed the existence of a hormonal activity during the four seasons with a decrease in winter and spring for progesterone and in summer for LH. This permit us to conclude that Ouled Djellal ewes raised under difficult climatic conditions of the south-west of Algeria are relatively non-seasonal with sometimes only a slight decrease in reproductive activity.