Jury’s still out on high oil corn


WILMOT, Ohio – With the introduction of high oil corn varieties into the market, livestock producers and dairymen in particular need to ask themselves whether it is cheaper to grow or buy fat for their feed rations.

Bill Weiss, professor with The Ohio State University, told producers attending a recent regional agronomy clinic at The Amish Door in Wilmot that while there are benefits to producing high oil corn, there are also some risks involved.

Weiss said there have been trials where high oil corn varieties didn’t pollinate as well as standard corn varieties and the yield difference is about 8 percent to 10 percent less than standard corn.”

On the plus side, high oil corn is about 31/2 to 4 percent higher in fat than regular corn, so producers need to compare high oil corn to other feed ingredients on an energy basis, Weiss said.

High oil corn has about 1.9 pounds of fat more per bushel than regular corn, he said. It also has more oil and more protein, but it has less starch. There is no change in the overall digestibility of high oil corn compared to regular corn.

Weiss cautioned producers to pencil it out first before switching to high oil corn for their rations, due to a good market for feed grade fat.

“The cost of energy should be the basis for your decision,” he said. “Corn oil is less valuable than other sources of fat such as tallow for dairy cows.”

Weiss said that producers should be aware that corn oil is toxic to rumen bacteria. It kills off the rumen bacteria, which hurts fiber digestion. Corn oil is a high energy nutrient, but the gain in fat energy is offset by the loss of fiber energy.

Weiss said producers should be particularly cautious about using both high oil corn and high oil corn silage in their ration, as it will increase the amount of corn oil in the diet by about 1.3 percent.

Studies show that high oil grain and corn silage rations result in considerably reduced milk protein percentages, he said. “But studies also show that it doesn’t have a big effect on protein yield or milk fat.”

Weiss said milk production response is consistent with changes in the energy value in the ration. You may have to modify the fat supplementation in the ration if you are feeding high oil corn, limiting vegetable fats to about one pound per ton of feed.

Weiss said that the economic value of high oil corn depends on what type of energy is needed in the ration. For example, if just energy is needed in the ration, high oil grain is worth about 8 cents more a bushel than regular corn, while high oil corn silage (3.5 percent dry matter) is worth $1 more per ton than corn silage from regular corn.

On the other hand, for diets that require energy from fat such as that for market hogs or broilers, high oil corn is worth about 13 cents a bushel more than regular corn and high oil corn silage is worth about $1.45 per ton more than corn silage from regular corn.

“If you are raising high oil corn, you can usually sell it for a better premium than you would receive if you fed it to your dairy cows,” he said.

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