Measures for intensive cultivation of fish fry in autumn

First, improve the growth environment. After several months of breeding, the water quality of the ponds that used to cultivate fish species is gradually aging, which is disadvantageous to the growth of fish species. Efforts should be made to improve it. One is to add new water, the water in the original pond can be released into 1 beat 3-1 tap 2, and then add new water with the same temperature. Second, fertilization, fermented manure can be properly applied, generally about 150 kg per mu, once every 7-10 days, a total of 500-750 kg, generally adopt the method of small pile stacking or sprinkling in the whole pool. In addition, it is necessary to apply chemical fertilizer appropriately, generally 1.5-2.5 kg urea per mu and 3-5 kg superphosphate per mu, once every 5-7 days. In order to prevent the deterioration of water quality, it is best to add fresh water every time you apply fertilizer, so that the transparency of the pool water is kept at 20-30 cm. Third, regular disinfection, every half a month with quicklime 10-15 kg per mu and concentration of 1 ml / kg bleach solution, alternately sprinkle the whole pool once.

Second, adjust the specifications of fish species. The pond, which mainly cultivates grass carp, can match 30% of silver carp and bighead carp species. Those who mainly cultivate silver carp and bighead carp should be matched with 30% grass carp fingerling. The proportion of silver carp to bighead carp is 5:1, and if the size of bighead carp is small, the proportion should be reduced. The stocking density should be determined according to the size of the water surface, the water depth, the size of fish species and the conditions of feed supply. In a pond with a general water depth of 1.5m, there are 3000-4000 fingerlings of about 10 cm per mu.

Third, ensure adequate nutrition. The Beginning of Autumn to White Dew is the fish species feeding stage, it is necessary to strictly control the number of bait, in order to make 80% of the fish full. Grass carp and blunt snout bream should be supplemented with fresh green feed, while herring should add more crushed snails, clams and so on. The ponds where silver carp and bighead carp are mainly fed with moderate fertilizer and water are suitable. After the Autumn Equinox, it is still the golden period for the growth of fish species. Adequate palatable feed should be put into the feeding fish. Silver carp and bighead carp should not only ensure proper fertilizer and water, but also feed appropriate amount of wheat bran, rice bran and crushed cakes. Before and after Frosts Descent, when the temperature falls, feed should be added, green fodder should be reduced as appropriate, and the amount of fertilizer applied to fish ponds should also be reduced. The daily dosage of concentrate feed should account for 3% of the fish stock in the pond. Keep feeding when the water temperature is above 7 ℃.

Fourth, strengthen the regulation of water quality. In early autumn, the weather is changeable, in order to prevent the pond from lack of oxygen, we should strengthen the change of water. Generally change the water once every 7 days, before and after the Autumn Equinox, the weather becomes cool, and the water can be changed once in about 10 days. The transparency of the water in the silver carp and bighead carp fry ponds should be kept at 20-25 cm, and that in the grass, bream and carp ponds should be kept at 25-30 cm.

Fifth, do a good job in the prevention and control of fish diseases. Insist on patrolling the pond sooner or later, and take timely measures to find problems. Usually regular disinfection of the water body, feeding should be regular, positioning, quality, quantitative, and timely fishing out the remaining bait residue, in addition, twice a month feeding bait, each time for 5 days, mashed garlic, leek, according to every 100 kilograms of fish fry with the proportion of 0.5 kilograms into the feed, can prevent Gill rot, hemorrhagic disease and enteritis and other common diseases.