New corn with higher phosphorus digestibility when fed to hogs may help thwart water pollution.

Secretary of Agriculture Dan Glickman calls low-phytate corn, "great news for those of us who want to reduce the amount of nutrients running into our waters."

Developed and patented by Victor Raboy, a USDA-ARS geneticist in Aberdeen, ID, low-phytate corn contains less phytic acid than does regular corn. Phytic acid stores phosphorus in a form unusable by one-stomached animals such as hogs and poultry.

When swine or poultry eat regular corn, the undigested phosphorus ends up in manured soils. Excess phosphorus in soil can reduce grain yields and harm water quality. Phosphorus runoff is suspected to be the cause of excessive algae blooms in some bodies of water, including the Chesapeake Bay.

Cattle and other animals with multiple stomachs have natural enzymes that break down phytic acid. Feed for one-stomached animals can be treated with similar enzymes, but low-phytate corn could be a less expensive option, according to USDA scientists.

In USDA-ARS studies, low-phytate corn plants cut phosphorus in chicken and hog manure by 25% to 40%.

USDA-ARS is negotiating licenses with seed companies to develop low-phytate hybrids. To date, Pioneer Hi-Bred International and Dekalb have licensed the new technology, says Raboy.

One low-phytate hybrid, developed jointly by Pioneer and USDA-ARS, was tested by Gary Allee, a University of Missouri-Columbia swine nutritionist. It boosted the availability of phosphorus five-fold compared to normal corn, reducing phosphorus in hog waste by nearly 40%.

Allee compared the performance of hogs fed low-phytate corn to that of hogs fed regular corn with an inorganic phosphorus supplement. There was no difference between the two groups in rate of gain, backfat, feed efficiency or carcass value. The low-phytate corn actually showed a slight advantage in the loin area, probably because of improved amino acid availability.

The results were consistent all the way from 20-lb pigs to 260-lb market hogs. No adverse effects from feeding low-phytate corn were seen.

"This is a tremendous success story of the corn industry asking what it can do to genetically improve nutritional value of corn for pigs," says Allee. "It's one of the most exciting things I've seen in the last few years.

"My crystal ball says that, in the future, corn producers will probably know the end use for corn before it is planted. We will see trait-stacking that will allow a pork producer to buy low-phytate, high-oil, high-starch hybrids for hog feed."

Low-phytate hybrids should be available in two to three years.