Biofuel co-products as livestock feed - Opportunities and challenges

Sustainable and competitive use of co-products as feed in the rural bio-ethanol industry 281flocculation and coagulation processes, which result intwo products, vinasse and clarified sludge. Table 4 showsthe bromatological composition of four types of vinasse.Table 5 presents the minerals and nutrient content of purevinasse, clarified vinasse and clarified sludge, from sugarcane biofuel processing.CLAYUCA-CIAT, in partnership with Soil Net (Soil NetLLC, Polymers Solutions, a private company in the UnitedStates) and Universidade Federal do Rio Grande do Sul,Porto Alegre (UFRGS; a Brazilian University), has developednew potential solutions and alternatives for sustainable,competitive management of the effluents generated inbiofuel distilleries. One of these alternatives is proteinand energy supplementation for ruminants by mixing thevinasse with cassava products (roots and foliage). Thenutritional supplements developed with vinasse have beenoriented principally to feed ruminants. The composition andcharacteristics of products can be adjusted to suit the ageand type of animal to be fed.The organic matter contained in the flocculated sludgeis mixed with other products and co-products obtainedduring the process, such as cassava and sweet potatoleaves and stems, and sweet sorghum bagasse. Othercomponents that are included are urea, minerals and additives.The formulation of the nutritional supplement is scientificallydesigned with the help of a computer programto obtain a final product that is competitive, nutritionallybalanced and highly efficient in the feeding of ruminants.Photo 2 presents the different steps required to prepare thenutritional supplement.Organic matter removed from vinasse, together withproducts and co-products from biofuel processing (cassavaand sweet potato leaf and stalks; sweet sorghumand sugar cane bagasse) and other ingredients such usurea, minerals and additives, are combined to providea balanced protein, mineral and energy supplement forruminants (Patino et al., 2007; Martin, 2009). The supplementscan be presented in different forms, depending onthe animal feeding programme: multinutritional blocks,pellets or meal (Photo 3).In the preparation of the multinutritional blocks, theingredients (bagasse, molasses, vinasse, urea, sodiumTABLE 4Chemical composition and in vitro dry matter digestibility (IVDMD) of four types of vinasse (all values are percentagesexcept for trace minerals)Nutriment/ParameterVinasse sourceCassava Sugar cane Sweet potato Sweet sorghumDry matter 8.5 13.0 2.6 3.4Organic matter 93.5 – 92.8 90.8Crude protein 11.6 2.0 12.5 7.2Starch 0.7 – – –Ether extract 4.9 0.4 22.3 0.8Crude fibre 60.4 – 27.0IVDMD 64.7 – – –Ash 5.2 32.3 7.2 9.2Total Digestible Nutrients – – 74.5 77.8P 1.42 0.45 0.39 –Ca 5.38 1.04 0.50 –K 1.49 2.08 1.9 –Mg 0.40 0.24 0.63 –S 0.48 0.30 0.18 –Na 0.34 – 0.31 –Zn (ppm) 40 – 44 –B (ppm) 16 – 10 –Mn (ppm) 104.5 – 58 –Fe (ppm) 3305 86 584 –Cu (ppm) 14 1 17 –Al (ppm) 3121 – – –Sources: CLAYUCA, 2008TABLE 5Nutritional content of the products obtained in clarification of sugar cane vinasseProductP total K total Ca total Mg total S Fe Cu Na Zn Crude protein OM(%) (mg/kg) (%)Sugar cane vinasse 2.97 10.24 0.88 1.14 1.23 986 6.0 3.066 54.0 7.0 56.8Clarified sugar cane vinasse 0.00 1.06 0.48 0.12 0.14 32.0 0.0 366.0 3.0 0.8 6.8Sugar cane clarified sludge 2.75 2.99 14.26 0.20 9.30 525 47.0 467.0 19.0 5.2 27.5Note: OM = organic matter. Source: CLAYUCA, 2007.