Modelling of Mechanistic Systems to Predict and Monitor Animal Health and Production: Case Study of Laying Hens

Antibiotic and pesticide usage in poultry requires careful monitoring to prevent residues while maintaining bird health and productivity. Mechanistic modelling approaches provide sophisticated tools for understanding and optimizing bird health and production systems. This study presents integrated frameworks for analysing chemical toxicity in laying hens through the modelling of hormonal balance and physiological responses.

We adapted and extended mathematical models initially designed for chemical toxicity risk assessment in avian species. To model physiological processes in pharmacokinetics (PK—what the body does to the drug) and pharmacodynamics (PD—what the drug does to the body), we employed ordinary differential equations to describe the evolution of drug concentrations and their effects over time. To elucidate the interaction between PK and PD in laying hens upon exposure to hypothetical endocrine-disrupting chemicals, our modeling incorporated endocrine dynamics on the ovulation cycle over weeks.

The developed model could predict organ-specific compound distribution and temporal dose–response patterns of hormonal homeostasis disruption. Our simulations demonstrate how altered hormonal levels influence egg production, including scenarios of 50% reduced productivity. This study further revealed how disrupted ovulation cycles affect pesticide pharmacokinetics in laying hens' eggs. Our PKPD modelling predictions provide quantitative metrics applicable to food safety evaluation for human health. The adverse outcome pathway framework was utilized to illustrate processes and enhance understanding of animal health in a harmonized and transparent manner.

Our systems modelling approach provides a mechanism-based framework incorporating biological processes to elucidate the production dynamics of hens upon exposure to chemicals. Future work will focus on integrating in vitro as well as legacy in vivo data to calibrate models for different avian species. Overall, the integrative modelling effort can advance the One Health vision of protecting human, animal, and environmental health in a sustainable way.