INDUCTION OF OVULATION IN JENNIES FROM LOCAL BREEDS AFTER TREATMENT WITH GNRH AND HCG

N. Vasilev, A. Atanasov, A. Antonov, I. Fasulkov, A. Werend

Abstract: During the past years, there was an increased interest to reproduction in jennies. Different hormonal preparations could be used for induction of ovulation, including human chorionic gonadotrophin (hCG) and gonadotrophin releasing hormone (GnRH). The aim of the present experiment was to investigate the possibility to induce ovulation in jennies from local breeds, treated with GnRH and hCG at the time when growing follicle attained a specific size. The follicular growth was monitored by means of transrectal echography with 5 MHz linear transducer. The animals were divided in three groups. Jennies from group I were given a single intramuscular dose of 100 µg GnRH, and those from group II – a single intravenous dose of 2 500 IU hCG at follicle size ≥30 mm. The third group included untreated controls, in which the spontaneous onset of ovulation was followed out. In hormone-treated groups, ovulation occurred within 48 hours after the treatment, without statistically significant differences between groups. The mean diameter of preovulatory follicles in experimental groups was lower (Р<0.001) that in controls. The synchronisation of ovulation in jennies from local breeds could be performed by means of GnRH analogues.

Keywords: GnRH; hCG.; induction of ovulation; jenny

Date published: 2023-01-03