Xingen Lei (right), with his team of assistants, uses pigs for phosphorous research.

When Animal Science Professor Xingen Lei surveys our system for food-producing animal agriculture in an increasingly sensitive environment, he sees two things wrong: the gastrointestinal tracts of swine and poultry (as well as pre-ruminant calves) lack the enzyme to digest phytate-phosphorus in plant-based feed, so tons of phosphorus are excreted in manure to become an environmental pollutant. Yet, inorganic phosphorus—an essential supplement in animal feed—costs more and more as natural deposits dwindle.

His answer to the two-pronged problem is a patented, protein-engineering approach that puts bacteria and yeast to work producing the enzyme phytase, which could change food-animal production practices worldwide and help keep phosphorus in its place. When chickens and hogs get AppA2 phytase in feed supplements—such as Optiphos, one of the licensed applications of the Cornell technology—the animals can digest and utilize phytate-phosphorus in their feed, their manure contains less phosphorus waste, and their bones are strengthened.

The Cornell-developed phytase is said to be three to four times more effective in swine and poultry diets than other commercially available phytases. This new generation of phytase was approved by the FDA as a feed additive in 2005 and is being used in the U.S., Asia, and South America. It has the potential to help keep 90,000 tons of phosphorus a year from polluting the waterways and to reduce U.S. animal-producers’ supplement bills by $360 million a year.

The experience in phytase production has the Cornell animal scientists looking at deficiencies in another animal, the human kind. Between 30 and 50 percent of the world’s population suffers from nutritionaldeficiencies of iron and zinc—and again, phytate-phosphorus in plant-based f ood is what’s wrong. Phytate in foods reduces the absorption of dietary iron and zinc in the human digestive system.

Research in Lei’s Cornell lab (with hogs, not humans) demonstrates that supplemental phytase releases phytate-bound iron in corn and soy for hemoglobin synthesis. Because research at other institutions has shown the same effect of phytase in humans, Lei and his international collaborators in the plant world are currently testing a reasonable proposition: with genetic-engineering help from molecular biologists, crop plants such as rice should be able to produce the phytase enzyme themselves—and for the humans and other animals that consume the plants. (Roger Segelken)

• OptiPhos