Biofuel co-products as livestock feed - Opportunities and challenges

502Biofuel co-products as livestock feed – Opportunities and challengesScene setterDistillers grain co-products have been fed to livestock formore than a century. Currently production far exceedsthat of glycerol. Emerging new markets include aquaculture,horses, companion animals and human foods, butthese market applications need research support.Shurson, Tilstra and KerrSmall-scale approachesIn India, decentralized crushing and syrup-making unitsare based on sweet sorghum, providing food, feed, fodderand fuel. The system encompasses small-scale farmersand complements the centralized approach applicable tolarger farmers.Rao et al.EconomicsToday, grain, sugar and oilseeds are the major agriculturalcommodities for biofuels. This could lead to modestincreases in livestock and poultry production costs,but substitution of co-products for traditional feedstuffscould mitigate these increases.Cooper and WeberJatrophaJatropha is a drought tolerant shrub or tree growingwild on degraded land in Central and Southern America,Africa and large tracts of Asia. Seeds are rich in oil and thekernel meal rich in crude protein. After treatment, bothJatropha curcas and J. platyphylla residues can replaceover half the protein in diets of fish. Non-toxic Jatrophaspecies could be valuable feed resources for the future.Makkar, Kumar and BeckerMicro-algaeProduction of energy through photosynthetic organisms,like micro-algae, harnessing solar energy might be a viablesolution avoiding competition for land, or land-basedresources such as fresh water. Residues have potential aschemicals, foods and feeds, but prudent energy auditsare needed.Ravishankar et al.Oil PalmOil palm residues come from the field and processingmills. Their diversity allows complete diets from oil palmproducts for various livestock species, including in aquaculture.Malaysia needs to increase ruminant productionand there is huge potential to integrate this with the oilpalm industry.Wan Zahari, Alimon and WongBACKGROUNDDistillers grain (DG), originally a by-product of the alcoholicdrink and beverages production industry, has been fed tolivestock for many years, initially to pigs and dairy cows.The upsurge in the use of DG was itself a by-product of thesearch for transport fuel other than from fossil fuels, whichin recent years has been supported by a large increase inresearch funding into the use of co-products (Shurson,Tilstra and Kerr, 3). Currently, co-products are an importantfeed resource in over 50 countries, for ruminants, nonruminantsand aquaculture (Table 1). The co-products arethe residues after extraction of the biofuel, whether ethanolor biodiesel. Biofuels contribute to the twin objectives ofincreasing fuel security and reducing emissions of greenhousegases (GHG) (Cooper and Weber, 1). In Europe, theuse of fossil fuels for transport contributes an estimated18 percent of all GHG emissions, a figure that has the potentialto be reduced by half through increased efficiencies inuse and a projected four-fold increase in the production ofbiofuels by 2020 (Hippenstiel et al., 11). If achieved, this rateof increase would result in 6 percent of global fuel needscoming from biofuels. As the majority of currently usedfeedstocks to produce biofuels are crops grown on existingagricultural land, the requirements for food, feed andfuel must be balanced so that the quest for biofuels doesnot result in an inflationary rise in the cost, or shortage, offood or feed. This raises the question of second-generationfeedstocks from cellulosic sources, the use of crop residuesand stubbles and woody material grown on marginal landwith a minimum of resources, including irrigation (Braid,25). This approach raises the potential for promoting littleusedand non-conventional feeds, such as oil-palm products(Wan Zahari, Alimon and Wong, 13; de Albuquerque etal., 14), micro-algae (Ravishanker et al., 24), Jatropha species(Makkar, Kumar and Becker, 21), lipid co-products(Wiesman, Segman and Yarmolinsky, 18), Pongamia glabra(karanj) and Azadirachta indica (neem) seed cakes (Dutta,Panda and Kamra, 22), sugar cane bagasse (Anandan andSampath, 16) and Camelina sativa (Cherian, 17). Some mayrequire detoxifying to produce safe livestock feed (Anandanand Sampath, 16; Dutta, Panda and Kamra, 22; Abbeddouand Makkar, 19; Makkar, Kumar and Becker, 21).ETHANOLCereal feedstocksThe European Union has set targets both for the inclusionof non-fossil fuels for road transport and for reductionof GHG emissions, embodied in the RenewableEnergy Directive (RED) and the Fuel Quality Directive(FQD) (Lywood and Pinkney, 2). The USA introduced the