Loach Farming Methods and Technical Key Points in Wooden Boxes
Where there is a water source but it is not suitable to build a pond, loach can be farmed in wooden boxes, and they can be harvested after half a year of rearing, with each box producing 15-20 kg of loach.
1. Wooden box construction Specifications 1 m×1 m×1.5 m, with a spatial capacity of 1.5 m3.
Install a water inlet and outlet with a diameter of 3-4 cm on one or both sides, and fit them with 2 mm metal mesh. Fill the bottom of the box with manure and dredged soil (or a layer of straw and a layer of soil), with soil on the top layer, and keep the water depth in the box at about 30-50 cm. The wooden box can be placed in a sunny flowing-water spot so that water can flow in through one hole and drain out through the other. Several boxes can be connected together for linked-box production.
2. Stocking density Each box can be stocked with 1-1.5 kg of loach fry longer than 3 cm.
3. Feeding and management
Loach is an omnivorous fish. In flowing-water wooden box loach farming, artificial feeding is the main method. Feeds include fish meal, animal viscera, pig blood meal, soybean cake, wheat bran, sauce distillers' grains, rapeseed cake and other plant-based feeds. The compound feed consists of 50% wheat flour, 20% soybean cake powder, 10% rice bran powder, 10% fish meal or silkworm pupa powder, 7% blood meal, and 3% yeast powder. Add water to the compound feed and knead it into ball-shaped bait. The feeding amount is 1%-2% of the loach body weight in the box. Loach appetite is related to water temperature, so the proportion of animal and plant-based feeds and the feeding amount should be adjusted according to season and temperature. When the water temperature is below 20°C, plant-based feed should account for 60%-70% of the total. When the water temperature is 23°C-28°C, plant-based feed should account for 30%-40%. Generally, feed twice a day: at 7-8 a.m. feed 70% of the whole day's bait amount, and at 1-2 p.m. feed 30%. Loach starts feeding at a water temperature of 15°C, and as the temperature rises the feeding amount gradually increases, generally 7%-8%. When the water temperature is higher than 30°C or lower than 10°C, feed less or stop feeding.
4. Loach disease prevention and control
To prevent the occurrence of loach diseases, while ensuring the quantity and quality of feed, quicklime, bleaching powder, etc. should be used to regularly disinfect the box body. Once enteritis is found, 20 g of furazolidone can be added to 10 kg of feed, fed twice a day for 3-5 consecutive days. Red fin disease is extremely harmful to loach. After loach is infected with this disease, the fins, abdominal skin and area around the anus become congested and ulcerated, and the tail fin and pectoral fins turn white and rot away. Once this disease is found, immediately soak and wash the loach body with a 0.1/10000 concentration tetracycline solution for 1-2 hours, or bathe it with a 0.2/10000 concentration furazolidone solution for 24 hours. Alternatively, mix 0.04% (proportion of drug to fish body weight) furanace into the feed and feed continuously for 3 days. If saprolegniasis is found, soak and wash the diseased loach with 4% salt water for 5-10 minutes, or soak and wash with a 4×10-6 copper sulfate solution for 20-30 minutes. If parasitic diseases are found, 0.7×10-6 copper sulfate and ferrous sulfate (the two in a 5:2 ratio) can be evenly sprinkled over the linked boxes, which can prevent and control trichodiniasis and epistylidiasis.
5. Precautions When it rains, prevent the box water from overflowing and causing the loach to escape, and also prevent pesticides and chemical fertilizers from contaminating the water and entering the box.