International Federation for Information Processing (IFIP)
Abstract
International audienceWhile insemination at first estrus is not recommended, most studies agree on the benefits of early puberty, both for reproductive performance and sow longevity. In the swine population in France, sexual maturity is expected at ca. 200 days of age. Although age at puberty is crucial information, it is not recorded on farms. Since selection for low boar taint influences male puberty, it raises questions about its potential side effects on female reproductive ability. This study was carried out as part of a project that assessed impacts of selection against boar taint on the reproduction of Landrace females. The sexual maturity of 1878 gilts at ca. 200 days of age was evaluated on five farms using quantitative plasma progesterone analysis in two blood samples taken 10 days apart. Cutoff values of 2.5 or 5.0 ng/mL gave similar estimates of 19% immature gilts, with a large variation among farms (8-49%). Insemination was not performed for 4% of gilts, 9% were re-inseminated during the first cycle and 15% did not farrow. The rate of earlyreproduction difficulties varied greatly among farms. The influence of immaturity at 200 days was generally low, with a large farm effect. Further investigation is required to analyze long-term effects of late puberty