(Editor’s note: Second of two-part series on feeding distillers grains and gluten.)
Distillers grains (DDG) aren’t the only game in town when it comes to supplementing beef diets. Gluten feed also works well as a source of protein and energy in a wide range of cattle diets for feedlot cattle, backgrounded calves and cows/heifers, but it doesn’t get all the attention given to DDG.
Gluten feed is a co-product of wet milling plants that produce human-grade product such as starchand high-fructose corn syrup that is used to sweeten many soft drinks. Gluten that can be fed to cattle comes in a wet mash, usually either a 40 or 60% dry matter product, or in a dry (approximately 90%) pelleted form.
Gluten feed can reduce the roughage needed in feedlot diets and can be used to replace high-quality hay or stretch forage resources in cow-calf operations. “Distillers grains are not as effective at reducing forage needs in feedlot rations but can also be used in combination with low-quality forages in cow-calf operations,” explains beef nutritionist Ki Fanning, PhD, Great Plains Livestock Consulting, Eagle, Neb. “The past three years, co-products have been more economical to feed than high-quality forage. Gluten is a better roughage replacement than DDG and in dry years can help extend grass or hay better than DDG.”
“Distillers is getting much of the press and is known in the industry because of all the new plants being built,” Fanning notes, “but gluten has been around for over 100 years and is relatively unknown and, therefore, a better price per unit of energy in many locations.”
Gluten will not have the growth that DDG will because of the smaller number of plants and the lack of subsidies, even though some of those wet milling plants have expansion plans or are in the process of expanding.
Gluten is useful as a protein and energy source in most beef cattle operations that are close enough to a plant to be economical.
Gluten contains 20% crude protein compared with 30% from DDG and is about 80% degradable intake protein compared to only about 50% in DDG. “The energy value of gluten feed varies with dry matter and source,” says Jeremy Martin, PhD, Great Plains Livestock Consulting, Lexington, Neb. Gluten makes a great supplement because of its high digestibility, low starch concentration (which is detrimental to fiber digestion) and high protein content. Gluten does have a large portion of its protein as degradable protein; therefore, if the diet needs more degradable protein, it meets those needs faster than DDG.
Gluten is high in phosphorus and needs to be correctly balanced with a high calcium mineral to prevent any urinary calculi problems. Phosphorus is very important in growth and development of animals as far as energy storage and structure of muscle and bone. It has increased in cost significantly over the last several years and is the major cost of range mineral. “By feeding gluten feed with a correctly balanced range mineral, a significant amount of money can be saved on the mineral costs,” Fanning adds.
Gluten feed can cause polio problems if the total dietary sulfur level is not monitored and thiamine is not supplemented. Gluten can actually improve conception rates if it is used to increase body condition score and meet the protein and energy needs of the animal. Gluten feed can be fed at a higher rate more safely than DDG due to the fat level in DDG; however, that level would rarely come into play prior to meeting the requirements of beef cows.
Sourcing and storing
Gluten does vary widely from plant to plant, and some plants have greater variability from day to day than others. Moisture content is, of course, the greatest determining factor of the economics of feeding gluten feed. Martin suggests that producers make sure they characterize the gluten from the specific plant they source from.
Many of the same concerns exist with transportation and storage of gluten as DDG. “Shelf life is probably three to five days in the summer and seven to nine days in cooler weather,” Martin explains. “Gluten can be stored in bags or silos like DDG, and the 60% dry matter product can be bagged readily without addition of other feedstuffs.”
When stored in silos, it is important to exclude oxygen by packing it well, which may require the addition of dry feed with gluten feed of lower dry matter content. Because gluten comes from a food-grade plant, aflatoxins may not be an issue unless there are storage problems (see molds sidebar).
Wet gluten can be mixed with corn silage during the ensiling process or can be packed in a silage bunker with a preservative to store for extended periods of time. The wet product is delivered on dump, belt or live-bottom trailers.
Economics of gluten
In the past, if you were the same distance from a gluten plant and a distiller’s plant, gluten was a better economic value. This was mainly due to the demand for DDG by swine, poultry, pet food manufacturers and dairy cattle. “The first three cannot use gluten feed, and, therefore, the demand for gluten is not as great,” Fanning says. “With the number of dry milling plants being built, that may change, and the distance from a plant plays a role on which product you use.”
Martin says Nebraska research suggests producers may be able to save money by using gluten feed in conjunction with standing forage resources to limit the amount of harvested forage fed to pregnant heifers.
Gluten feed, relative to DDG, has been inconspicuous due to the number of dry milling plants being built, many owners of beef cattle own shares in plants, and the amount of press and advertising the ethanol industry receives.
