EVALUATION OF PROTEIN AND FIBER FROM DISTILLERS GRAINS PLUS SOLUBLES IN FINISHING BEEF CATTLE DIETS

Four studies were conducted to evaluate the components of distillers grains plus solubles in finishing beef cattle diets. Experiment 1 evaluated the effects of five composites of feedstuffs formulated to be similar in nutrient composition to DDGS on finishing performance of cattle. Experiment 2 evaluated isolating the protein from distillers grains using a feedstuff from the wet milling ethanol industry to determine the impacts of protein on the feeding value of WDGS in finishing performance of cattle. Experiments 3 and 4 evaluated the effects of protein from distillers grains with the diets used in Exp. 2 on site of digestion, ruminal VFA concentration and pH. In Exp. 1, replicating distillers grains plus solubles with proportions of high-protein distiller grains, corn bran, and condensed distillers solubles did not result in similar performance as cattle fed distillers grains plus solubles. Cattle consuming the CaO treated corn stover and byproducts were less efficient than cattle fed the composite with corn bran. Replacing high-protein distillers grains from the composite diet with condensed distillers solubles and corn bran resulted in greater DMI and tended to improve feed efficiency. In Exp. 2, protein made up a large portion of the calculated feeding value of the distillers grains plus solubles. In Exp. 3 and 4, DM and NDF total tract digestibility were greater for protein of distillers grains than for distillers grains plus solubles. Excess protein, from distillers grains plus solubles, above the animals requirement does serve as an energy source to beef cattle on finishing diets. Advisors: Jim C. MacDonald and Matt K. Luebb