Developing a novel welfare assessment tool for loose-housed laying hens – the Aviary Transect method

Abstract

This study compared welfare assessment results in aviary flocks using 3 approaches: 1) A novel Aviary Transect method, 2) AssureWel, and 3) the Norwegian farm advisors’ NorWel method. The Aviary Transect time requirement, interobserver reliability, and within- and across-house sensitivity to detect welfare indicators were also evaluated. The study was conducted on 6 randomly chosen commercial white-strain layer flocks of similar age and flock size, kept in multitiered aviaries. The Aviary Transect method comprised standardized walks along each aisle while screening the whole flock for 12 welfare indicators: feather loss ( FL ) on head, back, breast, and tail, wounds on head, back, tail, and feet, dirty birds, enlarged crop, sick birds, and dead birds. AssureWel involved scoring FL on head and back, and dirtiness of 50 random birds, and flock-level evaluation of beak trimming, antagonistic behavior, flightiness, birds needing further care, and mortality. NorWel involved scoring 8 welfare indicators on 50 random birds: FL on head, back, breast, and tail, dirtiness, and wounds on head, back, and tail. The AssureWel detected flock differences in both minor and major FL on the back ( P < 0.01) as well as somewhat dirty birds ( P < 0.01). The NorWel method detected flock differences in both minor and major FL on the head ( P < 0.01), back ( P < 0.001), breast ( P < 0.001), and tail ( P < 0.001) and somewhat (score 1) dirty birds ( P < 0.05). The Aviary Transect method detected flock differences in FL on head, back, breast, and tail (all P < 0.001), dirty birds ( P < 0.05) and enlarged crop ( P < 0.001). More birds with FL on breast, and more dirty birds, were found in wall vs. central transects ( P < 0.05). There was good interobserver agreement, except for dirty birds ( P < 0.01), and positive correlations ( P < 0.05) were identified between the Aviary Transect method and the other sampling methods for FL on head and back, and dirtiness. The three methods took similar time to complete (about 20 min/flock). In conclusion, all 3 methods detected significant differences in welfare indicator prevalence between flocks. The new Aviary Transect method provides egg producers with an efficient and sensitive whole-flock assessment of hen welfare status in multitiered aviaries.

Welfare of laying hens on farm

“…For larger wounds often visual inspection without manipulation will do, as these are situated in areas that are less covered by feathers. The transect method is valid for assessment of soft tissue and integument damage in laying hens without picking up birds, involving simple counts of the number of hens noted in a defined flock walk through, including wounds to head, back, tail or feet (Vasdal et al, 2022a).…”

Welfare of broilers on farm

“…Depending on the used protocol, visual scoring is supported by example pictures and calculation templates. For flock assessment, the transect method developed for poultry welfare assessment (Marchewka et al., 2013 , 2015 ) is an efficient and sensitive method to effectively and efficiently quantify plumage damage in commercial flocks housed in alternative systems (Vasdal et al., 2022c ). Interpretation Although plumage damage is most likely not directly painful, the action that resulted in the damage or the removal may have been (Gentle and Hunter, 1991 ).…”

Flock Factors Correlated with Elevated Mortality in Non-Beak Trimmed Aviary-Housed Layers

“…In addition, clinical scoring of 50 randomly selected hens was recorded when walking through the barn, according to the method described in detail by Vasdal et al [ 29 ]. The sampling spots were predetermined, so that birds from all heights and all transects were included.…”