Comparison of females treated with oestradiol or testosterone to detect oestrus in dairy cattle maintained indoors year-round

Abstract

The effectiveness of three females treated with oestradiol and three females treated with testosterone to detect oestrus was examined in 304 dairy cows maintained indoors year-round. Three heifers were treated weekly with 10 mg oestradiol benzoate per 250 kg of body weight. One cow and two heifers were treated with 10 injections of testosterone propionate (200 mg) every other day and an injection of testosterone enanthate (500 mg) every 10 days thereafter. During one year, there were 858 periods of oestrus detected by herdsmen observation - using standing, mounting, mucous discharge and any combinations thereof and, or, the hormone-treated females. Of these, the herdsmen detected 94% compared with 51% by the hormone-treated females. The 6% not detected by the herdsmen were detected by the treated females only. Oestradiol-treated females detected oestrus in cows as effectively as testosterone-treated females.