Feeding gilts and sows to maximize mammary development and lactation performance

Increasing sow milk yield is essential to achieve maximal growth of suckling piglets, and nutrition can stimulate milking capacity. From 90 days of age until puberty, replacement gilts should not undergo major feed restriction as it will inhibit mammary development. Providing phytoestrogens in that period will stimulate mammary hyperplasia. During gestation, feed intake of gilts must ensure that backfat at the end of gestation is above 16 mm to support mammary development. In the last third of gestation, providing 40% more lysine than requirements via the addition of soybean meal increases mammary mass in gilts, but not in multiparous sows. A high nutrient intake during transition is crucial, whereby providing sows 12.6 Mcal metabolizable energy and 22.0 g standardized ileal digestible (SID) Lys daily ensures a high colostrum production and maximizes milk yield in the following lactation. During lactation, there are quadratic effects of energy and protein intakes on the weight of suckled mammary glands and sows should not be restricted-fed to avoid excessive mobilization of body reserves. Furthermore, the provision of adequate lysine is critical to maximize litter growth, with optimum daily intakes between 47.7 and 51.3 g SID Lys for primiparous sows and 51.3–67.2 g SID Lys for multiparous sows.