Molecular analysis has revealed parts of commercial pigs’ genomes associated with resilience to stressors that they are likely to face during their life in production, which may pave the way for new breeding approaches.
Scientists at University of Lleida-Agrotecnio-CERCA Center in Spain had previously identified two resilience indicators in young pigs: deviation from expected body weight and levels of the protein haptoglobin after vaccine challenge. Lower weight changes and levels of the protein suggest that the pig is resilient.
In the current work, they used a challenge with an Aujeszky’s disease vaccine to explore these indicators in 445 commercial Duroc pigs. Vaccinated pigs were compared to an unvaccinated control group in order to see which deviated from expected growth curve to a lesser extent, highlighting their resilience. They then used genome-wide analysis to explore the underlying factors.
They found that four chromosomes were associated with body weight changes and three with haptoglobin levels, and that these areas explained a substantial degree of variations in these characteristics.
“Taken together, our results highlighted genomic regions that are associated with two resilience indicators in pigs that capture variation in growth depression and immune innate responses following vaccination,” the researchers wrote in the journal Genetics Selection Evolution.
“The associated regions harbour potential candidate genes that are related to immune response and signal transduction pathways that lead to growth. Our findings provide new insights into the genetic background of resilience.”
Some of the potentially most important candidate genes identified in the work regulate inflammation and help antibodies respond effectively to disease.
A lack of knowledge of the genetic background of resilience in pigs has, to date, limited the potential application of selective breeding approaches that could result in more disease-resistant lines of animals. While the new work goes some way to addressing this issue, further validation is needed, they added.
