Commercial fish farming has gone on in Bangladesh for a long time, and many unemployed young people have become self-reliant through it. Because it is profitable, fish farming is growing day by day. To make it even more profitable, fish must be given supplementary feed alongside natural food. In modern fish farming, about 60 per cent of the cost goes on buying feed.

The ingredients commonly used as supplementary feed in Bangladesh are rice bran, wheat bran, mustard oil cake, sesame oil cake, fishmeal, and the blood and offal of cattle and goats, as well as aquatic plants such as water hyacinth and duckweed.

Farmers mix these ingredients as needed to make fish feed. Factory-made commercial feed can also be used. Whatever feed is used in the pond, its quality must be good.

Without good-quality feed, healthy fry and fish cannot be produced. Fish fall ill easily, mortality rises and growth falls short of expectations. Storing feed ingredients and prepared feed properly is therefore very important for keeping quality, and attention must be paid to following the rules.

If fish feed contains more than 10% moisture, fungi or insects can grow in it. The same can happen if the relative humidity of the air is above 65%. Excess heat destroys the feed's nutritional value. Insects can breed at 26-30 degrees Celsius; they eat the feed and can spread bacteria through their droppings.

If feed is left open in sunlight, ultraviolet rays destroy some vitamins within just a few minutes. Left open, oxygen in the air can cause rancidity (oxidation of fats), which damages the feed's quality. Oxygen also helps fungi and insects to grow.

Dry feed and feed ingredients must be kept in airtight polythene or jute bags, or any sealed container, in a cool, dry place. It is good to dry the feed in the sun again from time to time.

Feed must be kept in a clean, dry, safe and well-ventilated room. In a store, keep it not on the floor but on a wooden platform 12 to 15 cm above it. Ash can be sprinkled under and around the sacks to control insects. Feed should not be stored for more than three months and should be used within that time. Store it where there are no rats or other animals, and never keep it with pesticides or other toxic substances.

If fresh small fish are used to make feed, they must be fed immediately or kept in a refrigerator. Oily and fatty feed should be kept at low temperature in black or opaque containers. Vitamins and minerals should be kept in the refrigerator in containers free of air and light. Following these rules will keep fish feed in good condition.

Source: Jagonews24. First published in Bengali on The Agro News.