Tilapia Feed Formulation Methods and Key Feeding Techniques

Different species of tilapia have somewhat different nutritional requirements at different growth stages. For Nile tilapia (Oreochromis niloticus) fry, the optimal protein requirement is 35%-40%, while for fingerlings over 50 g it is 20%-25%; for blue tilapia (Oreochromis aureus) fry, the optimal protein requirement is 36%, and for fingerlings and adult fish it is 26%-36%. In grow-out feed for tilapia, the crude protein content should be controlled at above 25%; in intensive culture, the crude protein content should be controlled at 30%. The ratio of animal to plant protein in the feed should preferably be 1:2.8-3.4. The fat content in the feed is 4%-6%, and the cellulose content ranges from 5%-20%. The required amount of mixed inorganic salts in the feed is 3%-5%, and the suitable range for phosphorus is 0.54%-1.14%. Under pond culture conditions, tilapia can meet their vitamin requirements by feeding on natural food organisms. In intensive culture, the amount of vitamins added is about half that added for common carp, and the same effect of vitamin supplementation can also be achieved by combining the feeding of green fodder.

1. Bran and rice bran types

Rice bran is mostly used in the south, while wheat bran is mostly used in the north.

2. Oilseed cake types

Oilseed cakes and meals are all good feed for fish. In the north, soybean cake and meal, flax cake and meal, and sunflower cake and meal are mostly used; in the south, rapeseed cake, cottonseed cake and meal are mostly used. In addition, hemp cake and peanut meal, etc., are also used, and these are relatively large in quantity. Cake and meal types have high protein content, but they also contain toxic factors unfavorable to fish growth. For example, soybean cake and meal contain urease, anti-trypsin, etc., and it is best to use heated, cooked cake when using them. Flax and rapeseed-cottonseed cake and meal also contain toxic factors such as glucosinolates and free gossypol. When using them, several cake types should be used together with bran and rice bran to reduce the amount of any single variety. It is worth noting that in the feed formula, when the cotton cake component reaches 50%, it will affect the reproduction of tilapia.

3. Aquatic and terrestrial plant feed

Among aquatic and terrestrial plants, duckweed (Wolffia arrhiza), small duckweed (Lemna minor), and purple-backed duckweed (Spirodela polyrhiza) are feed favored by tilapia fry, fingerlings, and adult fish. Aquatic plants such as water lettuce (Pistia stratiotes), water hyacinth (Eichhornia crassipes), and alligator weed (Alternanthera philoxeroides), after being chopped or pulped, can be fed directly or mixed into compound feed, and are also good feed for tilapia. Tilapia fry, fingerlings, and adult fish can all feed on and digest algae such as Microcystis and blue-green algae in ponds very well.

4. Distiller's grains, residues, and grain-type feed

Distiller's grains and residues can also be used as feed for tilapia. Grain-type feed is best fed in the form of malt and grain sprouts. The malt and grain sprouts referred to here are those in which the wheat or grain has just sprouted upon contact with water but has not yet produced seedlings; these can be used as feed and are excellent supplements of biologically active substances such as vitamins and hormones.

5. Animal-based feed

It is mainly used as a raw material for compound feed and is not suitable for feeding fish alone. The main characteristic of animal-based feeds such as fish meal, blood meal, and meat-and-bone meal is that their protein content is generally higher than that of oilseed cakes and meals; they are not only easy to digest but are also rich in lysine, which plant-based feeds lack.

6. Compound feed

II. Compound Feed for Tilapia

At present, the production and application of compound feed for tilapia in China is already very common. Feed formulas can be composed of multiple raw materials according to local feed source conditions and based on the nutritional requirements of tilapia and the nutritional composition of feed raw materials. In tilapia feed formulas, whether used for pond culture or intensive culture, the addition of mineral salts in the formula is very important. For pond culture, the vitamin mixture may be omitted, and tilapia can obtain it by extensively feeding on natural food organisms; but for intensive cage culture and warm flowing-water culture, mineral salts must be added.

III. What are the artificial compound feeds for tilapia?

At present, there are two forms of artificial compound feed for tilapia in China: one is ordinary pellet feed, and the other is extruded feed. When producing ordinary pellet feed, the feed conditioning temperature is best controlled between 80-95 degrees C. After sufficient conditioning, the feed has good gelatinization, a longer stabilization time in water, and a smooth and attractive appearance. When producing extruded tilapia feed, an ultra-fine grinding process is used, with more than 80% passing through an 80-mesh sieve. The produced tilapia feed has an attractive appearance and causes little wear to the extruder, extending its service life. Whether ordinary pellet feed or extruded feed, the particle size is basically between 1.5-5.0 mm. However, the classification of feed application stages varies: there are names such as fry feed, fingerling feed, and adult fish feed; there are also names such as fish fry, larval fish, juvenile fish, and medium grow-out fish feed; and there is also classification according to fish body weight. Generally, the price of extruded feed is higher than that of ordinary pellet feed, but the culture effect of extruded feed is superior to that of ordinary pellet feed, with outstanding culture benefits.

IV. Feed Feeding for Tilapia

Feed feeding——fixed location, fixed time, fixed quality, fixed quantity