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Looking for ways to manage the pain

The cattle industry is moving toward low stress handling, better ways to manage cattle, etc., but one issue that still needs to be addressed is pain management for routine procedures such as branding, castrating and dehorning.

Dr. Eugene Janzen at the University of Calgary says the veterinary profession is rapidly changing its attitude to pain management in food animal production. “If a veterinarian in Alberta castrates a cat or horse without using anaesthetic and pain mitigation, that veterinarian would be at risk of losing his/her license. Yet if we are castrating a calf or bull, no one notices,” he says.

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The cattle industry has a long tradition of having to do routine surgical tasks without the means for pain suppression. We’ve streamlined and adjusted some of the ways we handle cattle so it’s easier on them, but are still not addressing pain.

“As veterinarians we have not sufficiently investigated pain mitigation methods for food animals. When ranchers ask me what to do, there’s not much I can tell them. This forces a sense of urgency to keep looking for ways to address this.” There will be increasing pressure on the livestock industry to use more humane methods because some surgical procedures are a necessary part of animal husbandry.

Studies on pain management

“One of the things that concerned me some years back was having to castrate mature bulls in a feed yard. This is why we did one of our first studies, using an epidural anaesthesia when castrating bulls, and it worked very well. The main drawback was that it had to be given 20 minutes before the surgery. The animal has to have it on board before you initiate a painful procedure.” When the dentist blocks your jaw, for instance, he does not immediately began to drill.

“There are many injectable products and we looked at three — ketoprofen, flunixen, and eloxicam. We do have some of them available in Canada for use in food animals,” says Janzen.

“These injectable drugs work well and are simple to administer. They can be given subcutaneously, but you need to inject them 20 to 30 minutes before you do anything painful to that animal. They will not eliminate pain completely. To do that, you’d need anaesthesia, like you would get with an epidural. For dehorning, you could use a cornual nerve block for pain elimination. I have been at brandings and blocked the horns for pain elimination, and asked the cowboys to leave the animals lying there for three minutes before we burn the horns off — to give it time to be effective,” says Janzen.

calf being treated with an injection

Effective injectable products need to be given up to 30 minutes before processing the calf.
photo: Dr. Eugene Janzen

“For a couple of years I’ve used meloxicam for pain on a certain ranch, and last year we medicated a subset of calves three hours ahead of time. Even the ropers who dragged the calves to the fire could tell there was a big difference. The calves did not vocalize and didn’t struggle as much. They were almost sedated. This demonstrated that a person could mitigate pain on a ranch if you just changed the production practices a little bit.”

In another experiment during the summer of 2014 he divided a group of 150 cow-calf pairs to try to determine the best time to castrate bull calves. “We did some at birth, some at two months, some at four months, and some at seven to eight months. If we didn’t medicate them, it didn’t matter which age; we could easily measure a significant difference between the medicated ones and non-medicated ones,” he explains.

“We used a number of behavioural measurements, including stride length. We walked them through a narrow chute and focused a camera on them as they walked away from the calf table or chute. Stride length becomes measurably stilted, and hence a reasonably good indicator of pain. This is a complicated measurement, however, because someone has to sit at a computer and look at all those videos and measure stride length.”

Cortisol is another good measure of pain and stress. “We took saliva samples and measured salivary cortisol levels. You can block that cortisol response with an analgesic like meloxicam if you are castrating them. There is good evidence that pain medication helps,” he says.

“We also looked for a product in the bloodstream, a biomarker for pain called substance P. Some of the preliminary results are very encouraging. They mimic the salivary cortisol results,” he explains.

Castration pain

“It didn’t matter whether you did that to a baby calf (a day old) or to a post-pubertal bull. It was painful at first at any age — and we could easily measure that,” Janzen says.

“If we did them surgically, all we could tell, within the first 36 hours, was that they lay around more. After that, their appetite began to increase and they moved around. Within a week it was difficult to tell anything from their behaviour, except if we palpated the surgical sites. When I ran them through the chute on a weekly basis, I could tell that the healing was varied; some didn’t heal as quickly as others. This was in contrast to the ones that were banded. The banded calves, once they got past the first 24 to 36 hours, did pretty well for the next two weeks —until about day 17 to 21. By then the band breaks through the skin,” says Janzen.

That’s when the area becomes inflamed/infected above the band. “Day 28 is the worst time. We can measure the inflammation with an infrared camera or by doing a simple complete blood count.”

The calves’ feed intake was significantly reduced during that time. They were uncomfortable, and not eating as much. “Average daily gain goes down, but what was very interesting is that the average daily gain goes down more than the intake goes down. That tells me there is a metabolic cost; the calf is using up energy trying to fight the inflammation and pain,” he explains.

“Twenty-five years ago, when we started using the Callicrate bands, I was an advocate for this method. It was easier on the feedlot cowboys and the complications were less than with surgical castration. But if we are looking exclusively at pain, to do it surgically it is probably more painful for the first three days and then the calves gradually do better (unless there are complications),” he says. They don’t suddenly become more painful three weeks later as they do when banded.

