Control methods of Streptococcus in Tilapia fry
At present, there is no complete control method for Streptococcus tilapia. In the high temperature season, we can take some effective measures to reduce the damage of tilapia Streptococcus to aquaculture.
1. When selecting the fry, Lianfeng aquaculture suggested that the majority of aquaculture farmers should purchase the seedlings from the regular seedling base, and select the high-quality fish fry with strong resistance for breeding.
2. Select the feed with stable quality
In the breeding process, the tilapia formula feed produced by the whole factory with stable quality and balanced nutrition should be selected. In particular, during the onset of the disease, feed should be stopped or the amount of feed should be reduced as much as possible. After the symptoms of streptococci are fully healed, the feed can be fed quantitatively gradually.
3. Reduce the direct discharge of livestock manure
The direct discharge of livestock manure is one of the causes of Streptococcus in tilapia. Friends who use three-dimensional culture mode to cultivate tilapia suggest that the discharge of livestock manure can be reduced. If it is really necessary to discharge livestock manure, it is necessary to treat the livestock manure and then discharge it into the pond.
4. The water quality should be adjusted as soon as possible so as to balance the reproduction of algae and bacteria.
Nitrite and ammonia nitrogen content should be detected frequently for fish ponds with three-dimensional culture or inconvenient water source. When the content of nitrite and ammonia nitrogen is too high, it should be degraded and regulated as soon as possible. When drugs are used in water with high nitrite content, attention should be paid to sterilization instead of algae to keep algae stable. When the ammonia nitrogen is too high, we should pay attention to adjust the sediment and strengthen the reproduction of beneficial bacteria.
5. Add aerator
In high temperature season, there are many sultry days. The aerator should be opened at noon for 2-3 hours. If conditions permit, bottom aeration can also be used in fish ponds to balance water temperature, increase dissolved oxygen content and return visit of ammonia nitrogen, so as to promote normal fish feeding.
6. The fish pond should be disinfected regularly and the bottom should be changed thoroughly
The fish pond should be disinfected and sterilized regularly. If conditions permit, the water body of the fish pond should be replaced by slow discharge and slow irrigation before or after sterilization. Remember to discharge and irrigate in a short time. The large amount of water to be changed in a short period of time is likely to cause adverse stress of fish.