Improving maternal care of free farrowing sows

Housing systems for sows during lactation are shifting from crated systems towards non-restrictive systems to improve sow welfare. However, the increased behavioral freedom of sows in such free farrowing systems currently comes with an increase in piglet mortality. In these systems, piglet survival becomes highly dependent on the quality of maternal care. A good mother is calm, careful, and responsive to the needs of her litter. Yet, there are clear differences in maternal care between sows. Therefore, it is crucial to increase our understanding of maternal behavior in these systemsC

During this project, large-scale behavioral observations will be performed on free farrowing sows with known genetic backgrounds to identify maternal behaviors around parturition and during lactation and to relate these to piglet survival and litter weight gain. The second part of the project will build upon the first and intends to elucidate the underlying endocrine regulation of maternal care behaviors.

In our first study, we aimed to validate sow breeding values for mothering ability (EBVma, Topigs Norsvin) in a Free Farrowing system. The EBVma reflects the genetic merit of a sow to raise live-born piglets entrusted to her until weaning. While EBVma effectively predicts piglet survival in traditional farrowing crates, their effectiveness in Free Farrowing systems is less certain. Therefore, our study investigated the effectiveness of EBVma in a Free Farrowing environment by comparing early piglet mortality, litter characteristics, and farrowing performance of Free Farrowing sows with sows that were housed in a traditional farrowing crate for the first five days of lactation. Our findings showed that sows with higher EBVma had significantly lower piglet mortality, especially in Free Farrowing systems, mainly by reducing deaths from piglet crushing, a common problem in these systems. This study demonstrated that selecting sows with a higher genetic merit for piglet survival can effectively reduce piglet mortality in Free Farrowing systems.

In our second study, we aimed to assess behavioral differences between sows by comparing peri-partum postural behavior of sows with different breeding values for mothering ability within both crated and free farrowing environments. An algorithm was developed for the automated detection of sow posture to gain insight into the amount of time spent in different postures. This study will provide insight into the behaviors underlying the breeding value for mothering ability and, thereby, piglet survival.

The data obtained during these studies will form the basis for a large scale behavioral study on the new free farrowing nucleus farm of Topigs Norsvin in Canada, called “Innova”. Ultimately, this multidisciplinary approach that combines behavioural, physiological and genetic information, will form the basis for the genetic selection of sows with high quality maternal care in free farrowing systems.