Is there an optimal age and method of castration for calves under 6 months of age?
K.Schwartzkopf-Genswein, D. Melendez, E. Janzen, E.Pajor and S. Marti
Producers typically castrate their bull calves anywhere between 1 week and 5 months of age and less commonly between 6 to 9 months of age with the exception of bulls destined for breeding. The most common methods used are band castration that restricts blood flow to the testicles and knife castration that involves immediate removal of the testicles by cutting. We know that both methods cause acute and chronic pain, increase stress and discomfort, and can reduce immune function and weight gain. In some instances these methods can cause infection or death due to complications. It is because of this that there is heightened interest by the public and legislators regarding management of pain in food animals.
The Canadian beef industry has made a consistent and concerted effort to promote and implement science informed, welfare conscious production practices.A prime example of this is the revised Code of Practice for the Care and Handling of Beef Cattle (www.nfacc.ca) that was completed in 2013. The new Code specifies that as of January 1st 2016, bulls older than 9 months of age must be castrated using pain control, and as of January 1st 2018, pain control will be mandatory for bulls older than 6 months of age. Currently, there is no requirement for pain control in calves castrated under 6 months of age. Instead, there is a recommendation that calves be castrated as young as possible to reduce pain and possible complications. Although veterinarians and animal scientists agree and recommend that castration be done as early as possible, there are no studies in calves < 4 months of age identifying the best age, method and pain mitigation strategy (in terms of animal welfare) to castrate beef cattle. As a result, the Beef Cattle Research Council (BCRC) identified such a study as a high priority for funding. In 2013 the BCRC approved a 5 year study lead by Drs Karen Schwarzkopf-Genswein of AAFC in Lethbridge and Ed Pajor at the University of Calgary and in collaboration with Dr.Eugene Janzen (U of C) with the main goal of identifying the best age, method and pain mitigation strategy for the castration of young calves (4 months of age or less).
The study helped to fund
The research team conducted three experiments at the Lethbridge Research Centre to evaluate the effects of band and surgical castration on indicators of stress and pain in beef calves at three different ages (36 calves/age group): newborn (Experiment 1, calves were 5 ± 1.1 d of age, and weighed 43 ± 6.61 kg); 2 months of age (Experiment 2, calves were 62.5 ± 1.0 d of age, and weighed 91.5 ± 11.93 kg); or 4 months of age (Experiment 3, calves were 131.3 ± 1.34 d of age and weighed 157.6 ± 22.5 kg). In each
The study helped to fund
The research team conducted three experiments at the Lethbridge Research Centre to evaluate the effects of band and surgical castration on indicators of stress and pain in beef calves at three different ages (36 calves/age group): newborn (Experiment 1, calves were 5 ± 1.1 d of age, and weighed 43 ± 6.61 kg); 2 months of age (Experiment 2, calves were 62.5 ± 1.0 d of age, and weighed 91.5 ± 11.93 kg); or 4 months of age (Experiment 3, calves were 131.3 ± 1.34 d of age and weighed 157.6 ± 22.5 kg). In each
In terms of acute pain, newborn and 2-month old surgically castrated calves tended to have higher cortisol (stress hormone) levels compared to
The combined results of the acute and chronic welfare assessments suggest that newborns showed fewer signs of pain compared to 2 and
The results presented here are just a portion of the entire body of work being conducted as part of this study. The team has recently completed several other experiments assessing different pain mitigation strategies including the comparison of single and multiple drug combinations, time of drug delivery, and the effect of single or multiple procedures on pain relative to the age and castration methods being evaluated. The final conclusions from the completed study will be available in late 2018.