The experiment used sows in 13 consecutive weeks,with approximately 45–50 sows each week. The treat-ments were as follows: FTPCAI1 (n = 199) – sows receiveda 5-mg (4-ml) intramuscular injection of pLH (Lutropin-V®, Bioniche Animal Health, Belleville, Ontario, Canada)at oestrus onset, and were inseminated once, 24 h afterpLH application; FTPCAI2 (n = 199) – sows received thesame hormonal treatment as FTPCAI1 sows, but they wereinseminated twice (at oestrus onset and 24 h after); andMultPCAI (n = 199) – sows did not receive pLH, and thefirst insemination was performed at oestrus onset (0 h)and repeated every 24 h while the sows were on standingoestrus