Fish Feed Raw Materials and Nutritional Feed Formulation

The nutrient requirements of fish are a complex process. When choosing a comprehensive feed formula, we should start from the existing raw materials, and develop a new protein source, fat, and carbohydrate, that is suitable for freshwater fishes. On the basis of meeting the nutritional requirements, a comprehensive and relatively low-cost of feed should be prepared, which can promote the development of freshwater aquaculture, to develop a good feed, it is necessary to have a comprehensive understanding of the nutritional composition of the feed.

I. Three Elements Should be in Fish Feed Formulation

In the design of freshwater fish feed formulation, the main considerations are protein, vitamins, and minerals.

Protein:
Protein is generally the first consideration in the formulation of the nutritional elements, Fish needs twice or three times the amount of protein as livestock, and because of the poor ability to use carbohydrate, fish needs to consume part of the protein as a source of energy. Feed price is mainly determined by the level of protein, so the design of feed formula often firstly considers the level of crude protein, but attention needs to consider the balance of digestible protein (DP) and amino acids more important, in addition to considering the level of crude protein.

Vitamin:
Fish have short intestinal, and the type and quantity of bacteria are rare, so the synthesis ability of some vitamins is poor, a lot of vitamins need provided by the feed. Such as vitamin C does not need to be added to livestock and poultry feed material, but in fish, feed is needed, as it can improve fish-free immunity and anti-stress ability.

Minerals:
Fish absorb most of the mineral elements from the water through gills and skin, especially calcium, Fish will not appear calcium deficient, even if the feed does not supply calcium. Fish have different absorption rates for various minerals, When adding minerals to the feed, we should choose inorganic salt, organic salt, or chelate salt, which with high absorption rates. It is necessary to add the right amount of trace elements in the fish feed, because Fe deficiency can lead to anemia, Zn, Mn, and Co will cause short trunks.

II. Formula of Compound Additives

The following are some of the most representative freshwater fish:
A. Formula of compound additives for omnivorous fishes
The omnivorous fish compound additive is according to the omnivorous fish biology design features, generally divided into two kinds: mineral additives and vitamin additives.
Tilapia：
The basic raw material: wheat bran (30%), soybean cake(35%), fish meal (15%), corn(5%), sophora leaves(5%), barley(8.5%), auxin(1%), salt (0.5%), feed coefficient is about 2.03.
Additives:

Carp:
The basic raw material: fish meal(10%), shrimp bran (20%), wheat bran (50%), corn(10%), dried sweet potato powder(10%), this is for adult fish.
Additives:

B. Formula of compound additives for carnivorous fishes
Aquatic catfish:
The basic raw material: bean pulp(24%), peanut dregs(24%), fish meal(5.1%), rice bran(43%), bone meal(2%), crude protein(28%), feed coefficient is about 2.2.
Additives:

C. Formulation of compound additive for herbivorous fishes
Grass Carp:
Grass carp is a typical herbivorous fish, adults mainly eat weeds, and fish fry in the early stage of cultivation mainly feed tiny protozoan, but they like to eat artificial fine feed in each growth stage.
The basic raw material: Dry grass powder 45% (peanut vine, sweet potato vine ), soybean cake(15%), rice bran(15%), wheat bran(10%), fish meal (3.5%), corn(10%), bone powder(1%), salt(0.5%).
Additives:

Gurnard:
Gurnets have wide feeding habits, mainly feeding on submerged plants like Vallisneria natans, Hydrilla verticillata, Potamogeton distinctus, terrestrial grasses, and leaves.
The basic raw material could be: Silkworm pupa powder(5%), rapeseed meal(20%), soybean(13%), cottonseed(5%), corn(10%), rice bran(10%), wheat bran (20), grass powder(15%), crude protein(25%), feed coefficient is about 2.6.

III. Scientific Feeding Method

Feed is one of the biggest costs of fish farming, Pay attention to the scientific feeding method, it is not only conducive to the healthy growth of the fish, but also can save the feed, and effectively improve the benefit of fish culture.

A. Fish feed pellet: The diameter of pellet feed is usually 2.5 mm -8 mm, length is 5 mm ~10 mm. The fish feed pellet sizes differ when manufacturers change the die of the fish feed extruder. Pellets can be directly cast in the fishing pond, if the feed becomes wet, it should be dried and then used, if the feed goes bad, stop using it anymore to prevent fish from being poisoned.

B. Oil-cake feedstuff: For fingerlings, the oil-cake should be cracked, soaked, and ground into a thick liquid, For adult fish, soaking and being soft is OK.

C. Grain feed: Large particles of grain like corn should be crushed by a fish feed crusher first, small particles of grain like paddy should use its buds, The tender bud has a high nutritional value, and for fish, it is easy to digest, absorb, and grow.

D. Plant feed: Plants, after removing the soil, are generally used to feed medium and adult fish. For fingerlings, plant feed should be crushed and ground into a thick liquid, mixed with 0.2% salt then splashed into the water. Fingerlings are more like the cooked plant feed, which with some bran and soda.

E. Bran feed: For fingerlings, bran should be soaked and ground into thick liquid; for adult fish, should be used when it fermented to a wine aroma. At the beginning feed fish with a small amount of bran, then gradually increase the amount, but can’t feed more than 30% of the total daily food.

F. Protein feed: Earthworms, maggots, and insects are high-quality animal protein feed for fish and can feed fish without processing. It is better for fish to dry and process this little animal into powder, then mix it with other fish feed. The massive animal feed should be chopped finely ground, then use adhesive to make small globular pellets.

G. Feces feed: Chicken manure, pig manure, and cow dung are quality fish feed. Dried this manure and ground into powder, then mixed with other feed in accordance with a certain proportion. The common proportion is 40%-50% for chicken manure, 50%-70% for cow dung, and 30%-50% for pig manure.