Literature update on effective environmental enrichment and light provision in broiler chickens

The results of a literature study to the effect of different types of environmental enrichment and light conditions on broiler chickens welfare are described, in order to attempt to provide an environment to slow-growing broiler chickens that better meets their behavioural requirements. With respect to environmental enrichment, a review paper has been used as a starting point and more recent information has been collected and summarised. With respect to lighting, in consultation with stakeholders we chose to limit the literature study to a fewpotential interesting areas of research (e.g. natural light provisionand its variation across the broiler house). There are several research questions in relation to enrichment provision, e.g., optimal perch design, multiple use of enrichments and the actual number of enrichments that should be provided. Currently, little is known about the need for light in slow-growing broiler chickens and how this interacts with the environmental enrichment offered. Future research priorities include theoptimization of methods of natural light provision (which is often applied in higher welfare indoor systems with slow-growing breeds), testing effects of ultraviolet wavelengths on chicken behaviour,and light colour preferences in slow-growing breeds.