The knowledge summary was commissioned by the Norwegian Food Safety Authority. The Poultry Regulations, which regulate animal welfare for Norwegian poultry, are 20 years old and need to be updated.

Animal and stocking density, lighting, and restrictive feeding

VKM has not found new studies indicating the welfare of chickens for meat production is weakened by following the regulations for animal and stocking density. However, some studies point out a possible positive effect on the welfare of slow-growing breeds.

Studies also show that animal welfare can be improved by creating an environment where the birds can live as naturally as possible.

In poultry production, artificial lighting is used both to improve production and the welfare of the birds. VKM emphasizes that lighting that is favourable for production is not always favourable for welfare. This means, for example, that lighting intended to prevent unwanted behaviour among the birds may be too poor for them to carry out normal activities.

Restrictive feeding, i.e., the birds get less feed and water than they need, is a common practice in duck farming, but not for laying hens and turkeys.

Restrictive feeding can cause moulting (poultry losing feathers), and the eggs to become smaller and have poor shells. Young birds can become sleepy from restrictive feeding.

The main pathological findings of restrictive feeding are renal failure and decreased muscle mass. Cannibalism in response to hunger has not been observed in poultry.

Methods

The results are based on data and information from literature searches. There was no language restriction on the literature, but publication was limited to the period 2001 - 2022.

Uncertainty about the results is due to the low number of studies and that study design varies between these. Some of the studies were also not relevant for conditions or poultry found in Norwegian production.

The knowledge summary has been approved by VKM's scientific Panel for Animal Health and Animal Welfare.