Induced estrus and breeding during lactation: Effects on sow and litter performance

ne method for increasing sow prolificacy (i.e., pigs per sow per year) is to increase litters per year by reducing the interval between farrowing and subsequent conception. Although this objective may be realized by weaning the litter earlier, short lactations are often associated with reduced sow reproductive performance.1 A potential alternative to earlier weaning is to induce ovulation and conception concurrently with lactation. Estrus and ovulation can be induced during lactation by temporarily separating the sow and litter2 and by group-housing lactating sows with boars.3 Unfortunately, the reproductive response to these strategies are variable and unpredictable.