The traditional breeding mode in China is not feeding feed during the long wintering of fishes, so that the fish can only sustain life by depleting the nutrients accumulated in the body during the winter. The fish will lose weight and survive after a long wintering period. This phenomenon is especially noticeable when the fish species is overwintering. Tests have shown that in the traditional way of management, after the wintering season, the fish species lose more than 10% of body weight and the mortality rate is 8%~15%. In particular, some fish species with thin constitutions can sometimes reach 40% or more mortality during the wintering period. In addition, due to long-term fasting, the digestive function of fish is reduced, metabolic function is disordered, and disease resistance is deteriorated. It takes a long time to restore constitution after the spring and affects the aquaculture production in the next step. Therefore, changing the traditional breeding mode, strengthening the overwintering management of fish species, and paying attention to the feeding of winter fish species can increase the survival rate of fish species, shorten the breeding cycle, and increase the breeding efficiency.
To strengthen the overwintering management of fish species is mainly to do the following:
Adjusting the water quality in winter It is of special significance to regulate the water quality of the fishing pond in winter. On the one hand, it can provide enough oxygen for the fish to reduce the harm of harmful substances. On the other hand, the temperature of the pool water can be appropriately increased, which will facilitate the wintering of the fish species and promote the growth of the fish. . Therefore, attention should be paid to the regulation of water quality in winter. The regulation of winter water quality is mainly about adding water and changing water. Usually 15 days to 20 days, add water or change the water once. The specific amount of water to be changed depends on the quality of the water. Usually 10 cm to 20 cm can be used. Usually pay attention to the measurement of water temperature, when the water temperature is higher than the pool water temperature, can change the water in time, first discharge part of the pool water, and then add new water, in order to facilitate the pool of water temperature increases; in the late winter, a large water change, completely improve water quality, promote Fish species eat early and grow early.
Pay attention to feeding in time The traditional culture method in our country is that the fish do not feed during the wintering period. In order to ensure the smooth wintering of fish species, reasonable feeding should be adhered to in order to ensure the supply of nutrients. Generally, as long as the fingerlings feed, they should feed the feed. In sunny weather, they can be fed once a day to three days. The daily feed amount can be 1% to 2% of the fish's weight. After the ice is sealed, a small amount of fine material can be placed in the ice hole to facilitate the timely feeding of fish.
Appropriate top-dressing, fertilizer and winter topdressing are not only beneficial to the reproduction of phytoplankton, increase dissolved oxygen, but also can play the role of warming and heat preservation. Therefore, the top of the fingerling pool should pay attention to the application of top dressing in the winter. It is better to topdress with organic fertilizer, generally 15 days to 20 days once, each time can be fermented good cattle, pig manure 100 kg to 200 kg, but also according to the water quality conditions. For fish ponds with more silt in the bottom of the pond, chemical fertilizers can be applied, which can be applied according to the ratio of 1:0.1 of nitrogen and phosphorus (refer to the ratio of active ingredients). Each application of chemical fertilizer has 4 kg/mu~6 kg/mu; if the water quality is relatively Fertilizer can not be applied.
Pay attention to disease prevention and treatment The most common disease of winter fish species is saprophytic disease, which is mainly caused by fish species being injured or frozen due to low water levels when ponds are stocked or stocked. Therefore, in order to prevent the occurrence of the disease, it is necessary to avoid Fish body is injured, and when ponds and stockings are handled carefully, avoid bruising. Before stocking, soak fish with 3%~5% salt water for 10 minutes to 15 minutes; pay attention to maintain the water level, and keep the water level shallow and frozen fish species. . Once the disease was discovered, it could be treated with a 40% solution of formaldehyde in Quanchipi at a rate of 0.5ppm, or 2.5kg to 5kg of wolfberry juice per acre, 1.5kg to 1.0kg of salt, and 5kg to 20kg of human urine. , mixed, Quanchiposa treatment.
In addition, fish species are also prone to oral filarial, trichoderma, oblique tuberculosis, vertical scale disease, etc. in the winter. Usually, attention should be paid to observation, fish diseases should be found, and effective measures should be taken in time for treatment.
Other types of management in the northern regions of China will have different ice-sealing periods. In order to ensure the successful wintering of fish species, the following work should be done during the ice-sealing period:
Playing ice holes to play ice holes can help observe the activities of fish species, observe the quality of water, and help increase dissolved oxygen. In general, 0.5 square of ice hole 3 to 4 can be played per acre of water.
After sweeping snow and ice, if there is snow or other dirt on the ice, it will affect the light transmission, affect the photosynthesis of phytoplankton in the water, affect the production of dissolved oxygen, and easily lead to accidents. Therefore, it should be kept after the ice is sealed. Ice clean.
In short, during the overwintering season of fish species, the traditional breeding mode should be changed and the management in all aspects should be strengthened in order to increase the survival rate.