Hormone Treatment for Ovarian Activity and Its Effect on Conception in Dairy Cows

Abstract

This study evaluated the efficacy of Gonadotrophin releasing hormone (GnRH) analogue in combination with Prostaglandin in treating ovarian inactivity and its effect on conception in dairy cows. Fifty four cows diagnosed with ovarian inactivity were divided into two groups and treated as follows: Group 1 (n= 30) was given a GnRH analogue, buserelin (Receptal®, Hoechst, Germany) on Day 1 (day of first treatment), Prostaglandin analogue,  cloprostenol  (Estrumate® ICI,  England)  on  day  8  and  bred  by  artificial insemination 72 and 96 hours after Prostaglandin treatment. Group 2 (n=24), was left to recover spontaneously and inseminated upon observation or oestrus.   Treatments were repeated up to three times in animals that did not respond. Pregnancy rates at day 60 post insemination were lower (P,0.05) in Group 1 when compared with Group 2, but calving to conception period  was shorter in Group 1.   Calving to conception periods (mean ± SD) were 128 ± 34 and 152 ± 28 days in Group 1 and 2, respectively.    It was concluded that hormone therapy for ovarian inactivity is not of much value as long as factors causing the   disorder continue to act on the animal.