title: Physical Health Problems and Environmental Challenges Influence Balancing Behaviour in Laying Hens.
abstract: With rising public concern for animal welfare, many major food chains and restaurants are changing their policies, strictly buying their eggs from non-cage producers. However, with the additional space in these cage-free systems to perform natural behaviours and movements comes the risk of injury. We evaluated the ability to maintain balance in adult laying hens with health problems (footpad dermatitis, keel damage, poor wing feather cover; n = 15) using a series of environmental challenges and compared such abilities with those of healthy birds (n = 5). Environmental challenges consisted of visual and spatial constraints, created using a head mask, perch obstacles, and static and swaying perch states. We hypothesized that perch movement, environmental challenges, and diminished physical health would negatively impact perching performance demonstrated as balance (as measured by time spent on perch and by number of falls of the perch) and would require more exaggerated correctional movements. We measured perching stability whereby each bird underwent eight 30-second trials on a static and swaying perch: with and without disrupted vision (head mask), with and without space limitations (obstacles) and combinations thereof. Video recordings (600 Hz) and a three-axis accelerometer/gyroscope (100 Hz) were used to measure the number of jumps/falls, latencies to leave the perch, as well as magnitude and direction of both linear and rotational balance-correcting movements. Laying hens with and without physical health problems, in both challenged and unchallenged environments, managed to perch and remain off the ground. We attribute this capacity to our training of the birds. Environmental challenges and physical state had an effect on the use of accelerations and rotations to stabilize themselves on a perch. Birds with physical health problems performed a higher frequency of rotational corrections to keep the body centered over the perch, whereas, for both health categories, environmental challenges required more intense and variable movement corrections. Collectively, these results provide novel empirical support for the effectiveness of training, and highlight that overcrowding, visual constraints, and poor physical health all reduce perching performance.
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Stephanie
authors.initials: S
authors.lastname: LeBlanc
authors.affiliation: Division of Biological Sciences, University of Montana, Missoula, Montana, United States of America.
authors.forename: Bret
authors.initials: B
authors.lastname: Tobalske
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Margaret
authors.initials: M
authors.lastname: Quinton
authors.affiliation: Department of Integrative Biology, University of California, Berkeley, California, United States of America.
authors.forename: Dwight
authors.initials: D
authors.lastname: Springthorpe
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Bill
authors.initials: B
authors.lastname: Szkotnicki
authors.affiliation: Division of Animal Welfare, VPH Institute, University of Bern, Bern, Switzerland.
authors.forename: Hanno
authors.initials: H
authors.lastname: Wuerbel
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Harlander-Matauschek
mesh_terms: D000822:Animal Husbandry / Q000379:methods*; D000827:Animal Welfare; D000818:Animals; D002645:Chickens / Q000033:anatomy & histology* / Q000502:physiology*; D004531:Eggs / Q000032:analysis; D004777:Environment; D005260:Female; D006799:Housing, Animal; D010058:Oviposition; D004856:Postural Balance; D011201:Poultry Diseases / Q000453:epidemiology