Released from phytate
Phytate holds 60–72% of the phosphorus in soybean meal and corn.
Unlocking the minerals already in the feed.
Most of the phosphorus in grain and oilseed meal is locked in phytate, a compound birds cannot break down well. Phytate also binds calcium, zinc and iron. Farmers pay for minerals twice: once in the grain and again as supplements to make up for what the bird cannot use.
Mineral-solubilising bacteria in the gut produce phytase enzymes that break phytate apart, and organic acids that keep calcium and other minerals soluble where they can be absorbed. The bird gets more from the same feed, and less phosphorus ends up in the litter and the soil.
This has been shown in principle: when broilers on a phosphorus-deficient diet were given Lactobacillus strains engineered to produce phytase, they grew as well as birds on a diet with adequate phosphorus.
Where feed phosphorus is locked up
Share of total phosphorus held as phytate versus other forms.
Corn72% phytate
Soybean meal60% phytate
Bound in phytate
Other forms
Shell and bone
Probiotics increased eggshell thickness and weight in laying hens.
Freed from binding
Breaking down phytate also releases the trace minerals it holds.
Only 10–30% of the phosphorus in these ingredients is available to poultry. Source: Mississippi State University Extension. The proportions shown are illustrative, not measured results.