Quantifying Individual Response to PRRSV Using Dynamic Indicators of Resilience Based on Activity

Area of Science:

• Animal Science
• Veterinary Medicine
• Biotechnology

Background:

• Pigs face various life perturbations, including management practices and natural causes.
• Resilience, the ability to cope with or recover from perturbations, is crucial for animal health and productivity.
• Activity patterns and their deviations can potentially quantify individual resilience.

Purpose of the Study:

• To investigate the potential of Dynamic Indicators of Resilience (DIORs) derived from activity data to indicate resilience to Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) infection.
• To assess whether pre-challenge DIORs predict resilience and if post-challenge DIORs reflect the impact of PRRSV challenge.

Main Methods:

• Individual activity data were collected from 232 pigs using ear tag accelerometers after PRRSV inoculation.
• DIORs, including average, root mean square error (RMSE), autocorrelation, and skewness, were calculated for pre- and post-challenge phases.
• Clinical scores and mortality were recorded to classify pigs as resilient or non-resilient.

Main Results:

• Pre-challenge DIORs did not predict morbidity or mortality.
• Higher post-challenge RMSE and greater changes in activity level and RMSE from pre- to post-challenge correlated with increased clinical signs (poor resilience).
• Increased post-challenge skewness and larger changes in skewness increased mortality risk, while decreased skewness lowered it.

Conclusions:

• Post-challenge DIORs of activity are effective indicators for quantifying resilience to PRRSV challenge in pigs.
• Activity-derived metrics, particularly post-infection, offer valuable insights into an animal's ability to withstand and recover from disease.