Response of anestrus rural buffaloes (Bubalus bubalis) to intravaginal progesterone implant and PGF2alpha injection in summer.

An investigation was conducted to study the genital condition and response of intravaginal progesterone implant with and without administration of PGF2alpha in anestrus rural buffaloes during summer (April-June, 2001) in tropical climate. The ovarian status of 40 lactating (1st to 4th lactation) noncycling buffaloes and 15 noncycling buffalo heifers (3.5 to 5.0 years of age) maintained under village management condition were examined per rectum. Inactive genitalia with [12] and without [28] palpable corpus luteum (CL) were detected on per rectum examination in buffalo cows. The PGF2alpha-injection caused luteolysis and induction of estrus in 83% buffaloes having distinct corpus luteum. Implantation of progesterone in form of CIDR (Controlled Internal Drug Release device) intravaginally for 10 to 14 days induced resumption of estrus among 83% of anestrus buffaloes within 12 to 120 h after implant removal. Of those detected estrus about 80% of buffaloes conceived following natural service. Implantation of CIDR in combination with intramuscular injection of PGF2alpha was more effective than CIDR alone in terms of exhibition of estrus and conception rate. Long term of 10 to 14 days CIDR implant was superior to short term of 8 days in terms of resumption of estrous cyclicity. The observation suggests that during summer about 30% of rural buffaloes were cycling but due to lack of estrus detection they were declared anestrus, though they were having distinct corpus luteum on ovary. The summer sterility can be overcome by raising progesterone level for 10 to 14 days in buffaloes under rural managemental condition.