Completeness of reporting and risks of overstating impact in cluster randomised trials : a systematic review

Acknowledgments We received no funding specifically for this systematic review. ELT is funded in part by awards R01-AI141444 from the National Institute of Allergy and Infectious Diseases and R01-MH120649 from the US National Institute of Mental Health; both Institutes are part of the National Institutes of Health (NIH). JAG and ACP's support of this project was made possible (in part) by grant number UL1TR002553 from the National Center for Advancing Translational Sciences of the NIH, and the NIH Roadmap for Medical Research. JEM is supported by an Australian National Health and Medical Research Council Career Development Fellowship (APP1143429). SN was supported by an award that is jointly funded by the UK Medical Research Council (MRC) and the UK Department for International Development (DFID) under the MRC/DFID Concordat agreement, and part of the EDCTP2 programme supported by the European Union (grant reference MR/R010161/1). ABF acknowledges funding support from the National Health and Medical Research Council of Australia (grant ID 1183303). KH is funded by a National Institute for Health Research Senior Research Fellowship SRF-2017-10-002. The contents of the research included in this manuscript are solely the responsibility of the authors and do not necessarily represent the official views of any of the funders. The research contributed by all authors of this manuscript are independent of their funders. Specifically, the funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We wish to thank the three reviewers for their insightful comments and constructive feedback.Peer reviewedPublisher PD

Soft perches in an aviary system reduce incidence of keel bone damage in laying hens.

Keel bone fractures and deviations are one of the major welfare and health issues in commercial laying hens. In non-cage housing systems like aviaries, falls and collisions with perches and other parts of the housing system are assumed to be one of the main causes for the high incidence of keel bone damage. The objectives of this study were to investigate the effectiveness of a soft perch material to reduce keel bone fractures and deviations in white (Dekalb White) and brown laying hens (ISA Brown) kept in an aviary system under commercial conditions. In half of 20 pens, all hard, metal perches were covered with a soft polyurethane material. Palpation of 20 hens per pen was conducted at 18, 21, 23, 30, 38, 44 and 64 weeks of age. Production data including egg laying rate, floor eggs, mortality and feed consumption were collected over the whole laying period. Feather condition and body mass was assessed twice per laying period. The results revealed that pens with soft perches had a reduced number of keel bone fractures and deviations. Also, an interaction between hybrid and age indicated that the ISA hybrid had more fractured keel bones and fewer non-damaged keel bones compared with the DW hybrid at 18 weeks of age, a response that was reversed at the end of the experiment. This is the first study providing evidence for the effectiveness of a soft perch material within a commercial setting. Due to its compressible material soft perches are likely to absorb kinetic energy occurring during collisions and increase the spread of pressure on the keel bone during perching, providing a mechanism to reduce keel bone fractures and deviations, respectively. In combination with genetic selection for more resilient bones and new housing design, perch material is a promising tool to reduce keel bone damage in commercial systems