Meta analysis of the prevalence of subclinical mastitis in dairy cattle

Subclinical mastitis is still considered one of the most important problems affecting the dairy industry. Therefore, studies on subclinical mastitis continue to be conducted. The presence of too many studies conducted worldwide to determine the prevalence and risk factors of mastitis has necessitated systematic review or meta-analysis studies on this subject. In this study, it was aimed to perform the meta-analysis for the prevalence of cow and udder quarter-based subclinical mastitis in 193 studies conducted around the world, and to determine the effects of some factors on the prevalence of subclinical mastitis using subgroup analysis and meta-regression methods. Because high heterogeneity was detected between studies in the analysis, the random effects model (Der Simonian-Laird method) (Q=15149.869, df=188, p<0.001, I2=98.759; Q=72142.706; df=174, p<0.001; I2=99.774) was used in this study. The publication biases in the study samples were determined by the use of Egger's linear regression test, Begg and Mazum-dar rank correlation test and funnel plots. As a result of the study, the pooled subclinical mastitis prevalence in cow and udder quarter-based studies were calculated as 0.46 (95% CI: 0.43-0.48) and 0.32 (95% CI: 0.30-0.34) respectively. The meta-analysis conducted in this study has enabled the elimination of inconsistencies in the prevalence of subclin-ical mastitis in individual studies conducted around the world, and has provided a stronger and more precise estimate.