Light during incubation: A significant, and understudied, welfare challenge for poultry


AWF Research Fund



Research Period


Area of study

Breeding for Better Welfare


Investigator(s): Dr Lindsay Henderson, Prof Simone Meddle

Project length: 18 months (ongoing)

The aim of this study is to inform industry on best practice to increase positive welfare in layer hens by the use of light during incubation.

Over 30 billion chickens are reared globally for meat and eggs every year. In the poultry industry, eggs are incubated in darkness across the 21-day incubation period. Currently little attention is taken regarding lighting conditions during the incubation cycle, particularly in regard to light intensity, wavelength or photoperiod.

Evidence suggests that light exposure during incubation improves hatchability and chick health in layer hens, while reducing fearfulness and stress responsiveness post-hatch in broiler chicken chicks. Recent research also suggests light exposure during incubation could reduce the incidence of injurious pecking in layer hens, which would significantly reduce accumulative suffering in layer hens.

The team will digitally record and quantify behavioural time budgets, interactions between individuals and engagement with enrichment in layer chicks that have been incubated in a light:dark cycle compared with those incubated in darkness. Importantly they will also investigate the effects of light during incubation on positive welfare indicators in layer chicks, such a time spent performing comfort behaviours and play as well as stress related behaviour such as fearfulness.