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THE NEEDS OF THE DOMESTIC PIG

Biologist Dr. Christian M. Hammer explains what pigs really need 

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The domestication of pigs began thousands of years ago. Today's approximately 150 breeds of the European domestic pig stem mainly from the European wild boar and crossbreeding with Asian pigs brought to Europe by British seafarers in the eighteenth century. For hundreds of years, pigs were kept in herds on meadows, in woodland or on the streets during the day and driven into sties at night. Intensive pig farming only started after the Second World War.  

The natural life expectancy of pigs is around twelve years. However, pigs are usually slaughtered only half a year, at roughly 200 lbs. Breeding sows are killed as soon as they no longer achieve the expected size of litter. This usually happens after a few years.   

A pig's basic needs

Pigs have an organised social structure with a strict hierarchy and regulated daily routines. Normally, pigs live in groups of twenty to thirty animals, comprising the mother animals and their offspring. The male animals leave the group after reaching sexual maturity, for a time getting together in separate gangs before ultimately leading a lone existence. They only rejoin the groups during the mating season.  

Contact and distance to other pigs

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With the exception of the oldest boars, pigs are extremely sociable mammals with a strong need for contact to other members of their species. The separation of established groups and the individual raising of young animals or sows causes stress. Both are common practices in pig farming. 

Pigs conduct most activities in the group or at least close to it. Due to their social hierarchy, there are sometimes situations or activities in which pigs will go out of each other's way or at least keep a certain minimum distance. When this distance is not respected, for example when feeding, aggressive conflicts can result. Such conflicts occur very often in the extremely confined conditions of intensive pig farming, since the animals are unable to steer clear of one another. Frequent injuries and a permanent, high level of stress are the result. Because groups are routinely recomposed, the pigs are never at peace. The arrival of newcomers or 'freed' positions in the social hierarchy lead to new fights over the ranking order.

Cleanliness and body care 

Images of pigs lying or even wallowing in feces in no way correspond to the nature of these animals. On the contrary: pigs forced to live in their own excrement in intensive farming suffer under such conditions. 

Because pigs are unable to sweat, they regulate their body temperature through bathing, rolling on cool earth or wallowing. Pigs raised in intensive farming have no opportunity to act out this instinctive behavior. Out of necessity, they try to cool down by splashing their drinking water or by wallowing in their own feces or urine.

Moreover, the combination of the overly warm climate in pig sheds and the increased level of ammonia gas in the air produced by excrement, poses a high health risk for farmed pigs. Cardiovascular problems and respiratory diseases, such as pneumonia, are not uncommon. 

In addition, these animals rely on suitable opportunities to scratch. Rubbing removes mud, excrement and parasites. Conditions in intensive farming offer no or completely inadequate facilities for scratching. Permanent itching and unrelieved instincts such as the need to wallow, produce a high level of frustration that often leads to increased aggressiveness towards others in the sty. 

Indicators of well-being

The appearance or absence of certain behaviors can inform the schooled eye about whether a form of farming satisfies the basic needs of an animal and can be described as suited to that species. Extensive playing, for example, is a good indicator for positive conditions. Piglets have a particularly strong urge to play, which they love to do in the near-natural conditions of free-range farms. Intensive farming offers neither the space nor adequate opportunities for the piglets to occupy themselves.    

The category of 'comfort behavior' includes actions that can be attributed to the sphere of 'body care'.  It also encompasses behaviors that express a sense of comfort, agree-ability, sociability and relaxation (for example: yawning, stretching, nesting). But caution is required when assessing comfort behavior. Some gestures such as yawning, stretching or scratching can indicate a switch in behavior triggered by a conflict or hostile situation. When assessing an animal, it is always important to take the whole behavioral context into account. Stereotypical behaviors, self-mutilation, apathy or exaggeratedly aggressive behavior culminating in cannibalism are indicators of inadequate conditions.  

Pigs bred in intensive farming very often demonstrate stereotypical behavior. This includes, for example, bar biting, sham chewing, and attempts at foraging. Apathy and excessive aggressiveness caused by permanent stress and a lack of withdrawal opportunities are very common.