Castration is one of the most common painful animal management procedures we do in the beef industry. As of Jan. 1, the industry’s revised code of practice for care and handling of beef cattle has a new requirement that stipulates pain control is necessary, in consultation with a veterinarian, when castrating bulls older than six months.
Many producers have already adopted pain control methods in younger calves and it has been my experience that once they have started using these products, they usually become strong proponents.
We are fortunate in Canada to have several products approved for pain control for cattle. These products are all non-steroidal anti-inflammatory drugs (NSAIDS), which are one particular class of drugs that work as analgesics. Analgesics are used to reduce pain, but do not eliminate all sensation.
When we take ibuprophen or aspirin for a headache, we are using an analgesic, which is also an NSAID.
A number of NSAIDS are licensed for cattle including Anafen, flunixin, and meloxicam (oral and injectable). Research trials carried out in Western Canada have demonstrated that flunixin or meloxicam in particular can reduce pain associated with castration in different ages of beef calves.
A recent paper published in the Journal of Animal Science describes further research evaluating the effect of oral meloxicam as a method of pain control after castration in beef calves. This research was carried out at the University of Arkansas and focused on bulls that were castrated as they entered the feedlot.
They divided slightly more than 150 bulls into four different treatment groups. Half were castrated surgically and half were castrated using a banding method. Within each of these two groups, half of the bulls received meloxicam and half received no pain control.
They also compared these castrated animals to a group of steers who had been castrated at birth before coming to the feedlot.
The researchers followed these bulls throughout the feeding period (about 200 days) but most of their measurements focused on the first 32 days post castration. They evaluated behavioural indicators, such as the number of steps taken and a physiological indicator known as serum haptoglobin, a blood protein that becomes elevated in response to stress.
Researchers also measured performance by evaluating average daily weight gain during the feeding period. The study focused on castration of calves at feedlot entry, although we would all prefer to have the procedure done at a much younger age. The beef industry code of practice states that we should castrate calves as young as practically possible.
The results of the study were similar to some of the Canadian studies that have been published by Dr. Karen Schwartzkopf-Genswein’s research group at the Agriculture Canada research centre in Lethbridge.
The Arkansas study found that both methods of castration reduced feedlot performance. Surgical castration tended to reduce performance during the first week post-castration and band castration decreased performance during the second week post-castration.
Band castration had a lower serum haptoglobin response compared to surgical castration and meloxicam reduced the serum haptoglobin response following surgical castration.
In this trial, it was not clear that meloxicam had a major effect on behavior traits, such as standing or lying time.
When evaluating the performance over the entire feeding period, the castration method did not have an overall effect on average daily gain. However, the authors reported a significant improvement in overall average daily gain when comparing the castrated bulls that received the meloxicam treatment to castrated bulls that did not receive meloxicam.
These differences were not apparent in the immediate post-castration period, but did show up over the 200-day feeding period.
These improvements in average daily gain are somewhat surprising as most other studies have not shown a performance benefit to using pain control products at the time of castration.
We should be cautious when interpreting these results from this single study, especially when looking at a performance benefit over such a long period of time. It would be great if there was a performance benefit to using these products. However, when reading through the scientific literature, the most likely conclusion is that the use of analgesics is unlikely to provide any long-term benefits in terms of performance measures such as average daily gain, despite the surprising results in the Arkansas study.
However, despite the uncertainty of any performance benefit, many producers are convinced it is the right thing to do. Public pressure is pushing all of us in the beef industry to practice good animal welfare and this provides one way to show we care about our animals.
The costs of using these products are probably not going to seriously affect our profitability and, in my experience, the producers who have used analgesics during castration are convinced it is a useful management procedure.