Stress prevention and control method during crab cultivation
There will be stress reaction in the process of dunking crabs, which is harmful and difficult to treat, which will have a great impact on the breeding efficiency. For prevention and control of crab stress, here are some countermeasures. First, the physical stress of crab cultivation Stressor: temperature, light, vibration, noise, heavy rain, etc. Stress response: Crawl, turn, flip, tremble, stun, coma, battle, change in body color, claws, etc. Features: In addition to the physiological tolerance of crabs on the physical factors, most of them are acute changes to the stress, elimination of undesirable factors, stress response can be alleviated, on the contrary, acute stress can lead to the death of dung beetles. Prevention: Deter crab breeding farmers should properly master the pond water temperature before bigeye larvae feeding, according to their actual breeding experience, so that the pond water temperature is consistent with the temperature of the bigeye larvae seedling bag, and the water grass should be well maintained during high temperature cultivation. Timely replanting (cutting) aquatic plants, timely adding fresh river water, deducting crabs to cultivate ponds, not to walk frequently, preventing natural enemies from using Skynet, not knocking Luo, setting off firecrackers, minimizing vibration and noise, and performing thunderstorm season before and after The water quality protection minimizes physical stress. Second, the crab artificial anthropogenic stress Stressor: feed nutrition, operation, abuse of drugs, release of unfermented organic fertilizer, free-range arbitriness, random access to drainage, etc. Stress response: anorexia, refusal to eat, turn over belly, body color becomes darker, shelling difficult and so on. Characteristics: Anti-stress ability, disease resistance, and immunity are in the lowest state. It is easy to send various diseases and it is difficult to treat. Prevention: The construction of the pond's ecological environment and the quality of feed are the key to the success of cultivating crabs. Both must be well mastered. After the former is done well, the latter must consider the comprehensiveness of feed quality, and the animal protein and vegetable protein As for the rationality of the ratio, there is currently a supply of biological feed on the market. It is recommended that farmers can try biological feed instead of the current pellet feed. At the same time, we must eliminate barbaric operations, scientific stocking, and scientific management. Third, the chemical stress of crab cultivation Stressors: dissolved oxygen, pH, salinity, organic matter content, sewage, organophosphorus pesticides, fishery drugs, and macroscopic larvae themselves. Stress response: slow crawling, turning belly, licking, licking claws, black silk, red silk, body cavity ascites, hepatomegaly and rot, hepatic light or congestive, gallbladder color light, spit yellow water. Features: acute stress, symptoms in the ankle, crawling, no shelling, long-term stress is mainly manifested in the visceral toxic lesions. Prevention: Renew ideas, and take the path of healthy breeding and ecological farming. The prevention of chemical stress diseases is mainly to strictly control the use of drugs. In special circumstances, Chinese herbal medicines can be used instead of chemical drugs to reduce the chemical products to the crabs. The internal organs are damaged. Fourth, the biological stress of crab culture Stressor: density, food, pathogens, predators, etc. Stress response: (in addition to pathogens) slow crawling, loss of appetite, long shelling period, crawling weird and so on. Features: It is not easy to be found in time, it is chronic stress, so it is difficult to treat. Prevention: According to the farmer's usual breeding experience, the amount of large-eyed larvae can be reasonably distributed. When the water quality changes, biological agents (photosynthetic bacteria, EM bacteria, Bacillus) can be used to regulate, and chlorine dioxide and bromochloroheine can also be used. Regular killing of pathogens, appropriate 0.5% of calcium dihydrogen phosphate during shelling, can also be put in the feed a small amount of shell powder and Baker powder, and at the same time to do a good job of Skynet engineering and water supply and drainage pipe network engineering, natural enemies and other Invasive alien animals. Hybrid Stepper Motors,Brushless DC Motors,Linear Motor,Gear Motor,Step-Servo Motors,Brushless Motors Changzhou Satidi Import and Export Co., Ltd. , https://www.guanjiejts.com