Effect of season and mating system in Awassi ewes superovulated with FSH on fertilization rate and embryo recovery
Iraqi Journal of Veterinary Sciences,
2010, Volume 24, Issue 2, Pages 75-79
AbstractThe aim of the present study was to evaluate the contribution of laparoscopic intrauterine insemination to the improvement of fertilization and embryo recovery in Awassi ewes superovulated with FSH in breeding and non-breeding season. Twelve nonpregnant and cycling Awassi ewes of 3-4 years of age were randomly allocated in equal numbers (n = 6) to two groups. Each ewe was treated with a progesterone impregnated intravaginal sponge for 12 days. All ewes were superovulated with FSH in eight reducing doses for four days in the morning and evening from two days prior to sponge withdrawal. Ewes of group 1 were mated naturally at least two times with Awassi rams of proven fertility. Ewes of group 2 had intrauterine insemination and were conducted 44-46 h after sponge removal, under laparoscopic visualization of uterine horns, depositing 1 ml of semen in the distal portion of each uterine horn. Ovarian response was assessed by determining number of corpora lutea by laparoscopy on day 6 after mating. Embryo recovery was performed by hand assisted laparoscopy and by flushing both uterine horns. Ovarian response of the ewes superovulated with FSH was decreased to half in the non-breeding season. High number of unfertilized ova (P<0.05) was observed in ewes superovulated with FSH in the non-breeding season when naturally inseminated compared to ewes inseminated intrauterine using laparoscopic technique. Higher rates of embryo recovery (P<0.05) were achieved in superovulated ewes in the breeding season when ewes were inseminated by laparoscopic intrauterine insemination. The fertilization rates in ewes inseminated intrauterine using laparoscopic techniques in breeding season and non-breeding season were 88.1% and 37.98%, respectively. It could be concluded from the results of the present study that the use of FSH to induce superovulation in Awassi ewes combined with laparoscopic intrauterine insemination can increase the fertilization rate in the breeding season.
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