Flock use of the range is associated with the use of different components of a multi-tier aviary system in commercial free-range laying hens

Frequent Visits to an Outdoor Range and Lower Areas of an Aviary System Is Related to Curiosity in Commercial Free-Range Laying Hens

“…In free-range and aviary housing systems, individual hen behavior can vary significantly, such that, some hens rarely access the outdoors while others utilize the range regularly [1][2][3][4]. Free-range and aviary housing systems provide hens with horizontal and vertical space, allowing for various choices, opportunities, and interactions; including dust bathing, sun bathing, perching, and exploration which are believed to improve hen welfare [5,6].…”

“…Free-range and aviary housing systems provide hens with horizontal and vertical space, allowing for various choices, opportunities, and interactions; including dust bathing, sun bathing, perching, and exploration which are believed to improve hen welfare [5,6]. However, not all hens access the outdoor range when provided with the opportunity [1,2,[4][5][6]. Individual differences in ranging behavior, and preferences for specific areas of the three-dimensional aviary system, may be associated with individual differences in temperament, such as fearfulness [7][8][9][10].…”

Managing Free-Range Laying Hens—Part B: Early Range Users Have More Pathology Findings at the End of Lay but Have a Significantly Higher Chance of Survival—An Indicative Study

“…On the other hand, hens that spent the majority of their time indoors would have used not only the litter area, but also the aviary system, where two manure belts, located at the top and bottom tier prevented hen exposure to excreta and subsequently interrupted the infection cycle of A. galli [ 38 ]. We previously showed that hens that chose their location on the top of the aviary system rarely access the lower tier, let alone the range [ 27 ]. These hens, which would represent most of the stayer population, would therefore experience similar conditions than caged hens in respect to the methods and frequency of manure collection.…”

“…However, ammonia levels were not measured. Details of the experimental set up are provided by Sibanda et al (2020a) [ 27 ].…”

“…Many investigators described a non-uniform range usage where up to 21% of hens within a flock never accessed the outdoors within a given time period [ 25 , 26 ]. The development of these ranging subpopulations within one flock is not only affected by flock size, genetics, weather conditions and other external factors, but also by early life experience, individual hen preferences and time budgets [ 25 , 26 , 27 ]. We previously showed that hens of different early range use (18–21 weeks of age) peaked their egg production at different ages, where to 10% difference of laying performance was observed at 22 weeks of age as well as at 72 weeks of age [ 28 ].…”