Sunday, April 23, 2017

24/04/2017: Catfish feed for Africa

by Dr Hanno Slawski, R&D Manager, Aller Aqua, Denmark

The African catfish is of increasing popularity as fish for aquaculture production

The versatility and robustness of Africa catfish allow the species to thrive in challenging environments.
Especially in Africa, catfish farming has been increasing over the last few years and is about to increase further. Some constraints, however, limit the production increase. Among them are feed quality and availability.

Farming and marketing of catfish In Africa, Nigeria is the biggest producer of African catfish. In hatcheries, catfish hypophysation for induced spawning is a common practice. Catfish fry are obtained continuously, thus, stocking material is available all year.

In small on-land tanks, fish are grown to 2-5g, and are afterwards stocked into earthen ponds or tanks. Due to water shortage and energy cost, fresh pond water is a limitation. Most tanks are filled with a certain amount of fresh water in the morning, replacing used water.

That means rapid changes in water quality after the water exchange. Often, the water exchange is followed by the first daily feeding. Multiple feedings or demand feeders are seldom principles. Instead, a meal in the morning hours and one in the late afternoon are common practice.

The typical market size of African catfish in Nigeria is around 1kg. It is said, that the fish should reach this size in approximately four months after stocking fingerlings into ponds or tanks. The preferred fish in the market is relatively short and round.

Catfish farmers therefore aim to produce catfish with a relatively high condition factor, letting the fish grow fast. The last period before selling the fish is called “fattening period”. Fish are fed to obtain the shape desired by the market.

Fish are mostly sold from the farm to small retailers, especially market women. They visit the fish farms before going to the market.

Thus, fish are harvested daily, keeping the supply chain for fresh fish intact. On bigger farms, several size classes of fish are standing stock, so that continuous supply of fish to the market is possible.

Feed quality
Challenges with power supply and water quality can occur, setting high demands on farm management and fish care. If the fish do not grow as fast as expected, feed quality is quickly questioned, since water parameters are difficult to monitor and less seen as a potential variable determining fish growth.

Thus, stable feed quality becomes an important tool to steer farming success. When approaching the Nigerian catfish feed market, Aller Aqua aimed at delivering high performance feeds that were different to available products.

For this, feeds were collected from the market and tested in feeding trials with African catfish in Aller Aqua Research in Germany.

The trial results delivered important information about composition and quality of catfish feeds and potential for improvements included in the newly created catfish feed range.

Read the full article HERE.

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