In recent years, Ben Tre farmers have raised snakehead fish but on a small scale. Farmed fish are susceptible to disease, require a lot of labor, are expensive, and have low profits. To overcome this situation, farmers should raise fish with industrial feed to achieve high efficiency. The farming environment is less polluted, the farmed fish are less susceptible to disease, labor is reduced, the farming density is higher, and input prices are stable. Currently, in the markets, snakehead fish is the main food source.
Some solutions for raising snakehead fish are as follows:
1/ Pond design
Snakehead fish live and grow well in areas with salinity from 0 to 8%o. Snakehead fish ponds have diverse areas, but the best is from 500 - 2,000m2, designed in a rectangular shape for easy harvesting later. The water depth must be from 2 - 2.5m. In particular, there must be a good water supply and drainage system.
2/ Pond renovation
If it is an old pond, clean out all the mud at the bottom of the pond, add 8-15kg of lime/100m2, if possible, dry the pond for 3-4 days. Then, add water to the pond to a depth of 1m, pay attention to filter the water taken in, avoid large fish from eating the young fish later, 3 days later, release the fish fry. After releasing the fish, add 10-15cm of water each week until reaching the specified depth.
3/ Selecting and releasing seeds
To ensure survival rate and future productivity, choosing the right breed is very important, the size should be from 6-10cm, the fish must be of uniform size, healthy, and without deformities. Before releasing the fish, use salt mixed with 3% water to bathe the fish for 3-5 minutes. The fish should be released in cool weather. The stocking density depends on the pond, such as depth, capital, according to experience, you can release from 10-50 fish/100m2.
4/ Care and management
a) Food and how to feed fish
Common food for snakehead fish is Cargill. UP, CP... Depending on the size of the fish, choose the appropriate size of food. In the first month, feed the fish 3 times a day (morning, noon, afternoon). From the second month onwards, feed twice a day. When feeding the fish, use a stick to knock on the bridge to create noise for the fish to gather. If the fish are not used to industrial food, they must be trained to gradually switch from trash fish food to industrial food.
How to do it: Use a bamboo or reed feeding screen, about 1m2 in area, with a distance of 1.5cm between the bamboo strips. Place it 4-5m from the shore, floating on the water surface. The food is fresh trash fish, washed and finely ground, each time you feed, mix in 2-3% of industrial food, leave the whole block on the screen, the fish will automatically pick at it to eat. Each time you feed the fish with industrial food, gradually increase it. After about 10-15 days, the fish will get used to industrial food and then switch to industrial food. When feeding, you need to mix in intestinal digestive enzymes and vitamin C to help the fish digest quickly and increase resistance. Note that when the fish are released for 20 days, you should only start feeding the fish with industrial food. Do not start too early as this will make the fish lose strength.
b) Pond management
Every day, you should monitor the fish's ability to catch prey. If the fish eat less or do not eat more, there is a problem. One is that the fish show signs of illness, two is that the pond environment is dirty, there is a lot of toxic gas, and low oxygen. Check the water color of the pond to have a reasonable way to change the water. Normally, farmed fish are susceptible to scabies, so you must monitor carefully to detect it promptly. When you detect scabies in fish, use IODINE at a concentration of 1ppm and sprinkle it into the pond. If the disease is mild, use the medicine once, if the fish are severely ill, treat it twice. Each time is 5 days apart. When the fish have been raised for 2 months, you can use microorganisms periodically to treat the bottom of the pond to help release toxic gas (microorganisms are treated according to the manufacturer). When they are young, fish often go to the shore, are easily eaten by birds and storks, so measures need to be taken to help reduce fish loss (use nets around the edges of the ditch). When feeding fish, spread food slowly to avoid excess food. Monitor fish growth to have appropriate treatment.
5/ Harvest
After about 5 months of raising, the fish will reach an average weight of 2-3 fish/kg and then harvest. The fish can also be left larger depending on the market. When harvesting with a basket, avoid scratching the fish, preserving the fish to live longer. If the pond is well managed and cared for, the feed conversion ratio is from 1 - 1.4 kg to 1 kg of fish. The average survival rate is from 60 - 80%.
Model of raising snakehead fish with industrial feed
Recently, the commercial snakehead fish farming movement in Binh Thuan has developed strongly, bringing stable economic efficiency to local people. However, for the current snakehead fish farming profession, the biggest difficulty is managing water sources and fresh trash fish food sources to ensure quality and quantity.
