NKJ 117 - Modification of rearing conditions to improve welfare of layers: Basic and applied ethological studies.

Although recent international legislation recommends loose housing systems for egg-laying hens, there are severe problems with fearther pecking, cannabilism and nervousness even in these alternative housing systems. Difficulties in eliminating these beha vioural problems may be related to the fact that most research in chickens has focused on studying the adult egg-laying bird with no consideration of the stressors to which the parental generation may be exposed. There is evidence from findings in other species indicating that effects of environmental stress to which hens are subjected may affect the development of physiology and behaviour in their progeny. This project therefore aims to study the effects of hormonal manipulation of the prenatal environ ment for chicks to illuminate effects on fearther pecking, cannabilism, nervousness and reduced ability to cope with the social environment. One challenge in the present project will involve the development of good methods for experimental manipulation of the prenatal hormonal environment. The knowledge gained through this project will form a basis for making recommendations regarding legislation and production rutinenes aimed at improving the welfare of laying hens as we ll as their parents by reducing the above-mentioned behavioural problems and the sources of stress causing them.