Due to the high levels of fibre in DGs, there has been interest in using DG in place of dietary roughage. However, the DG fibre particles are too small to effectively maintain proper rumen function and health, and have been associated with increased incidence of rumen acidosis and liver abscesses. A recent Canadian study found that 10% barley silage in a diet containing wheat DGS was a minimum to prevent a rumen pH drop (increased acidity) in calves fed barley diets supplemented with wheat DGS. Benefits for Feedlot Cattle Corn WDGS enhances feed efficiency of corn-based diets by up to 13% with response proportional to the level in the diet up to 50% (dry basis). Corn DDGS enhances feed efficiency up to 5%, with the maximum response from between 10 and 20% inclusion in the diet. At dietary inclusion rates up to 20%, wheat DDGS gives similar feed efficiency to a barley-based control. Above 20% inclusion, wheat DDGS has had no effect or caused a slight decline in feed efficiency, by up to 9%. Concerns for Feedlot Cattle Urinary calculi is Phosphorus (P) levels are high in DGS. a symptom in male Diets containing DGS must be fortified cattle of failing to with additional limestone over the amount balance the Ca:P used in grain diets to provide a ratio correctly. calcium (Ca) to P ratio of at least 1.1 to 1, and preferably 1.5 to 1. Sulfur (S) levels are high in DGS and quite One of those symptoms variable (0.35 to 1.4%). Levels of S in the of S toxicity in feedlot diet above 0.4% can be toxic to feedlot cattle. cattle, especially those S toxicity has not become a major problem fed barley based diets, is so far with feeding DGS and has been the polioencephalomalacia. subject of a recent research project funded by the BCRC (see below). Because mineral levels in diets containing DG often exceed animal requirements, manure from cattle fed DGS are unusually high in nitrogen (N) and P. In the application of cattle manure from DGS fed cattle to Land required for the agricultural land, P is usually the nutrient application of feedlot that will limit the amount of manure that manure is increased can be applied to avoid P run-off and leaching when DGS is fed. into groundwater. Nutrient management programs can be used to take soil and crop requirement into account in good management of manure from feedlot cattle. Feeding DGS to feedlot cattle does not consistently affect carcass grade and meat quality. However, there are two points worth noting: • Some studies have shown that DGS inclusion decreases marbling of meat but this is not a consistent finding and it cannot be easily explained. • Feeding DGS negatively affects meat colour and colour stability of beef in the retail case but significance of this in affecting consumer satisfaction is less clear. This effect of feeding DGS in feedlot diets can be counteracted by providing additional vitamin E.
88
There have been concerns that using DGS in feedlot diets may increase shedding of E. coli 0157.H7. However, results have been conflicting and results of some studies, including a recent one in Canada, have not confirmed this finding. Many factors affect shedding of E.coli 0157.H7 by feedlot cattle. With quality control during processing, beef from cattle fed DGS is as safe as beef from cattle fed conventional diets. Feeding Distillers’ Grains to Backgrounding Cattle DGS is an excellent energy and/or protein feed to use in completely mixed rations for backgrounding cattle for the feedlot. Calves fed forage/barley grain diets in western Canada where wheat DDGS has replaced most of the barley grain have performed equally to calves on the forage/barley control. DGS can be an ideal supplement for calves grazing summer pasture, stockpiled wheat or other forage in the late fall and early winter before being shipped to the feedlot. Feeding Distillers’ Grains to Cow-Calf DGS is an excellent energy source for supplementing any type of forage fed to cows and calves. Cows in mid-lactation have been fed as much as 15 kg of WDGS daily. Precautions noted for feedlot cattle regarding P and S must be noted in the feeding of DGS for cow-calf. Canadian Research on DGS Extensive research on distillers’ grains has been ongoing in the U.S. for decades. Canadian research work to determine if American results differ under Western Canadian conditions, since most Canadian feedlots are in the Western provinces, and to study the types of grains that are more typically used in finishing diets in Canada. Recent Canadian research has studied the effects of wheat, barley and oat DGS, regional differences, and effects on nutrient value of manure. Thank you to Beef Research and Dr. Jock Buchanan-Smith, retired University of Guelph professor and researcher of beef cattle nutrition and management for contributing his time and expertise in writing this page.