The aim of this study was to investigate the effects of a supplementation diet, composed of tributyrin and lactitol (TL), and a standard diet without growth promotors (EU). Then the effects were compared with a standard US diet. It was concluded that the US diet had a greater effect on growth performance and mucosal trophic status than EU diets, the supplementation with slowly released TL seemed to be an effective tool to partially overcoming the adverse effects of vegetable protein diets.