Dustbathing, pecking and scratching behaviours of laying hens in furnished cages are enhanced by the presence of rubber mats and litter distribution
Résumé
Furnished cages for laying hens exist in a wide variety of sizes and designs and should be equipped to allow hens to express some of their behavioural priorities. European Council Directive 1999/74/EC stipulates that litter must be provided for pecking and scratching but the type of litter and the pad where litter is delivered are not defined. In the same way, neither the maximum nor the optimum number of birds per cage has been defined. Two successive experiments were carried out to analyse pecking, scratching (PS) and dustbathing (DB) behaviours performed in different furnished cages with different designs. Three group sizes of ISA brown laying hens (20, 40 or 60 hens, with the same density in all the cages), with or without additional feed distribution as litter substrate, were compared in the first experiment. The second experiment focussed on DB behaviour and compared two pecking and scratching pads (artificial turf or rubber mats), with or without wheat bran distribution as litter substrate, in groups of 60 hens per cage. Irrespective of litter presence, group size, and type of pad, DB and PS were mainly performed in the pecking and scratching area, showing the attractiveness of this area. In the first experiment, feed–litter provision in pecking and scratching area increased PS and DB behaviours, while group size did not affect them. In the second experiment, hens performed more DB in the pecking and scratching area when wheat-bran litter was present than when it was absent. Rubber matting was more attractive to hens for DB than artificial turf matting. Durations of DB bouts were not affected by the presence or absence of wheat-bran litter or the choice of pecking and scratching pad. In furnished cages, hens clearly seek out pads and litter to perform PS, and providing litter (feed or wheat bran) or rubber in pecking and scratching area is attractive for hens to DB in it. However, the cage design could be improved to promote more DB activity, for instance by increasing space of pecking and scratching area in the cage.