Editor’s note: First of two-part series on feeding distillers grains and gluten.
Wet and dried distillers grains (WDG and DDG, respectively) have been around for a number of years, but recent increases in availability have increased the opportunities for cattle producers at every level to feed distillers grains.
With the current price of corn, acres normally used or forage production are being used to produce grain. “For the last four years, we have fed both lactating and gestating cows, as well as heifers and calves, WDG and either wheat straw or corn stalks during the winter and spring season,” says Ki Fanning, PhD, PAS, Great Plains Livestock Consulting, Inc., Eagle, Neb. “The production from these animals was at least as high as more traditional feeding.”
Because of the increasing importance of this feedstuff, veterinarians need to understand its benefits and drawbacks to help clients make it an effective part of feeding strategies. “This is another opportunity to become involved in the day-to-day management of an operation,” says Dan Goehl, DVM, Canton Veterinary Clinic, Canton, Mo. “In our practice, we have diligently tried to move from a pure medicine-type practice to being an information provider. This goes hand-in-hand with helping producers make decisions on EPDs, bull purchases, etc. We need to provide these services as well as get paid for them.”
Properly balanced diets contribute to the health of cattle and the effectiveness of animal health products. “Additionally, many veterinarians are being asked to help with dietary recommendations; therefore, a basic knowledge of these benefits, risks and guidelines would be beneficial,” Fanning suggests.
It is critical that veterinarians understand the opportunities and limitations present with supplemental ingredients such as distillers grains. “Veterinarians often have the most direct and frequent contact with producers and have the opportunity to influence management decisions,” adds beef nutritionist Jeremy Martin, PhD, Great Plains Livestock Consulting, Inc., Lexington, Neb. “As DDG use becomes more widespread in cow-calf operations, veterinarians must be aware of the opportunities and challenges associated with its use in order to provide the best possible service to their clientele. As with most ingredients, there are risks associated with feeding DDG, but these risks are easily managed and certainly do not outweigh the potential benefits and cost savings.”
Most ethanol plants prefer to sell wet distillers grains rather than dried, to avoid the cost of drying, Martin explains. “As ethanol production increases, and ethanol plants disperse geographically, more DDG will be produced to facilitate transportation further from the plants; and thus provide more opportunity for cow-calf producers to utilize DDG.”
More availability is good news for cow-calf producers in northeast Missouri where Goehl practices. Goehl’s producers are in the midst of the driest summer in nearly 25 years. Combined with the late spring frost and very low carryover of hay due to last year’s dry weather, it adds up to a precarious fall and winter feed supply. “Producers in this area are going to be forced into using alternative feedstuffs,” says Goehl. “The cow-calf producer traditionally has fed hay free-choice. This option is not possible when there is not enough hay to get through the year.”
Goehl says larger producers have been able to take advantage of wet products, but due to shortened shelf life, this does not work for smaller producers. “I have producers utilizing ground hay and by-products to feed cows a total mixed ration,” he says. “This goes back to economy of scale and helps larger operations decrease cost dramatically.”
Martin adds that there are a lot of opportunities to increase DDG usage because it works well in creep feeds, cow supplements, as a carrier for minerals and in diets for developing breeding stock. Future use of DDG in cow-calf operations will also depend on changes in fermentation technology and nutrient content of the resulting byproducts.
High in protein
In almost any type of beef cattle ration, DDG can serve as a source of protein and/or energy. DDG typically contain 28–30% crude protein, and about half to 65% of that protein is undegradable intake protein (UIP), or bypass protein (see UIP sidebar). The energy value of DDG varies depending on the ration, but it has greater energy value than corn in forage-based diets.
DDG also contain 8–14% fat, which has been shown to improve reproductive performance in some situations. “Pre-calving supplementation of cows and heifers with fat or UIP can improve subsequent reproductive performance depending on the situation, so DDG are a logical supplement choice prior to calving,” Martin explains. Recent research conducted by Martin et al. (2007) compared DDG or a control supplement as the sole source of supplemental protein and energy in heifers fed prairie hay. Heifers fed DDG at 0.57% of body weight from shortly after weaning through artificial insemination (AI) breeding had 75% AI conception rate compared to 53% in heifers fed the control supplement. “The main difference between the supplements was greater bypass protein in the DDG supplement,” Martin adds.
DDG are also high in phosphorous, a macromineral required for bone growth and energy metabolism. Phosphorus supplementation is often required, particularly in low quality forage diets. “Phosphorus is also the main driver of range mineral price; each percentage phosphorous in mineral adds $15–$25 per ton,” Martin notes. “Because DDG are relatively high in phosphorous, producers can reduce or eliminate phosphorous supplementation in mineral, significantly reducing mineral cost.”
DDG can be used as a source of energy and protein whenever one or both of those nutrients is needed in gestation or pre-breeding diets. Goehl says in cow-calf herds DDG can be supplemented by limit feeding it each day or every other day. “When hay supplies are short and we start to over supplement to replace a large percentage of the diet, there are some health issues to be cautious of,” he notes. “Polioencephalomalacia (brainers) is the most common ill effect we see.”
There is no pat answer as to the correct level of DDG in late gestation diets for cows or heifers because it depends entirely on the remainder of the diet and how much energy and/or protein is needed to meet the cows’ requirements. “Sulfur is ultimately the limiting factor concerning how much can safely be fed,” Martin says. “For a 1,300-lb. cow or 1,100-lb. bred heifer of average milking ability at 250 days of gestation, 20% DDG and 80% ground corn stalks (as-fed) will typically meet protein requirements and maintain body condition score.”
