Abstract Effective gilt management practices from birth lay the foundation for future performance and are critical to improving sow lifetime productivity (SLP). Recent data reported that of gilts originally served, 8 to 10% never farrowed a litter, 14 to 19% were removed between parity 1 and parity 2 and only about 30% remain in the herd after six parities. The loss of early parity females, particularly between parity 1 and parity 2, represents one of the biggest challenges for the industry. Decades of research have provided the scientific evidence that current gilt management practices are based on. Litter of origin factors such as birth weight, colostrum intake, pre-weaning growth rate and weaning weight are associated with future performance. A well-managed gilt development unit is essential to identifying gilts with the highest reproductive potential. Boar exposure is a critical factor influencing early puberty in gilts and daily, direct contact to a rotation of mature high libido boars maximizes the response to the boar effect. An early pubertal response (a measure of sexual precocity) is linked to better SLP and is the key driver in achieving the targets for age, weight and a recorded heat-no-serve event (HNS) at first mating. These eligibility traits are not independent of each other and interact to improve first litter size and to have lasting effects on a sow’s lifetime productivity and retention. Ultimately, the goal is to find the right balance between these targets to ensure that gilts enter the farrowing unit with the ideal weight and condition to support performance in the first lactation and successful rebreeding and farrowing at second parity. While the importance of these targets is well known, consistent implementation in a constantly changing production environment is a challenge. Questions remain of how to best translate science into practice given the changes in the modern female, the day to day production, health and labor challenges, and the integration of new technologies. It is important to determine the best metrics to measure success during gilt development, and how they can be used to provide feedback for improvement. In conclusion, the importance of gilts as the foundation of the breeding herd is well established, yet the industry still faces the challenge of consistently implementing this knowledge to fully realize the genetic potential of the females available in today’s industry.
Jennifer Patterson (Wed,) studied this question.