Preference for artificial range enrichment design features in free-range commercial laying hens

ABSTRACT

1. This study examined what elements of artificial enrichment structures attract hens in the outdoor range, and what behaviours hens perform around these structures. Three principles of cover design (height, orientation and visual density) were tested for laying hen preference in the outdoor range of a commercial egg farm using a 2 × 3 × 3 factorial design. The factors were height: 0.5 m or 1.5 m; orientation: vertical, horizontal or horizontal cover with one vertical side; and visual density: 0% (control), 50% or 90% UV blocking cloth.

2. A significant three-way interaction between all factors was found (P < 0.001). The most preferred visual density of these structures was the 90%, followed by 50% UV blocking cloth. Horizontal structures with one vertical side, of either height, were highly preferred. Short horizontal structures were preferred to tall ones, and tall vertical structures were slightly preferred over short ones.

3. The most common behaviours observed around the structures were interaction with the structure (pecks, scratches and vigilance directed at the structure; 32.7%), foraging (32.2%), locomotion (9.9%), and air foraging (pecks and snapping in the air; 9.0%). A three-way interaction between the design principles influenced the proportion of hens performing each of these behaviours (P < 0.001). Hens foraged more around structures with no shade cloth and interacted more with structures that had dense shade cloth.

4. These results highlighted the complexity of designing attractive outdoor environments for laying hens. By testing the combination of elements that hens prefer it is possible to understand how to design attractive outdoor ranges that attract hens and promote a diverse range of behaviours on commercial farms.

KEYWORDS:

• Behaviour
• chicken
• cover
• enrichment
• natural
• outdoor
• ranging
• welfare

Acknowledgments

The authors would like to thank Kinross Farm in allowing us to use their flocks for data collection and for their technical support. They thank Rebecca Woodhouse, Ingrid Reynish, and David Murden for their technical assistance.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was partly funded by a national competitive grant from Australian Egg Corporation Limited, and student sponsorship for Hannah Larsen was partly funded through the Poultry Cooperative Research Centre.