How Can the Disease Resistance of Fish Be Improved? 6 Effective Methods

Under current farming conditions, it is impossible to eliminate all pathogens. But to control the occurrence of fish diseases, we can start with scientific breeding management and maintaining the ecological balance of the aquaculture water body to improve the disease resistance of fish. As long as the measures are appropriate, we will achieve twice the result with half the effort.

1. Reasonable mixed culture

Reasonable mixed culture can not only increase the yield per unit area, but also has a certain effect on the prevention of fish diseases. Because the parasites suitable for different species of fish are not exactly the same, some parasites can only parasitize a certain species of fish, while other fish are not sensitive to them; after mixed culture, the population density of each species of fish is reduced, and the probability of an outbreak of infectious diseases will also be reduced. In addition, mixing fish with different activity water layers and different feeding habits can make full use of the ecological space of the aquaculture water body and various bait organisms and nutrients, reduce the content of organic suspended matter in the water body, maintain the ecological balance of the aquaculture water body, and reduce the chance of fish disease occurrence.

2. Early stocking

Implement early stocking, changing spring stocking to autumn, winter or early spring stocking. In autumn and winter, the water temperature is low, and the activity of fingerlings is weak, so they are easy to catch and transport, and are not easy to be injured and infected with diseases. Early stocking can also enable fish to adapt to the new environment earlier. By the season when diseases are prevalent after the water temperature rises in spring, they have already recovered their physique, started feeding, and enhanced disease resistance; moreover, the growth period is extended.

3. Implement the "four fixed" feeding

1. Fixed quality: The feed fed must be fresh, nutritionally balanced, free of pathogens and toxic substances, and not rotten or deteriorated.

2. Fixed quantity: Feed an appropriate amount according to the size and species of the fish. The feeding amount should be determined according to the season, weather conditions, the degree of water fertility and the feeding situation of the fish. Generally, the amount eaten within two hours is appropriate. When the breeding situation is normal, the feeding amount should not vary from time to time.

3. Fixed time: Feeding must be at fixed times. For example, if feeding twice a day, feed once at 8-9 am and once at 3-4 pm.

4. Fixed location: Feeding must be at a fixed place, so that the fish develop the habit of eating at a fixed location. This not only facilitates observing the dynamics of the fish, checking the feeding situation, and clearing away residual feed, but also facilitates applying drugs during the season when fish diseases are prevalent, achieving effective prevention and control.

4. Timely fertilization

The main role of fertilization is to increase the nutrients in the pond water, so that plankton grows and reproduces rapidly, maintaining the ecological balance of the aquaculture water body and providing natural bait organisms for fish. On the basis of applying sufficient base fertilizer, topdressing should also be applied in an appropriate amount during the middle stage of breeding. Topdressing should follow the principle of being timely, applying less, and applying frequently, and topdressing should preferably be fermented and decomposed organic fertilizer or the slurry of mixed compost, or chemical fertilizer can also be applied as topdressing.

5. Persist in patrolling the pond

Develop the habit of patrolling the pond every morning, noon and evening, observing the feeding and activity of fish, changes in pond water quality, etc., so that measures can be taken in time when problems are found. For example, through inspection and observation, early symptoms of fish diseases can be discovered in time, examined and diagnosed early, and effective prevention and control can be carried out in time to control the development of the disease. Pay attention to the environmental sanitation of the fish pond, frequently remove weeds around the pond, frequently eliminate enemies and intermediate hosts of pathogens, and promptly remove residual bait and dead fish; regularly clean and disinfect the feeding site. By observing changes in the pond water, timely topdressing, water replacement or injection of new water can be carried out to keep the pond water "fertile, lively, tender and refreshing."

6. Prevent injuries

Daily management, seine net fishing, moving into boxes, and breeding operations must be done carefully to prevent fish from being injured and infected with diseases.