THE EFFECT OF MATING ON PLASMA CORTICOSTEROIDS IN THE FEMALE PIG AND THE INFLUENCE OF INDIVIDUAL AND GROUP PENNING ON THIS RESPONSE

Abstract

Corticosteroid levels in the plasma of female pigs in behavioural oestrus were elevated within 5 min of the completion of mating in an unfamiliar pen. These levels were 25% higher than those produced by exposure to an unfamiliar pen alone (mean free corticosteroid levels were 7.5 and 5.6 ng ml-1, respectively). In two further experiments conducted in different seasons and times of day, there was a similar response to the boar, but it was greater in animals which had previously been kept in pens in groups compared to those kept in individual pens. It was concluded that stressors produced by the social environment may influence the postmating release of corticosteroids in female pigs. © 1982.