Kendall Swanson, NDSU Department of Animal Sciences
Faithe Keomanivong, NDSU Department of Animal Sciences
Mary Rodenhuis, NDSU Department of Animal Sciences
Marc Bauer, NDSU Department of Animal Sciences
Vern Anderson, NDSU Carrington Research and Extension Center
Chanda Engel, NDSU Carrington Research and Extension Center
Distillers grains are a byproduct of the ethanol industry that provide an excellent feed source for livestock. Distillers grains are produced at multiple ethanol plants in North Dakota. A portion is used as a feed source for livestock in the state but the majority is sent to other locations. The current process to remove corn oil from distillers grains may alter the nutrient density and affect animal performance. This may alter the demand and use of distillers grains potentially affecting domestic use and exports.
Corn is the primary grain used in finishing diets in the U.S., whereas barley is the major grain used in Southern Alberta, which is the major feedlot region in Canada and a large user of distillers grains produced in North Dakota. Therefore, it is important to study the effects of oil concentration in corn distillers grains in both corn and barley-based diets.
A collaborative study was conducted by researchers at the Carrington Research and Extension Center (CREC) and North Dakota State University (NDSU) to examine the effects of oil concentration in distillers grains and grain source (corn vs. barley) on growth performance, feeding behavior, ruminal fermentation, and digestion in finishing cattle.
A feedlot study was conducted at CREC using 154 steers group-fed to examine the effects of grain source (rolled barley vs. rolled corn) fed at 30% and 50% (growing and finishing phase) of the diet and corn distillers grains oil concentration (5.8% vs. 9.6%; low vs. moderate) fed at 26% of the diet on growth performance and carcass traits. Oil concentration of distillers grains did not influence growth performance or carcass traits in steers fed corn or barley-based diets.
A feedlot and feeding behavior study was conducted at NDSU using 81 steers to examine the effects of grain source (rolled barley vs. rolled corn) fed at 50% of the diet and corn distillers grains oil concentration (4.5% vs. 7.9%; low vs. moderate) fed at 25% of the diet on growth performance, feeding behavior, carcass traits, and blood metabolites. Feeding distillers grains with lower oil concentration reduced plasma urea concentration, a marker for changes in nitrogen utilization, but did not influence growth performance or carcass traits in steers fed corn- or barley-based diets.
A ruminal fermentation and digestion experiment was also conducted at NDSU utilizing eight steers to examine the effects of grain source (rolled barley vs. rolled corn) fed at 50% of the diet and corn distillers grains oil concentration (4.5% vs. 7.9%; low vs. moderate) fed at 25% of the diet on ruminal microbial digestive enzyme and volatile fatty acid (the primary energy source for cattle) production, and nutrient digestion.
Feeding distillers grains with lower oil concentration altered the activity of ruminal digestive enzymes but this did not result in changes in ruminal volatile fatty acid production or nutrient digestion. Overall, feeding distillers grains containing low vs. moderate oil concentrations had minimal effects on growth performance, rumen fermentation and digestion when fed at 25% of diet DM in finishing diets based on corn or barley.