Biofuel co-products as livestock feed - Opportunities and challenges

282Biofuel co-products as livestock feed – Opportunities and challengesStep 1. Raw material preparationStep 1. Raw material preparationStep 1. Raw material preparationStep 2. Mixing ingredientsStep 2. Mixing ingredientsStep 2. Mixing ingredientsStep 3. PressingStep 3. PressingStep 3. PressingStep 4. Drying 8-15 daysStep 4. Drying 8-15 daysbentonite and minerals) are first weighed and mixed in aStep 4. Drying 8-15 dayshorizontal mixer. The order of introduction of ingredients isdefined to avoid losses of molasses by adhesion to the wallsof the mixer and to enhance chemical reactions and heatgeneration, thus ensuring that the mix is in a form suitablefor the block compaction operation. First the bagasse, mineralsand sodium bentonite are mixed. Then a solution ofurea, diluted in the vinasse and molasses, is incorporatedin the mix. Finally, the calcium oxide is incorporated. Themixture is agitated for 15 minutes until homogenous. Theblocks are formed by pressing 18 kg of the mixture in asteel mould under compaction pressure of 2000 kg/cm 2 for5 minutes. Finally, the blocks are removed from the mouldand placed in a shaded area to dry for one week. For transportationand commercialization, the blocks are packed incardboard boxes.In the preparation of supplements specifically for cattlefeeding, co-products from sugar cane-based ethanol canbe included at between 50 and 80 percent. Tables 6 and 7present the components and nutritional composition oftwo products for ruminants: a multinutritional block anda mineral salt block, made with co-products from sugarcane-based biofuel processing, using the RUSBI process.Table 8 presents the bromatological composition of the twoPhoto 2Outline of the steps followed to prepare thenutritional supplements in the RUSBI approachTABLE 6General characteristics of a block nutritional supplementRaw materialInclusion level(%)Nutritional composition(%)Pre-digest bagasse 25.10 Crude protein 24.0Vinasse sludge 36.82 NPN (max.) 3.9Fly ash 4.32 TDN 33.0Molasses 9.89 Ca 2.21Other ingredients 23.87 P 1.00Total 100.00 S 0.36Notes: Other ingredients comprise urea, NaCl, flowers of sulphur,dicalcium phosphate, calcium oxide, sodium bentonite, micromineralpremix. NPN = Non-protein nitrogen; TDN = Total digestible nutrients.Source: CLAYUCA, 2009nutritional supplements (energy and protein), prepared asblocks with salt.As indicated in Table 8, the two nutritional supplementshave TDN equivalence, but they differ in the percentage ofprotein. Both the blocks and the meals are recommendedfor use in situations in which the available pastures haveprotein contents below 6 percent and where the TDN:CPratio exceeds 8. Also, the energy supplements are recommendedwith better quality pastures, with protein contentover 8 percent. All the nutritional supplements were formulatedto obtain a balance of 10 to 11 percent between con-