| 英文摘要 |
This project is divided into three key objectives: "Compilation of Domestic and International Trends and Situations in the Development of Converting Livestock Digestate Fiber into Feeds," "Demonstration Site for the Cultivation of Fish Food Organism from Digestate Fiber," and "Establishment of Technology for the Cultivation of Fish Food Organism from Digestate Fiber." The study first collects and summarizes domestic and international literature to complete a report on the trends and situations in the development of converting livestock digestate fiber into feeds.
Afterward, a specific livestock farm and an aquaculture facility were selected in Yilan County to conduct pilot-scale trials for cultivating red fish food organisms using digestate fiber. Additionally, laboratory-scale experiments were conducted to establish the technology for cultivating red fish food organisms using digestate fiber.
Data collected from the five-month pilot-scale trial indicated that the cultivation environment should avoid direct sunlight to prevent excessive algae growth, which could deteriorate water quality. Chironomidae larvae activity could be observed three weeks after the start of cultivation, with a maximum population of 17.5 individuals per liter. Laboratory-scale experiments found that at a controlled temperature of 25°C, adding double the wet weight of sludge worms in livestock slurry could provide enough food for the sludge worms for at least five days. Each gram of sludge worms could digest approximately 9.8 milligrams of dry-weight livestock digestate fiber.
Chemical analysis of the digestate fiber and fish food organisms revealed that the digestate fiber contained cadmium and lead over regulatory standards and couldn't be used directly as feed for aquaculture. However, when fish food organisms were cultivated using digestate fiber, this issue was avoided, and they could be used directly in aquaculture feed.
Finally, it was calculated that replacing composting with the cultivation of red bait feed organisms using livestock slurry could achieve a carbon reduction benefit of 70.0% to 81.5%.
Based on the preliminary results of this project, it is recommended that future cultivation of sludge worms or chironomidae larvae using sludge in aquaculture ponds should consider the installation of shading facilities. This helps prevent excessive sunlight exposure in the cultivation ponds. In addition to avoiding elevated water temperatures caused by sunlight, it also allows sludge worms or chironomidae larvae to thrive and reproduce in cooler environments.
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