Farm Animal Behavior

Evolution has selected animals for increased fitness in their natural environments over thousands of generations. Fitness in this context can roughly be defined as reproductive success (often measured at allelic level), and is not necessarily related to welfare; an animal with high fitness may have a poorer state of welfare than one with low fitness. One of the major achievements of behavioural research over the last decades is the realisation that animals are equipped with flexible behavioural programs, usually referred to as strategies.

During domestication, animals have been genetically changed in relation to their ancestors, which has affected various aspects of their adaptive traits, including behaviour (Price, 1997). However, as is obvious from many comparisons between domestic animals and their ancestors, behaviour is usually affected in a very limited manner. Generally, no new behaviours have developed and none have completely disappeared from the gene pool.

Whereas motivation is a common concept in ethology and psychology, there is no universally accepted definition. A recent text-book describes the concept as follows: "The internal state of the animal, which is the net result of stimuli arising from both inside and outside its body, constitutes its 'motivation'."

he example of the nestbuilding sow strikes some people as unlogical. If a sow is provided with a protected, thermally optimal farrowing site, such as a farrowing pen, the evolutionary appropriate action would appear to be to save energy and refrain from activity.