High-density loach farming techniques in cement ponds and key points for scientific feeding
AbstractCement pond selection and construction: You can choose to renovate an old pond, or build one with bricks, stones, etc. The water depth should be kept above 1 m, and water inlet and drainage measures and anti-escape measures should be well arranged. Preparation before stocking: Disinfect the pond, and apply organic fertilizer 5-7 days before releasing the fry to cultivate fertility. Releasing the fry: Select high-quality fry, soak and disinfect them in salt water before release, and release them on sunny mornings from early May to late June. Daily management: Feed scientifically and reasonably, regularly add and change fresh water, and do a good job in disease and pest prevention.
1. Construction of the cement pond
The cement pond for loach farming can be renovated from an old pond, or a new pond can be built with bricks, stones, etc. The area, shape, and size of the cement pond should be adjusted according to the farming scale and geographical location. The pond depth of the cement pond is best kept above 1 m. The water inlet and outlet should be enclosed with plastic nets or wire mesh. The pond bottom is best slightly sloped toward the drainage outlet to facilitate drainage and harvesting. The edge wall of the cement pond should be more than 50 cm above the water surface to prevent loaches from escaping. A shade net should be set up above the cement pond to shade the loaches and also help lower the temperature.
2. Preparation before stocking
Before stocking, dealkalize the cement pond. Fill the pond with water and soak for 10 days, changing the water once every 2 days; or use chemicals for dealkalization. After washing the unused cement pond clean with clear water, expose it to the sun for 4-5 days, then disinfect the pond with 20 g/m³ bleaching powder. After one day, drain the disinfectant completely, then put 16-20 cm of fertile mud into the pond and add 50-70 cm of fresh water. Apply organic fertilizer 5-7 days before releasing the loaches to fertilize the water, ensuring that there is enough natural food in the water for the loaches to eat. After 10 days, the loach fry can be released into the pond.
3. Fry release
Select high-quality loach fry from formal markets that are healthy, uniform in size, free of injuries and disease, agile in movement, and of suitable specification. Before release, soak them in 3%-4% salt water for 8-10 minutes for disinfection. From early May to mid-June, choose a sunny and windless morning for release. Loaches have a relatively high tolerance to low oxygen and can be farmed at high density. Generally, for loach fry of 8-12 cm, the stocking density can be controlled at 150-300 g/㎡.
4. Feed feeding
Natural food, small aquatic animals such as rotifers, river snails, attracted insects, artificially cultured earthworms, fly maggots, artificial feed, etc. are all feed for farming loaches in cement ponds. When feeding loaches, follow the “four fixed principles”, feed once each in the morning and afternoon every day, and the feeding amount should be suitable for the loaches to finish eating within 1-2 hours; the amount of feed fed each day accounts for 4-7% of the total weight of the loaches, and the specific feeding amount should be adjusted according to water quality, temperature, weather, and other conditions;
Two days after the loach fry are released, they can be fed feed such as rice bran and wheat bran, and afterward fed once every 1-2 days. Feed over a large area for the first few times, then gradually narrow the range; the feed fed to the loaches should be relatively constant, fresh, and palatable, and do not feed them spoiled feed. As the loaches continue to grow, gradually mix in plant-based feed such as soybean cake and rice bran, plus loach feed made by chopping fresh small fish and shrimp or other animal viscera scraps and mixing them with compound feed; in the middle and late stages of farming, appropriately increase the feeding amount of animal-based feed, or make it the main feed; within 7 days of releasing the loaches, the feeding amount for wild fry should be half of the normal amount, and after domestication and adaptation, feed according to the normal amount.
5. Water quality management
Set up a shade net above the cement pond, add and change fresh water in time, and the water temperature in the cement pond is best controlled below 30 °C. When adding and changing fresh water, avoid a water temperature change of more than 5 °C before and after the water change. In spring and autumn, ensure that the cement pond has sunlight exposure, and in summer do a good job of shading. The water transparency should be controlled at about 40-50 cm. Regularly apply organic fertilizer to the pond to fertilize the water quality. The amount and frequency of water changes should be adjusted according to the season. Generally, in spring and autumn, change 1/3-1/2 of the pond water every 7 days, and in summer change 1/5-1/4 of the pond water every 3 days.
6. Disease and pest control
During the farming process, patrol the pond every day and promptly remove harmful animals in the pond such as crabs, crayfish, rats, snakes, and birds. Before stocking, disinfect the cement pond and loach fry to prevent disease. They can also be fed medicinal bait such as allicin or Baogan Jiedu Ning once a month for 3-6 consecutive days to strengthen the loaches' constitution and prevent enteritis; regularly disinfect the pond with an appropriate amount of quicklime water; promptly remove moss or harmful algae in the pond.