As temperatures rise and water temperatures stabilize, spring is both the prime growth period for aquatic farming and a period with a high incidence of diseases. "The four pests of spring" - ichthyophthirius, rotting gills, intestinal inflammation, and parasites - are highly prone to outbreak. If prevention and control measures are inadequate, it can not only affect growth but also lead to significant yield losses on a large scale.
This authoritative, practical and immediately applicable spring disease prevention manual will help you control diseases at their source and lay a solid foundation for a successful harvest throughout the year!
1. Precise identification and targeted treatment of "four major diseases" that are prevalent in spring
Fungal disease (white disease)
High-risk conditions: water temperature between 10 and 20 degrees Celsius, injured fish, after being pulled out of the net and transferred to another area.
Typical symptoms: Grayish-white cotton-like fungal threads on the body surface, the fish becomes emaciated and moves slowly.
Key points for prevention and control
During the low-temperature period, reduce the use of nets, separate fish into pools, and minimize transportation to avoid mechanical damage.
On sunny days, use povidone-iodine / cuscuta powder for gentle disinfection.
After the onset of the disease: Mix salt and baking soda solution and sprinkle it throughout the tank; or apply methylene blue to the entire tank.
2. Bacterial diseases (rotten gills, erysipelas, enteritis, septicemia)
High-risk conditions: Water temperature around 15℃, deteriorated water quality, and leftover food contamination.
Typical symptoms: Rotting of gill filaments, body surface congestion, redness and swelling of the anus, and inflammation of the intestines.
Key points for prevention and control
Regularly disinfect with slaked lime / povidone-iodine solution
Oral administration: Mix and feed with fluconazole powder, sulfadimidine powder and allicin. Continue for 5-7 days.
Do not feed spoiled feed and control the amount of feed given.
3. Ciliate parasites (wheelworms, oblastarians, and minuscule gillworms)
High-risk conditions: Poor water quality / excessive water content, insufficient dissolved oxygen, excessive density
Typical symptoms: rubbing the body, floating to the surface, excessive mucus on the gills, and obvious spots on the body.
Key points for prevention and control
Adjust the water quality, reduce organic matter, and stabilize the algal community.
Use the copper sulfate + ferrous sulfate mixture, as well as saikosaponin and other national standard fish medications.
A small number of parasites can be left untreated to avoid excessive stimulation.
4. Overwintering Syndrome (Weak body, discolored skin, emaciated appearance)
The main reasons: poor wintering condition, high stress, and sudden change in weather in early spring.
Key points for prevention and control: First, stabilize the water conditions; then, feed the fish; avoid disturbing the water; and enhance immunity.
II. Core Measures for Preventing Diseases in Spring: Prevention is more important than treatment. Five steps ensure success.
1. Maintain water quality: Start by adjusting the water, then introduce the fish.
Monitoring: Dissolved oxygen, ammonia nitrogen, nitrite, pH
Change water regularly in small amounts multiple times to avoid temperature stress.
On a sunny morning, use spore-forming bacteria and photosynthetic bacteria to improve the water quality.
2. Strong foundation: Good bottom leads to good water.
Remove promptly, and break down the remaining food residues and feces.
On a sunny noon, turn on the aeration machine to break the stratification and increase the oxygen content at the bottom.
3. Strong constitution: Internal health care is key
Add the following to the feed: multiple vitamins, immune polysaccharides, and probiotics.
Start feeding gradually in the spring, without overfeeding or giving cold food.
4. Be cautious in your actions: Reducing stress = fewer illnesses
During the cold period, do not pull the net and do not add water at will.
Before releasing the fry into the pond, they undergo a medicated bath for disinfection. Only healthy and disease-free fry are selected.
5. Early Warning: Conduct three inspections during daily pond patrols
Check the food intake, check the movement, and check the gill area on the body surface.
When an abnormality is detected, first stabilize the water and increase its oxygen content, then make a diagnosis and administer medication.