Genetic Improvement of Reproductive Traits for Duroc Sows Differing in Post Weaning Performance

North Carolina State University Swine Genetics Research 2004-2005. Reproductive traits recorded in the U.S. Duroc population include number of pigs born alive (NBA), litter weaning weight (LWT), and number of pigs weaned (NW). Genetic evaluation procedures are used in the Duroc breed to produce breeding value (BV) estimates for a variety of traits. BV estimates rank animals according to their genetic merit as parents. Selection for improved leanness and muscling has occurred to meet consumer demand for healthy pork products. Selection for these traits has likely impacted the rate of reproductive trait BV improvement.