High mating frequency for boars: predicting the effect on sexual behaviour, fertility and fecundity

Abstract

ABSTRACTIn the first experiment there were significant correlations between the average product of the length and width of the boar's testicles and the sperm output of the boar under a high collection frequency over two 6-h periods and over a 6-week period (r = +0·80, d.f. = 4, P < 0·05 and r = +0·77, d.f. = 7, P < 0·05, respectively). In the second experiment there were no significant differences in the fertility or fecundity of mature boars that had either two or six copulations per week over a 25-week period. However, there was a significant correlation between the average width of the boar's testicles and the fertility of the boar under the high mating frequency (r = +0·74, d.f. = 8, P < 0·05). There were also significant correlations between the number of copulations achieved in two mating tests and the number of copulations achieved and the refusal rate to mate under the high mating frequency (r = +0·86, and r = –0·89, respectively, d.f. = 6, P < 0·01). The implication of these results to the development of tests to predict mating performance of boars is discussed