Grass carp culture technology
1, seed selection
Observe the swimming situation of fish in the fry pond, climb the edge, swim alone, and whether there are fried groups when eating. , are signs of fry disease. Fish fry with dark grass green body color and black body color cannot be used. It is suggested to choose fry with overall specifications, fast swimming speed and consistent body color.
2. Water quality management
Sprinkle quicklime regularly: generally every half month, the water level is 20kg per mu and the water depth is 20kg per meter, or apply bleaching powder 1PPM to the whole pond.
Planned water change: inject fresh water every 10 day, 20 ~ 30 cm each time, and change water according to the actual situation before mid-July, with the water change rate of 1/2.
Start the aerator every day: from June to mid-August. Grass carp is easy to float because of lack of oxygen. This festival lasts for 2-3 hours at noon on sunny days, 3-4 hours in the morning on cloudy days and once in the middle of the night to prevent fish from floating.
Patrol the pond carefully: keep abreast of the activities and food intake of fish in the pond, master the changes of water quality, and prevent and treat diseases early.
Clean up the sundries in the pond and remove the green fodder leaves left by grass carp.
3. Prevent fish diseases
Prevention is the key to fish diseases, which is also the key to intensive cultivation of grass carp. Therefore, in the whole breeding process, we should focus most of our energy on the prevention and treatment of fish diseases, strictly control the disinfection of each link, and regularly feed bait made of Chinese herbal medicines and immune enhancers for health care, mixing them 2-3 times a month for 2-3 days each time.
The main causes of grass carp diseases are water quality deterioration, aging, mildew of polluted feed, seasonal bacterial and parasitic outbreaks and so on. The most effective treatment for gill rot, erythroderma and enteritis of grass carp is oral administration plus external use, and injection can be used when the outbreak treatment is expected.
4. Feed collocation
50% of rice straw, 25% of rice bran and 25% of bean cake. 100 kg of the above mixture is added with 10 kg of flour leftovers as a binder. The feed crude protein content is 23.35%, the feed coefficient is 2.8, and the feeding specification is about 0.05 kg per tail.
50% rice straw, 22.5% rice bran, 5% wheat bran, bean cake 15%, fish meal, bone meal 1%, salt 0.5%, vitamin additive 1%, feed crude protein content 18.78%, and feed coefficient 2.
Flour 30%, rice bran 8%, wheat bran 38%, bean cake 10%, fish meal 10%, yeast powder 2%, premix 2%, feed coefficient 1.9, if green feed is added, the feed coefficient is 2.2.
Flour 30%, fish meal 10%, bean cake powder 15%, bran 25% and rice bran 20%. On the premise of keeping the total amount of basic diet unchanged, we can add 12% sweet potato powder, 0.5% salt, 2% auxin and 2% calcium hydrogen phosphate according to the actual situation, and the feed coefficient is 4.8.
5, timely fishing
Catching and selling large-scale adult fish in time is an important measure for high-yield culture of grass carp. The main purpose is to reduce the fish carrying capacity of pond water and promote the rapid growth of pond fish in the later stage. Generally, 1 time will be caught at the end of July, and it will be caught in the early morning when the water temperature is low.
Fish pond management
1, pond conditions
It is required that ponds should be far away from pollution sources, with an area of 5 ~ 10 mu, flat bottom, loam as the best substrate, micro-leakage as the best, sediment/kloc-0 ~ 20 cm, and water depth of about 2 m. Each pond should be equipped with a 3 kW impeller aerator and a 4-inch water pump to change water and aerate in time.
2. Cleaning and disinfection
Grass carp itself has many diseases, and ponds are more prone to epidemics. At the same time, removing miscellaneous fish is an important measure to ensure grass carp to eat normally and save feed. The specific method is to use 100 kg of quicklime or 100 kg of bleaching powder to dissolve in the warm water of the dry pond and sprinkle it on the whole pond to completely kill the disease.
3. Water quality requirements
The water quality of the pond requires a pH value of 7.5 ~ 8.5, the transparency of the pond water is kept at about 30cm during the peak period of culture (June ~ September), and the oxygen consumption of organic matter is18 ~ 20mg/L. ..