The process of fermenting cassava tubers and leaves for aquaculture feed.

Faced with the reality of rising prices for industrial feed for aquaculture while fish prices continue to fall, resulting in low economic efficiency for fish farmers, many farmers have significantly reduced their use of industrial feed and gradually switched to locally available feed sources such as rice, corn, cassava, and rice bran.

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In particular, the use of fresh cassava tubers directly in aquaculture ponds is prevalent, while dried cassava is rarely used. As a result, many farmers have "killed" their own fish due to the excessively high levels of hydrocyanic acid (HCN) in cassava tubers. To mitigate these unwanted risks and to scientifically and effectively utilize both cassava tubers and leaves as feed for aquaculture, thereby reducing feed costs and increasing profits after each farming season, the following introduces some benefits of cassava tubers and leaves and the process of ensiling them for aquaculture feed.

Benefits of cassava tubers and leaves for aquaculture: Cassava tubers contain 76.2–77.2% starch and 2.2–2.7% protein. Cassava leaves contain 21–28% protein.

The process of fermenting cassava tubers and leaves.

Step 1: Prepare the composting equipment.

Silage containers include earthenware jars, silage pits, plastic bags, and cement tanks; the most common are built-in silage pits and plastic bags. Because the silage environment requires airtightness, the containers must be airtight to ensure better fermentation.

Step 2: Prepare the fermentation ingredients.

Cassava tubers are thinly sliced ​​or crushed; cassava leaves are chopped into 5-10 cm pieces and mixed thoroughly with salt at a ratio of 1 kg of salt to 200 kg of fresh cassava tubers and leaves. Additionally, rice bran and corn flour can be added to the compost mixture as follows: 20-30 kg of rice bran and corn flour and 70-80 kg of fresh cassava tubers and leaves.

Step 3: Fermentation

Place the cassava tubers and leaves into the composting container, compress them tightly, and seal it. Note that you should compact the material every 15-20 centimeters. After 7 days, the compost pile will shrink slightly, so continue compacting it to make it even tighter. The tighter you compress it to prevent air from entering, the better the quality of the silage will be.

Step 4: Exploitation and utilization

With the above ensiling process, cassava tubers and leaves can be preserved well for over 6 months, and cassava leaves can be preserved for 3-5 months without affecting their quality.

Cassava tubers and leaves, after being fermented for 21 days, can be fed to fish. Fermentation reduces HCN toxicity, but not completely, so caution should still be exercised when feeding them to fish.

By making good use of cassava tubers, cassava leaves, and agricultural by-products such as corn flour and rice bran through anaerobic ensiling, we can create a high-quality feed source that promotes growth and prevents digestive diseases in aquatic animals.

According to khuyennonghanoi - LY