Characterization of growing pigs’ adaptive response when faced with environmental perturbations

The main objective of this work is to develop a mechanistic model to describe the influence of a generic and unknown perturbation on the feed intake of growing pigs. This latter is considered as a reliable indicator of stress in the environment, its representation by a model is useful to better understand the influence of the stress on the growth kinetics of pigs. Moreover, with novel monitoring technologies, it is now possible to evaluate the impact of these perturbations on animal performance in real time and with a high frequency. The proposed model is based on two sub-models: InraPorc, a model to describe growing pigs’ performance in standard conditions, and a well-known model in physics (spring and damper system) to describe the behavior of a system in the presence of external perturbations. Coupling these two models made it possible to represent the influence of environmental perturbations on the feed intake of growing pigs. In this new model, we introduced two parameters to characterize the response of animals when faced with perturbations. The main interest of this characterization is to define new standards to rank animals based on their performance and on their capacity to recover normal growth after perturbation. The results show that unlike animals with a slow growth, animals with rapid growth are less robust when faced with perturbations and take longer time to regain their standard growth trajectory. Currently, the model is able to simulate the performance of animals facing with a given stress; future development of the model will adapt it to the automatic detection and simulation of several perturbations with known or unknown origins.