Photoperiodism in chickens: neuroendocrine regulation and health and welfare implications

Photoperiodism has evolved in temperate animals to facilitate adaptation to seasonal changes in the environment.

The most abundant bird on the planet, the chicken, initiates reproduction in response to increasing day-length (photoperiod).

Accordingly, the egg industry employs photostimulation – an abrupt increase in the photoperiod – to trigger egg-laying in commercially-bred chickens.

Studies on animal models have shown the multifaceted effects of photoperiodism on physiology, behavior, and the immune system.

However, the regulation and the impacts of photostimulation on health and welfare remain poorly characterized.This interdisciplinary project aims to provide for the first time a multidimensional overview of photoperiodism in the chicken and assess the impacts of photostimulation on the health and welfare of laying hens.

To this end, we will systematically explore the effects of photostimulation on (i) physiology and behavior, (ii) immune system and immunocompetence, and (iii) cell-type-specific gene expression in the hypothalamus.By addressing the greatly overlooked health and welfare implications of photoperiodism, this project will contribute to good animal health and welfare.

Moreover, by combing extensive physiological, behavioral, and immunological phenotyping with cutting-edge single-cell-sequencing methods, this project will significantly improve our fundamental understanding of the neuroendocrine regulation of physiology and behavior in birds.