Abstract:
Abstract: Due to its high nutritional and medicinal value, Chinese soft-shelled turtle, pelodiscus sinensis, is a favorite food in many parts of Asia. Consequently, the cultivation of it has become commercial. Large-scale farming of turtle in Anhui province has been growing rapidly, and the production was about 40 000 t in 2015. As a poikilothermal animal, the juvenile is hard to survive in the cold winter. Over-winter in greenhouse is necessary for it. Considering high fuel prices and limitation of pollutant emissions, an environmentally-friendly greenhouse was designed and constructed to satisfy the demand of the intensive cultivation of Chinese soft-shelled turtle, and to reduce the use of fuel and the pollutant emissions. One greenhouse was approximately 780 m2, including nine 70 m2 culture tanks, one 35 m2 culture tank and one 35 m2 reservoir. Every culture tank was connected to a settling tank through underground pipe. Ground source heat pump was used for heating, wok shape tank bottom with “ل”-tape central drainage was used to discharge the residual feeds and faeces timely, and the culture tank skirt shape 3-D shelter, under water feeding platform were equipped to satisfy the living habits, which could reduce the fighting probability and mortality in a great degree. For one greenhouse within the cultural period of 10 months, coal consumption and CO2 emissions were reduced by about 35 and 84.01 t, respectively, by using ground source heat pump compared to fossil fuel (coal) boiler. Additionally, the cost was decreased by about ¥ 11086 during the ten months culturing period. At the start, 3500 juveniles were stocked in one 70 m2 culture tank with an average weight of 3.5 g. Effective microorganisms and vitamin C were added into feed to increase the resistance during feed preparation. The culture water quality was controlled by microorganisms and parameters were monitored and recorded every several seconds by Internet of Things. During the culturing process, dissolved oxygen concentration was maintained in the range of 5.83-7.68 mg/L, water temperature was kept at 31±0.5 ℃, the monthly mean content of ammonia was kept at 0.39-0.83 mg/L and the nitrite was 0.14-0.16 mg/L. After cultivation for about 10 months, the weight of juvenile could increase to about 581 g from 3.5 g, the survival rate was 86.2%, feed conversion rate was 1.18, and specific growth rate was around 1.77, which meant that 43.1 turtles were obtained in per square meter and the average daily weight gain of one turtle was 1.93 g. Good growth performance meant high economic benefits, especially survival rate and feed conversion rate, because the cost of feed accounted for 70% of total investment. The economic return of a greenhouse was about ¥ 157870. Therefore, it is promising to construct the greenhouse for its significant environmental and economic benefit. The results provided a great theoretical and practical significance for the cultivation of juveniles in greenhouse. In summary, the environmentally-friendly greenhouse for culturing juveniles could provide comfortable living conditions, showing high economic and social values. So the greenhouse has a great popularization value and practical significance.