Assessing environmental consequences of using co-products in animal feed

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• 作者：Hannah H. E. van Zanten (1) (2)
  Herman Mollenhorst (1) (3)
  Jerke W. de Vries (1)
  Corina E. van Middelaar (1)
  Heleen R. J. van Kernebeek (1)
  Imke J. M. de Boer (1)
  
• 关键词：Bioenergy ; Consequential LCA ; Co ; product ; Dairy cattle ; Land use change ; Livestock feed ; Pigs
• 刊名：The International Journal of Life Cycle Assessment
• 出版年：2014
• 出版时间：January 2014
• 年：2014
• 卷：19
• 期：1
• 页码：79-88
• 全文大小：421 KB
• 作者单位：Hannah H. E. van Zanten (1) (2)
  Herman Mollenhorst (1) (3)
  Jerke W. de Vries (1)
  Corina E. van Middelaar (1)
  Heleen R. J. van Kernebeek (1)
  Imke J. M. de Boer (1)
  
  1. Animal Production Systems Group, Wageningen University, PO Box 338, 6700 AH, Wageningen, the Netherlands
  2. Wageningen UR Livestock Research, Wageningen University and Research Centre, PO Box 135, 6700 AC, Wageningen, The Netherlands
  3. Business Economics Group, Wageningen University, PO Box 8130, 6700 EW, Wageningen, the Netherlands
  
• ISSN：1614-7502

文摘

Purpose The livestock sector has a major impact on the environment. This environmental impact may be reduced by feeding agricultural co-products (e.g. beet tails) to livestock, as this transforms inedible products for humans into edible products, e.g. pork or beef. Nevertheless, co-products have different applications such as bioenergy production. Based on a framework we developed, we assessed environmental consequences of using co-products in diets of livestock, including the alternative application of that co-product. Methods We performed a consequential life cycle assessment, regarding greenhouse gas emissions (including emissions related to land use change) and land use, for two case studies. Case 1 includes increasing the use of wheat middlings in diets of dairy cattle at the expense of using it in diets of pigs. The decreased use of wheat middlings in diets of pigs was substituted with barley, the marginal product. Case 2 includes increasing the use of beet tails in diets of dairy cattle at the expense of using it to produce bioenergy. During the production of biogas, electricity, heat and digestate (that is used as organic fertilizer) were produced. The decrease of electricity and heat was substituted with fossil fuel, and digestate was substituted with artificial fertilizer. Results and discussion Using wheat middlings in diets of dairy cattle instead of using it in diets of pigs resulted in a reduction of 329?kg CO2 eq per ton wheat middlings and a decrease of 169?m2 land. Using beet tails in diets of dairy cattle instead of using it as a substrate for anaerobic digestion resulted in a decrease of 239?kg CO2 eq per ton beet tails and a decrease of 154?m2 land. Emissions regarding land use change contributed significantly in both cases but had a high uncertainty factor, ±170?ton CO2 ha?. Excluding emissions from land use change resulted in a decrease of 9?kg CO2 eq for case 1 ‘wheat middlings-and an increase of 50?kg CO2 eq for case 2 ‘beet tails- Conclusions Assessing the use of co-products in the livestock sector is of importance because shifting its application can reduce the environmental impact of the livestock sector. A correct assessment of the environmental consequences of using co-products in animal feed should also include potential changes in impacts outside the livestock sector, such as the impact in the bioenergy sector.