Follicular dynamics, ovulation and reproductive hormones following GnRH pre-treatment in post partum suckled dairy buffalo- cows [electronic resource].

Includes references.

The objective of this study was to investigate the role of administration of gonadotropin-releasing hormone (GnRH) at day 12-14 postpartum on ovarian dynamics and conception rates in buffalo- cows. The study was conducted on twenty four, apparently healthy, lactating buffalo-cows in their second to fifth parity. The animals were divided into two groups; group I (n=10) considered as control group that did not receive any treatment and group II (n=l4) that received 100 Ug GnRH (Receptal ) for each animal during the period from 12-14 days post partum. Ovarian structures were monitored daily, from day 6 postpartum until detection of the third postpartum ovulation, using a real- time ultrasound. Blood samples were collected via the coccygeal vein from day 6 post treatment and every 3 days until detecting the third postpartum ovulation to estimate serum progesterone, serum luteinizing hormone, and Follicle stimulating hormone profiles. All animals ovulated before day 45 postpartum in GnRH treated group (14/14,100%); whereas, none of the cows in control group ovulated within this period of time. Interval from calving to the first ovulation and from calving to the second and the third ovulations in GnRH treated group was significantly shorter (23.6±1.4, 45.2±2.3 and 67.8±1.9 days respectively) than in control group (65.1±5.8, 87.6±6.4 and 119.2±6.3 days respectively).

Summary in Arabic.