Detailed Explanation of Key Technical Points for Semi-Wild Soft-Shelled Turtle Farming
Semi-wild soft-shelled turtle farming is a healthy farming method that imitates the natural growth habits of soft-shelled turtles. The farming cycle (3 to 4 years) is relatively long, so the soft-shelled turtles produced have the excellent quality of wild characteristics and sell very well on the market. The average yield is generally 250 to 300 kg per mu, with an average annual income of about 6,000 yuan per mu, achieving relatively good economic, social and ecological benefits. Through many years of farming practice, a relatively standardized set of production technical procedures has now been experimentally developed, briefly introduced as follows:
I. Construction of Ecological Farming Ponds
The farming base should be built in an area with a quiet environment, close to a water source and with unpolluted water quality. The farming ponds are required to all be earth ponds, preferably square, and the pond bottom soil should preferably be sandy loam, with silt thickness not exceeding 15 cm. The pond bottom is required to be flat, the pond depth 1.2 to 2.5 m, and the area generally 3-5 mu, preferably not exceeding 15 mu. Where conditions permit, parent turtle ponds, juvenile turtle ponds and hatchling turtle ponds may be built as supporting facilities. The farming ponds may use asbestos boards, brick walls, cement boards, etc. to build escape-prevention facilities. Aquatic plants should be transplanted into the ponds, and in spring an appropriate amount of snails, clams, river mussels and other shellfish should be stocked so as to form a good ecological environment in the ponds. In addition, several feed platforms and sunning/resting platforms should be set up as needed.
II. Breeding and Stocking of High-Quality Seedlings
1. Selection and cultivation of parents. Select wild Chinese soft-shelled turtles grown in natural waters as parents, requiring a body weight of 2 to 4 kg, 6-7 years of age, having reached sexual maturity, disease-free and injury-free, and robust in constitution, with a female-to-male ratio of 4:1. The selected parent turtles should be raised in dedicated ponds, with a stocking density of 0.3 to 0.5 turtles per square meter of water surface. In terms of feed, animal-based feed (live snails and clams, small trash fish, animal viscera, etc.) should be the main component, supplemented with an appropriate amount of plant-based feed (oilseed cakes, pumpkin, etc.) and compound feed, with a daily feeding amount of 5% to 8% of the total body weight of the turtles in the pond.
2. Artificial incubation and cultivation. While selecting and breeding parent turtles, turtle eggs should be observed and collected in a timely manner, and artificial incubation should be carried out indoors using a constant-temperature incubator or constant-temperature sand tray (the sand in the sand tray should be sifted through a 25-mesh screen), with the temperature required to be controlled at 33 degrees C to 34 degrees C, the humidity maintained at 81% to 82%, and the moisture content of the sand in the hotbed controlled at 7% to 8%. After 36-38 days, hatchling turtles and juvenile turtles are hatched. Hatchling turtles should be raised in graded separate ponds, mainly with live feed such as water fleas, tubifex worms and minced small trash fish for intensive cultivation. During the overwintering period, anti-freezing facilities should be well managed to increase the overwintering survival rate.
3. Stocking of seedlings. For normal-temperature turtle farming in earth ponds, stocking begins each year in spring from April to June. It is suitable to stock hatchling turtles weighing more than 15 grams, requiring uniform size, the same age and robust constitution. Turtle seedlings purchased from other places should be temporarily raised and intensively cultivated for 1 month before stocking, while seedlings bred and cultivated on site can be stocked directly. Before stocking, they should be disinfected with drugs such as potassium permanganate to prevent disease occurrence. The stocking density is generally 600 turtles per mu. In addition, an appropriate amount of silver carp, bream, yellow catfish, freshwater shrimp and other species should be stocked in combination in the farming ponds to improve water body utilization.
III. Normal-Temperature Rearing of Adult Turtles. Chinese soft-shelled turtles are farmed outdoors using natural water temperature. Efforts should be made to create an ecological environment for soft-shelled turtle growth as much as possible and to implement scientific management, mainly including:
1. Feed feeding. The feed should mainly be fresh live feed, combined with some plant-based feed as self-prepared feed. The main types include: fresh live snails and clams, small trash fish, animal viscera, oilseed cakes, bran, pumpkin, etc., as well as artificial compound feed. Feeding begins when the water temperature rises above 18 degrees C, with a daily feeding amount of 3% to 6% of the turtle body weight. Feed 1-2 times per day, depending specifically on water temperature and weather conditions. A small amount of biological preparations such as photosynthetic bacteria may be added during feeding. Generally, soft-shelled turtle pellet feed is not used, and additives and drugs containing hormones or residues are prohibited.
2. Water quality regulation and disease prevention and control. In the process of semi-wild soft-shelled turtle farming, the key to controlling soft-shelled turtle diseases and improving soft-shelled turtle quality lies in water environment control. The focus is on doing a good job in water quality regulation, creating the natural growth environment of soft-shelled turtles as much as possible, and establishing the ecological balance of the water body. The main things that should be done are: (1) Do a good job in the ecological setup of the pond. First, stock live snails, clams, river mussels and other shellfish, at 200 kg per mu in spring from March to April; second, transplant aquatic plants, including eelgrass, Elodea, water hyacinth, etc., with coverage reaching 1/3, creating a good ecological environment and achieving self-purification in the pond. (2) Regularly add and change water. Water should be appropriately changed and added every 10 to 15 days, and the amount of water changed should generally not exceed one third, so as to keep the water quality fresh and stable. (3) Regularly splash quicklime to regulate water quality and keep the pH value stable. (4) Control feeding to reduce damage to the water environment from feed. First, feeding should be controlled so that the feed is eaten within 2 hours; second, persist in inspection to avoid excessive feeding causing leftover feed to damage water quality. (5) Regularly add microbial products. Such as photosynthetic bacteria, etc., which can be regularly splashed and added to the feed every day, playing roles such as purifying water quality, preventing disease and promoting growth, and improving feed conversion rate. In terms of disease prevention and control, it is necessary to persist in giving priority to ecological prevention and control, with drug prevention as a supplement. As needed, medicated feed may be regularly fed and bactericidal and insecticidal drugs may be splashed for prevention. The use of drugs must comply with the provisions of NY5071-2001.
3. Pond separation management. Each year, according to the growth of the turtles, timely selection should be done, placing those of basically the same size together for rearing, to prevent cannibalism and disease occurrence, which is beneficial to soft-shelled turtle farming management and promotes growth. IV. Capture and Marketing. After 3 to 4 years of normal-temperature outdoor farming, the farmed soft-shelled turtles generally reach about 500 grams. At this time, they should be captured and marketed in a timely manner according to market demand, and may be caught with cages or by draining the pond. At the time of marketing, brand sales should be carried out externally under the unified organization of the company or association.