2006-11-15 / Farm & Home

Ag Line: Using distillers grains in beef cattle rations

By Wade Parker

County Extension Coordinator

As ethanol plants start forming in Georgia and across the nation, distillers grains will be a by-product produced during production. Distillers grains can be used as a feed supplement in beef cattle operations. As a bushel of corn is processed, approximately 30 percent of a bushel of corn remains after the starch is converted to ethanol. With over 2 billion bushels of corn expected to be used for ethanol in the next year, there is a considerable amount of distiller by-product available to feed cattle.

What are the nutritional components of distillers grains? Distillers grains are high in protein (28 to 30 percent) and energy (92 percent TDN). The fat content varies from 9 to14 percent which increases the energy content. In comparison, corn gluten feed is 21 percent protein and 80 percent TDN. Distillers grains are a good source of "bypass" protein for young cattle that have high protein requirements. The "bypass" protein is not degraded in the rumen, rather it escapes digestion in the rumen and is absorbed in the small intestine. About 70 percent of the protein is "bypass" protein in distillers grains, whereas, only 25 percent of the protein in corn gluten feed is "bypass." Distillers grains can be an economical source of supplemental protein, in addition to energy, when feeding poor quality hay to growing cattle or cows. In other words, this simplifies feeding, as one ingredient can provide all the needed supplemental energy and protein.

Calves consuming distillers grains will have greater gains than calves fed a similar amount of corn gluten feed. One study found that calves fed a diet of 40 percent roughage, 40 percent distillers grains, and 20 percent corn gluten feed had higher daily gains (2.77 vs. 2.53 lbs/ day) than calves fed a 40 percent roughage, 40 percent corn gluten feed, and 20 percent distillers grains diet. However,

calves fed the 40 percent level of corn gluten feed were more efficient (6.86 vs. 7.45 lb of feed per lb of gain) than calves fed the 40 percent distillers gains diet. When feeding high grain diets, distillers grains have generally not depressed performance or affected carcass traits when fed at 40 percent of diet dry matter, which equates to replacing 50 percent of the corn in the diet.

Distillers grains have also been evaluated as the primary source of energy in limit-fed grain rations for wintering cows. A study compared feeding lactating Simmental cows either distillers grains or corn gluten feed. Cows were fed either distillers grains or corn gluten at 77 percent of the diet with ground cornstalks at 23 percent of the diet. Cows were fed 8 percent more feed in the corn gluten feed (22.8 lb/day) vs. distillers grains (21.2 lb/day) group. No differences were observed for calf daily gains. These diets should be fed at approximately 1.75 percent of

body weight to mature cows producing 15 lb of milk per day. The energy value of corn gluten and distillers grains appears to be similar when provided as a supplement to lactating cows. The determining factor as to which feed to use should be based upon price and amount of supplemental protein needed.

As one can see, feeding distillers grains is an excellent source of supplemental protein and energy for cows fed hay. Producers should have a nutrient analyses conducted on each cutting of hay. The amount of distillers grains required to provide adequate protein and energy can easily be determined using the forage nutrient analyses. If you would like to borrow the forage auger to test your hay, please give me a call at the Extension Office.

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