Determination of ovsynch efficiency for estrus synchronization by plasma LH and P4 levels in Nili Ravi buffalo during peak and low breeding seasons
2013
Jabeen, S. (Quaid-i-Azam Univ., Islamabad (Pakistan). Faculty of Biological Sciences) | Anwar, M. (National Agricultural Research Centre, Islamabad (Pakistan). Animal Sciences Inst.) | Andrabi, S.M.H. (National Agricultural Research Centre, Islamabad (Pakistan). Animal Sciences Inst.) | Mehmood, A. (National Agricultural Research Centre, Islamabad (Pakistan). Animal Sciences Inst.) | Murtaza, S. (Nuclear Medicine, Oncology and Radiotherapy Inst., Islamabad (Pakistan)) | Shahab, M.
Oestrus synchronization may be used to overcome poor oestrus expression and seasonality of breeding in buffalo (Bubalus bubalis). The present work was conducted to compare the efficiency of an oestrus synchronization protocol "ovsynch" in Nili Ravi buffalo during peak (n=8) and low breeding seasons (n=11) by determining luteinizing hormone (LH) peak and progesterone (P4) rise in blood plasma using ELISA. Buffaloes were administered gonadotropin releasing hormone (GnRH) analogue (50 mug lecirelin; day 0) followed by prostaglandin F2-alpha (PGF2-alpha) analogue (150 mug cloprostenol; day 7) and again GnRH analogue at 36 hours after PGF2-alpha. Blood sampling for LH was started 12 h after PGF2-alpha injection and done at 3 h interval up to 108 h. An animal was considered to have responded to ovsynch protocol if it showed LH peak within 48 h after PGF2-alpha injection (and within 3-6 h after second GnRH injection) and showed a P4 concentration of greater than 2.0 ng/ml on day 18 after the 1st GnRH injection. 87.5% animals showed positive response to ovsynch protocol in term of oestrus and ovulation synchronization during the peak season as assessed by LH peak and P4 level while only 36.36 % animals responded to synchronization treatment during low breeding season (P less than 0.05). The LH peak in responsive animals was 11.48 plus minus 1.98 and 10.38 plus minus 1.77 ng/ml in peak and low breeding season respectively. It is concluded that ovsynch protocol in buffaloes resulted in a significantly better response during peak breeding season as compared to that in low breeding season.
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