NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665
September 30, 1999
Hard red spring and durum wheat can be used with good success as a concentrated source of nutrients for dairy cattle and in starter rations for dairy calves, says a dairy specialist at North Dakota State University.
"A considerable amount of wheat has been damaged by weathering this year, but as long as the grain is not moldy, that damage has little effect on feed value," says J.W. Schroeder of the NDSU Extension Service. "However, wheat is not a common ingredient in dairy rations and many producers have little experience feeding it. If they're going to feed wheat, they need to be aware of a few precautions."
For example, feeding finely ground wheat should be avoided as the gluten causes it to become gummy and form sticky masses in the rumen resulting in digestive upset. Gluten is the protein found in wheat that is responsible for the pasty nature of wet wheat flour which is important to the baking industry.
To avoid problems when feeding wheat, limit wheat to about 35 to 40 percent of the total grain mixture. If wheat is fed separately, in addition to the regular grain mixture or if it is added to silage as supplemental grain, the amount should be limited to about 10 to 12 pounds of the total daily intake per cow, Schroeder recommends.
Add wheat to the ration gradually, he cautions. Adding wheat too rapidly can cause cows to go off feed because the rumen microbes need to adjust to the different feed. One approach is to add wheat gradually over a two-week period until wheat makes up 20 percent of the grain mixture. Then, after the initial adjustment period, the wheat content can be increased up to 40 percent of the ration.
"Keep an eye on your milkfat test. A good indicator of excess wheat in the diet is reduced milkfat," Schroeder says. "It is not clear why milkfat drops, but it's a reaction that's frequently observed. If you feed a total mixed ration, there is less chance of this milk component being affected."
How well does wheat fit in the dairy ration? The nutrient content of wheat and shelled corn are similar, although wheat is usually 30 to 50 percent higher in crude protein, Schroeder says. For dairy cattle, wheat, corn, and commonly used plant protein supplements have similar energy contents. With wheat's higher protein, adding it to the ration usually means the protein supplement can be reduced. The calcium and phosphorus content of wheat are about the same as corn; both are very low in calcium. Using wheat in the ration does not change the mineral supplementation required.
In calf starter formulations, wheat has about the same feed value of shelled corn. Because starter intake is usually on a limited basis for calves, the amount of wheat substituted for shelled corn in the mixture does not pose a problem.
Feeding sprouted (not moldy) wheat requires few additional adjustments, Schroeder says. Slightly sprouted wheat is almost equal to non-sprouted in feed value. Shrunken and shriveled wheat, similarly, can be valued by the degree of loss. Bushel weight is the best measure value of shrunken and shriveled wheat. Sprouted wheat weighing 56 pounds per bushel should be almost equal to 60 pound wheat in nutrients and can be even more palatable.
Wheat as low as 50 to 52 pounds will usually be slightly higher in protein, but energy will be lower. If additional wheat is fed to make up for lower energy, gains will be about the same but feed efficiency somewhat poorer. It is likely that the usable energy is 5 to 9 percent less available in lightweight wheat. The greatest effect will be reflected by how and in what combinations the wheat is fed.
"The bottom line," Schroder says, "is to allow cows to adjust gradually, don't overfeed and test grain for protein content. Wheat varies considerably in its protein content."
###
Source: J.W. Schroeder (701) 231-7663
Editor: Tom Jirik (701) 231-9629