Pigs Behaviour


By: Dikla Arad- Veterinary student

'Discuss how constraints imposed by intensive husbandry systems affect the social behaviour of farm animals, with reference to their health and welfare' 

In the last decade there has been intensification of farming due to the demands of the public for more good quality and cheap products Thus, causing constraints affecting farm animal’s social behaviour, and causing problems with their health and welfare.The main differences between natural environment and artificial environment are in flexibility and in the composition of the group. In natural environment there is social dynamic and the group is usually composed of relatives with females and offspring, in contras to a fixed environment with unrelated organisms that may be of the same sex and/or age.In a new environment organisms will still express behaviour for the environment in which they have previously been in and therefore adapted (in terms of evolution). Despite their evolutionary heritage, animals can adjust to novel environments to varying degrees, but the system must be adjusted to suit the animal in order for it to express it’s natural behaviour, and to enable the opportunities available to perform it.When behaviour is restricted (in an artificial environment) the social interaction, breeding, foraging and feeding behaviour may be affected. Animals in restricted environment cannot escape or free, therefore stress is induced, causing aggression, which can lead to fatal fights and even cannibalism. Major social limitation is keeping animals isolated either temporary or permanently. Isolation can give rise to a physiological stress response, meaning the experience is unpleasant. Furthermore, can disrupt development.

It is very clear to see that pigs in intensive farms are very stressed; especially the ones in the growing units when they are all packed together in a confined space.Rearing young in isolation can also cause competitive disadvantage when they are later joined to more socially experienced group. And rearing females in isolation can cause damage to their maternal behaviour. When sows are farrowing, they often get put in crates so they don’t lie down on the piglets and kill them. Another social limitation may occur when mixing unfamiliar individuals together and in unnatural combinations.Abnormal social groups can cause an increase in competition and stress.An example for that will be in the dairy herds. In a common dairy herd you will have 300 to even 1000 cows, only females, and sometimes even not separated into different age groups. The heifers will be together with the adult cows, and will be bullied. The heifers will get to eat last, be shoved while milking. Thus causing stress and injury.With piglets, they are often separated because of size differences or group numbers. Usually it benefit them more than it can cause problems because they are all in the same size and cannot hurt each other as easy. Restriction of avoidance behaviour is also a social limitation, causing stress and injury.When sows are in heat, one of their behavioural characteristics is to mount each other. when mounting the bottom sow get bruised on her shoulder, and may even break her foot due to lack of opportunity to escape.

Pigs have an hierarchy, so there will always be one pig that will be packed by all. If the other sows decide they don’t want her in their group they can all mount her and kill her, because she has no place to escape to. In this case, taking the sow and putting her in another group will benefit her as she will be put will other injured sows that won’t be able to hurt her or each other. In some cases social behaviour may be affected due to disruption of communication, and can lead to aggression and reduced growth.A study has shown that fan noise in farrowing units can disrupt vocal communication between sows and their piglets during nursing, causing a decreased in milk intake by the piglets thus, reduced growth. Agonistic behaviour may also be a consequence of restricted environment. It usually occurs with social species such as pigs and poultry.Cannibalism is a problem that occurs in these species. In pigs it is mostly tail biting and ear biting, and it spreads very fast. In chickens it can be feather packing.Tail docking, teeth cleaving and amputation of the peak are all actions that can control these problems, as well as putting dim lighting.  In conclusion, the constraints imposed by intensive farming systems on farm animals affect their social behaviour, causing health and welfare problems.

The ancestral relatives of domestic animals are adapted to specific environments, and domestication does not radically alter most adaptations. Keeping animals in environments different from those to which they are adapted can result in a variety of health and welfare problem, including disease and injury nutrition problems, reproductive problems, and behavioural problems.