Vol. 8, Issue 3 (2019)

Author(s):
E Niyas, MO Kurien, C Jayakumar, RS Abhilash, KS Anil and S Reshma

Abstract:
Follicular dynamics (FD), luteal growth and regression characteristics as well as the progesterone (P4) concentration in repeat breeding (RB) cows with prolonged oestrus was assessed. Ten normally cycling cows with oestrus period of less than 36h formed the control group while ten RB animals with prolonged oestrus (>36h) formed Group II. 95 per cent of the selected animals exhibited either two or three waves per cycle. Duration of persistence of pre-ovulatory follicle was longer in RB animals (>24 hrs in 70% animals). The luteal growth and regression rate differed non-significantly between the normal and RB animals. In RB animals, a significant difference in P4 concentration was observed on the day of oestrus (0.67±0.03ng/ml) in contrast to cows in control group (0.36±0.03 ng/ml). In conclusion, a higher duration of persistence of pre-ovulatory follicle and suboptimal luteal profile were observed in RB animals with prolonged oestrus.