Phosphorus has been known as “master mineral” because it is involved in most metabolic processes. Phosphorus, which is stored in bones and teeth, is often discussed in conjunction with calcium. Research indicates the effect of the calcium: phosphorus ratio on ruminant performance has been overemphasized. Dietary Ca:P ratios of between 1:1 to 7:1 results in similar performance, provided the phosphorus adequately meets the requirements. Generally, it is recommended not to allow total daily phosphorus intake to exceed daily calcium intake for young animals, as this may provoke urinary calculi. A major consideration with respect to phosphorus availability is the proportion of phosphorus in the plants in the form of phytic acid. which must be degraded by phytase to produce phosphoric acid to make it available to the animals. It has been reported that naturally occurring phytic acid is hydrolysed in the rumen. Poultry and swine, however, are not able to utilize this complex.
During the growing season, phosphorus is usually adequate in forages. However, phosphorus is deficient in some situations, such as drought. Worldwide P is the most marked deficient mineral. Cereal grains and oilseed meals contain moderate to high levels of phosphorus. Supplemental sources of highly available phosphorus include in order monocalcium phosphate / dicalcium phosphate > sodium phosphate > phosphoric acid > ammonium polyphosphate > bone meal > fish meal / meat meal > defluorinated phosphate > urea phosphate and monoammonium phosphate.