DOI: 10.36347/sjavs.2015.v02i03.001

Pages: 156-165

The study was conducted on eighteen postpartum silent oestrus (> 45 days postpartum) Surti buffaloes, divided into three equal groups (6 in each) to evaluate the efficacy of Norgestomet ear implant alone (Gr.-I) and in combination with PGF2α (Gr.-II). The buffaloes in Group-I and Group-II were implanted with Crestar ear implant for 9 days with 2 ml i/m injection of Crestar solution (estradiol Valerate) on the day of implant insertion. In Group-II, additionally 500 μg Cloprostenol was given i/m on one day before implant removal. The buffaloes in Group-III served as untreated silent oestrus controls and were given 5 ml Normal Saline i/m as a placebo treatment on 0 and 8th day. The estrus was induced in cent per cent of buffaloes in the Gr-I and Gr-II with mean estrus induction intervals of 2.17 ± 0.06 and 2.03 ± 0.05 days, respectively. These intervals were significantly (P<0.05) shorter as compared to control Gr-III (8.33 ± 2.01 days). The duration of estrus differed significantly (P<0.05) longest (29.17 ± 1.086 hrs) in Gr-II followed by Gr-I (27.83 ± 0.95 hrs) and the least in control Gr-III (19.33 ± 1.05 hrs). The intensity of estrus differed significantly (P<0.05) between treatment groups as well as between each treatment and control group. The conception rate at induced estrus was highest (66.67 %) in Gr-II followed by Gr-I (33.33 %). The overall conception rate of 3 cycles was found to be highest (83.33 %) in Gr-II followed by Gr-I (66.67 %) and the least in Gr-III (50.00 %). It could be concluded that Norgestomet ear implant alone and in combination with PGF2α can be successfully used to induce fertile estrus in the postpartum silent oestrus Surti buffaloes.