Sow longevity is becoming an increasingly imponam issue in many U.S. commercial swine operations. According to PigCHAMP1 summaries, the average annual sow replacement rates have been approximately 50 percent for the past five years. Rising feed costs have dramatically increased gilt development costs. Additionally, feed costs for the en tire operation have risen to levels not seen in recent history, contributing to high costs of production and reduced profit margins for both breed-to-wean and farrow-to-finish operations.

The poor longevity prevalent in many herds can have a negative impact on profitability and may be a welfare concern. Improving sow longeviry can improve both the production and economic efficiency of commercial swine operations. Furthermore, improving sow longevity has the potential to have a positive impact on a pork producer's profitability by reducing replacement gilt expenses and associated development, isolation, and acclimation costs. The challenge for many producers is determining the importance of longevity among the many other economically significant production traits.