Defi nition of the diff erent systems
Alternative production systems can be defined as a non-cage system with nests, adequate perches and a scratching area.
Within alternative production systems different housing sub systems can be defined as:
• A barn (deep litter) system is a house where birds have access to a litter area, and are able to practice natural
behaviour like dust bathing and scratching. A barn house also provides nest boxes and can have a slatted area
where water and feed are presented.
• An aviary house (multi tier) is like a barn house, in addition, birds are able to move among different levels.
Feed is presented on different levels and water is mainly presented in front of the nest box. Birds need to move
through the system to eat, drink, rest and produce eggs.
• Free range is either a barn or an aviary house from which birds have access to an outside range area.