Beef transportation research reveals sources of stress

The speed of shrink on beef animals increases at heat rises

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The more time beef cattle spend in transport over 24 hours, the more likely they’ll experience shrink (a loss of fluid from body tissue), lameness and even death. That’s according to Dr. Karen Schwartzkopf-Genswein, an Agriculture and Agri-Food Canada research scientist in Lethbridge, Alberta.

She also said younger cattle fare better than cull cows or calves and there are many other factors such as high and low temperatures and driver experience that also have an effect on the animals’ health and welfare during transport.

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Schwartzkopf-Genswein did a presentation that summed up about 15 years of research into cattle transportation on Beef Day during Grey-Bruce Farmers’ Week.

Why it matters: Assessing how beef cattle react to stress and adjusting how they are handled during transportation can prevent losses for producers.

She said that the way to assess how beef cattle are reacting to transport stress is to look at that animals’ behaviour and physiology.

“What you’re looking for is a change from normal,” she said.

Among the stressors the animals can encounter are being introduced to a new environment, mixing with other cattle, having their feed and water restricted, the conditions on the trailer, the density of the animals in the trailer, the energy it takes to remain standing on a moving vehicle, how long they’re on the road, and any injuries they might sustain.

What to look for

Her team has done a battery of behavioural assessments before, during and after transport.

They looked at respiration rates, checked for panting or drooling (an indication of dehydration), measured feeding and drinking at the feedlots, clocked the amount of time the animals spend lying or standing, rumination (cattle ruminate less when they’re stressed), and recorded any slipping or falling during loading and unloading.

In terms of physiology, she said that blood, hair or saliva tests can yield results for cortisol levels (a stress hormone), substance P (an indicator of pain), immune functions (white blood cell counts), shrink (weight loss) and many other indicators, including genetic markers.

Researchers have also investigated the micro-climate inside a trailer using up to 45 data loggers that are about the size of a nickel. They logged at one minute intervals during the entire trip. They also put sensors outside the trailer to get ambient measures. They also collected 7,000 surveys from truckers for the study.

“For every one degree Celsius rise in ambient temperature, shrink increases by .04 per cent,” she said.

Optimal truck time and temperature

There’s a direct correlation between temperature, time on the truck and shrink. At 30 hours, the animals have lost all their fill and water and are getting to the point of tissue loss, which is why Schartzkopf-Genswein recommends an optimal time of no more than 24 hours.

Her research has also discovered that, on a 20C day with 30 hours on a truck, average shrink would be at seven per cent. She said that amount increases by 1.56 per cent for feeders, 2.60 per cent for calves and 3.56 per cent for cull cows.

“This is to give you a guide to the types of cows and what may happen to them when they’re on the truck for that length of time at a certain temperature,” she said.

She also said that delays – at the U.S. border, during unloading or driver rest stops, encountering bad weather or traffic tie-ups – are important to factor into transportation times.

Researchers found that 77 per cent of the time, truckers encountered border delays of an average of 1.3 hours and in one case, it took 15 hours to be processed. Temperatures below -15C and above 15C exponentially increase the possibility of lameness, downers and death.

The amount of shrink decreases as the experience of the driver increases. Drivers that have been transporting cattle longer are better able to handle them, recognize when it’s too hot or too cold, and know how to brake and corner to better ensure they don’t stumble or are unduly stressed.

New rules coming

The Canadian Food Inspection Agency has been working on developing new transportation rules under the Health of Animals Regulations since 2006, and they haven’t been updated since 1977.

Among the proposed new rules are a reduction in the maximum amount of time animals can be in transport without access to food, water or rest, and clarified definitions for ‘compromised’ and ‘unfit’ animals.

During consultations, the agency heard from more than 11,000 respondents who had 50,000 comments. The new rules are expected to be published this winter.

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