“In these competitive times, nutrient tests of forages and proper diet formulation can now be done very inexpensively and can save a producer a lot of money,” Fanning says. “Custom mineral mixes to complement gluten feed can enhance performance at a lower cost than standard floor-stock minerals.”
Properly balanced diets are important for the health of cattle and the effectiveness of vaccinations and antibiotics. Additionally, many veterinarians are being asked to help with dietary recommendations; therefore, a basic knowledge of these benefits, risks and guidelines would be beneficial.
Veterinarians have a great opportunity to help prepare their clients to utilize byproduct feeds as they become available in many areas. “Correctly balanced rations and supplements are essential, and many veterinarians get questions about byproducts on a daily basis,” Martin explains. “Therefore, I think it’s critical the veterinarians are aware of the potential uses, benefits and possible risks that are present with any of these ingredients.”
AIP and WDG?
Steve Ensley, DVM, PhD, Veterinary Diagnostic Laboratory, Iowa State University, says that several veterinarians in Iowa believe there is an association between acute interstitial pneumonia (AIP) and mold in wet distillers grains. “We’re seeing AIP in Iowa, and a particular sweet potato mold has been shown to cause clinical signs of AIP,” he explains. 4-ipomeanol, a furanoterpene produced in sweet potatoes (Ipomoea batatus) by the fungus Fusarium solani, can damage the pulmonary epithelium and produce lesions characteristic of atypical interstitial pneumonia in cattle which consume moldy sweet potatoes.
However, Ensley notes that if it’s not a mold problem contributing to AIP, that it is also believed it may be due to high sulfur levels contained in corn co-products. “Cattle eructate hydrogen sulfide gas, and the inhalation of that gas may cause lung damage,” he says. “Sulfur is normally absorbed through the rumen wall, but eructated hydrogen sulfide gas can damage the respiratory cilia.” Ensley adds that this has not been substantiated at this time. When cattle exhibiting signs of AIP are taken off the co-products and fed forages, they seem to improve.
Another problem that is being investigated is the potential link between high-sulfur-containing co-products and bovine foot problems and hoof wall integrity. “High sulfur may cause hoof problems because it can potentially tie up zinc and even copper,” Ensley says. “Some researchers are looking at high-sulfate feeds and how they may contribute to zinc or copper deficiencies.”
Some issues Ensley believes the cattle industry needs to look for in the coming year, as a result high inclusion rates of co-products, are re-breeding (especially if there is copper deficiency) and lower reproduction rates, as a result of high-sulfur-content feeds, and vitamin E and selenium deficiencies which are being seen in sheep where, potentially, the elevated sulfur in the diet is decreasing the availability of vitamin E and selenium. “We will be monitoring this in cattle because we’re using a lot more corn syrup in cow diets this year as a cheap source of feed.”
If veterinarians suspect problems caused by molds, mycotoxins or other substances in feeds, Ensley encourages them to send samples to a diagnostic lab that can evaluate the feed.
Body condition scores
Body condition scores (BCS) of beef cattle at calving will vary somewhat with geography, forage availability and cattle breed. Beef nutritionist Jeremy Martin, PhD, prefers a BCS at or above 5 at the time of calving. “Body condition score at the time of calving is more important than the fluctuation in BCS, in my opinion,” Martin explains. “In other words, thin cows that gain BCS during the last third of gestation and reach a BCS of 5 by calving breed back as well as cows that are maintained at a 5 year-round. Research indicates cows that calve at BCS below 5 may experience longer postpartum interval, so I prefer to have a herd average BCS of 5 or greater at the beginning of the calving season for cows.” Heifers need to be .5 to 1 BCS higher at the beginning of the calving season due to their additional nutrient requirements for growth.
Beef nutritionist Ki Fanning, PhD, likes to see cows closer to a BCS of 5.5 or 6 at calving time. “They can drop to 5 to 5.5 at breeding and should not fall below 4.5,” he says. Depending on the feed prices and time of calving, he adjusts these levels. Fanning likes to see cows at BCS 5.5 prior to cold weather, and adds that first-calf heifers need to be on the high side of these recommendations.
Monitoring BCS year-round is ideal because producers identify problems early and have more opportunity to manage for their target BCS before calving. This is important because nutrient requirements increase in the last third of gestation and are even greater during early lactation, relative to any other time in the production cycle. “In my opinion, annual fluctuation in BCS of two units is acceptable as long as a reasonable minimum BCS is maintained,” Martin says. “For instance, fall-calving cows in the Midwest can experience fluctuations of two BCS units simply because they are in such good condition during the summer grazing period.”