Published online by Cambridge University Press: 02 September 2010
Twenty-seven mature boars were housed in individual pens for 9 weeks under one of the following social conditions: isolated from female pigs; near sexually non-receptive female pigs; and near sexually receptive female pigs. The sexual behaviour of the boars during the 9-week treatment period was observed weekly in standard 15- min tests. The sum of the individual courting behaviour activities and the total time spent ejaculating were significantly greater for the boars housed near either sexually receptive or sexually non-receptive females than for those boars isolated from female pigs (P<0·01 and P<0·05, respectively). Although the boars housed near sexually receptive and sexually non-receptive females achieved 43 and 38% more copulations, respectively, than those isolated from females, the difference was significant only for the latter comparison (P<005). There was no consistent difference in testosterone concentration over a 12-h period between boars housed near sexually-receptive females and those isolated from females.