During the north wind season (usually lasting from October to March of the following year), the source of sea fish is scarce and the price is also much higher than the southern fish season (usually lasting from April to September). Besides, Binh Thuan is not a province with abundant fresh water sources like the provinces in the Southwest, so snakehead fish is only suitable for some locations - where there is abundant fresh water all year round - to facilitate daily water changes in fish ponds.
In addition, feeding with fresh food quickly pollutes the water source in the pond, and to minimize the situation of sick fish, farmers have to change the water daily or continuously let water in and out of the pond. Some farming areas do not have favorable water conditions, so raising snakehead fish becomes very difficult because the fish often get sick, and the use of antibiotics and disinfectants seriously affects the health of consumers. In addition, because the quality of trash fish must be guaranteed to be fresh, people have to buy fish every day, then process them (wash, grind or chop...) before feeding them. This work takes a lot of time, effort and money from the people.
To contribute to improving the efficiency of the production process of the people, in August 2011, the Binh Thuan Agricultural Extension Center implemented the model "Raising snakehead fish with industrial feed" with a scale of 500m2 at Mr. Chau Minh Tam's household, Vinh Hao commune, Tuy Phong district. The model was accepted on December 26, 2011. After nearly 4 months of raising, the fish reached an average size of 420g/fish, with a survival rate of 60%. The results show that snakehead fish adapt well to environmental conditions and water sources in the farming area. Snakehead fish also adapt well to industrial feed and achieve good growth rates.
Binh Thuan Agricultural Extension Center briefly introduces the implementation process as follows:
1. Prepare the pond
– Pond area: 2,000-5,000m2. Large areas will be relatively difficult to manage and care for fish.
– For new ponds, the pond must be rinsed by soaking in water for about 2-3 days, then draining and then continuing to add water to soak and drain. Carry out the rinsing process at least 2-3 times before stocking to create a stable pond environment for fish to grow.
– For used ponds: Drain the pond water, rinse or dredge the mud to clean it. Reinforce the banks, culverts, and pond fences to prevent pests such as frogs, snakes, and storks from eating fish. Use electric shock or Saponin (10kg/1,000m2) to kill any remaining fish in the pond. Apply lime in an amount depending on the acidity of the soil. Then dry the pond for 5-7 days before adding water.
For alum ponds, do not drain the water completely to avoid alum leakage.
The need for liming depends on the soil type and soil pH:
|
soil pH |
Lime requirement (kg/ha) |
|
Pond bottom is rich in humus or clay |
Pond bottom is sandy loam |
Sand bottom |
|
> 6,5 |
No fertilizer |
No fertilizer |
No fertilizer |
|
6,1 – 6,5 |
1.700 |
1.500 |
No fertilizer |
|
5,6-6,0 |
3.500 |
1.700 |
500 |
|
5,1-5,5 |
5.000 |
3.000 |
1.500 |
|
4,6-5,0 |
8.000 |
4.000 |
3.500 |
|
4,0-4,5 |
10.000 |
5.000 |
4.000 |
– Supply water into the pond through a filter to prevent miscellaneous fish and pests from entering the pond to eat the fish. The water level is from 0.6-0.8m. Create water color by mixing rice bran (1kg) + Soybean powder (1kg) mixed with water and soaked overnight, sprinkle evenly over 1,000m2. Sprinkle twice a day, soak at night then sprinkle in the morning, soak in the morning then sprinkle in the afternoon (4-5pm). Add 2kg of cooked, finely ground miscellaneous fish every day and sprinkle evenly over the pond for better water color. After 2-3 days when the water color is good, release the fish fry. Water color can also be created in many other ways such as using chemical fertilizers, manure or biological products that cause water color.
2. Release the seed
– Stocking density: Snakehead fish is a high-value fish, but the cost of farming is relatively high, so depending on the conditions of water sources, ponds and family economy, people decide on the density of low or high. Usually, snakehead fish are raised at a density of 20-30 fish/m2. Ponds with unfavorable water sources should only have a low density of no more than 10 fish/m2.
– Stocking season: Because of the proactive food source, farmers can stock fish all year round, depending on the conditions of water sources, fish sources and calculating the cost after harvest. The main stocking season is from May to August every year, at this time the source of fish and water sources is also abundant, but the commercial price after harvest is often lower than the off-season due to the abundant harvest from many localities.
