Abstract: The objective of this experiment is to describe the influences of biostimulation on oestrus behaviour, ovulation time, progesterone levels and conception rate in beef cows. Three groups of cattle were investigated; CNB, PB and MB which comprised 17 multiparous, 12 primiparous and 13 multiparous cows, respectively. On the 3rd day of CIDR insert, three bulls were introduced into the MB and PB groups for biostimulation and breeding. CNB cows were AI 12 h after standing heat. Blood samples were collected every 3 days from CIDR insertion to end of experiment. Ovulation time and pregnancy were determined by ultrasound twice daily for 4 consecutive days and on day 35 after CIDR removal, respectively. Overall, mean percent of cows in oestrus was 90.52%. PB and MB scored higher than CNB for oestrus intensity. Mounting another cow being mounted but not standing and standing oestrus were commonly exhibited during oestrus. Oestrus duration was significantly longest in PB. Conception rate in PB and MB were three times higher than CNB. Only primiparous cows displayed longer, more intense oestrus and longer ovulation time. Conception rate is higher by natural mating than AI.
N.P. Khanh, Y. Rosnina, M.A. Omar, G.K. Dhaliwal, H. Wahid, A.M. Khumran, K.C. Yap, M. Fahmi and A. Azmil, 2012. Effects of Biostimulation on Oestrus Behaviour, Ovulation Time and Conception Rate in Primiparous and Multiparous Beef Cows. Journal of Animal and Veterinary Advances, 11: 404-411.