New tool measures heat to understand animal stress

Infrared thermography provides a quick and non-invasive way to measure stress, 
and that has big implications for livestock producers

A new ‘eye’ on how animals respond to stressful situations is providing researchers with a valuable tool that could one day have a big impact on how livestock are treated.

Infrared thermography — or IRT — can tell a lot of stories by measuring body heat in a specific area. Using a device that looks like a radar gun, it’s a non-invasive way to learn what animals are going through. And it’s giving scientists like Drs. Christy Goldhawk and Ed Pajor of the University of Calgary a window on what animals are experiencing.

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girl riding a horse in a rodeo

Goldhawk is conducting post-doctoral research through a fellowship position partnership between the university’s faculty of veterinary medicine and the Calgary Stampede. So she spends half her time in and around the Stampede facilities and events. In July, that meant using her IRT tool behind the chutes during the Stampede rodeo.

“Specifically, what we have been looking at, at the Stampede is the idea behind, ‘Are the animals aroused and stressed?’” said Goldhawk.

“When they do react, it takes energy — both mental energy as well as physical energy. So infrared measures that heat response.”

Heat response

Having a way to physically measure stress would bring measurable evidence to what has been a matter of opinion — with critics claiming rodeo animals are mishandled, and those from the rodeo world insisting they like to perform, said Pajor, an animal welfare expert.

man wearing cowboy hat at a rodeo

“The more technology, the more approaches we have to try to understand what’s going on… the better we can understand whether this is good stress or bad stress.” – Ed Pajor
photo: Submitted

Their work initially focused on rodeo animals in the chutes.

“We started with wanting to describe what the animals are experiencing prior to their performance in the rodeo,” said Pajor. “So the first couple of years we looked at the behaviour of the animals in the chutes just before they started bucking: Were there fear behaviours being shown?”

Their studies then expanded to include IRT, and also to look at the behaviour of the animals in the back pens and the loading area.

“We had to do it in a non-invasive manner because this is a real rodeo with real timelines, rather than a controlled setting for an experiment,” he said. “But that’s the beauty of IRT as an indicator of physiological response.”

The reading is taken off the eyes, so it’s a lot easier to do than other response indicators, such as blood tests or heart rate monitoring. Plus it doesn’t add any additional stress for the animals.

So what has the Stampede study found?

Calm in the chute

The behavioural study found experienced animals were calm in the chute setting, while the novices had more of a response. The IRT results found the same thing, which is evidence it is a credible method to measure stress.

Pajor is now using IRT in another study on castration in cattle to see whether the age of the animal impacts the stress it experiences.

“IRT is one of a number of measures, but it allows us to look at the animal’s immediate response to the procedure, whether it be surgical or banding. It also allows us to look at how things progress in terms of the healing rate.”

The next phase of the project will examine the effect of using some pain mitigation along with the procedures, and again IRT will be one of the measurement tools. It’s a key to developing a whole picture of what’s happening with the animal, he said.

Both Pajor and Goldhawk said being able to accurately and easily measure stress could affect a wide range of animal management practices, from how to best move show animals in and out of buildings to developing recommendations for animal care codes of practice.

Not always negative

Goldhawk has a cowgirl background, and adheres to the teachings of legendary natural horseman Ray Hunt, who said when handling and working with animals you want to fly under their radar, so they don’t react as much. But she is also quick to say that just because an animal’s response is heightened, it’s not always a negative thing.

“As a researcher I get sticky on the term ‘stress’ because there’s good stress, especially when you’re thinking about learning,” she said. “It’s stressful to learn something you don’t know, and it’s a challenge, but it’s good to learn.

“If we use infrared as a stand-alone measurement, that’s not a great idea, because you have to put it in context of other parts of what the animal is doing, and what’s being done to the animal.”

That includes factoring in long-term implications, such as whether stress diminishes after the animal figures out the handling system, or becomes familiar with the new pasture, or, in the case of rodeo, knows what to expect when the chute gate opens.

Pajor agreed, calling it dangerous to take a single-minded approach to animal behaviour.

“The more technology, the more approaches we have to try to understand what’s going on, with behaviour or physiological response, the better we can understand whether this is good stress or bad stress.”

Good and bad stress

But if it’s the latter, the ‘it’s always been done that way’ defence isn’t good enough, said Pajor.

“In agriculture there’s an awful lot of tradition in terms of how things have been done,” he said. “Often, there’s not a lot of evidence for that. Sometimes what we’re doing with research is just finding evidence that demonstrates the ranchers are correct in terms of why they were doing things. But other times we find the evidence says maybe this is a technique or a process that could be done better.”

Infrared technology is also rapidly improving, said Goldhawk, an early adopter who has been using it for five years.

Used in everything from home inspection to military operations, the measuring tools are getting less cumbersome, the images better, and the software and editing functions easier to use.

However, it’s not useful on the ranch level just yet, she added.

“Don’t go buy one today or tomorrow, but get thinking about it,” said Goldhawk. “Because there are a lot of applications, and research is working on it. Like with the wireless technology we have in our smartphones now, a lot of it can come from ranchers’ own ingenuity about how (best) to apply it.”

Videos of Goldhawk’s work at the Calgary Stampede can be found on YouTube.

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