No abstract

No abstract

13Laying hens in loose housing systems have access to group-nests which provide space for several hens at 14 a time to lay their eggs. They are thus rather large and the trend in the industry is to further increase the 15 size of these nests. Though practicality is important for the producer, group-nests should also cater to the 16 egg-laying behaviour of hens to promote good welfare. One of the factors playing a role in the 17 attractiveness of a nest is the amount of enclosure: hens prefer more enclosure when having a choice 18 between different nest types. The aim of this study was to investigate if hens prefer smaller group-nests to 19 lay their eggs given that they may seem more enclosed than larger nests. 20The relative preference of groups of laying hens for two nest sizes-0.43 m 2 vs. 0.86 m 2 -was tested in a 21 free-access choice test. The experiment was conducted in two consecutive trials with 100 hens each. They 22 were housed from 18 to 36 weeks of age in five groups of 20 animals and had access to two commercial 23 group-nests differing in internal size only. We counted eggs daily as a measure of nest preference. At 28 24 and 36 weeks of age, videos were taken of the pens and inside the nests on one day during the first 5 25 hours of lights-on. The nest videos were used to record the number of hens per nest and their behaviour 26 2 Accepted to Applied Animal Behaviour Science, February 2014 with a 10 min scan sampling interval. The pen videos were observed continuously to count the total number 27 of nest visits per nest and to calculate the duration of nest visits of five focal hens per pen. 28We found a relative preference for the small nest as more eggs, fewer nest visits per egg and longer nest 29 visit durations were recorded for that nest. In addition, more hens-including more sitting hens-were in the 30 small nests during the main egg-laying period, while the number of standing hens did not differ. These 31 observations indicate that even though both nests may have been explored to a similar extent, the hens 32 preferred the small nest for egg-laying. 33 Keywords 34Laying hens, nest size, group-nests, nest choice, preference test, animal welfare 35 36 3