Biofuel co-products as livestock feed - Opportunities and challenges

Land use in Australia for biofuels and bio-energy: opportunities and challenges for livestock industries 461was found that, as well as the economic benefits, biomassproduction can provide benefits by controlling drylandsalinity, wind erosion and carbon emissions reduction.These results suggest that the integration of biomassproduction in the form of SRC eucalypts with pasture andlivestock grazing may provide a good outcome in resilienceand land conservation while maintaining economic productivityof the land.KNOWLEDGE GAPS AND FUTURE RESEARCHNEEDSIntegration of cropping, grazing and bio-energy productionpresents a complex set of biophysical, social and economicinteractions that will need to be well understood toensure sustainable development of such land use. Whilesome recent research at landscape scale has been reportedhere, there is need to continue this at a range of scales,including sociological, to better understand likely land usechanges in Australia associated with developing bio-energyindustries.Knowledge from this research will be needed in the continuingdevelopment of certification of sustainable biofuelproduction. Current certification, such as the Roundtableon Sustainable Biofuels (RSB) Certification Scheme, and thesustainability standard upon which it is based (Roundtableon Sustainable Biofuels, 2011), have been developed fromcertified sustainable forest management and as such tendto address sustainability issues as applying to single landuse energy crops. Assessment of the sustainability of thecombined production of food, fibre and bio-energy biomassfrom integrated land use will require re-examinationof the criteria and indicators within biofuel sustainabilitystandards.CONCLUSIONSThe current small biofuels industry in Australia, based largelyon the use of co-products of grain and sugar industry, isnot a significant challenge to the availability of feedstocksfor the intensive livestock industries, and only provides arelatively small amount of co-product for livestock feed. Anexpansion of the current first-generation biofuels industrywould increase direct competition for grain, but wouldalso increase the availability of protein feedstuffs – DDGSand oilseed meals – which could provide a useful sourceof supplementary protein for livestock grazing low-protein,dry, summer pastures. DDGS is particularly suitable for thisrole in ruminants.New non-food biomass production systems for biofueland bio-energy are being researched and developedin Australia. These include the use of ligno cellulosic feedstocksfrom agricultural residues and on-farm plantingsof SRC eucalypts; and new bio-oil feedstocks such as thelow-rainfall oilseed crop Brassica juncea, the oilseed treePongamia pinnata and algae. Much work remains yet to bedone to fully design, test and implement suitable productionsystems.Research has been undertaken in Australia into the useof biodiesel co-products in pigs. Both juncea meal followingoil extraction from Brassica juncea, and crude glycerolfrom the trans esterification process to convert bio-oils tobiodiesel have been trialled.Algal biofuel production has yet to be commercializedanywhere in the world. The algal meal remaining after theextraction of bio-oil may not be suitable for livestock feeddue to the use of CO 2 flue-gas from coal-fired power stations,which may contain heavy metals and other toxinsthat are likely to be taken up by the algae.Pongamia pinnata plantations are being developedin Australia for the production of biofuel, which couldresult in the availability of pongamia meal for livestockfeed. However, despite considerable research and effort toreduce residual oil and toxicity factors in pongamia meal,studies have shown that Pongamia pinnata meal is onlyuseful and safe as an animal feed at low inclusion levels.There is a benefit from pongamia containing the unpalatablekaranjin and pongamol, as it allows the integrationof grazing livestock in Pongamia pinnata plantations withminimal risk of the animals grazing and damaging the trees.The harvesting of stubble for bio-energy should havelittle impact on grazing livestock in mixed grazing-croppingfarming systems. There is little of nutritional value in stubblefor grazing livestock. When modelled as part of a wholefarm system, the value for livestock of grazing stubble isvariable, often marginal or negative. The use of long-phaseperennial pasture rotations in the cropping-livestock systemis the most beneficial practice in the long-term maintenanceof cropping soils and will always provide the majoropportunity for livestock within the system, whether stubbleis harvested for bio-energy or grazed.The re-introduction of trees for bio-energy and biofuelsinto cleared agricultural lands in Australia will providedirect benefits in livestock productivity and animal welfarethrough the provision of shade and shelter, as well as longtermbenefits through land conservation for the grazinglivestock industries. The integration of biomass productionin the form of SRC eucalypts with pasture and livestockgrazing may provide a benefit in improved resilience andland conservation while maintaining economic productivityof the land.The development of new, second-generation biofuelsmay have an impact on the availability of grain to theintensive livestock industries, as some current grain-producingland is planted with SRC eucalypts as feedstock forbiofuel or bio-energy. Combined with a loss of croppingproductivity associated with climate change, this could besignificant.