A study on the possible effects of administration of human chorionic gonadotrophin, at 5th day after AI, to improve conception rate and serum progesterone concentration in Holstein dairy cattle
Subject Areas : clinical veterinary science, O Ataie 1 , بهرام Salasel, 2 , A. Mehrabi 3
1 - Derpartment of Clinical Sciences, Faculty of Veterinary Medicine, Karaj Branch,
Islamic Azad University, Karaj, Iran
2 - Derpartment of Clinical Sciences, Faculty of Veterinary Medicine, Karaj Branch,
Islamic Azad University, Karaj, Iran
3 - Graduated from Faculty of Veterinary Medicine, Karaj Branch, Islamic Azad University,
Karaj, Iran
Keywords: progesterone, conception rate, dairy cattle, HCG,
Abstract :
The objectives of this study were to determine the effect of administration of exogenous hCG 5 days after artifcialinsemination (AI) on serum progesterone concentration and conception rate in dairy cows.39 lactating dairy cattlerandomly allotted to 2 experimental groups: Treated group included 19 dairy cows that received 3000IU hCG on day5 after AI and non treated (control) group included 21 dairy cows that only received 5ml normal saline 5 day after AI.Blood sampling obtained on day 5, before administration of exogenous hCG and normal saline, and also on day 13after AI to measure serum progesterone concentrations. Pregnancy diagnosis was performed by rectal palpation 40-60 days after AI. On day 13 average serum progesterone concentrations were 7.72ng/ml and 8.25ng/ml in hCG andcontrol groups respectively. Pregnancy proportion in hCG and control groups were 31.6% and 47.6% respectively.Statistical analysis of results did not show any signifcant difference between two groups in respect to pregnancyproportion or progesterone concentrations (p>0.05).