Researchers with the Western College of Veterinary Medicine are using the measurement of hormones deposited in the hair of pigs as an indicator of animal welfare.Biological markers are characteristics that can be measured to determine whether an animal is in a state of good health and well being.
Two studies, conducted by the Western College of Veterinary Medicine through the NSERC Industrial Research Chair in Swine Welfare Research Program, looked at the levels of two hormones measured in the hair, cortisol which is indicative of stress and dehydroepiandrosterone or DHEA.Darian Pollock, a PhD candidate in the Department of Large Animal Clinical Sciences at the Western College of Veterinary Medicine, says her focus was chronic stress.
Quote-Darian Pollock-Western College of Veterinary Medicine:
In terms of the rearing environments, we didn't find any differences in the hair hormone concentration. We did see some behavioral differences in the first study looking at straw versus no straw. There was at a couple of time points more aggression in the group without straw and some minor increases skin lesions at a couple of time points and then no difference in terms of productivity like average daily gain.
From that we can conclude, although straw might bring some positive welfare benefits, it wasn't consistent across their lifetime so it's possible that straw wasn't doing enough to alter the physiology that we measured and it's also possible that maybe our measures weren't sensitive enough.But, in both of our studies we did see quite a large amount of individual variation so we'll be looking into that more.
In my pigs that were lame in the farrowing period, so pre-weaning, the pigs with lameness had an increased cortisol to DHEA ratio, so the ratio of cortisol to DHEA and increasing that ratio is suggestive of increased stress. Full details on this work can be accessed through swinewelfare.com.For more visit Farmscape.Ca.
Source : Farmscape.ca