臺灣豬隻生產的生命週期評估研究—桃園市、新竹縣、台中市及苗栗縣選定豬場案例分析

Abstract

畜牧產業提供了人類動物性蛋白質等飲食上的需求，但因環保意識的抬頭，讓民眾以更高的標準檢視畜牧生產環境。隨著評估環境衝擊方法學的發展，碳足跡(Carbon Footprint)、水足跡(Water Footprint)，到現今歐盟推行的環境足跡(Environmental Footprint)，也已經從製造產業擴散到各個部門進行運用。這些環境足跡採用生命周期評估(Life cycle assessment, LCA)進行系統分析，對產品系統自原物料的取得到最終處置的生命週期中，進行投入和產出及潛在環境衝擊的彙整與評估。本研究針對臺灣畜牧業中產值與規模最大的養豬產業，採用生命周期評估方法，對臺灣北部豬場進行豬肉生產過程進行環境衝擊盤查，建立資料並提出改進的方向。研究執行上以搖籃到大門的生命週期評估方式，將豬隻生產分成原料來源、製造過程、產物處理三個階段，分析對環境產生的影響。以豬隻生產1kg活體重做為功能單位，使用生命週期評估軟體SimaPro 8.5，選用ReCiPe 2008的衝擊評估方法，來進行中點與終點環境衝擊分析。分析結果顯示7個自配飼料一貫養豬場，在中點衝擊產生的影響方面，氣候變遷(全球暖化潛勢)介於5.34~6.57公斤二氧化碳當量，水資源耗竭0.135~ 0.213 立方公尺。經過標準化對比後，發現臺灣養豬產業在優氧化與環境毒性的衝擊會較為顯著，在陸域毒性的衝擊介於0.0641~0.367公斤1,4-對二氯苯當量。各豬場資料都顯示「養豬飼料生產」對於環境產生的可能衝擊最大，佔總體終點衝擊的80~92%。依據本研究成果，未來豬隻環境衝擊除了飼養管理與糞尿處理外，飼料來源的選擇將會是考量的方向之一。

This study targets Taiwanese largest and most valuable animal husbandry- the pig production industry. The life cycle assessment method is adopted to examine the environmental impacts on the pork producing process in a pig farm in northern Taiwan. Through the approach of life cycle assessment, the entire producing process is divided into three stages for analyzing its environmental influences: raw material sources, energy consumption in agricultural process and the process of waste and excreta disposal. Taking 1kg of live weight as a functional unit, we use the life cycle assessment software, SimaPro 8.5 and select ReCiPe 2008, as the impact assessment method to carry out environmental impact analysis of midpoint and endpoint. The results based on 1kg live pig weight showed that in seven on-farm feed and farrow-to-finish pig farms, the global warming potential was 5.34-6.57 kg CO2 eq, and the water depletion was 0.135-0.213 m3. Based on the comparison, it is found that the impact of eutrophication and environmental toxicity in Taiwanese pig industry are relatively higher, and the impact on terrestrial toxicity ranges from 0.0641 to 0.367 kg 1,4-DB eq. The information on each farm indicates that “pig feed production” has the greatest potential impact on the environment, accounting for 80-92% of the overall endpoint impact. In addition to feeding management and manure treatment, the choice of feed source will be one of the considerations.