– Selecting breeds: The breeds are uniform in size, healthy, have bright and beautiful colors, well-proportioned bodies, and do not show signs of infection. It is best for people to choose to buy at reputable manufacturing facilities.
3. Food and feeding
a. Case of feeding fish with industrial bran from a young age
Because newly released fingerlings are still small and not used to eating industrial pellets, the training of fish to change food types should be carried out according to the following steps:
* Training phase 1: Training fish to get used to the taste of industrial food:
– Newly released fingerlings: Daily food ration is 10% of the fish's weight. Mix according to the ratio: 70% fresh trash fish + 30% industrial bran. If it is in the form of powdered bran, mix it with trash fish according to the above ratio and then grind it. In the case of pelleted bran, soak it in water until soft, then mix it with fresh trash fish and grind it.
– The ground feed mixture is put into a sieve for the fish to eat.
– Increase the amount of industrial bran in the mixing ratio by 10% every day until reaching the ratio of 50% trash fish
+ 50% industrial bran, then move to the training phase of eating pelleted bran.
* Feeding phase 2: Get the fish used to eating pellets:
– After about 5 days of training, the fish get used to the taste of industrial feed, then continue to train the fish to eat pellets.
– How to do it: Mix in 5% more industrial pellets (in the total amount of food fed to the fish daily). Initially, the pellets should be soaked in water to soften and then mixed with the ground feed mixture of the first feeding phase. The above feed mixture is spread on the sieve for the fish to eat. Initially, the fish may not be used to it and will spit out the pellets. In such cases, it is necessary to continue training with the above mixing ratio for another 2-3 days until the fish no longer spit out the pellets.
– In the following days, the amount of pellets continues to increase by 10%/day and the soaking time is also gradually shortened until no more soaking (to get the fish used to eating hard pellets). When the fish are completely used to eating pellets, switch to feeding them completely with industrial pellets.
* Phase of feeding completely with pellets:
– From the second month until harvest: Fish are used to eating pellets, then feed them completely with pellets. The feed portion ranges from 3-7% of body weight, depending on the development stage of the fish. Because the quality of each type of pellet is different, people should feed according to the manufacturer's instructions for the best results.
– At this stage, the food is spread directly into the pond for the fish to eat, no longer fed in a sieve.
b. When necessary, train fish to eat industrial feed.
Due to the omnivorous eating habits of fish, farmers can completely flexibly switch between using industrial feed and trash fish at any time during the farming season to be proactive about food sources while reducing food costs. For fish that have been raised commercially for over a month, training them to switch to eating industrial pellets is relatively easy, helping farmers to be completely proactive about fish food. Let the fish starve for 1 day, then mix soaked pellets with finely ground trash fish in a ratio of 70% trash fish + 30% pellets. The steps are carried out as in the second feeding training phase. It will only take 3-5 days for the fish to get used to eating industrial pellets.
4. Care and management
– Monitor the feeding status, weather and health of the fish daily to increase or decrease the amount of food accordingly. Feed according to the manufacturer's instructions, do not overfeed to avoid the fish getting bloated and dying.
– Because of feeding with industrial bran, the water environment is also much less polluted than when raising with trash fish. However, for farming areas with active freshwater sources, water should be added to the pond regularly every day to stimulate the fish to eat bait and develop. For areas without abundant water sources, the water should be changed every 2-3 weeks depending on the environmental conditions and health of the fish in the pond, and at the same time, periodically every 7-15 days, biological products should be added to help decompose waste, toxic gases and stabilize the pond environment.
Ensuring each step in the recommended process, the model can be widely applied in all freshwater aquaculture areas in the province, contributing to solving difficulties in water resource management and ensuring fresh trash fish feed in the traditional farming process.
Using industrial feed to replace trash fish feed in the commercial snakehead fish farming process has many advantages compared to the traditional farming process using trash fish feed:
- It does not take much effort to buy and process before feeding, significantly reducing labor costs.
- The supply and quality of food are always proactive and stable.
- Significantly reducing the cost of supplementing supplements to help fish improve their resistance and digestion because the above ingredients in industrial feed have been carefully calculated and mixed according to the needs of the fish.
- Less pollution of water sources, thereby reducing the need to use water sources and reducing the situation of fish getting sick due to polluted environments without water to replace.
– Significantly reduces the use of antibiotics and chemicals during the farming process.
– Suitable for farming areas far from sources of trash fish and where water sources are not really favorable.