A Methodology to Quantify Resilience in Growing Pigs

There is a growing concern about the genetic determinism of resilience and its possible implementation in breeding programs. The objective of our study was to elaborate novel resilience indicators in growing pigs based on the deviation from the expected growth curve and the increment of the acute-phase protein haptoglobin (HP) after applying a common vaccine. A total of 445 pigs were vaccinated with an attenuated Aujeszky vaccine at 12 weeks of age. Deviation from the expected body weight (Delta BW) given the growth curve of unvaccinated pigs at 28 days post-vaccination (DPV) and the increment of HP at 4 DPV (Delta HP) were suggested as resilience indicators. Challenged pigs that maintained their productivity and had a minor activation of HP were deemed resilient, whereas pigs that had low increment BW values and a high activation of HP were deemed susceptible. Pigs were also classified based on increment BW and increment HP relative to the expected BW at 28 DPV and to the basal level of HP, respectively. The concordance was high between both methods, indicating that Delta BW and Delta HP are not sensitive to the animal's expected BW nor the basal level of HP. The heritability estimates were moderate for increment BW (0.33) and low-to-moderate for increment HP (0.16). Our study suggests Delta BW and Delta HP as novel resilience indicators in pigs. The suggested indicators capture different aspects of resilience, are easy to measure, and are genetically controlled. Thus, they may be improved through selective breeding. Further analyses are needed to validate our findings.

Automated summary

There is increasing concern about the genetic determinism of resilience and its implementation in breeding programs. This study aimed to develop novel resilience indicators in pigs, using deviation from expected growth curve and increment of the acute-phase protein haptoglobin (HP) after vaccination as indicators. Results show that deviation from expected body weight and increment of HP can be used as resilience indicators in pigs, they are easy to measure and genetically controlled.