Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Phytic acid (known as inositol hexakisphosphate (IP6), or phytate when in salt form) is the principal storage form of phosphorus in many plant tissues, especially bran and seeds. Inositol penta- (IP5), tetra- (IP4), and triphosphate (IP3) are also called phytates. Phosphorus in phytate form is, in general, not bioavailable to non-ruminant animals because they lack the digestive enzyme phytase, which is required to separate phosphorus from the phytate molecule. On the other hand, ruminants readily use phytate because of the phytase produced by rumen microorganisms.