The environment experienced early in life can shape an individual’s long-term physiology and behaviour. Here, we investigated the effects of light as sensory stimulus during artificial poultry egg incubation and provision of a post-hatch dark shelter enrichment on layer White Leghorn chicken chick growth and behaviour. Eggs were incubated under either full-spectrum white light (24L:0D) or darkness (0L:24D). After hatching, chicks (both sexes) were reared in either standard pens or pens with dark shelter enrichment. Chick behaviour was digitally recorded over four weeks to quantify behavioural time budgets and dark shelter use. We discovered that light during incubation did not affect hatching success, but did have age- and sex-specific effects on body weight. By four weeks of age, female chicks incubated under light tended to be heavier than those incubated in the dark. The dark shelter enrichment reduced overall chick activity and foraging whilst increasing resting behavior; effects were more pronounced in light-incubated chicks. Furthermore, in standard. Non-enriched pens, light-incubated chicks were more active and foraged more than dark-incubated chicks. Our findings suggest that light during incubation shapes early-life behavioural phenotypes and modulates chick interactions with their post-hatch environment.Research support: The Animal Welfare Foundation & the BBSRC.
Kosin et al. (Tue,) studied this question.