The Hogs and Cattle Chime In On GM

University research shows cattle have no preference for GM or non-GM feed.

The following information corresponds with the article "The Trait Debate." You can find the article in Farm Journal's 2013 Seed Guide issue.

Some livestock producers believe that non-genetically modified (GM) corn provides animals with healthier feed, but university researchers are not always in agreement.

Rumors still abound of cattle overlooking GM cornstalks to eat non-GM cornstalks, and sows fed GM corn having higher instances of abortions.

Two years ago, West Bend, Iowa, hog farmer Mark Fehr says he started planting more conventional corn because his soil was not maintaining its mineral health due to continued use of Roundup.

"I had the best corn I ever had last year, during the drought, with non-GM corn," Fehr says. "My average yield was 217 bu. There is no yield drag with non-GM corn that I’ve found."

Good yields and lower seed costs reinforced Fehr’s decision, especially since he feeds his corn to 1,400 sows in his farrow-to-finish operation. There are nutritional benefits for feeding hogs non-GM corn, he adds.

"We’ve been using non-GM hybrids for two years. Usually we break with PRRS at least once or twice every year, but we’ve gone a whole year without an outbreak. That’s huge for us, and I think a large portion of that is better nutrition with non-GM corn," Fehr says.

Research results. University of Nebraska-Lincoln (UNL) researcher Terry Klopfenstein has heard all the rumors—he just doesn’t much put stock in them.

In the past 15 years, multiple university studies have found little difference in the feed quality of GM versus non-GM corn, he says. "We’ve done research on three levels—feeding grain to cattle in the feedlot, feeding corn silage to cattle in the feedlot and letting calves graze cornstalks after grain harvest," he says. "The GM changes to corn up to this point have resistance to insects and Roundup. Neither one of those affect nutritional value of either the corn grain or the residue."

In the third UNL study, a GM hybrid and the non-GM hybrid with the same genetic parent material were planted side-by-side. "We’d heard that cattle didn’t want to graze GM corn as well as non-GM. So we gave calves, which you would think would be more discerning than cows, a choice of which field to graze in," Klopfenstein says.

Each day, UNL researchers counted the number of cattle on the two fields. "It was even. About half the time they were on the control and half the time they were on the GM-corn field. It didn’t matter to them," he says.

A small difference did arise with Bt corn hybrids having less stalk lodging, Klopfenstein says. "The favorite feed for cattle is downed corn grain. When we counted ears, there were more down ears in the non-GM control fields. So, that might draw cattle to those fields at first entry.

"A farmer is going to do what is most economical in producing corn grain," Klopfenstein says. "Then he puts on his feeding hat. To me, there would be no advantage to using non-GM corn for livestock production."

Klopfenstein says the next step for researchers is to look at new hybrids that have changed nutritional properties—such as high-oil corn intended for biofuels.