Investigation of Fertility Rate and Plasma Level of Ovarian Hormones in Makuii Breed Ewes Treated by CIDR and PMSG

The objective of this study is to investigate fertility rate and determine plasma levels of ovarian hormones in the Makuii breed ewe treated by CIDR and PMSG. This investigation conducted in 80 fat-tailed Makuii breed ewes during the breeding season. All animals were divided randomly into four groups then a single intramuscular (IM) injection of PMSG (group 1, 300 IU; group 2, 400 IU; group 3, 500 IU, group 4) was made apart from 1 ml normal saline solution which was used as control group at the time of CIDR removal. Blood samples collected from the jugular vein at the days of CIDR insert removal, Estrus after PMSG treatment and the day 30 of pregnancy for the determination of plasma E2 and P4 concentrations. Estrus responses were similar in all groups. Pregnancy rates were 85%, 90%, 95% and 64.7% in groups 1, 2, 3 and the control group, respectively. Pregnancy rates were higher in groups 1, 2 and 3 than in control group (P<0.05). There were significant differences (P<0.05) between the treatment groups and the control group regarding the plasma E2 levels at days of CIDR insert and estrus. Differences between the treated and the control animals in the Plasma P4 levels at day estrus and the day 30 of pregnancy were significant (P<0.05). The result of current research showed that an injection of PMSG after CIDR removal can be more effective on the fertility response of Makuii breed ewes during breeding season.