Understanding the implications of rearing experiences on the conduct and bone integrity of laying hens may help inform options to animal welfare and administration issues.
Analysis into laying hen housing has targeted totally on the layer atmosphere (put up 16-18 weeks of age). It’s nicely documented that early experiences can have lasting developmental results on hen cognition and musculoskeletal well being. Furthermore, mounting proof signifies that pullet housing and administration selections can have measurable impacts on many points of hen welfare, productiveness and ease of administration. We evaluation the methods during which early environments can have an effect on hen growth, and supply examples of implications for hen welfare and administration.
The elevated use of cage-free aviary housing programs inside the egg trade has been accompanied by an upsweep in pullet housing and administration analysis. This isn’t stunning on condition that these early situations are skilled for the primary 16-18 weeks of a pullet’s life; a interval of pronounced cognitive and musculoskeletal growth. Alternatives to interact with complicated early environments can have constructive long-term penalties on each points of growth, which in flip affect social conduct, and area and useful resource use. For instance, as in comparison with cage-reared hens, birds reared in aviaries have been proven to have higher working reminiscence and decreased fearfulness when evaluated of their layer environments. At 19 weeks of age, shortly after being transferred into an identical layer housing, hens that had been raised in multi-tier aviaries used elevated elements of their pens to a larger extent than cage-reared hens. Regarding musculoskeletal well being, aviary versus cage rearing has been related to larger whole and cortical bone cross-sectional areas for the radius and tibia at 16 and 73 weeks of age.
Variations in bone mineral distribution have additionally been reported between the 2 rearing teams. Layer housing was an identical for each rearing teams inside every examine, emphasizing the position of early experiences on the described outcomes.
Whereas the rearing programs described above differed in lots of dimensions, much less pronounced modifications of early housing can even lead to measurable variations in cognition, musculoskeletal well being, and consequently area and useful resource use. Withholding perch entry from placement to eight weeks of age lowered the pullets’ talents to maneuver upward throughout perches, probably because of lowered spatial cognition. Alternatively, early perch entry throughout rearing has been related to lowered prevalence of ground laying and cloacal cannibalism in mature flocks. Early perch entry has additionally been proven to enhance musculoskeletal well being by finish of lay.
As beforehand famous, developmental points of cognition, musculoskeletal well being, and useful resource use can contribute to, or mitigate, hen welfare and administration issues. The prevalence of keel bone fractures, which could be painful and have an effect on hen productiveness, is an instance of 1 such concern. Though keel bone fractures can happen in all sorts of layer housing, larger prevalence has been related to elevated housing system complexity. Nevertheless, variations in keel fracture prevalence reported amongst mature layers might mirror variations in keel fracture susceptibility grounded in early expertise. A big-scale, multi-institutional mission is at the moment underneath option to decide the impacts of early rearing experiences on the event of spatial consciousness, bone well being, and keel fracture danger for laying hens.
Preliminary outcomes counsel that early experiences have an effect on the best way during which pullets reply to vertical buildings when examined on a visible cliff, the trajectory of bone growth, and the distribution of hens inside multi-tier aviary layer housing. The concentrate on early expertise and identification of broadly outlined developmental mechanisms underlying keel bone fractures (and different welfare and administration issues assist the design of custom-made early mitigation methods to deal with issues noticed throughout the numerous sorts of present layer housing programs, making this a very highly effective method.
References can be found on request
From the Proceedings of the Midwest Poultry Federation Conference – 2022