Nest alternatives: Adding a wire partition to the scratch area affects nest use and nesting behaviour of laying hens in furnished cages

Abstract

Furnished cages (FC) are designed to accommodate highly motivated behaviour patterns like nesting; however, how hens perceive the resources provided in FCs is not fully understood. Our previous research of hens in FCs with a curtained nest (plastic mesh floor) and a scratch area (smooth plastic floor) indicated that hens laid more eggs outside of the nest in a design of FC that had a wire partition bisecting the scratch area. The objective of this study was to compare the egg laying behaviour of hens in the same FCs either with (W) or without (NW) the wire partition. Forty-eight groups of LSL-Lite hens (six hens/group) were each transferred from conventional cages into one of 12 FC for 5days when they were between 20 and 23 weeks of age. Twelve new groups were observed each week over 4 weeks and treatment (W, NW) alternated between FCs each week. Egg location was logged for 5days. Hens in top-tier cages (N=16 groups, 96 hens) were individually identified and video recorded for 3days. Behaviour performed in both the nest and scratch areas during the hour pre-lay was scored for hens with visible ovipositions (N=15 groups, 55 hens). Egg location and behaviour patterns were analyzed using a mixed model ANOVA; day within week was the repeated measure. More eggs were laid in the scratch area in W (18.3±1.8%) compared to NW (7.3±1.3%; P<0.0001). Hens in the W treatment entered (38.5±5.0 vs. 19.6±3.1; P=0.033), spent more time in (8.0±0.8min vs. 3.5±0.5min; P=0.003), and searched the scratch area more than NW treatment hens (15.2±1.6min vs. 6.1min±1.2; P=0.006). Hens in the NW treatment entered (26.1±1.6 vs. 18.6±1.7; P=0.016) and spent more time in the nest (27.4±1.8min vs. 15.7±2.0min; P=0.001), were more aggressive (28.5±3.7 vs. 18.2±2.9; P=0.032), and performed more displacements than W hens (6.4±0.8 vs. 3.0±0.5; P<0.0001). Adding a simple wire partition to the scratch area resulted in more eggs being laid outside the nest, but facilitated more settled nesting behaviour. Hens in FCs may benefit from providing more than one enclosed area for nesting that is distinct from the scratch area.