Studies on hormonal changes after mating in synchronized Awassi ewes

Abstract

The study was conducted in animals farm / department of animal technical production -Al-Musaib Technical College from 1-10-2012 to 1-3-2013. 10 Awassi ewes aged 2-4 years old. Estrus synchronization was done by intravaginal progesterone sponges containing 20 mg of fluorogestone acetate (FGA) for a period of 14 days. The ewes were intramuscular injected with 750 IU of equine chorionic gonadotropin (eCG) at the sponges removal. The ewes were naturally mated with fertile rams (1 ram / 5ewes) . Blood samples were collected weekly from mating day until 10th week through jagular vein puncture. Blood serum separated and stored at -4Cْ until assayed for hormones. The hormones were measured by Enzyme–linked Immunosorbent Assay (ELISA). The results showed the progesterone concentration increased by the first week after mating and remained at high levels until 10th week. The concentration of estrogen were high at mating and then decreased to basal levels during the first 4 weeks and increase gradually from the 5th to the 10th week. The concentration of LH hormone were showed significantly increase during mating day and subsequently decrease to its basal level. The FSH concentration was high during estrus and decreased there after and remained low near the basal levels. The prolactin concentration was showed significantly decreased during first 4 weeks and increase from 5th week .