Average daily gain of intact and castrated calves during the backgrounding phase

Abstract

The study was conducted in Osorno Chile, in order to assess the effect of castration on average daily gain of weaned calves during the backgrounding phase. The study considered a total of 20 weaned calves of a beef biotype whose average live weight was 189.5 kg (± 4.3 SEM). Two groups of 10 animals each were randomly assigned to two treatments consisted in calves castrated after weaned and intact calves. Both groups were handled similarly; grazing natural pastures composed mainly of Trifolium repens L., Achillea millefolium L. and Anthoxanthum odoratum L. The study was conducted as a completely randomized design, with each animal being considered as experimental and observational unit. Data were analyzed using the statistical package JMP (SAS Institute, N.C. USA) by using a covariance analysis (ANCOVA by initial body weight) with a significance level of 5%. The evaluation period was 90 days and animals were weighted fortnightly. Total weight gains during the study period were 113.6 y 117.6 kg (± 5.7 SEM) for castrated and intact calves, respectively. No differences were observed between average daily weight gain (castrated = 1.27 vs. intact = 1.30 kg/d ± 0.06 kg/d). We conclude that there are no productive advantages by keeping intact animals, thereby increasing the risk of stress, suffering and risk of operators to perform the castration.