Fish farming
Summer is the peak season for fish, shrimp and crab farming, and it is also the hottest at the same time. This season, the water temperature and air temperature are the highest in the year. Although it is the best peak season for breeding, it is also the most difficult time for breeding control. In order to protect fish production and fish health, farmers need to pay attention to the following A few points to prevent the high temperature in summer from harming fish.
1. Conventional freshwater fish breeding
1. July-August is a critical period for the cultivation and stocking of conventional fish fry. Therefore, the cultivation of summer flowers and fish species should be done from July to August. The seedlings should be immediately cleaned and disinfected before stocking. When stocking, they must be disinfected with salt water or potassium permanganate to avoid bacterial infection. When buying seeds from other provinces, disease detection and quarantine must be carried out to avoid introducing germs.
2. Adult fish breeding control: (1) July-August is the peak season for fish growth, and fattening and feeding should be consolidated. For pools dominated by fat water fish, fat chasing should be carried out immediately according to the water color and transparency. Pools or cages that mainly eat fish should be fed feed immediately. And work on the "four fixes" of feeding (fixed quality, quantity, positioning, and timing) and the "four looks" of feeding (look at the fish, look at the sky, look at the water, and look at the season); (2) Pay attention to water quality control. Instantly increase oxygen and change water according to weather changes. Because fish grow rapidly from July to August, their food intake increases greatly, and permeates also increase, so water quality can easily reverse and cause hypoxia. Therefore, the aerator should be turned on immediately every day to increase oxygen. If encountering hot weather, it should be appropriate to extend the start-up oxygenation time. At the same time, new water should be added frequently, the water level should be raised to more than 1.5 meters, and part of the lower layer water should be replaced appropriately. The use of beneficial microbial agents to improve water quality and substrate is proposed. During high temperatures, it is best to use photosynthetic bacteria or em bacteria and other microbial agents every 15 days; (3) Prevention of dry diseases. The temperature is higher from July to August, but the water temperature is relatively suitable. Various diseases in the water are easy to grow and develop. This is the season when fish are prone to disease. If prevention is ignored, fish diseases can easily be induced. The main diseases that are prone to outbreak and circulation in July and August are bacterial hemorrhagic disease, gill rot disease, enteritis, anchorworm disease, Chinese worm disease and anthyloidosis, etc. Shen Xin should do a good job in preventing bacterial hemorrhagic diseases and parasitic diseases. Fishing chemicals such as quicklime, chlorine dioxide, hydantoin and insecticide should be used for regular disinfection. (4) Strengthen daily control and keep pond patrols on duty. The weather in July and August is changeable, and thunderstorms and typhoons are prone to occur. Pay more attention to the feeding status of fish and the lack of oxygen floating heads. If signs of hypoxia are found, new water should be added immediately and the aerator should be turned on.Prevent fish from flooding the pond.
Two. Crustacean farming
1. Macrobrachium rosenbergii farming: It has been more than 2 months since the seeds were raised from May to July , the shrimp density, feeding amount, and oxygen consumption in the pond were significantly reduced, and breeding management entered a critical stage. (1) Under normal weather conditions, feed the shrimp as much as possible to allow them to eat up. In particular, it is necessary to invest in a good amount of feed throughout the day, and the feed required to be fed must be of high quality, fresh, and without deterioration; (2) Turn on the machine and increase oxygen in a timely manner. Since Macrobrachium is in its peak growth season from July to August, and the water temperature and temperature are relatively high, special attention must be paid to changes in dissolved oxygen in shrimp ponds to prevent hypoxia. Therefore, the aerator should be turned on immediately to increase oxygen according to the weather and water quality conditions. Tips for turning on the aerator: Turn it on at noon on a sunny day, turn it on at midnight on a cloudy day, and turn it on at midnight on a rainy day; (3) Managing water quality is a key link in breeding management. It is suitable for reducing the flushing frequency of shrimp ponds, which can not only improve the water environment, but also stimulate the shelling and growth of Macrobrachium. Generally flush once every 7-8 days, frequently increase the water depth by 10-15 cm, and require water flow; (4) Reasonable use of biological agents. In high temperature weather, it is best to use compound microbial preparations such as em Benlu every 15-20 days, which can effectively improve water quality and promote the rapid growth of Macrobrachium, and can prevent the outbreak of various shrimp diseases.
