Experiment station researcher looking for missing links in corn

A scientist with the Texas Agricultural Experiment Station said the development of corn with improved protein quality would reduce the need for soybean additives when feeding corn to swine and poultry. Corn is deficient in two essential amino acids, lysine and tryptophan. Increasing the relative content of these two amino acids is the project of corn researcher Dr. Javier Betran.

The resulting nutritionally-improved corn, known as Quality Protein Maize, could have positive implications not only for livestock feeding, but also for human consumption – particularly in developing countries in Latin America, Africa and Asia. There, corn is the main food staple.

Nobel laureate Dr. Norman Borlaug, a distinguished professor of international agriculture at Texas A&M University, has said new technological advances are key to helping developing countries meet future food supply demands.

He has said his greatest worry is Africa, because of its high rates of population, little application of improved technology and escalating food deficits. Borlaug and the International Center for Wheat and Maize Improvement are promoting the development and adoption of Quality Protein Maize in developing countries around the world.

While better protein corn would help human nutrition, it would vastly improve feeding costs in segments of animal agriculture by reducing the need of better protein supplements, Betran said.

“Corn is mainly used for animal feeding in the United States,” Betran said. “About 65 percent goes into animal feed. If you feed poultry the same corn, you need to supplement it with another product. Soybeans or synthetic lysine are commonly used to provide the protein quality that the corn doesn’t have. Our approach is to improve corn to enhance the content for these two essential amino acids.”

In the early 1960s, scientists discovered a “mutant” maize that contained protein with nearly twice as much lysine and tryptophan as found in normal maize. Called “Opaque-2 maize,” the protein had a 90 percent of the nutritive value of the proteins in skim milk – the standard against which cereal protein is normally measured.

But it was later discovered by incorporating the “Opaque-2” mutation to corn, it yielded less grain. It also had a higher moisture content and was more susceptible to fungal and insect infestations.

“Those facts right there are not well received by farmers,” Betran said. “Our challenge is to put together the protein quality with a competitive yield grain. We want it to be a value-added trait that perhaps has good appealing characteristics. Farmers are not ready at this time for something that has the protein quality but is not a high-yielding variety.”

The research includes another component — making a variety that is less susceptible to aflatoxin, which has been a nemesis for Texas farmers the past decade. Aflatoxin, a mold that commonly develops during periods of drought, can cause illness or death in livestock that consume it.

“We want to have something that is high quality, but yet have low-risk to aflatoxin and it is adapted to our growing conditions,” Betran said. “We are selecting and breeding materials from different origins to develop a value-added corn with a desirable combination of traits.”