In this study, the effect of deslorelin implant on the induction of ovulation, ovulation time, mating number per marc and pregnancy rate were investigated in the mares have more than 30 mm in diameter ovarian follicle.
Forty thoroughbred mares 5-12 years old from TJK İzmit Stud and private studs were used as material. Forty mares with more than 30 mm ovarian follicle don't have any reproductive problem by ultrasonography and rectal palpation were divided into two groups. 2.2 mg deslorelin acetate (Ovuplant-Fort Dodge Animal Health) implant were administered subcutaneously to 20 normally cycling mares in oestrus with a dominant ovarian follicle more than 30 mm in diameter. Also 0.5 cc placebo were administered subcutaneously to 20 control mares. (0. hour) All mares were mated naturally every other day from the administration till ovulation. Ovulations were monitored every 24 hours by ultrasonography. The pregnancy diagnosis were made by ultrasonographic examinations on 20-22 days after ovulations.
The ovulation time was 57.6 ± 17.6 hours after administration, the mating number per mare was 1.6 ± 0.68 and the pregnancy rale was 70% in deslorelin treated mares. These parameters in the control group were 79.2 ±21.4. 2.3 ± 0.47 and 65% respectively. The ovulation lime after administration was decreased in deslorelin treated marcs (p<0.0l) and also the mating number per mare was decreased in deslorelin treated marcs (p<0.001).
Pregnancy rates were similar in the both groups. The ovulation rates in 48 hours after administrations were 75% in treated marcs and 30% İn the control mares and this difference was statistically significant (p<0.0l).
No local reactions or systemic side effects were determined in the deslorelin treated mares.
These results indicated that deslorelin treatment could be used successfully in the mares with dominant ovarian follicle {>30 mm) to induction of ovulation within 48 hours after administration and reduction of mating number per mare.