Interpretive Summary: Associations among individual gilt birth weight, litter birth weight phenotype, and the efficiency of replacement gilt production
By Anne Zinn
Sow lifetime productivity is a complex trait that is influenced by both sow productivity and longevity. Numerous factors, including fertility, nutrition, management, and herd health, can impact sow productivity. Decades of selection for high prolificacy in sows have successfully increased the total number of pigs born, but an associated increase in the proportion of low birth weight pigs and in preweaning mortality has been linked to gradual increase in sow prolificacy; individual low birth weight gilts are at risk for increased mortality, lower retention, and poor growth from birth until selection into the breeding herd. Therefore, as part of a coordinated National Pork Board research strategy to understand key factors limiting sow lifetime productivity, the present study hypothesized that a repeatable sow birth weight phenotype would affect the efficiency of replacement gilt production at the production nucleus-multiplication level and have lasting effects on the performance of gilts selected for breeding.
Recently published in the Journal of Animal Science, the study aimed to first characterize sow birth weight phenotype in a population of sows at the commercial nucleus-multiplication level of a large commercial production system. Additionally, the research team aimed to determine the effect of sow birth weight phenotype on the efficiency of replacement gilt production using agreed criteria for non-selection and the application of proven protocols for final gilt selection involving both direct and fence-line contact daily with mature boars in purpose-designed facilities, as well as the effects of sow BWP on the productivity and retention of selected replacement gilts were determined.
The results of this study provide evidence that sow birth weight phenotype is an important factor in the overall efficiency of replacement gilt management. In addition, the results confirm that effective gilt selection and prebreeding management protocols support excellent sow lifetime productivity and mitigate the risk of a high birth weight phenotype in the litter of origin affecting retention in the breeding herd.
The full paper will soon be available on the Journal of Animal Science website.