As a county with animal husbandry as its primary economic activities, Yunlin is known for the most swine and husbandries, especially Mailiao Township. At this scale, waste and odor has become a significant issue for local residents. To address environmental pollution, the local environmental protection bureau has taken a multi-pronged approach: in addition to auditing, policy adjustments have been made to dedicate in animal husbandry waste recycling and reuse counseling. Anaerobic fermentation technique is used to reduce odors, while the biogas, slurry and residues obtained from the process are rich in nitrogen, phosphorus and potassium, and can be used as a replacement of synthetic fertilizer. The biogas from digestion, when desulfurized and purified, can be used for power generation, which reduces the release of methane, a greenhouse gas, and the power generated is sold to Taiwan Power Company. The residues are bioprocessed with black soldier flies, which are also used as protein-rich feed materials. Processed slurry can be discharged into waterways or used for irrigation. With these uses, the wastes are more useful resources and energy sources than those directly discharged, and makes animal husbandry sites more than a source of meat products, but a multi-purpose industrial site supporting green energy and circular economy systems. This also aligns with the European Commission’s 2020 European Green Deal and their Farm to Fork Strategy.