Association of serum biochemical parameters with growth performance and gut microbiota in large white pigs

Results showed that serum creatinine (sCr) was negatively correlated with residual feed intake (RFI), average daily feed intake (ADFI), feed conversion ratio (FCR), and backfat thickness (<i>r</i> = -0.13 to -0.25, <i>p</i> < 0.05), but positively correlated with loin muscle area (<i>r</i> = 0.13, <i>p</i> < 0.05). Lactate dehydrogenase (LDH) was negatively correlated with FCR (<i>r</i> = -0.24, <i>p</i> < 0.05) and RFI (<i>r</i> = -0.26, <i>p</i> < 0.05). At the genus level, LDH was positively correlated with <i>Prevotella</i>, <i>Faecalibacterium</i>, <i>Roseburia</i>, and <i>Desulfovibrio</i>, and negatively correlated with <i>Fibrobacter</i>. Meanwhile, sCr showed positive correlations with <i>Treponema</i> and <i>CF231</i>, and negative correlations with <i>Subdoligranulum</i>, <i>Eubacterium</i>, and <i>Dorea</i>. These genera may serve as microbial biomarkers for sCr and LDH levels. Our findings provide valuable insights for early-stage breeding selection and further research into blood biochemical indicators in pigs.