A comparison of entire and ovariectomized beef heifers treated with ethylestrenol

Abstract

SUMMARYTwenty-eight Hereford cross Friesian heifer calves aged 3 months were allocated in randomized blocks to two main treatments, namely, ovariectomy (spaying), performed by flank laparotomy, and anabolic steroid oral administration (Ethylestrenol). The cattle were tied in stalls and individually fed ad libitum on a ‘barley-beef’ type cereal mixture until slaughtered weighing approximately 340 kg.Ovariectomy reduced overall rate of live-weight gain and food conversion efficiency but differences were not significant. Spayed heifers, however, grew significantly taller than entires. Although fat and bone proportions of the side were increased slightly, carcass grading and composition were not appreciably altered by ovariectomy.Steroid treatment failed to improve performance but lean content of the side was slightly increased. This failure in response may have been due to incorrect dosage.