The effectiveness of microbial phytase is because it frees up phosphorus bound in phytate in feed ingredients. The effect of microbial phytase in proportion to the total amount of phytic phosphorus: the more phytates, which contain phosphorus, the more phosphorus is released under the influence of microbial phytase. Phosphorus availability is increased by adding phytase of microbial origin to the feed. Therefore, the feed composition should be calculated in accordance to the amount of phosphorus that bound in phytate.
Diets based on grains, enhance the absorption of phosphorus contained in phytic complexes to a higher level than rations containing dry fermented grains with solubles, or high-protein dry fermented grains, which contribute to the very low absorption of phytic phosphorus.
Microbial phytase activity is different for each component
The impact of microbial phytase on the different types of feed is different, so you can not accurately make a diet for pigs, taking into account the overall mechanism of action of microbial phytase. However, if you know that for digestion of phytate phosphorus to occur, microbial phytase needs to be added, you can then determine the exact amount by which you need to increase the energy value of the feed, via microbial phytase addition.
All components must have some indicators of phosphorus digestibility, in accordance to the phosphorus availability with and without microbial phytase. For example, indicators of digestibility of phosphorus in cereals should be introduced in the development of programs form 40.9% (without phytase) to 67.5% (with phytase). If different levels of microbial phytase are added, the digestibility of phosphorus derived from each level of phytase must be specified. This approach will lead to the most accurate way to determine the energy value of phytase addition to the diet of pigs.