“We still are not sure about the best time to castrate, looking at the four times we did it. Should we concentrate our efforts on baby calves or two-month-old calves? When can we scientifically say this is the best time to castrate a calf, and then spend our efforts on pain mitigation on that class of animal?”

“The weaned post-pubertal calves that come into a feed yard at eight to 10 months of age can be castrated using the xylazine epidural for pain management. I’ve seen feed yards run 10 of them through the chute and a veterinarian gives them the epidural ahead of time. The first three go into one pen, the second three into another pen, etc., and then they run them through again and castrate them, and get excellent pain control,” says Janzen. “I’d like to find an oral medication. If you need to castrate a group of weaned calves, you could top-dress their feed bunk with medication. If a feed yard received a load of calves and there are 15 bulls in the group, they could be sorted off, put in a separate pen, and you could manage their castration according to a pain mitigation protocol,” he suggests. The oral medication might work nicely, if they are accustomed to eating from a bunk, and they all eat the medicated feed.

“If a person is going to band calves rather than cut them, the banded calves probably need pain management between days 17 and 30. You are not going to run them through the chute for this on a daily basis and inject them. If there was a way to do it orally, with their feed, it would preferable. This might work well for feedlot cattle, but would not for baby calves at pasture with their mothers.”

Castration by vaccination

This was used experimentally some years ago, but the project was dropped because it was considered too dangerous to humans. “If you accidentally injected yourself or the cowboy next to you, it would not be good!”

“We did a trial in which we vaccinated post-pubertal weaned bull calves in January and again in March. We harvested that group the end of July when they were ready for slaughter. From the time of their first injections we bled them every two weeks to check hormone levels. The vaccination obliterated serum testosterone for 60 days. Thus if you wanted to effectively castrate them, you’d have to revaccinate them every two months — a series of vaccinations until they were nearing the time of harvest.”

The volume/size of testicles in vaccinated bulls was only 30 to 50 per cent of the size of the intact bulls of their age. The testicles didn’t develop; they stayed the same size they were at a younger age.

Janzen wants to do an experiment vaccinating calves at branding, again at weaning, and again upon arrival at the feed yard. “The calves could be revaccinated in the feed yard when we reimplant them or rehandle them for whatever purpose,” he says. We already give calves various vaccines and boosters, and it would be feasible to revaccinate male calves with the anti-hormone product at those times.

“I found two ranches that retain ownership of their calves and would be willing to try this, and not have to worry about the discount that might accrue if they went through an auction yard. The testicles would still be there (inactive, smaller than normal, but still there) and buyers might not believe that they were not bulls,” he says.

“I am not sure if this anti-development vaccine will work on a baby calf that doesn’t have much male development yet, not being triggered by hormones at that stage of life. They have to reach puberty before much development begins. But if this would work, we could diffuse a lot of the negative connotations about castration,” he says.

Pain mitigation can be a plus

“So I asked Grandpa Watson why he liked it,” recalls Janzen. “He told me that through all the years of traditional castration, he noticed that the day after branding, cows that had heifer calves would be two miles away from the branding corral, and cows with bull calves would be within half a mile because their calves were lying around, uncomfortable, and didn’t want to travel. Then the years that he used ChemCast, the cows with bull calves and heifer calves were evenly distributed on the range. It was not as painful for bull calves as traditional castration.”

“One of the things we’ve done for several years is give half the bull calves meloxicam and nothing to the other half. We painted these two groups different colours. I had the students go out on horseback to see where those calves were. Grandpa Watson’s observations were accurate. The calves we gave pain medication were out with their mothers travelling and grazing, like the heifer calves,” he says.

“One of our large ranchers in Western Canada tried this. I asked him later if he could tell whether it controlled the pain. He said his crew of 10 people got home for lunch an hour and a half sooner. The way they brand and castrate calves is to go out in the morning and select about 200 pairs from the mountain and bring them to the branding trap. After the procedure they turn the calves out and let them mother up, and then move them out of that field, along a three-mile trail. The calves with pain medication mothered up quicker and travelled better.”

Even if the meloxicam was given at the time of branding and castration (rather than ahead of it), the calves mothered up afterward more quickly, the calves nursed their mothers quicker, and trailed easier. They weren’t trying to flop down somewhere along the way getting left behind.

“He told me that traditionally after they took cattle back to the mountain, they’d go out the next day and there would be several cows coming back through the fence to look for their calves that got left along the way. Or there might be a calf fall in the creek. After they started controlling pain, these problems didn’t happen and the ranch crew had an easier day.”

Change from within

“I think the kids will help facilitate change. They wonder why calves have to experience so much pain, and if they know there’s a way to mitigate the pain they will probably say, ‘Gee Grandpa, why aren’t you doing that?’ This could have a huge effect.”

Our industry will come a lot further, faster, if people want to change something for the better, rather than being forced to do it because of a requirement. “We keep doing some things because it’s the way we always did it, or because we had to do it that way, but then the kids come along and say ‘why?’ It makes people think.”

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