Determination of Space Use by Laying Hens09 April 2014
Researchers at the University of California, Davis, have assessed the amount of space a hen needs to carry out basic behaviour, including standing up, lying down, turning around and wing-flapping.
Two states in the United States now have legislation requiring that laying hens be provided with sufficient space to perform particular behaviours, according to Joy Mench and Richard Blatchford at the University of California, Davis.
Writing in current issue of Poultry Science, they report that they used kinematic analysis to measure the amount of space needed for White Leghorn hens to stand, turn around 180°, lie down and wing flap and thus provide a framework for translating these performance standards into a space requirement.
Hyline W-36 hens (n=9) were marked on the tops of their heads and the tips of both wings and three toes with black livestock marker. Each hen was then placed in a floor pen (91.4 × 91.4cm) and filmed using two high-speed cameras.
The resulting images were processed using a software programme that generated three-dimensional space use for each behaviour.
Because none of the hens lay down in the test pen, the two-dimensional space required for lying was determined by superimposing a grid over videos of the hens lying down in their home cages.
On average, hens required a mean area of 563 (± 8) cm2 to stand, 1,316 (± 23) cm2 to turn around, 318 (± 6) cm2 to lie down, and 1,693 (± 136) cm2 to wing-flap.
The mean heights used were 34.8 (± 1.3) cm for standing, 38.6 (± 2.3) cm for turning and 49.5 (± 1.8) cm for wing-flapping.
However, space requirements for hens housed in multiple-hen groups in cage or non-cage systems cannot be based simply on information about the space required for local movement by a single hen, said Mench and Blatchford.
It must also incorporate consideration of the tendency of hens in a flock to synchronise their behaviours. They added that it must include not just local movement space but also the space that hens may need to use for longer-distance movements to access resources such as food, water, perches and nest boxes.
Mench J.A. and R.A. Blatchford. 2014. Determination of space use by laying hens using kinematic analysis. Poultry Science. 93(4):794-798. doi: 10.3382/ps.2013-03549
You can view the full report (fee payable) by clicking here.