The PGF2α, a less costly and invasive means than progestogens to manipulate the sexual activity in out-breeding season of the “Ouled Djellal” Algerian ewes

The sexual activity of 237 ewes of the most representative of Algerian sheep breeds (about 70%): the "Ouled Djellal", was studied during the anestrous season i.e. in spring (April 2016), in Constantine, a north-eastern Algerian province. A number of 50 ewes, chosen randomly from the flock, were subjected to a double injection of PGF2α at an 11 days’ interval and the 187 females remaining have served as a control group. 80% of the ewes treated started mating about 60 hours after the release, with the whole flock, of 14 rams that have been previously separated from the flock but not sensory isolated. A lambing percentage of 90 spread over 23 days and 98.9 spread over 47 days occurred respectively in the treated and control group. Both treated and untreated ewes with PGF2α exhibited estrus (April and May), got pregnant and lambed within a period of less than 2 months. The use of PGF2α, through the luteolysis it induces during spring: first confirms the results of previous studies reporting the ability of “Ouled Djellal” ewe to exhibit sexual activity throughout the year, second shortens considerably the laming period and last and more importantly can be substituted to the use of the progestogens impregnated sponges, far more invasive, time consuming and more costly, as a means to manipulate the female sexual activity.