Evaluation of insulin and dextrose pretreatment to Ovsynch protocol on induction of cyclicity and conception in buffaloes during summer.

A study was undertaken in 24 true anestrous Murrah buffaloes to determine the efficacy of insulin and dextrose pretreatment to GnRH on induction of cyclicity and conception during summer. The animals were of 7 to 10 years of age and at third to fifth parity having quiescent ovaries (i.e., absence of palpable corpus luteum and ovarian follicle) as confirmed by per rectal examination twice at 10 days intervals. The acyclic buffaloes were randomly divided in four treatment groups. The buffaloes in Group I (n=6) were treated with GnRH + PGF 2a + GnRH (Ovsynch protocol); Group II (n=6) with GnRH + PGF 2a + GnRH + insulin; Group III (n=6) with GnRH + PGF 2a + GnRH + dextrose and Group IV (n=6) buffaloes served as control. Artificial insemination was performed in buffaloes of all groups that showed signs of estrous. Highest percentage of buffaloes (100%) exhibited estrous in group III as compared to other treatment groups (66.67% in group I, 50.00% in group II and 16.67% in group IV). Overall conception rate (%) was 33.33, 0.0, 66.67 and 16.67 in groups I, II, III and IV, respectively. The hormone levels determined on day 0, 7 and 9 by radio-immunoassay method revealed comparatively higher levels of progesterone and insulin on day 7 in groups II and III. However, rise in estradiol-17 β concentration was observed on day 9 after treatment with prostaglandin on day 7 in groups I, II and III, while there was no change in the levels of progesterone, estradiol-17 β and insulin in control group. This study revealed better manifestation of ovarian cyclicity and higher pregnancy rates in animals pretreated with dextrose. This might be due to the reason that positive energy balance by dextrose enhanced the ovarian activity due to optimum availability of energy level that helped the animal to combat environmental stress during summer.