Fish farming
2. South American white shrimp farming: July-August is At the peak period of the growth of vannamei shrimp, the water temperature is high at this time, the shrimp grows quickly, eats a lot, and has a lot of permeates. The water quality is easy to reverse, and it is easy to lead to pond flooding. It is also a period of high disease incidence. Therefore, in order to protect the healthy and safe growth of vannamei shrimp, breeding control should be strengthened. (1) Consolidate water quality control. Keep turning on the machine at midnight and noon every day to increase oxygenation for 2-3 hours. If encountering low pressure and hot weather, the startup time should be extended. At the same time, change the water frequently according to changes in water quality. Change the water in small and frequent steps, changing 1/3 of the pool water every 7-8 days, and then increase the water level appropriately and keep it above 1.8 meters. In addition, due to the large amount of feed in the shrimp pond and the large amount of permeate in the pond, the water pollution will increase and the water color will become thicker. Zeolite powder should be used from time to time to control the water color. In shrimp ponds where it is difficult to change the water, em bacteria or bacillus and nitrifying bacteria can be used to improve the water quality. Pumping twice a month can effectively analyze the organic matter in the pond and reduce the concentration of ammonia nitrogen and nitrite in the water. (2) Strictly control the amount of feeding. Feeding should be carried out separately and with small amounts and frequent meals. Feeding 3-4 times a day, 70-80% day and night, 20-30% during the day%. The daily feeding amount should be flexibly controlled based on the weather, water quality, health and movement status of the shrimp, etc.; (3) Prevention of diseases. The important disease prevention measure from July to August is to disinfect water bodies regularly, generally once every 15-20 days. Disinfection drugs include ultraiodized quaternary ammonium salt, bromochlorohydantoin, dibromohydantoin, em bacteria, nitrifying bacteria and other environmentally friendly prescriptions. At the same time, pharmaceutical additives such as vitamin C, immune polysaccharide and virus spirit should be added to the feed regularly to enhance the body's disease resistance. At this time, the important diseases of white shrimp include red body disease (tora disease), white spot disease, black gill disease, red leg disease and nitrite poisoning. Among them, red body disease, vitiligo, and nitrite poisoning are relatively common. Therefore, accurate diagnosis and treatment should be based on different symptoms, and timely control should be carried out to prevent delayed circulation; (4) Catch them immediately and take turns to catch them and recuperate them. At this time, the shrimps grow rapidly and the amount of shrimps in the pond is too high. During the breeding process, the shrimps should be caught immediately and the small ones should be caught. The shrimps that have reached commercial specifications will be caught and put on the market to maintain a reasonable shrimp density in the pond and promote the control of shrimps. Shrimp grow.
3. River crab breeding: The weather is hot and the water temperature is high from July to August, which is the key season for river crab breeding. At this time, management should be strengthened and raised carefully to ensure that river crabs survive the summer safely and improve the breeding survival rate. At this time, the following points should be noted: (1) There is a sufficient supply of aquatic plants. The water surface should be stocked with some shade aquatic plants such as water peanuts and water chestnuts, or some emergent plants such as reeds and wild rice should be planted in advance. A large amount of young aquatic plants such as Black Algae and Vallisneria should be maintained in the crab pond to facilitate crab feeding and avoid predators; (2) Maintain water purity. Always check the water quality, change the water frequently, and remove leftover food and dirt promptly. The depth of the pool water should be kept above 1 meter to prevent the crab body from being burned by the boiling water and causing growth; (3) Pay attention to the feeding of sinking bait. The high temperature stage should be suitable for reducing the ratio of plant food. For example, wheat, pumpkin, vegetable cakes, etc. are all plant-based feeds that river crabs like to eat. When feeding, make these feeds into pellets or lumps and place them on the food table for crabs to eat; (4) Do a good job in disease prevention. Important diseases during this season include tremor disease, black gill syndrome, sessile ciliate disease, etc. It is necessary to maintain ecological disease prevention as the mainstay and drug prevention as the supplement. Normal disinfection is mainly based on quicklime, bromochlorohydantoin, etc., or beneficial microbial preparations such as em benzene are regularly used to maintain the stability of the microecology in the crab pond.
3. Important matters for breeding
1. It is necessary to strengthen daily control and maintain pond patrol duty. In seasons with changing weather conditions, we must pay close attention to observing the eating status and behavior of fish, and do the "four fixes" of feeding (qualitative, quantitative, positioning, and timely) and the "four look" (look at the fish, look at the fish) Check the weather, the water, and the season); in thunderstorms or hot weather, it is especially necessary to detect signs of hypoxia immediately, inject new water immediately, and turn on the aerator to avoid the occurrence of dead fish in the pond.
2. Water quality control should be consolidated. The quality of water is the key to fish breeding, so water quality management work should be done well. (1) Turn on the aerator: Turn on the aerator at noon on a sunny day to adjust the water quality to improveThe water body crosses the flow, reducing the dissolved oxygen in the lower pool water and dispersing toxic gases; the startup time can be appropriately extended when the weather is hot, shortened when the weather is cold, and floating water in the middle of the night shortens the startup time. (2) Pour biological agents: Regularly pouring biological agents such as photosynthetic bacteria and EM bacteria can make the water quality meet the requirements of "fat, live, tender and refreshing", maintain good water quality, prevent bacterial fish diseases, and improve the feeding ability and ability of fish. Immune efficacy. (3) Add new water: Adding new water can reduce dissolved oxygen and nutrient salts, and weaken organic matter and toxic substances in the pool water. Generally, water is added every 7 to 10 days, and 15 to 20 cm of new water is added frequently.
3. Do a good job in disease prevention. Summer is the peak period for fish diseases, especially hemorrhagic diseases, gill rot and enteritis. Therefore, attention should be paid to the disinfection of fish ponds and the quality of feeds. It is strictly forbidden to add rotten feed and toxic substances into the pond. At the same time, when applying pesticides, it should be noted that the stable water depth of the fish pond is less than 80 cm. When the water temperature is above 30°C, drugs cannot be poured into the entire pond; when the water quality is thicker and the temperature is low, the dosage should be increased, and vice versa. ; The pouring time is generally in the afternoon or evening, and pesticides cannot be sprayed at noon. It is not suitable to pour the entire pond when other fish are floating or just stopped; when spraying pesticides in the wind, pour them from the upper side to the downwind position; when spraying pesticides, Feeding cannot be done at the same time. Generally, the medicine is applied after feeding. However, food should be stopped for 1 to 2 days before feeding or taking medicine. Do not pull the net within 1 to 2 days after applying the medicine.
June to August is the hottest time of the year. Fish, shrimp and crabs are the peak season for high yields in these months. Many farmers rely on this important time of the year. It takes a few months to make money, so while maintaining high yields, you must not neglect breeding techniques to avoid unnecessary damage.
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