A protocol of two inseminations (12h and 36h; time schedule) per estrous was applied in fifty sows in order to study the individual influence of the insemination order on the offspring composition. Analyses of microsatellites were used for identification of the paternity. The first and the second inseminations contributed respectively with 34.8% and 65.2% of all piglets that were born. Piglets were born from both inseminations (mixed litters) in 80% of the farrowings. Each of the first or the second insemination contributed to 10% of the litters. Although the first insemination was applied before the first half of the estrous, it contributed to the piglets that were born in 90% of the farrowings.
artificial insemination; litter composition; paternity identification