Fig. 3

Number of papers stratified into different categories in A) year of publication, B) taxonomy identification method, C) WHO geographical region, D) sample size, E) cattle breed, F) specimen type, G) sequencing platform and sequencing region, H) microbiome DNA isolation method and I) rationale. Papers were classified as “Not specified” when the metadata was not available, “Multiple” if multiple study designs were implemented and “Other” if the study design was not commonly used