Influence of Genetic Lines on Maternal Performance
Producers have long known the positive economic implications of a productive sow herd. Herd production goals focus upon producing large numbers of high quality pigs from a sow herd during multiple parities. To date producer attempts to improve reproductive performance have focused upon management, nutrition and herd health protocols that maximize genetic potential of the sow herd. The completion of the NPPC Maternal Line Program (MLP) gives all pork producers the opportunity to make valid genetic comparisons among available commercial lines and information about how to manage these lines for maximum profit. The MLP is a large-scale genetic evaluation involving six genetic lines for four parities. Table 1 shows the number of litters born by line and parity. Traditional reproductive traits associated with both the litter and the sow were evaluated to quantify genetic differences among available commercial lines and parities as well as the interaction between parities and genetic line. In addition, analyses were preformed on a cohort basis of 20 to 30 females per cohort group to evaluate sow longevity and lifetime productivity.