What is going on? Chickens are pulling out one another's feathers, pigs are biting one another's tails and sheep are chewing one another's wool! Farmers are mystified. Which is why the Welfare Quality project is looking at these behavioural problems in farm animals.
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Of all farm animals, Europeans are most sympathetic to the plight of poultry. Living in close proximity can lead to aggressiveness and violence among birds. This photo shows a chicken that has had its feathers pecked out by another chicken.
© ASG-Wur (NL) |
Most deviant behaviour among farm animals is oral in nature. Chicken farmers faced with the problem of feather pecking sometimes find a substantial part of their flock plucked bare. As to tail biting in pigs, this can lead to serious injury, infection and stress.  |
In certain circumstances pigs bite one another's tails. Bristol University (UK) has developed a device to examine this abnormal behaviour.
© Poppy Statham |
But what is making them do it? To try and find out, a group of researchers in the Welfare Quality project have developed an experimental device to measure the propensity for tail biting (caudophagia) in pigs. Traditionally, tests were carried out on an individual animal by attaching a substitute (generally a piece of rope) to a wall and then observing whether or not it was bitten. However, an animal does not show the same behaviour when alone as it does in a group situation. The method was improved by attaching the ropes or other substitutes to a support that could be approached from all sides and, therefore, used to test a group of animals – ten seems to be the ideal number. Some studies have suggested that making straw or other material available to pigs so that they can engage in an alternative oral activity greatly reduces the development of tail biting. This hypothesis now needs to be verified by researchers and further tests carried out to determine which periods are most appropriate for providing the straw. The aim here is to provide farmers with an effective ‘code of conduct'.
The genetic component of tail biting will also be studied closely. Consanguinity is often pronounced among pigs that are generally selected on the basis of productive criteria, in particular growth rate. It is possible that these practices reinforce aberrant behaviour that could be reduced by a better choice of breeding pigs.
Other types of problem could also have a genetic component. For example, an animal may well become excessively timid because it lives in a stressful and noisy environment or the farmer's management may have been inappropriate. However heredity, (the pig's genetic background) is also a very influential factor. Therefore, selective breeding could be a way of reducing undesirable behaviour.
