Leopold Center for Sustainable Agriculture

Project seeks winning combo for DDGs, grazing operations

Back to Leopold Letter Fall 2009

By MARY SWALLA HOLMES, Special to the Leopold Letter

To some, it’s a simple formula. As demand from the biofuels industry increases the demand for corn, corn acres go up and pasture acres go down.

For individual farmers, it’s a more complicated equation. They always are looking for ways to maximize the economic potential of their farming operations while retaining the long-term sustainability of their land. So Ron Dunphy, who grazes beef cows on 600 acres in Union County, was happy to participate in on-farm trials that supplemented his pasture-fed cattle with dried distiller’s grains (DDGs).

“As it happened, that year we’d had lots of rain and the pasture was in great condition. We had two groups of cows, one that was supplemented with cubes of DDGs and one group that was only on pasture. In the end, there was no difference in scores for condition or the number of pregnancies for the two groups. In that particular year, under those conditions, supplementing added costs and did not improve pasture conditions,” said Dunphy. “But this year, it has been very dry here, and the pasture is short, so in these conditions, it would make sense to supplement with DDGs.”

Dunphy went on to say that the form and cost of the DDGs makes a big difference. “A cubed product such as I used in the on-farm trial was easy to use. I picked it up at the local elevator weekly and delivered it to the cows daily. But if it is in the bulk form, which is finely ground and dry, it is difficult to handle and the costs in labor add up quickly. You also have more loss in the pasture, due to wind and trampling.”

Dan Loy of the Iowa Beef Center and ISU Extension beef specialist Joe Sellers led the three-year research project funded by the Leopold Center Ecology Initiative. They explained that through the course of the study, the availability, packaging and cost of DDGs changed quite a bit.

Many products tested
“We were able to evaluate several different types of products,” Sellers said. “When we first started the research, cubes were available, but they didn’t hold together well because the oil content was too high. By the second year, the cubes had gone up in price and the only cost-effective product was the dry DDG meal. This form was difficult to work with in a pasture situation. It works fine in feedlots with bunkers, and was getting a lot of use there, but we were interested in supplementing cows on pasture.

“Then, some of the new generation ethanol plants began using ‘fractionation’, which means that they pull out the oil content of the corn seed, as well as the starch. Once the oil is gone, then the DDGs can be pelleted and cubed in a cost-effective manner, so we used that product for the last year of the study,” he said.

Research leds to new materials
A new summary of the research details the three on-farm demonstrations that evaluated systems of feeding and delivering DDGs to beef cows in pasture and in corn stalk grazing situations. Researcher Loy noted other factors for producers to consider.

“These demonstrations show the feasibility, palatability and practicality of using co-products to provide additional nutrients to beef cows in grazing-based production systems,” he said. “Of course, every production system is different, and each producer needs to assess their pasture situation and weigh the costs of labor and fuel, along with the form and cost of the DDGs. Distance from an ethanol plant can be a factor, too. Inclement weather can be a limitation in getting it to the field or pasture.”

In addition, two stocker grazing trials at the ISU McNay research farm evaluated the level of supplementation on pasture substitution and stocking rates. These studies established that levels of supplementation must be greater than .5 percent of bodyweight in order to reduce pasture consumption. At lower supplementation rates, cows simply increased their overall intake, increasing nutrient consumption and gaining extra condition, but consuming pasture at their normal rate.

“At the lower supplementation rates, the cows just consumed additional calories, and there was no improvement to the condition of the pasture, so that was neither a financial nor an environmental gain in that case,” explained Sellers. “It makes the most sense when pasture is limited, either in acres or because of condition.”

He warned that many pastures this year have had trouble with fescue toxicosis. “Fescue can become infected with an endophytic fungus Acremonium coenophialium, which in turn affects the palatability and the rate of gain for the cows,” he said. “In a pasture with infected fescue, supplementing with DDGs this fall would help a lot to dilute the effects of the toxins and improve the rate of gain.”

As the biofuels industry continues to grow in Iowa, availability of DDGs likely will increase and prices decrease. This new research will provide a useful tool for farmers with cows on pasture or grazing cornstalks as they weigh the benefits and costs of supplementing with DDGs. 

Back to Leopold Letter Fall 2009