Optimizing farrowing rate and litter size and minimizing nonproductive sow days

The most universally accepted measure of reproductive performance is PSY. Excellence is achieved by reducing NPD, increasing liveborn litter size, and reducing preweaning mortality. To reduce NPD, farm management should be directed to improve farrowing rate. Matings that occur in late summer usually are less fertile as the result of the pig's normal seasonal variation. Confinement gestation stalls are the best prevention for the reduced farrowing rate caused by season. Liveborn litter size is the result of a mixture of genetic and management variables. F1 females have the highest heterosis. The management variables of age at first mating, wean-to-service interval, skip mating, lactation length, and parity all influence litter size.