REPRODUCTIVE RESPONSE OF PRIMIPAROUS AND MULTIPAROUS BUFFALOES OF BULGARIAN MURRAH BREED WITH OVARIAN INACTIVITYAFTER GnRH-PGF2α-GnRH THERAPY | РЕПРОДУКТИВЕН ОТГОВОР ПРИ ПЪРВОТЕЛКИ И МНОГО РАЖДАЛИ БИВОЛИЦИ ОТ ПОРОДАТА БЪЛГАРСКА МУРРА С ОВАРИАЛНА ХИПОФУНКЦИЯ СЛЕД ПРИЛОЖЕНИЕ НА GnRH-PGF2α-GnRH ТЕРАПИЯ

The aim of the present study was to determine the reproductive response of primiparous and multiparous buffaloes of Bulgarian Murrha breed with ovarian inactivity after GnRH-PGF2α-GnRH - OVSYNCH therapy. The study was carried out on 45 Bulgarian Murrha buffaloes without detected clinical estrus from parturition until therapy. The study was conducted during the period from August to November. The diagnose inactive ovaries was based on the absence of large dominant follicle and corpus luteum, on the two consecutive transrectal ultrasound examinations, which were done 10 days apart. The buffaloes were assigned to two groups - I Group - primiparous; n=21 and II Group multiparous; n=24. Buffaloes in Group I received intramuscular injections of 100μg GnRH analogue on the 0 day - day of the second ultrasound examination, 500 μg PGF2α analogue on the 7th day and 1500UI hCG on the 9th day. All buffaloes were artificially inseminated twice on 16th and 25th hours after hCG injection. Before the artificial insemination the two groups were subjected to transrectal ultrasound examination and the mean diameter of the largest follicle was determined. In both Groups the clinical signs of oestrus – uterine tone, presence of cervical mucus and ease of cervical passage were defined. Ovulation was confirmed by ultrasound examination of the ovaries on the 7th day after end of the treatment, by visualization of corpus luteum periodicum. The ultrasound pregnancy check was carried out on the 35th day after insemination, and pregnancy rate was determined in the two groups. The mean diameters of the largest follicle at the beginning of the experiment - day 0 in Group I and II were 5.41±2.07 and 6.31±2.01mm respectively and didn't differ significantly. On the 10th day buffaloes in Group II had bigger follicle - 13.47±2.35mm compared to the initially found on day 0 - P0.05 and to the animals in Group I 11.78±1.81mm P0.05 on the same period. Such a difference was recorded in the Group I on the 0 and the 10th day of therapy. Pronounced uterine tone, presence of cervical mucus and good cervical passage were observed in 100%, 63.6% and 71.4% in Group I and in 95.8%, 62.5% and 70.8% in Group II respectively. Ovulation was confirmed in 81% and 75% of buffaloes in Group I and Group II. Pregnancy rate was 36.4% in Group I and 33.3% in Group II. Implementation of GnRH-PGF2α-GnRH - OVSYNCH therapy to primiparous and multiparous Bulgarian Murrha buffaloes with ovarian inactivity conducted qualitative reproductive response, which is followed by resumption of ovarian activity, ovulation and successful conception. This protocol could be used successfully for treatment of buffaloes with the above mentioned disease.