Wheat midds, corn gluten feed, dried distillers' grains and soy hulls are some of the byproducts that are common protein supplements, says beef nutritionist Greg Lardy of North Dakota State University’s Department of Animal and Range Sciences.

Lardy has found many byproducts work well in cattle diets, and says, "There aren't too many nutritional mistakes you can make when feeding byproduct, because the starch has usually been removed by the ethanol or milling industry, leaving just fiber and protein." However, there are some considerations:

First, it’s important to identify the correct nutrient deficiency that needs to be supplemented in the herd. For instance, Lardy says if degradable protein for a dry pasture situation is needed, oil seed meals, such as canola meal or sunflower meal — which typically contain 30-40% crude protein — may be a good choice. Conversely, soyhulls may not provide enough protein in some situations, he says.

He reports that another common mistake with byproducts is not taking into account some of the hidden costs, particularly freight and transportation.
"In some scenarios after paying for delivery, a locally available commercial supplement may have been just as economical," he says. "Most people who use byproducts effectively are aggressive at negotiating. They also look at volume discounts through railcar loads or back-haul opportunities."

Also, take into account storage considerations. For instance, wheat midds should be stored in bins with an aeration fan to keep mold development to a minimum.
And, depending on the product, pellet quality can be an issue. "Oilseed meals often pellet better, whereas dried distillers' grains are difficult to pellet due to fat content," Lardy says.

Final Tips
Whenever supplementing the cowherd, here are some final points to evaluate:

Watch your forages. Texas A&M's Ed Huston advises paying close attention to the forages available: "Gain all the knowledge you can on plant species, their nutrient content and growth cycles." Testing forage nutrient content is also a good idea but, once a history of forage analysis is developed, it doesn't need to be done annually, he adds.

Additionally, Huston advocates using a rotational grazing system and trying to match peaks in available forage nutrients to the time of the cow's greatest nutritional needs — usually shortly after calving through breeding.

Growing forages are typically highest in nutrient quality. Dormant forages will support dry, gestating cows, but are usually not suitable for lactating cows, says Lardy.

Consider sorting. "The better you can sort animals into uniform feeding groups to better target their needs, the better off you are," says Huston. For example, he suggests sorting thin or younger cows from older boss cows. "When fed in one large group, intake can be variable. Often, those who need nutrients the most get the least due to the bully factor," he adds.

Evaluate different protein types. Huston suggests utilizing a natural protein when possible. Urea or non-protein nitrogen is only about 75-90% as effective as natural proteins. So unless there is a real cost savings, use natural protein based on a price vs. protein content ratio, he says.

Lardy suggests considering field peas, which contain 22-24% crude protein, as an option as well. And, don't underestimate alfalfa hay. Year in and year out, alfalfa hay is an inexpensive source of supplement protein, they say.

Supplementing Energy
While protein supplements work to complement available forage, energy or grain supplements may be needed to stretch forage supplies or boost performance on stockers. "Energy or grain supplements are typically used as a substitute for forage," says Montana State's Jan Bowman.

For instance, if forage is in short supply due to drought, grain could be supplemented to take grazing pressure off the grass. "This can be economical if grain prices are low," Bowman says.

Supplemental grain may also be needed for stockers if the forage digestibility is lower than the animal's growing requirements.

Wheat midds and soyhulls can be used to stretch forage supplies as well.
"These products generally contain low amounts of starch (soyhulls don't have any), but contain digestible fiber, so the negative effects of starch on forage digestibility are not an issue," says Lardy.

But, extra energy usually isn't necessary for cows grazing medium- to high-quality forages. When forage is adequate, feeding grain can decrease the animal’s intake and digestibility of the forage — and cost you money, says Texas's Huston.