Vol. 10, Special Issue 12 (2021)

Author(s):
A Suresh, C Joseph, T Sarath, R Sureshkumar and S Jaishankar

Abstract:
The present study was designed to compare serum estradiol-17β and progesterone levels during estrus of repeat breeders with normally cycling cows and 40 crossbred cows, divided into two groups, normally cycling (Group 1, n=20) and repeat breeders (Group 2, n=20) were used for the study. Blood was collected on the day of estrus for hormonal analyses of estradiol-17β and progesterone using ELISA kits. A significant (p<0.05) difference was found in the serum estradiol levels, higher in Group 1 (50.49 pg/ml) than Group 2 (41.85 pg/ml). No significant difference was seen in serum progesterone levels. Lower estradiol-17β concentrations during estrus in repeat breeder cows can affect the final stages of follicular growth and development besides expression of estrus behaviour, and can be a potential cause of repeat breeding.