During lactation sows were housed in individual farrowing crates and were fed a commercial lactation diet.After a gradual increase in feeding level during the first week of lactation, sows were fed ad libitum for the remaining lactation. Actual feed intake per sow was not recorded. During the weaning to insemination interval, sows were individually housed in crates and were fed a commercial gestation diet with a maximum of 3.5 kg of per day. Sows were checked for estrus twice a day using a mature boar. On the first day of standing estrus sows were inseminated using a commercial AI dose. A second insemination took place when the standing estrus extended to the next day. An ultrasound pregnancy check was done 4 weeks after
insemination. During pregnancy sows were housed in stable groups with either feeding stalls (farms A and B) or feeding stations (farm A). Sows were fed a commercial gestation diet. Feeding level on farm A was 2.5 kg per day for the first 60 days of gestation, 2.8 kg per day from days 61 to 85, and 3.4 kg per day from day 86 for the remaining gestation. Feeding level for farm B was 2.6 (parity 1) or 2.8 (parity >1) kg per day for the first 85 days of gestation, and
3.0 (parity 1) or 3.4 (parity 2) kg per day for the remaining gestation.