The influence of male contact on plasma cortisol concentrations in the prepubertal gilt.
Large White X (Large White X Landrace) prepubertal gilts, 165 days of age, were fitted with indwelling venous catheters and housed in modified metabolism crates. After a period of acclimatization, frequent blood samples were taken at regular intervals before, during and after the 7 gilts were exposed to various degrees of contact with male pigs. The plasma samples were assayed for cortisol concentration using a competitive protein-binding radioassay. Significantly elevated concentrations of plasma cortisol (P less than 0.001) occurred only when full physical contact between the boar and the gilts was allowed. Boar exposure without full physical contact induced only minor changes in plasma cortisol concentrations of gilts. Plasma cortisol concentrations have been shown to constitute a reliable indicator of a stress response in pigs, and so the results of this study suggest that tactile stimulation from a male pig induces a stress response in the recipient prepubertal gilt. This stress response in the gilt may be involved in the stimulation of puberty onset by contact with a mature boar (i.e. the 'boar effect').
Pearce
G P
GP
Department of Animal Physiology and Nutrition, University of Leeds, U.K.
Hughes
P E
PE
D000819:Animal Communication; D000818:Animals; D005260:Female; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D013552:Swine / Q000097:blood*; D014110:Touch / Q000502:physiology*
D006854:Hydrocortisone