Characterizing Resilience to Weaning Stress and Its Impact on Behavioral Differences in Finishing Gilts

Introduction

Resilience is a vital aspect of an animal's robustness, as it determines its ability to adapt to various stressors and return to a stable state. In pig farming, understanding and characterizing resilience to stress is crucial, as it can influence an animal's welfare, productivity, and overall well-being. In this study, we explore the concept of resilience in gilt piglets, focusing on their ability to cope with weaning stress and its potential long-term effects on behavior.

Weaning stress is a significant challenge in a young pig's life, making it an ideal model for examining resilience to social stress. Weaning has been shown to impact various aspects of a pig's life, including the immune system, behavior, and growth traits. However, the concept of resilience to weaning stress has not been extensively studied, leaving us with several questions. Can we measure and classify individual pigs based on their resilience to weaning stress? And if so, are there lasting behavioral differences associated with resilience or vulnerability?

The Significance of Resilience in Pigs

Resilience in pigs is a multifaceted trait that is essential for their ability to adapt to environmental challenges and stressors. Robust pigs are not only more productive but also better equipped to handle stressors, ultimately leading to positive welfare outcomes. Failing to adapt to perturbations can result in detrimental responses to the production environment, which can have severe consequences for both the animals and the industry.

Social stress, a common occurrence in pig farming, poses a considerable threat to an animal's robustness. It has been linked to aggression, increased susceptibility to gastrointestinal disease, and changes in immune system responses. Social stress is challenging to manage because it depends on the social status and coping personality of individual animals. Despite its importance, there has been limited research into measuring resilience to social stress and understanding its long-term effects.

Measuring Resilience to Weaning Stress

Weaning, as a major social stressor for piglets, provides an excellent opportunity to study resilience. Weaning stress not only affects immediate well-being but also has long-term consequences on growth and behavior. However, to study the effects of resilience or vulnerability to weaning stress, we must first measure and classify individual animals accurately.

A simplistic measure of the physiological stress response, such as cortisol levels at a single timepoint, is insufficient to understand an animal's resilience fully. Resilience involves dynamic patterns of response and recovery, which vary between individuals. Researchers have observed substantial variability in initial behavioral and physiological responses to stressors and the subsequent recovery rates in various species, indicating the potential for quantifying and selecting for resilience.

Behavioral Manifestations of Resilience

An animal's response to stress is not limited to physiological changes; it also includes behavioral adaptations as the animal copes with the stressor. Different coping strategies can influence behavior, and animal interactions can produce or inhibit long-term resilience. Pigs with proactive coping strategies tend to be bolder, more aggressive, and less adaptable to change. To understand resilience comprehensively, it is essential to measure both the physiological stress response and the behavioral manifestations of coping strategies.

Conclusion

Resilience is a critical component of an animal's robustness, affecting its ability to adapt to stressors and return to a stable state. In the context of pig farming, understanding and characterizing resilience to weaning stress is essential for improving animal welfare and productivity. Measuring resilience is a crucial step towards selecting and breeding more robust pigs, particularly gilts and sows, better suited to group-housing environments. By identifying resilient animals, pig producers can enhance the overall well-being of their herds and optimize production potential.