Butyricacid,ashort-chainfattyacidproducedbymicrobial fermentation, primarily in the large intestine, is known to be involved in the mucosal immune response, and to have an anti-inflammatory effect in animals. It is also known to have a direct effect on mucosal cell proliferation, maturation and differentiation, because it can influence gene expression and protein synthesis (Sengupta et al., 2006). It is certain that butyric acid, while it is a very simple molecule, it can have very complex and diverse modes of action. Because of its very pungent smell, butyric acid is commonly used in its butyrate (B) form (calcium or sodium salt). After butyrate supplementation, an increase in villi height and crypt depth has been observed in pigs and poultry (Galfi and Bokori, 1990; Leeson et al., 2005)