Stress Hormones In Hair of Pigs Offer Potential to Help Identify Genetic Lines Resilient to Disease

Farmscape for March 23, 2023

An international research effort is looking at the potential of measuring hormone levels in the hair of pigs to identify genetic lines that will be less affected by stress and more resilient in warding off disease.
Researchers with Iowa State University, the Universities of Saskatchewan and Alberta and CDPQ are collaborating on a project under which the levels of three stress hormones in the hair of pigs, cortisol, dehydroepiandrosterone and cortisone are being measured to evaluate the effect of stress on performance and disease resilience.
Dr. Jack Dekkers, a distinguished professor in the Department of Animal Science at Iowa State University and the Principal Investigator, explains, by correlating the levels of stress hormones in the hair to growth performance and disease resilience, it should be possible to identify which genetic lines of pigs will be more or less affected by stress.

Clip-Dr. Jack Dekkers-Iowa State University:
The initial findings are quite promising.
One of the things we look at is how heritable are the things we measure because that's what breeding companies are interested in.
If a particular thing we're measuring isn't heritable, isn't affected by genetics then it's of no use for them.
We find that the level of cortisol in hair is quite heritable.
About 25 percent of the differences, we find in cortisol levels in hair at that time point between pigs, are due to genetics and the rest is due to other environmental effects.
It's a similar level of heritability as what we get for growth rates typically and we know that breeding companies can very effectively select for growth rate so they will also be able to select fairly effectively for the level of cortisol in blood if that's what leads to a better outcome.

Dr. Dekkers expects full results of the study to be available by early 2024 at which point we'll have a good idea of whether this is a good measure to use to select for response to stress and to disease.
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Bruce Cochrane.

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