Comparison of ovsynch and progesterone-based protocol forinduction of synchronized ovulation and conception rate insubestrous buffalo during low-breeding season

ABSTRACT

The objective of the present study was to compare the impact of ovsynch and progesterone-based ovulation synchronization protocol on ovarian response and conception in buffalo [n=19] exhibiting subestrus during low-breeding season [maximum ambient temperatures and relative humidity ranging from 36-45°C and 30-80%, respectively]. Group I buffalo [n=10] were administered ovsynch protocol [d 0 and d 9, 20 microg Buserelin acetate; d 7, 500 microig Cloprostenol sodium; i.m.] followed by AI on days 9 and 10. During the same period, another group of buffalo [n=9] were administered intravaginal progesterone [1.38 g] for 10 days along with the administration [i.m.] of 500 microg Cloprostenol sodium on day 9 and 20 microg Buserelin acetate on day 11, followed by AI on days 12 and 13. With ovsynch, all the buffalo ovulated in response to 1[st] GnRH and had functional CL [plasma progesterone, 1.61 +/- 0.23 ng/ml; corpus luteum, CL, 11.36 +/- 0.67 mm] on day 7. Thereafter, subsequent to 2[nd] GnRH, five buffalo ovulated within 24 h and the remaining five between 24 to 48 h. In comparison, with progesterone-based protocol, a better synchronization of ovulation [P<0.05] was observed as seven buffalo ovulated between 24 and 48 h and the remaining two between 48 and 72 h following GnRH administration. Moreover, in comparison to ovsynch, conception rate was better with progesterone-based protocol [30 vs. 66.7%; P<0.05]. In summary, progesterone-based protocol was superior to ovsynch for synchronization of ovulation and subsequent conception rate in buffalo exhibiting subestrus during the low breeding period