Data from: Space use by 4 strains of laying hens to perch, wing flap, dust bathe, stand and lie down

The laying hen industry is implementing aviary systems intended to improve
welfare by providing hens with more space and resources to perform
species-specific behaviors. To date, limited research has examined spatial
requirements of various strains of laying hens for performing key
behaviors and none has been conducted within an alternative housing
system. This study investigated the amount of space used by 4 strains of
laying hens (Hy-Line Brown [HB], Bovans Brown [BB], DeKalb White [DW], and
Hy-Line W36) to perform 5 different behaviors in the litter area of a
commercial-style aviary. Hens were recorded standing [S], lying [L],
perching [P], wing flapping [WF], and dust bathing [DB] on an open-litter
area with an outer perch between 12:00 and 15:00 at peak lay (28wk). Still
images of each behavior were analyzed using ImageJ software for 16 hens
per strain, and maximum hen length and width were used to calculate total
area occupied per hen for each behavior. Brown hens required, on average,
89.6cm2 more space for S (P≤0.021) and 81.5cm2 more space for L (P≤0.013)
than white hens. White hens used, on average, 572cm2 more space to perform
WF than brown hens (P≤0.024) while brown hens used 170.3cm2 more space for
DB than white hens (P≤0.022). On average, hens of all strains were wider
while perching than the 15cm commonly recommended per hen (e.g., DW:
18.03; HB: 21.89cm), and brown hens required, on average, 3.38cm more
space while perching than white hens (P≤0.01). Brown and white hens occupy
different amounts of space when performing key behaviors. These
differences, along with factors such as behavioral synchrony, clustering,
and preferred inter-bird distances associated with these behaviors, should
be considered when creating industry guidelines, crafting legislation and
designing and stocking laying hen facilities to ensure hens can fulfill
their behavioral needs.