Sows have the potential to produce 60-70 pigs in their life, but their actual numbers are often only half that due to premature culling. The main reasons for earlier culling are reproductive failure and lameness. Improving sow longevity decreases the size of the replacement gilt pool needed, and results in improved overall financial return. Breeding recommendations will often suggest waiting until gilts reach a certain weight and/or fatness before first breeding, with the idea that fat gilts will have sufficient body stores to be successful through pregnancy and lactation. While some studies suggest increased lifetime liveborn numbers with increased backfat, many other studies have failed to identify any correlation between fatness and lifetime reproductive success. Improved fitness may be a better way to avoid early culling, and body condition scores are useful to assess fitness. Contrary to popular belief, BCS are generally gauges of musculature rather than fat, except for very over conditioned sows. Proper BCS, and proper management when sows are outside the acceptable range, can help prevent reduced reproductive performance. Lameness is a major reason for culling, and may contribute to reduced reproductive performance and other health issues. High BCS and rapid weight gain can add to a predisposition for lameness. However, certain management strategies can help reduce the prevalence of lameness in a herd. Flooring with a bedding material like straw, and reducing slip risks can help prevent injuries. As well, a significant change in flooring between gilt rearing and breeding areas can lead to increased foot and leg injuries in gilts. Finally, one other factor that may affect gilt performance is air quality, specifically ammonia levels. Different management strategies to improve gilt fitness and reduce lameness can help increase longevity and improve lifetime reproductive performance in sow.