Characterization of intestinal organoids from farm animals. A Pig colon organoids stained for Villin (orange). Scale bar: 20 µm. B Monolayer of rabbit caecum organoid cells stained for actin (red). Scale bar: 100 µm. C Pig colon organoid stained for E-cadherin (red), and proliferating cell nuclear antigen (PCNA, green). The arrow indicates a proliferative zone in the organoid bud. Scale bar: 100 µm. D Pig colon organoid cells were seeded in Transwell inserts at several densities. Transepithelial electrical resistance (TEER) of pig organoid cell monolayers was measured 3 days post-seeding. Kruskal–Wallis test indicated a significant effect of cell density on TEER. E Pig colon organoid stained for mucins (Periodic Acid-Schiff staining). Scale bar: 20 µm. F Characterization of chicken intestinal organoid by transmission electron microscopy. The polarized organization of the cells, the brush border and the intracellular dense vesicles containing packaged mucins (marked with asterisk) were morphologically distinguishable. L: lumen. Scale bar: 2 µm. G Pig colon organoid stained for chromogranin A (CgA, orange). Scale bar: 20 µm. A, B, C and G: DNA (nuclei) is stained in blue.