Ruminant milk fat contains a wider range of fatty acids than any other lipid system – up to 400 fatty acids have been reported in bovine milk fat; the principal fatty acids are the homologous series of saturated fatty acids with an even number of C-atoms, C4:0–C18:0, and C18:1. The outstanding features of the fatty acid profile of bovine milk fat are a high concentration of short- and medium -chain acids (ruminant milk fats are the only natural lipids that contain butanoic acid, C4:0) and a low concentration of polyunsaturated fatty acids.