Effect of management system on the productivity and welfare of broiler chickens from different commercial lines

The aim of this experiment was to determine the effect of the litter barn and free-range management systems on the productivity and behaviour of broiler chickens from three different commercial lines. Broiler chickens were assigned to the following groups: Group I - chickens of the Cobb 500 commercial line, kept on litter without access to free range; Group H - chickens of the Hubbard commercial line, kept on litter without access to free range; Group III - chickens of the Ross 308 commercial line, kept on litter without access to free range; Group IV - chickens of the Cobb 500 commercial line, kept on litter with access to free range; Group V - chickens of the Hubbard commercial line, kept on litter with access to free range; Group VI - chickens of the Ross 308 commercial line, kept on litter with access to free range. It is concluded that the best fattening results were obtained by broilers from the Cobb 500 commercial line and the poorest by Ross 308 broilers, regardless of the rearing system. This may indicate that genetic factors in addition to rearing conditions have a considerable effect on production results. Broiler chickens with access to free range showed their natural patterns of behaviour much more frequently, while birds kept in the barn system had limited scope for expressing these patterns. Hence it is concluded that the management system with access to free range is characterized by improved bird welfare compared to the barn system, as manifested in broiler behaviour. When planning to rear broiler chickens in the system with access to free range, commercial lines giving good fattening results in the free range system should be chosen, as the present experiment shows that the material from some companies may achieve poor production parameters in this management system.