Effect of rearing systems on combs, wattles and shanks colour in layers: preliminary results

Alternative housing systems for hen eggs production represents a clear evidence of the animal housing and husbandry trend towards extensive rearing methods. Consumers demand is oriented towards healthy foods controlled not only under a safety point of view but also under a welfare assessment in animals' life conditions. Among the different alternative systems deep litter and organic production in the recent years have been improved in Italy. The EU regulation pointed out the importance of animal welfare in organic production, nevertheless the production system and associated standards do not automatically provide good animal welfare; thus the organic standards have often been developed under the influence of consumer concerns rather than been based on animal needs. The colour evaluation has been used in different animal species in order to assess food quality but there are few studies on the relationship between body colour and animal temperament or welfare. Comb and wattle colour are very supplied with blood and are mainly influenced from climate and rearing condition. The aim of this study was to evaluate if different rearing system for laying hens may influence comb, shank and wattle colour. Moreover the research had investigated the correlation between colour and reactivity in three groups of laying hens. The study was carried out in one litter floor housing system, one organic housing system and one caged hens facility. In each system the same strain of lying hens (Hyline Brown) was housed. At 70 weeks of age (in summer) the comb, shank and wattle colour have been recorded, using L, a*, b* method (Minolta® CR-400) in 30 birds per rearing system. Moreover the same animals where once tested with the Tonic Immobility (TI) test. The results showed some differences among the three rearing system in comb and wattle colour; hens reared on litter floor showed a significant higher comb a* coefficient compared with both the cage and the organic systems (27,49 floor vs 24,69 cage vs 19,33 organic; p