Effect of Castration Upon Arrival on Health and Performance of High Risk Calves During a 44 day Receiving Period

Abstract

The interaction between stress, the immune system, disease and performance of domestic animals has been reviewed (Breazile, 1998; Colditz, 2002). For beef cattle, the major stressor occurs when cattle are weaned, transported to a new environment, commingled and exposed to different pathogens, especially respiratory pathogens. In recent years, preconditioning programs have been developed, and although the specific components of each preconditioning program vary, they generally include weaning, castration, dehorning, deworming and vaccination against common respiratory pathogens (Peterson et al, 1989). According to Capucille et al (2002), beef cattle are castrated to prevent aggressive male behavior, control unwanted matings and to avoid consumer prejudices against beef from intact males. Based on a 1997 US National Animal Health Monitoring System report, surgical castration is the preferred method used by US cow-calf producers before weaning; however, post weaning techniques were not surveyed. This survey also reported that 25.5% of the cow/calf operations do not castrate their bull calves before selling them. Intact males represent a challenge for veterinarians and producers involved in backgrounding, stocker and finishing operations. Potential stress associated with post-weaning castration may include depressed immunity, expressed through the suppression of lymphocyte blastogenesis (Muratta, 1997) and interferon gamma production (Fisher et al, 1997). The objective of this study was to evaluate, in a controlled field study, health and performance of weaned calves arriving as bulls or steers during a 44-day receiving period.