Immune Variability in Poultry: Interactions between Genetics, Microbiota and Environment to Improve Flock Health

The article synthesizes current research on the determinants of poultry immune variability by framing the bird and its associated microbial communities as an holobiont. It details how host genetics, gut microbiota composition, and environmental conditions influence resistance, tolerance, resilience, and overall health robustness. Individual and collective health indicators are reviewed, highlighting trade-offs between immune function and production traits. The authors propose integrating immunological, microbiological, and behavioral datasets into selection programs and sanitary management to develop more resilient and sustainable poultry production systems.