Treatment of postpartum anestrus Sahiwal cows on the basis of VMI and ultrasonography using single injection of GnRH

摘要

Four postpartum anestrus Sahiwal cows which has not shown the signs of estrus even three months after parturition and having no corpus luteum in one of the ovaries at two examination made by rectal palpation 11 days apart were selected. Ovaries of allthe animals were monitored at 4 days interval for 24 days by the use of Real-time B-mode ultrasonography machine. Vaginal mucus impedance (VMI) was monitored daily with help of vaginal probe and impedance meter for 24 days. Correlation between VMI and follicular diameter was found to be negative and significant (r = -0.83, P< 0.01). On this basis treatment was instituted at lowest possible probe reading in individual animals using aqueous solution of synthetic analogue of GnRH i.e. Busereline acetate,20 mu g (Receptal~(R), Sml marketed by Intervet Laboratories Ltd., Pune) after 24 days of monitoring in cows showing a clear increasing and decreasing trend in VMI. Two animals with VMI values of 21 and 25 showed external signs of estrus at days 19 and 21 post treatment respectively. Other two animals with lowest VMI values of 20 and 25 did not show external signs of estrus but one was suspected to be in silent estrus as indicated by decreasing probe reading. The changes in VMI between pretreatment andpost treatment period were significant (P< 0.05). The interval between injection and induction was 16.25±2.10 days. It was indicated from the present study that treatment of postpartum anestrus cows with single injection of GnRH on the basis of VMI andovarian ultrasonography may give satisfactory response.