It's actually not quite a complete feed. But a mixture of distillers grain and chopped corn or alfalfa makes a nutritious, economical silage for dairy cows, says Alvaro Garcia, South Dakota State University extension dairy specialist.
“Ensiling distillers grain in combination with forages stretches out forage supplies while improving the nutritive value of the blend,” says Garcia.
In addition, wet distillers grain chunks can be difficult to break up in winter. That problem is greatly reduced when the grain is ensiled with a forage.
“An added benefit of the blend seems to be the greater production of acetic acid, which improves preservation and aerobic stability at feed-out,” says Garcia.
Eastern South Dakota has five ethanol plants, so distillers grain is readily available in that area. Dairymen Greg Moes and Dustin Ludens tried harvesttime mixing in 2002, and Garcia suspects that others did it this year.
During the past 18 months, Moes, of Goodwin, SD, has achieved success mixing wet distillers grain with various crops for his own 300 Holsteins plus cows owned by other South Dakota producers. He operates the dairy in partnership with his brother and their three sons. They also have a custom forage chopping and bagging business, plus they sell TMRs to others.
“Collaborating with South Dakota State University since March 2002, we have experimented with mixing wet distillers grain with corn silage, soybean hulls and haylage,” Moes says. “Haylage plus distillers grain works the best for us because it comes out of the silo bag fresher than the other combinations. Plus, we have 1,000 acres of alfalfa hay available all summer.
“Our cows each get 8 lbs of wet distillers grain/day, so we use about 10 tons/week. Adding it to our haylage creates a product that contains protein, fiber and energy all in one.”
Milk production is up 4 lbs/cow/day because of this ration, Moes reports. “Because of the fat and phosphorus in the distillers grain, we save about 30¢/cow/day on mineral costs,” he says.
Dustin Ludens milks 200 cows near Geddes, SD. In August 2002, below-average rainfall had him worried about low grain levels and high nitrate levels in his corn silage. So he decided to blend wet distillers grain as he harvested corn to reduce nitrate concentration and boost protein and energy levels in his silage.
It was a good plan because, ultimately, Ludens' 2002 corn yielded a pitiful 5-8 bu of grain per acre. After consulting with his nutritionist, Ludens blended 30% wet distillers grain with 70% corn silage by weight.
“We loaded all the corn silage and the distillers grain into our vertical mixer in 6-ton batches, then packed the mixture into bunker silos,” he reports.
He mixed 50-60 batches of silage a day over a 10-day harvest period. One drawback was the need for additional labor.
“Normally we have one person cutting the corn in the field, two people hauling it back to the dairy in trucks, and one person pushing and packing the corn into the silo,” Ludens relates. “We needed an extra person to load the corn and distillers grain into the mixer wagon.”
Another problem was extra wear and tear on the mixer wagon.
His finished product contained 17% crude protein, 30% ADF, 40% NDF and 0.74 Mcal/lb net energy lactation.
“This total mixed ration has worked very well in lactating cows, but has been difficult to use in dry cows and heifers,” Ludens says.
That's because the mixture is so high in energy that dry cows and heifers gain too much weight, says Garcia. “Heifers gained 2-3 lbs per day, even when the TMR was fed mixed with a stemmy brome hay.
“A fermentation analysis showed high levels of acetic and lactic acid, which could have been caused by the low pH levels of the distillers grain,” he adds. “That could, in turn, remove the need for adding inoculants.”
While high concentrations of acetic acid improve the shelf life of ensiled feed by controlling the growth of mold and yeast, research in the past has shown that it can cause a reduction in dry matter intake, Garcia notes.
“In more recent research at the University of Wisconsin, inoculating silages with acetate-generating bacteria increased bunk shelf life of the feed and had no effect on feed intake in lactating dairy cows,” Garcia says.
“Using wet distillers grain was a good experience for us because it saved money and gave us a way to use our corn,” Ludens points out. In his area, wet distillers was priced at $20/ton earlier this summer, compared to $140/ton for the dry counterpart.
“The cows really seemed to like the new ration. Because of the additional moisture, the distillers grain stuck to the other feed components, so it was hard for them to sort it out.”
Milk production neither increased nor decreased with the innovative TMR, Ludens reports. “My herd averages about 78 lbs/cow/day on 2X milking,” he says.
Ludens' successful experimental blend lasted until June 1 this year, then he fed corn silage that was left from the previous year, plus dry distillers grain. He's contemplating the possibility of mixing wet distillers grain and corn silage again, depending on cost and availability. But he hopes to find an easier way to mix it.