Effect of gonadotrophin releasing hormone on reproductive performance and steroid profile of postpartum suckled Surti buffaloes*

Abstract

he effect of GnRH (250 µg im) on postpartum Surti buffaloes with smooth inactive ovaries till day 40 was studied on 6 animals, and 5 were kept as control. Blood plasma profiles of P4 and E 2-1713 were estimated by standard RIA procedures. The reproductive performance and ovarian events recorded with the help of rectal palpation findings were correlated to p₄ and E₂ profiles. Significanlly higher progesterone levels were observed in the GnRH treated than the control buffaloes on 9-10 weeks (2.78±0.71 vs 0.87±0.49 ng/ml) and 11-12 weeks (2.86±0.83 vs 1.04±0.52 ng/ml) postpartum. The plasma E,17 β levels following GnRH treatment increased for variable periods with a typical profile in 3 buffaloes folloWed by oestrus. GnRH treated buffaloes resumed ovarian activity on day 45.83±0.30 postpartum in contrast to day 64.00±2.27 in 4 untreated buffaloes. The occurrence of first heat postpartum in GnRH treated vs control group was 54.83±2.18 vs 96.75±14.39 days (P<0.05). The Treatment to ovulation interval in 5 of 6 treated buffaloes was 15.40±2.58 days with an overall mean of 19.00±4.16 days. All GnRH treated buffaloes conceived by 80 days postpartum. Of them. 33% buffaloes conceived within 60 days and 67% between 61-80 days postpartum. In control group, conception rate before day 60. 61, 80, 81-90 and 121-150 postpartum was 0,20,20 and 20% respectively. The remaining 40% control buffaloes conceived after 370 days postpartum. Thus, GaRH treatment has a good therapeutic action to initiare early ovarian activity and to enhance reproductive efficiency in Surti buffaloes.