Butyric acid (from Greek , meaning "butter"), also known under the systematic name butanoic acid,abbreviated BTA, is a carboxylic acid with the structural formula CH3CH2CH2-COOH. Salts and esters of butyric acid are known as butyrates or butanoates. Butyric acid is found in milk, especially goat, sheep and buffalo milk, butter, Parmesan cheese, and as a product of anaerobic fermentation (including in the colon and as body odor). It has an unpleasant smell and acrid taste, with a sweetish aftertaste (similar to ether). It an be detected by mammals with good scent detection abilities (such as dogs) at 10 ppb, whereas humans can detect it in concentrations above 10 ppm.Butyric acid is used in the preparation of various butyrate esters.Due to its powerful odor, it has also been used as a fishing bait additive.