Brewers' and Distillers' Byproducts and Yeast in Livestock Feeding

Report Introduction: In the manufacture of beer, distilled liquors and alcohols, vinegar and yeast, various byproducts having considerable value in livestock feeding are recovered after cereal grains or other carbohydrate - containing raw materials have been fermented by yeast or other micro-organisms. These byproducts include spent grains, slops, and brewers' yeast. Recent improvements in the processes used in some of the larger distilleries have replaced the distillers' wet or dry spent grains and distillers' slop by distillers' solubles, distiller's' dried grains with solubles, distillers' oil-extracted dried grains, and oils. All of these byproducts of the fermentation industries contain liberal quantities of proteins; the carbohydrate content is much lower than in the raw materials; and those byproducts that contain yeast and yeast-formed substances or other micro-organisms and their products are valuable sources of the B vitamins. For the year ended June 30, 1942, the production of distillers' dried grains amounted to approximately 300,000 tons, an increase of more than 50 percent over that of the preceding year; and the production of brewers' dried grains was approximately 140,000 tons, an increase of more than 30 percent over the preceding year. Further great increases in the production of distillers' grains, due to the production of alcohol for war purposes, are anticipated. It is also possible that further developments in the production of yeasts, from such wastes as the spent sulfite liquor of the paper-pulp and cellulose industries, may provide additional large quantities of wood-sugar yeast for livestock feeding.