Effect of AO3 supplementation on intestinal morphology, barrier integrity, and nutrient transportation. (A–D) Villus height, crypt depth, and ratio of V:C in jejunum under different treatments. (E,F) Protein levels of intestinal barrier function in jejunum. (G) Relative gene expression levels of amino acid transporters. (H) Relative gene expression levels of amino acid transporters. (I) Relative gene expression levels of fatty acid transporters and fatty acid binding proteins. n = 18 total pigs, 6 replicates per group. Data are expressed as mean ± SEM. * indicates p < 0.05. Different letters indicate differences between groups.