Overfeeding and polio
DDG are high in sulfur, over 1% on a dry matter (DM) basis or greater in some cases. High dietary sulfur is linked to polioencephalomalacia in cattle. “Thiamine supplementation will help control polio outbreaks in cattle fed high sulfur diets, but any time I have producers feeding over 20% DDG (DM basis), I prefer to have both feed and water tests to insure reasonable sulfur levels in the diet,” Martin explains. “In most cases, with proper thiamine and trace mineral supplementation, DDG can be fed at levels nearing 40% of the diet DM (sulfur level 0.35–0.40% diet DM) with no adverse effects, although these levels are probably not needed in cow-calf operations.”
If dietary phosphorous is elevated much higher than the calcium, urinary calculi (water belly) can occur, adds Fanning.
Overfeeding fat and therefore interfering with normal rumen metabolism is also a concern with diets containing WDG or DDG. Ruminal fiber digestibility is depressed by high levels of dietary fat. Practically speaking, sulfur is more likely to limit inclusion in beef cattle diets.
Aside from the possibility of sulfur toxicity or depressing ruminal fiber digestibility, Martin doesn’t know of any negative effects of DDG on reproduction. “However, when feeding high DDG diets to developing bulls or to females prior to the breeding season, I would caution producers to make sure they are feeding adequate trace minerals, especially copper,” Martin advises. Complexes of sulfur with copper, iron, zinc, and possibly other trace minerals impair absorption of these minerals. “Producers need to be sure adequate trace minerals are supplied to compensate for this reduced bioavailability, and should utilize some chelated trace minerals in these types of rations.”
Source DDG wisely
DDG can vary widely and some plants focus more on the quality and consistency of their byproducts than others. There can also be considerable load-to-load variation from a single plant. Fanning keeps a database of routine samples that have been analyzed from each plant. “From that information we can more accurately formulate rations using the highest level of sulfur detected to prevent polio problems and a lower level of protein to prevent protein deficiency.”
Nutritionists and veterinarians need to help clients carefully scrutinize the quality of the distillers grains they intend to feed. Fanning explains that when drying DDG, unfermented sugar can cause a non-enzymatic browning reaction causing the protein and energy to be tied up and unavailable to the animal. It also causes a darker color of product, so the lighter-colored product is preferred. “The product color should be the same color as the grain it originated from,” Fanning notes.
When producers make the decision to utilize DDG it is important they have a consistent supply, particularly if they invest in additional storage. “I would recommend contracting enough DDG to meet your projected needs, rather than relying on the spot market,” Martin advises. “Commodities marketing companies can be very helpful in this regard.”
Northeast Missouri is fortunate to have several geographic advantages when it comes to sourcing distillers grains. “We are very close to the Mississippi River allowing for cheap transportation, and my clients are in or near the Corn Belt,” Goehl explains. He adds that several new ethanol plants are either operating or in construction, making by-product feeds more readily available. “The smaller cow-calf producers often purchase product from feed mills for convenience,” Goehl says. “This way they can buy smaller quantities. Stockers and larger cow-calf operations are able to take advantage of the close proximity and feed wet product.”
Fanning adds that availability of distillers grains is always better in the summer when demand is low. “In some cases we have stored the wet or dry distillers during these times for times when the product is more difficult to get.”
The economics of DDG
It is sometimes hard for a producer to comprehend that the economics dictate selling the feedstuffs raised at home such as corn, and purchasing alternative feed, says Goehl. It is also important to remember that pound-for-pound you get a disproportionate advantage from these types of feedstuffs compared to corn when fed in a forage-based diet.
Fanning explains that the price of wet distillers grains needs to be compared on a dry matter basis to get the best deal (i.e. a 32% dry matter product costing $32 per ton delivered is equal to $48 per ton product that is 48% dry matter).
When feeding DDG as a protein supplement (generally 15% of diet DM or less) every other day supplementation is sufficient, Martin says. However, if DDG is fed as an energy source, at levels higher than 15% of diet DM, supplementing every day is advantageous.
Today, nutrient tests for forages and proper diet formulation can be done very inexpensively and can save producers money. “Custom mineral mixes to complement DDG can enhance performance at a lower cost than standard floor stock minerals,” Fanning says.
There is a benefit to keeping records and looking at the cost of production. “The cost of production can be compared with the average producer’s cost of production and should show a trend of being lower compared with the average over time,” Fanning says.
“As veterinarians, it is our responsibility to understand the total operation and not just the pathogens that are present,” Goehl sums. “Reviewing records is one of the best ways to do this. Not only do we need to look at the feeding program by itself, but we need to look at corresponding body condition scores and how these correlate to the herd’s performance.
Next issue: Supplementing beef cattle with corn gluten.
What’s up with UIP?
Dried distillers grains (DDG) are high in ruminally undegradable methione, the first limiting amino acid in cattle. Undegradable intake protein (UIP) refers to protein that is not digested by rumen microbes. Digestible intake protein (DIP) is digested by microbes in the rumen and provides nitrogen for microbial growth. The microbes subsequently get washed out of the rumen and provide microbial protein that is digested in the lower gut.
When UIP leaves the rumen, it is also available for digestion enzymatically in the small intestine. On average, UIP’s digestibility in the small intestine is around 80%. Available data indicates postruminal digestibility of UIP in DDG may be closer to 88%.
“Together, microbial protein formed using nitrogen from DIP and UIP contribute to metabolizable protein, the protein that is actually absorbed from the small intestine and is available to the animal,” explains beef nutritionist Jeremy Martin Ph. D. “Microbial protein has a relatively constant amino acid profile, while the amino acid profile of UIP varies with protein source. Therefore, UIP is important for meeting metabolizable protein requirements and may supply specific amino acids required by the animal.”