Most of the people that I've ever known who grew pigs only kept them for a year. The sow would have a litter in the spring, they feed up the piglets all summer,

Most of the people that I've ever known who grew pigs only kept them for a year. The sow would have a litter in the spring, they feed up the piglets all summer, then slaughter them before winter. Pigs are pretty easy and efficient sources of protein grown like that - on a family-scale farm you have plenty of excess produce and food waste anyway.