Comparative efficacy of E-17beta and GnRH administration on day 0 of a controlled internal drug release [CIDR] based protocol on synchrony of wave emergence, ovulation and conception rates in Murrah buffalos [Bubalus bubalis]

The study was undertaken to compare the efficacy of an estradiol-17beta + CIDR based protocol with the conventional ovsynch + CIDR based protocol for synchrony of wave emergence and ovulation in Murrah buffalos. In group I [n=25], on day 0 [beginning of experiment], buffaloes were administered a CIDR device [1.38 g P[4]] and concurrently received 1.5 mg E-17beta. On day 9, the CIDR was removed and a prostaglandin [PG] F[2]alpha analogue [500 micro g] was administered. On day 11, buffaloes were administered a gonadotropin releasing hormone [GnRH] analogue [20 micro g] and inseminated twice at 12 h and 24 h following GnRH injections. Group II [n=25] protocol was based on an ovsynch regimen plus CIDR for 7 days followed by double insemination at induced estrus. Group III [n=10] served as control and was not given any hormone on day 0 of the protocol. In groups I, II and III, the duration of new follicular wave emergences were observed on days 4.22 +/- 0.12, 3.12 +/- 0.33 and 5.14 +/- 0.42, respectively. In group I, synchrony of wave emergence was more and the diameter of pre-ovulatory follicles was larger [P<0.05] compared to groups II and III. The first service conception rate [FSCR] was higher [P<0.05] in group I while ovulation rates were not different between groups I and II. In conclusion, more synchrony of wave emergence, larger diameter of dominant follicles and higher first service conception rate was observed following the E-17beta + CIDR based protocol in buffalos

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

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