Department of Animal Sciences, University of Illinois, Urbana-Champaign, IL 61801, USA.
J Anim Sci. 2010 Apr;88(13 Suppl):E143-50. doi: 10.2527/jas.2009-2526. Epub 2009 Nov 20.
The number and nutrient composition of corn-based coproducts will expand as ethanol producers seek to optimize the efficiency of ethanol production and the value of the coproducts they produce. For example, modified wet distillers grains plus solubles are produced by adding the condensed solubles to partially dried distillers grains so that the resulting product contains approximately 50% DM. Other innovative technologies have been developed to fractionate corn or distillers dried grains with solubles (DDGS), or both, for recovering additional coproducts and improving nutritional composition of DDGS. Two (i.e., wet and dry) corn-fractionation technologies have been developed to remove the germ, pericarp fiber, or endosperm fiber before fermentation, resulting in a significant reduction in the amount of DDGS produced and a corresponding increase in its protein content. Other fractionation technologies include removal of oil by centrifugation after fermentation but before DDGS production or removal of oil by solvent extraction from DDGS. Technology to recover pericarp fiber by sieving and aspiration after DDGS production has also been developed. Germ, pericarp fiber, endosperm fiber, or oil can be used as feedstocks for producing other marketable coproducts or can be used as ingredients in animal diets. One example of a new corn coproduct available to the beef industry is bran cake. This product results from combining corn bran (i.e., pericarp fiber) and distillers solubles produced from a corn dry fractionation process. When bran cake replaced a mixture of high-moisture and dry-rolled corn at up to 45% of a finishing diet, BW gains and feed efficiency were improved. In high-forage diets, the corn bran had approximately 85% the energy value of distillers grains. How rapidly these technologies are adopted will be driven by the economic advantages achieved over the traditional dry and wet milling processes.
随着乙醇生产商寻求提高乙醇生产效率和所生产副产物的价值，基于玉米的副产物的数量和营养成分将不断增加。例如，通过将冷凝物添加到部分干燥的酒糟中，生产出改良的湿酒糟加可溶性物，使最终产品含有大约 50%的 DM。还开发了其他创新技术，以对玉米或酒糟干燥谷物加可溶性物（DDGS）或两者进行分级，以回收其他副产物并改善 DDGS 的营养成分。已经开发了两种（即湿和干）玉米分级技术，在发酵前去除胚芽、果皮纤维或胚乳纤维，从而显著减少 DDGS 的产量，并相应增加其蛋白质含量。其他分级技术包括在发酵后但在 DDGS 生产之前通过离心去除油，或从 DDGS 中通过溶剂萃取去除油。还开发了在 DDGS 生产后通过筛分和抽吸回收果皮纤维的技术。胚芽、果皮纤维、胚乳纤维或油可用作生产其他有市场价值的副产物的原料，也可用作动物饲料的成分。一种可供牛肉行业使用的新型玉米副产物是糠饼。该产品是通过将玉米糠（即果皮纤维）和来自玉米干法分级过程的酒糟可溶性物结合而成。当糠饼取代高水分和干压玉米混合物，占饲养日粮的 45%时，体重增加和饲料效率得到提高。在高草料饮食中，玉米糠的能量值约为酒糟的 85%。这些技术的采用速度将取决于与传统的干法和湿法碾磨工艺相比所获得的经济优势。
