1Professor,
2Assistant Professor,
3 Assistant Professor,
4 Professor & Head.,
Thirty three repeat breeder dairy cows maintained under field conditions and were inseminated at spontaneous estrus were utilized for the study. Cows in treatment group (n=16) were administered with 2.5 ml of injection Gonadotropin Releasing Hormone (GnRH) on the day of AI. Cows in control group (n=17) served as a control without any treatment. Blood samples were collected from all the cows on the day of AI and day 6 post-AI for serum progesterone estimation. Pregnancy diagnosis was done on 45th day post-AI. There is no significant difference in the serum progesterone concentration between the two groups on the day of AI but there was significant difference on day 6 post-AI. The overall conception rate obtained in control and treatment groups were 29.41% and 43.75% respectively.
Repeat breeder cows, GnRH, Serum progesterone, Conception rate