Key Technical Points and Management Methods for Loach Cage Culture

In recent years, loach farming has developed rapidly, with a wide variety of farming models. The advantages of pond cage loach farming are fast growth, fewer diseases, easy management, and easy harvesting; it is a farming model with relatively good economic returns and great development prospects.

I. Pond Requirements

The pond should have an ample water source, fresh water quality, convenient water intake and drainage, abundant natural food organisms, and a wide range of artificial feed sources, with a bottom of neutral or slightly acidic clay soil. There is no limit on size; generally, about 3000 sq m with a water depth of 1.5-2 m is suitable. For cages used in mud-based loach farming, the water level is slightly shallower. Equip one small management boat for feeding.

II. Cage Setup

1. Cage area.

The cage area depends on the pond surface area. For large water surfaces, 20 sq m is suitable, with a length of 5 m, a width of 4 m, and a height of 1.8 m; for small water surfaces, the cage area should be 2-8 sq m, with length, width, and height determined according to actual needs.

2. Netting and mesh size.

The cage is made of polyethylene netting. The mesh size should be such that loach fingerlings cannot escape and water exchange inside and outside the cage is facilitated; generally, 0.5-1 cm is used.

3. Cage placement.

Cages are arranged with their length running east-west and their width running north-south. The spacing between cages is about 2 m, and the row spacing is 3 m. For small cages, the spacing is 0.4 m, and the row spacing is 1 m. Regardless of size, cages should protrude 0.4 m above the water surface and extend 0.5-1 m below the water surface. The cage setup should not exceed 50% of the pond area. Cages can be floating or fixed. Floating cages naturally rise and fall with changes in water level; to prevent loaches from escaping, the cage must always remain 0.4 m above the water surface.

Floating cages are suitable for large ponds or ponds with relatively large water level fluctuations. Fixed cages are secured at the four corners with bamboo poles or wooden stakes. For cages used in soil-free loach farming, the bottom of the cage is 0.5 m above the pond bottom. For cages used in mud-based loach farming, the bottom rests on the mud, and the bottom layer of the cage is first spread with 10 cm of manure, then with 10 cm of soil. Place the cages 15 days before stocking loach fry and fingerlings so that algae attach to the cage walls, and transplant some water peanuts or water hyacinths into the cages, with the plant growth area accounting for 1/3 of the cage area.

If the water peanuts or water hyacinths in the cages grow too luxuriantly during the farming process, remove them promptly and always keep the aquatic plant growth area no more than 2/3 of the cage area.

4. Set up feeding platforms. Set up 1-2 square frames 40 cm long and 10 cm wide as feeding platforms in each cage, with the feeding platform about 20 cm below the water surface.

III. Stocking Loach Fingerlings

1. Pond clearing and disinfection. Twenty days before stocking loach fingerlings, choose a sunny day and use quicklime to clear and disinfect the pond. The amount of quicklime used is 50-70 kg/mu. After the effect of the medicine disappears, loach fingerlings can be stocked.

2. Time for stocking loach fingerlings. Loach fingerlings are generally stocked at the end of March or the beginning of April, with 250-300 fingerlings of 4-5 cm body length stocked per square meter. Loach fingerlings are raised separately by size. Before entering the cage, disinfect the fingerlings with 3% salt water, soaking for 5-10 minutes at a water temperature of 10-20°C.

IV. Loach Feeding and Management

1. Feeding method.

After entering the cage, loach fingerlings go through a period of adaptation to the environment, so feed them after 2-3 days. For feed, you can choose artificial compound feed for loaches or process feed yourself. If processing it yourself, you can mix wheat flour, silkworm pupa powder, rapeseed meal, small trash fish, snail meat, etc. evenly and make it into balls or strips, then feed it regularly on the feeding platforms. At first, feeding time is every evening, scattering all over the cage; later, gradually narrow the range, and finally concentrate the feeding on the feeding platforms. After domestication, change to feeding once each at about 8 a.m. and 18 p.m. Loaches eat a large amount at night, so the afternoon feeding amount accounts for about 70% of the daily feeding amount.

The initial feeding amount is 2%-5% of the total weight of the loach fingerlings, the middle period is 5%-6%, and the later period is 8%-10%, adjusted as appropriate according to the loach's food intake. Food intake changes with the loach's growth condition, water temperature, water quality, weather, etc. In principle, the feed on the feeding platform should be finished in about 2 hours.

2. Water quality regulation.

Loaches like fertile water. The water for raising loaches should be “fertile, lively, tender, and refreshing.” Yellow-green water color is best. Too clear water affects loach growth. Keep transparency at about 20 cm, and pH neutral or weakly alkaline. When the water is too fertile, change the water promptly to increase the dissolved oxygen content of the pond water. Generally, change the water once every 7-10 days, each time by 20-30 cm.

In high-temperature seasons, when the water temperature exceeds 30°C, change the water 2 times per week. Frequently brush and wash the netting to maintain water exchange inside and outside the cage, increase the dissolved oxygen in the water inside the cage, and facilitate the entry of feed organisms into the cage. To improve water quality and increase pond utilization, other fish can be raised outside the cages, such as polyculturing crucian carp, silver carp, bighead carp, grass carp, bream, etc.

3. Disease prevention and control.

Regularly use quicklime or other harmless disinfectants to sterilize and disinfect the cages. The disinfection time should be flexibly controlled according to the loach's tolerance. When processing feed, 0.5% oxytetracycline or allicin, etc. can be added. Prevent pollution from pesticides, chemical fertilizers, etc. and invasion by predators. Check the cages frequently, and repair any holes immediately.

V. Harvesting for Market

For cages in soil-free loach farming, adult loaches that reach market size in autumn should be harvested promptly; small loaches that have not reached market size should also be removed from the cages before Frost's Descent and moved to small loach ponds for overwintering, otherwise they will freeze to death. For cages in mud-based loach farming, because there is soil at the bottom of the cage, after adult loaches are removed from the cages, the juvenile loaches that have not reached market size are gathered and moved to cages with a thickened bottom soil layer for safe overwintering.