AI sires were also evaluated and selected on semen
production, it may be possible to reduce the number of boars required to service sows
thereby improving the productivity and profitability of the boar stud. As litter size traits
have a low heritability of about 0.1, only a small to moderate genetic progress in these
traits will be possible. Therefore, a moderately heritable trait which could be measured in
the male and which is positively correlated to improved reproduction in the female would
be useful in selection to improve female reproductive ability