Sow longevity continues to be both an economic and welfare concern for the pork industry. High culling levels, particularly at younger ages, result in decreased lifetime sow productivity. Within a single operation, culling of breeding herd females prior to reaching a profitable productivity status is not economically sustainable for a long period of time. The length of productive life necessary to reach a break-even point varies from herd to herd because of differing investment, productivity, variable cost and other factor levels (Stalder et al., 2003; Stalder et al., 2000). Improving sow longevity would improve a pork producer’s profitability by reducing replacement gilt expenses and associated development, isolation, and acclimation costs. Additionally, an even greater impact is possible if improving longevity results in improved health levels in finishing pigs by maintaining an older sow herd.