Systematic review of the effect of perch height on keel bone fractures, deformation and injuries, bone strength, foot lesions and perching behavior

Abstract

This report provides a summary of four systematic reviews on the impact of perch height on laying hen keel bone fractures, deformation and injuries, bone strength, foot lesions and perching behavior. After conducting a scoping review and identifying outcomes of interest, the review protocols were developed. An extensive literature search was conducted in information sources such as CABI, PUBMED and relevant conference proceedings. 1518 abstracts were assessed for relevance and 9 studies reported perch use and 1 reported keel injuries. No studies reported summary effect sizes; therefore it was not possible to conduct a meta-analysis. In lieu of a formal meta-analysis, a descriptive analysis was conducted, which plotted reported perch height against metrics of perch use. This descriptive analysis was not able to account for lack of independence, differences in sample size and other importance sources of heterogeneity such as cage height. The descriptive analysis suggested a positive association with metrics that measured perch use and height, i.e., increased usage was associated with increased height. KeywordsSystematic review, poultry, cages, aviaries, perches, keel bone, welfare ABSTRACTThis report provides a summary of four systematic reviews on the impact of perch height on laying hen keel bone fractures, deformation and injuries, bone strength, foot lesions and perching behavior. After conducting a scoping review and identifying outcomes of interest, the review protocols were developed. An extensive literature search was conducted in information sources such as CABI, PUBMED and relevant conference proceedings. 1518 abstracts were assessed for relevance and 9 studies reported perch use and 1 reported keel injuries. No studies reported summary effect sizes; therefore it was not possible to conduct a meta-analysis. In lieu of a formal meta-analysis, a descriptive analysis was conducted, which plotted reported perch height against metrics of perch use. This descriptive analysis was not able to account for lack of independence, differences in sample size and other importance sources of heterogeneity such as cage height. The descriptive analysis suggested a positive association with metrics that measured perch use and height, i.e., increased usage was associated with increased height.

Keel bone fractures in Danish laying hens: Prevalence and risk factors

“…The lack of true risk factor identification for keel bone fracture development, to some extent at least, may be due to lack of separation of deviations, damage and fractures, which are likely to have different pathogeneses. Just like it has been documented that perches have a significant role in the development of deviations at the rim of the keel [14,21,22]. As no single cause of keel bone fracture development has yet been identified, the efforts in risk factor identification have to some extent been inconclusive and argue for more research into understanding these fractures.…”

Space use and navigation ability of hens at housing in the aviary for the laying phase: effect of enrichment with additional perches and genotype

“…According to the literature, access to perches during rearing of pullets could positively affect their cognitive and physical abilities to use perches in the laying environment ( Wichman et al, 2007 ). However, perches are considered also a cause of injury ( Sandilands et al, 2009 ), and they can have a significant role in the development of keel deviations ( Pickel et al, 2011 ; Harlander-Matauschek et al, 2015 ; O'Connor et al, 2015 ). In fact, housing systems containing perches can have a greater prevalence of keel bone fractures; perch height has also been positively correlated with the prevalence of fractures, suggesting the influential role of perches in collisions ( EFSA AHAW Panel (EFSA Panel on Animal Health and Animal Welfare), 2015 ; Stratmann et al, 2015b ).…”

Information retrieval for systematic reviews in food and feed topics: A narrative review

“…Systematic reviews in food and feed topics are increasingly influencing policy‐making at both the national and international levels. The UK Department for Environment, Food and Rural Affairs (DEFRA), the Food Standards Agency (FSA), the European Food Safety Authority (EFSA), and the Food and Agriculture Organization (FAO) of the United Nations have all commissioned and funded recent systematic reviews to inform their work. This is particularly apparent in the context of risk assessment where systematic reviews align with the One Health agenda.…”