Impact of housing system on intestinal microbiota of laying hens – A systematic review

• Published in: Research in veterinary science Vol. 170; p. 105184
• Main Authors: Pires, P.G.S., Oliveira, G.S., McManus, C., Santos, V.M., Moraes, P.O.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2024
• Subjects: 16S rRNA; Alternative housing; Cage-free; Cecal microbiota; Free-range; 16S rRNA; Free-range; Alternative housing; Cage-free; Cecal microbiota
• ISSN: 0034-5288; 1532-2661; 1532-2661
• DOI: 10.1016/j.rvsc.2024.105184

Studies on the housing system's impact on laying hens' intestinal microbiota were retrieved from the Web of Science, PubMed, and Scopus (between 2017 and 2022). Inclusion criteria were studies that discussed measurable effects related to the topic written in English, Portuguese, and Spanish. Of 3281 articles in the identification stage, 12 studies were used in the systematic review. Asia developed most research relating to the subject. Most studies compared the intestinal microbiota of laying hens from conventional cages versus Cage-Free or Free-Range. However, no study has evaluated the intestinal microbiota of laying hens maintained in an organic system. Greengene and Silva were the most used reference in the studies. According to the results observed in the studies included in the systematic review, there is greater alpha diversity in the alternative system and a high dissimilarity between the conventional and alternative systems. Exposure to environmental factors such as soil, vegetation, natural lighting, access to pastures, and ingesting fibrous foods can lead to changes in the intestinal microbiota. A brief outline of published scientific evidence demonstrates that the housing system can change the gut microbiome of hens. This study summarises the relationship between the housing system and the intestinal microbiome of laying hens and provides a roadmap for future research regarding the gut microbiome of hens. [Display omitted] •A systematic review of production systems and gut microbiome was performed.•12 research articles about production systems were investigated.•Asia was ranked as the first in establishing investigations.•Silva and Greenbase were the most used reference databases.•The housing systems can affect intestinal microbiota.