The choice of litter material to promote pecking, scratching and dustbathing behaviours in laying hens housed in furnished cages

Abstract

Since 2012 in the EU, cages for the housing of laying hens must provide nests, perches and a pecking and scratching area to promote natural behaviours and enhance animal welfare. Previous studies highlighted the difficulty of finding adequate materials for pecking and scratching areas in such cages, mainly due to hygiene problems and technical constraints. This study investigates whether alternative materials could stimulate dustbathing (DB), pecking, and scratching behaviours and examines if hens show any preferences for these materials compared to other well-known litter materials such as sand, peat and artificial turf. We set up two separate experiments: one to simultaneously compare four litter materials (wheat bran, sand, shell sand and peat) and one to simultaneously compare four alternative non-litter, pad-type solutions (plastic mat, artificial turf mat, a slightly friable experimental block made of wood and oyster shells, and a slightly friable experimental sand block). For each experiment, 15 groups of four hens were observed over four days in a multiple choice test. Wheat bran was found to promote pecking and scratching behaviours better than the other litters. Peat induced more dustbaths than wheat bran but duration of DB bouts was similar for both materials. However, the number of dustbaths in wheat bran increased throughout the test, while the duration of DB bouts decreased in peat, showing an increasing preference for wheat bran. The shell sand was found to be the least preferred for pecking, scratching and DB. In the second experiment, pads were found to be less attractive than litters for pecking, scratching, and DB. The plastic mat was very rarely used for DB compared to other solutions in the pad choice test. As hens rarely pecked or scratched any of the pads, no significant differences were noted between the four different types. However, experimental blocks stimulate DB as much as artificial turf mats and seem promising, as their use for DB increased throughout the test. This study shows that wheat bran could be an optimal litter for use in furnished cages to improve hen welfare. In addition, research on new experimental blocks is worth being developed, as it has the advantage of not needing to be renewed during a laying period.