Feeding broiler breeder flocks in relation to bird welfare aspects

To ensure health and reproductive capacity of the birds, broiler breeders are fed restricted during the rearing period, and to a lesser extent also during the production period. Although restricted feeding improves health and thereby bird welfare, on the other hand the birds are chronically hungry and suffer from frustration of the feeding motivation, which has a negative effect on bird welfare. The aim of the current paper is to give an overview of the relation between feed restriction and broiler breeder welfare, and the role of feed (nutritional aspects as well as feeding management) as a possible tool to improve broiler breeder welfare. Possible strategies are 1) dietary dilution, by reducing the energy content and/or increasing the NSP content, by adding soluble (e.g. sugar beet pulp) or insoluble (e.g. oat hulls) fibres to the diet; 2) adding appetite suppressants (e.g. calcium propionate) to the diet; 3) scattering feed in the litter; 4) feeding twice a day, or 5) skip-a-day feeding. Some of these strategies, i.e. dietary dilution or adding appetite suppressants positively affect behavioural patterns of the birds, by reducing stereotypic pecking and eating motivation, and increasing the time spent sitting. These changes, however, can only be considered as indirect parameters of improved bird welfare. It is clear that nutritional strategies can be helpful in reducing hunger stress in broiler breeders. Nutrition, however, cannot fully solve the broiler breeder paradox. The main reason for this paradox is related to breeding goals, that are focussed on improving feed conversion and increasing breast meat percentage. On short term, using dwarf broiler breeder hens could be an alternative. On long term, future genetic selection should be directed on assigning economic values to welfare and including integrity traits in an extended breeding goal.