Analysis On Environmental Impact Of Livestock And Poultry Breeding Based On Life Cycle Assessment

With the constant rising of China’s consumption level,the consumption of meat,eggs and milk showed rapid growth.While playing an important role in satisfying people’s demand for animal by-products,increasing yield and revenue of farmers,activating rural economy in such aspects,animal husbandry also brings serious environmental impact problems.Domestic and foreign scholars had further studied livestock and poultry production and its impact on environment,which is of great practical significance for the scientific promotion of cleaner production of animal husbandry.However in our country,there exist extensively small raising household and cultivation community,whose production scale,functional areas,waste treatment methods and impacts on the environment are obviously different from large scale cultivation.By using the theory of life cycle assessment(LCA)and systematically deducing the domestic and foreign studies in the field of livestock and poultry production and its environmental impacts,this article respectively took 1kg pork,beef,milk,chicken,and egg as functional unit,and divided animal life cycle into 6 stages: forage crop planting stage,food processing stage,feeding stage,manure treatment stage,slaughtering stage,and haulage stage.This article mainly aimed at four environment category,namely global warming,acidification,eutrophication,photochemical oxide formation,and carry on parameter collection of whole life cycle of material flow,flow of energy input and output and construction of life cycle inventory.We also carried on horizontal comparative analysis on the environmental impact of the described three modes and systematically studied the effects of whole life cycle of different livestock and poultry and different feeding modes on the environment through characterization,standardization and weighting evaluation process.At the same time comparing it with the data obtained by ecoinvent data base and Simapro software,we analyzed the differences and similarities in inventory construction and different types of environmental impact between the two inventories.Based on the life cycle assessment results of different kinds of cultivation types of livestock and poultry production,we can put forward corresponding suggestions for the cleaner production of livestock and poultry products,the corresponding formulation of environmental protection policies of animal husbandry and the sustainable development of agriculture in our country.Important conclusions are as follows:(1)Of the 5 kinds of livestock and poultry,4 kinds of environmental impact type characteristic value of beef cattle is the highest,mainly caused by the big beef cattle feed consumption,short breeding period,ruminant characteristics and so on.Strictly operating in accordance with the relevant rules of the green food production,prohibiting the use of banned drugs,controlling hormone use are reasonable measures to reduce environmental impact of beef cattle.(2)According to the business accounting of 2013 national environmental impact load of pork,the environmental impact load under large-scale cultivation,cultivation community and small raising household were respectively 175.36×10~8、131.87×10~8、140.99×10~8,the largest environmental impact load is large-scale cultivation,because the amount of pork under large-scale cultivation is the biggest.Under the same conditions,environmental impact load of large-scale cultivation is bigger.Thus carrying out cleaner production and energy conservation and emissions reduction large-scale pig breeding within the conditions of the economy is of great significance.(3)The order of livestock and poultry’s environmental impact contribution is as following: feed crop planting stage > manure treatment stage > livestock feeding stage > food processing stage > haulage stage > slaughter stage;According to the analysis of livestock and poultry production and the cause of the environmental impact,the combination of planting and breeding is an effective way to reduce the environmental impact of livestock and poultry production.(4)Compared with calculation results of commercial database of environment impact,we found that the potential global warming impact of pigs production large-scale cultivation is 2.51 kgGWP higher than the result from SimaPro software.This is because that the pollution emissions of greenhouse gases and equivalent coefficient of coal,electricity and fertilizer it used is different from that of our country,which leads to the difference of calculation.Therefore,it is of practical significance to do localization coefficient correction work and to accelerate the establishment and improvement of localization life cycle database and environmental damage analysis methods in line with China’s national conditions.