author(s)
Aayush Yadav, GP Lakhani, Biswajit Roy, Sudipta Ghosh and Bhavna Aharwal

abstract
The study was aimed to investigate the effect of mustard oil supplementation on the reproductive efficiency of lactating Murrah buffaloes. Twelve advance pregnant Murrah buffaloes were selected 21 days pre-partum and divided in 2 groups of 6 each; CON as control and MO as mustard oil supplemented @ 200 ml/animal/day upto 90 days post-partum. The results revealed non-significant improvement in average birth weight of calves by 6.54%, first post-partum estrus by 12.34 days, service period by 14 days and time for the expulsion of placenta by 1.25 hrs. in MO as compared to CON. Both the groups shared similar first service conception rate (50.00%) and there were no positive cases of retention of placenta in MO however it was 16.66% in CON. This study affirms that the overall reproductive efficiency was better in MO than CON which is imperative to renew the lactation cycle and increase the longevity of dairy animals.