Profile Of Reproductive Hormones Secretion During Estrus And Pregnancy Associated With Different Estrus Synchronization Methods In Awassi Ewes In Non-Breeding Season

Abstract

The study was conducted from March to August 2020 at the Al-Shatra Sheep and Goat Research Station in Thi-Qar Governorate, Iraq, to assess the estimation of the concentration of the reproductive hormones, luteinizing hormone (LH), Follicle-stimulating hormone (FSH), estrogen, and progesterone in Awassi ewes in various physiological states during the outbreeding season. Thirty-two mature, healthy Awassi ewes in the non-breeding season were used. Ewes were randomly divided into four equal groups (eight animals each) according to the following: Control; The animals were kept in a control group and were not given any hormones. First, treatment group (T1) (MAP+ equine chorionic gonadotropin (eCG); The animals received (intravaginal sponges saturated with 60 mg medroxyprogesterone acetate) (MAP) inserted in the ewes for 12 days. Second treatment group (T2); ewes were given double subcutaneous (s.c) melatonin ear implants for 35 days. Third treatment group (T3); The ewes were given s.c double melatonin ear implants for 35 days and on the 25th day from the beginning of melatonin implantation, the animals were treated with (MAP) for 12 days. All animals’ groups received 400 IU of (eCG) at the end of the treatment. Rams were introduced to the flock directly after eCG injection of each group and all groups were visually monitored twice a day for signs of estrus. The results revealed that administration of exogenous progestogens (MAP)as intravaginal sponges and melatonin as ear implants alone or with MAP followed by eCG appear to be effective in synchronization of estrus, maintenance of pregnancy, and parturition in hormone-treated ewes in Non- breeding season confirmed by the levels of reproductive hormones (FSH LH, estradiol, and progesterone during estrus and pregnancy).