ESTRUS INDUCTION AND FERTILITY RESPONSE IN POSTPARTUM ANOESTRUS SURTI BUFFALOES TREATED WITH NORGESTOMET EAR IMPLANTS ALONE AND IN COMBINATION WITH PMSG

摘要

The study was conducted on eighteen postpartum anoestrus (> 45 days postpartum) Surti buffaloes, divided into three equal groups (6 in each) to evaluate the efficacy of Norgestomet ear implant/Crester alone (Gr-I) and in combination with PMSG (Gr-ll).The buffaloes in Group-! and Group-ll were implanted with Crestar ear implant for 9 days with 2 nil i/m injection of Crestar solution (estradiol valerate) on the day of implant insertion. In Group-ll, additionally 500 lU PMSG was given i/m on the day ofimplant removal. The buffaloes in Group-Ill served as untreated anoestrus controls and were given 5 ml normal saline i/m as a placebo treatment on days 0 and 9. The estrus was induced in all buffaloes in Gr-I and II with mean estrus induction intervalsof 2.56 ± 0.34 and 2.40 ± 0.29 days, respectively. These intervals were significantly (P<0.01) shorter as compared to control Gr-lll (30.33 ± 0.95 days). The duration of estrus differed significantly (P<0.01) being longest (25.50 ± 0.76 hrs) in Gr-llfollowed by Gr-I (22.17 ± 0.65 hrs) and the least in control Gr-lll (18.67 ± 0.77 hrs). The intensity of estrus differed significantly (P<0.05) among these three groups. The conception rate at induced estrus was highest (66.67 %) in Gr-ll followed byGr-I (33.33 %) and Gr-lll (16.67%). The mean of number of services per conception did not differ significantly among the treatment and control groups. The service periods of the anoestrus buffaloes under Gr-I and II were significantly (P<0.01) shorter than in control Gr-lll. It could be concluded that Norgestomet ear implant alone and in combination with PMSG can be successfully used to induce fertile estrus in the postpartum anoestrus Surti buffaloes.