Correlation analysis between health parameters and cecal microbial composition in the genus levels in quails. With SPSS Statistics 26.0, Spearman's correlation analysis was conducted, and the results were visualized with R (https://www.xiantao.love/products). The red and blue circles represent positive correlation and negative correlation, respectively. Abbreviations: ADFI, average daily feed intake; ADG, average daily gain; F/G, feed-to-gain ratio; GSH-Px, glutathione peroxidase; HSP, heat shock protein; MDA, malondialdehyde; SOD, superoxide dismutase. Thymus, bursa of Fabricius, and spleen refer to their organ index. * P < 0.05, ** P < 0.01.