Follicular dynamics during synchronization of ovulation of nuliparous buffaloes cows during unfavourable reproductive station

Abstract

The experiment was conduct to assess the follicular dynamics, time and synchrony of ovulation in nuliparous Murrah buffaloes (Bubalus bubalis) treated with an ovsynch protocol associated with progesterone. Eight nuliparous cycling buffaloes received an intravaginal CIDR device containing 1.9 g of progesterone and 100 mg of a GnRH analogue i.m. (Gonadorelin, Profertil) without regard to the stage of the estrous cycle (day of treatment, day 0) followed by 500 UI eCG (eCG, Novormon) 7 days later and 0.150 mg of PGF2α i.m. (d-Cloprostenol, Prolise) 8 days later at the time of CIDR device removal. A second- treatment of the same GnRH analogue (100 mg, i.m.) was given 48 h after PGF2α. All buffaloes presented a BSC of 3,5 (scale 1 to 5, 1 = very thin and 5 = fat) Follicular dynamics was monitored by transrectal ultrasound (Pie Medical, linear transducer of 7.5 MHz ). Only one female ovulated after first GnRH application. The diameter of the ovulatory follicle at the day of device removal was 7.5 ± 1.0 mm and at the day of second GnRH injection was 10.5 ± 1.2 mm. The interval between device removal and ovulation was 67.0 ± 6.0 hours and ovulation rate was 75% (6/8).

Keywords

• Buffalo, Estrus Synchronization, CIDR, GnRH