Texas dairy cattle may soon be putting out more milk for consumers and bringing more dollars to their producers, fueled by an ethanol by-product, according to a Texas Cooperative Extension specialist.

Distiller's grain, or the substance left after ethanol production, will increase in availability as ethanol plants begin opening in Texas in 2008, said Dr. Ellen Jordan, Extension dairy specialist in Dallas.

"As we look at the current research, we see there is a potential by incorporating distiller's grains into our rations to increase milk yield, as well as feed efficiency, in the dairy cows," Jordan said.

Nationwide, only about 45 percent of the dairies use some level of distiller's grains, Jordan said.

"But as we have more ethanol plants and their production of distiller's grains, we're trying to increase the utilization of those products," she said. "Research shows now that we can have up to 20 percent of the dairy cow's ration come from distiller's grains, if the price is right."

The distiller's grains would replace soybean meal and potentially some corn - depending on the protein and energy value of the distiller's grains, Jordan said. Currently, Texas is a net importer of these feedstocks primarily from the Midwest, but distiller's grains might provide an advantage when produced locally.

The research to date indicates both the milk fat yield and the milk protein yield also could be increased by feeding distiller's grains, she said. This is especially important to the cheese plants, because it increases the yield of cheese in the manufacturing process.

"We do need to be aware though as we change forages, we can have some different responses," Jordan said.

The feed efficiency with distiller's grains is higher when feeding straight alfalfa hay than when feeding corn silage as the forage source, she said. Results from small studies also indicate milk production, fat yield and protein yield may increase when feeding alfalfa hay as the forage source in rations with distiller's grains. One issue dairy producers or consultants should be aware of when adding distiller's grains to rations is that lysine will be the limiting amino acid in corn silage-based rations, Jordan said, while methionine may be the limiting amino acid in alfalfa hay-based rations which incorporate distiller's grains.

These key amino acids might need to be supplemented from outside sources to optimize milk production, she said.

Product consistency in the ration is important in dairy production, Jordan said. This includes the use of a constant feedstock, whether it is corn, grain sorghum or a defined mixture.

"If it is consistently dried the same way for the same time at the same temperature, that is good," Jordan said. "If you overheat it, you can make the protein indigestible and it will pass through the cow without providing nutrient value."

She said while dairy producers have had experience with distiller's grains for some time, the product from ethanol plants has changed over the past five to 10 years.

Knowing the nutrient analysis is important when using distiller's grains as a feed source, she said. Using actual protein levels for formulation of the ration provides cows with the nutrients they need to optimize production without overfeeding protein.

If the fat content is too high and adjustments aren't made, it can cause rumen upset, Jordan said. As a result, the cows eat less and decrease their milk production.

The mineral levels also have changed, she said. Phosphorus levels are higher, which could mean less supplemental phosphorus needs to be added to rations.If this adjustment isn't made, more acreage may be needed to distribute the manure from these cows to allow fertilization of crops at agronomic rates.

Producers also need to be aware that the production process for distiller's grains does not destroy aflatoxins in corn, she said. Instead, it increases the concentration. Therefore, producers must make sure the suppliers of distiller's grains are monitoring aflatoxin levels in the ingredients they use.