Building structure for late-parity sows

Most sows are culled after parity 3 for other reasons. [...]to get more sows reaching the later parities we need to focus on the issues that cause their removal in parities 1 through 3, viz. reproductive failure and feet and leg soundness. [...]producers should carefully understand the productivity of their females and select gilts with sufficient numbers of teats to raise all the piglets they farrow.