Improvement of the environmental performance of broiler feeds: a study via life cycle assessment

Abstract

In this study, environmental impacts caused by the production of “animal-mixed” and “vegetarian” feeds were investigated via life cycle assessment using the ReCiPe assessment method and covering fourteen impact categories: 1) climate change, 2) ozone depletion, 3) human toxicity, 4) photochemical oxidant formation, 5) particulate matter formation, 6) terrestrial acidification, 7) freshwater eutrophication, 8) marine eutrophication, 9) terrestrial ecotoxicity, 10) agricultural land occupation, 11) natural land transformation, 12) water depletion, 13) metal depletion, and 14) fossil depletion. The scope of this work encompassed production of feed ingredients, overseas transportation of the feed ingredients, and the feed production process at mills. The results of this study showed that the main impact factor for the feeds was the production of energy-rich and protein-rich ingredients (more than 60%). The impact from overseas transportation was significant (more than 15%) in the categories of ozone depletion and photochemical oxidant formation. The impact from the production process at the feed mills was relatively small in all categories. The major causes contributing to the large impact of the energy-rich and protein-rich ingredients came from the maize drying process and the planting of crops used as ingredients, i.e., land provision via deforestation and the release of nutrients and metal from fertilizers, as well as chemicals from pesticides. The energy used in the maize drying process alone contributed more than half of the total impact of the feeds in the fossil depletion category. As a result, the vegetarian feeds, having a relatively high crop ratio, exhibited higher impacts than the animal-mixed feeds. Five options to improve environmental performance of the feeds were proposed, and significant impact reductions were demonstrated. The best option depends on the impact category of interest because the reduction of the impact in one category might lead to the increase of the impact in another category. If all options were applied to the supply chain of the feeds produced in Thailand in 2011, the potential reduction of climate change would be equal to the emissions from the production of 0.92 million tons of low-alloy steel, and the potential reduction of fossil depletion would be equal to the fuel used for the production of 3.6 million tons of low-alloy steel.