The first insemination was performed 12 h after
detection of estrus in sows and immediately after
detection of estrus in gilts. Sows were subsequently
inseminated at 12-h intervals as long as they exhibited
standing estrus (for the first three insemination and at
24-h intervals thereafter if estrus persisted). Semen was
collected and processed in the farm. Sperm motility was
evaluated at 12-h intervals and semen doses with
motility below 70% were not used for insemination.
Females were inseminated with semen doses of 100 mL,
containing 3.5 109 sperm cells diluted in Beltsville
Thawing Solution (BTS), stored at 17 8C for a maximum
of 48 h.