Best practices for pain mitigation after castration

By Tim Kalinowski

Researchers at Agriculture and Agri-Food Canada may have definitively answered some age-old questions about the most painless ways to castrate young calves.

Dr. Karen Schwartzkopf-Genswein, senior research scientist based at the AAFC research station in Lethbridge, completed a five-year-study in 2018 on the subject funded by a grant from the Beef Cattle Research Council.

The study looked the ideal age to castrate calves, whether or not to use pain mitigation drugs when doing so, and what method, knife or band castration, was best for limiting pain.

“The public is concerned about those things,” explains Genswein. “As a producer organization (BCRC), and as a scientist working in this area, we have an obligation on both sides: To find a solution that addresses consumer wants for humane handling of cattle, and also for producers— to make it practical, cost effective and something that actually works.”

Genswein says her study confirmed what most producers already know— the younger you do the procedure the less painful it is for the animal to endure.

“One of the first things we did before we even tested the (pain mitigation) drug is there is actually very little research on the effects of castration on young ages,” says Genswein. “Veterinarians and producers have always advocated to do the procedure as early as possible because it is a less painful removal, presumably, at that age.

“Given that, producers wondered if we did it at one week of age— ‘Really, do we need to use any kind of pain mitigation at all?’ So one of our first studies was looking at different types of ages. We looked at both banding and knife-castration. We looked at one week of age, two months of age and four months of age. In that study, we showed very clearly at any age castration is painful, and in each age group we saw indicators of pain. But as time went on, from one week, to two months, to four months, those indicators of pain were much worse. So it is true the younger you do the procedure, the less stressful it is— although not painless.”

The second thing Genswein’s study was able to confirm was the least painful method for doing the operative procedure. She looked at knife castration versus band castration in a number of animals for comparison.

“Knife castration gives the most indicators of pain,” she confirms, “but there is a contradiction as well. We saw the healing in knife-castrated calves was faster than in the banded animals. The banded animals at about three to four weeks post-band castration go off feed, and there can be quite a bit of inflammation above the band. So to say banding is not painful— you have to watch and see if there are any complications with that. I would say if you have those complications that pain lasts over a longer period of time than knife castration, which has greater procedural pain but it is shorter lived.”

One last major area Genswein’s study looked at was whether or not the addition of certain analgesic and anaesthetic drugs is something producers should seriously consider to lessen the pain animals experience during the castration procedure.

“Our whole research project focused on a generic product called meloxicam,” she says. “It’s a non-steroidal, anti-inflammatory analgesic that acts on reducing inflammation post-operatively. The reason we selected that drug is it is already registered in Canada for use. The benefit of that drug is it has a long half-life, and the greatest number of days for coverage for pain of any on the market— up to three days post-procedure.”

Genswein says unsurprisingly using meloxicam is an effective way to help mitigate the pain of castration, and even helps when you add an additional aggravator like branding at the same time.

“We know an analgesic should work by the nature of what it is; it should reduce the pain,” she states. “We did find meloxicam, overall, works to reduce pain. What we did in this research was come up with an optimal day and time, and we found band-castration overall had the fewest indicators of pain. Our recommendation is if a producer is not going to use pain mitigation that they band animals at two months of age or less. Even one-week-old animals could benefit from pain control, and the optimal procedure is to give them meloxicam.

“We also found that there was no added benefit of administering (meloxicam) three or six hours before castration compared to immediately before castration,” adds Genswein. “Meloxicam is not an anaesthetic, so it doesn’t block procedural pain, and so we did not see a benefit to giving meloxicam sooner. This finding is good news for producers because it means that the calves don’t have to be handled twice.”

Genswein did look at using a true anaesthetic, lidocaine, in combination with the meloxicam to see of additional benefits could be derived. The results here were somewhat more surprising, she admits.

“In that study we found something we didn’t expect,” says Genswein. “The combination of meloxicam and lidocaine when given together didn’t provide better pain control at any one point in time we measured. These drugs act at different points in time. If your goal is to cover the procedural as well as the post-operative pain that’s the best combination.”

Genswein says lidocaine is best used in the first few hours after the castration procedure, and that meloxicam tends to cover the first 48 hours post-operation to help bring inflammation down and control pain in the calf.

Genswein recommends farmers seriously consider using meloxicam, or lidocaine and meloxicam in combination, to castrate calves in the most humane way possible.

“Social licence is such a strong thing now, and it is one of the main pillars of production and sustainability,” concludes Genswein. “So it just makes sense to mitigate pain whenever possible.”