According to different processing techniques, aquatic feed products are mainly divided into three types: powder feed, pellet feed (traditional hard pellet feed), and extruded feed.

Comparison of Aquatic Feed Processing Technology

Compared with granular materials, the processing technology requirements of extruded materials are more complicated. The main differences lie in several processes of quenching and tempering, puffing and liquid spraying:

(1) Conditioning: In the process of conditioning, water and steam are added together for the production of extruded materials, and the moisture content after conditioning is about 25%, while only steam is added for the production of pellets, and the moisture content after conditioning is low. It is about 17%.

(2) Expansion and liquid spraying: There is no puffing process and liquid external spraying process in the production of pellets, but an additional granulation process. The extruded feed processing technology requires finer crushing of raw materials, and the high-temperature extruding process can increase the maturity of starch, which is conducive to the digestion and absorption of feed by fish.

(3) Advantages of puffed materials: puffed materials require finer crushing of raw materials, and the high temperature in the processing process not only improves the maturity of starch, but also the instant strong rubbing of high temperature, high humidity and heat during the puffing process can kill some harmful bacteria in the raw materials , so compared with ordinary pellet feed, extruded feed can improve the digestion and utilization rate of feed and reduce the incidence of disease.

On the other hand, the extruded material has a stability of 12-36 hours in water, which is convenient for visually checking the feeding situation of fish schools and reducing water pollution.

Comparison chart of puffed material and granular material

With the enhancement of the concept of environmental protection and green and healthy breeding, pellets will gradually be replaced by extruded materials. Compared with powdered feed and granular feed, although the price of extruded feed is higher, the feed conversion rate is higher, the overall benefit is better, and the pollution to water is less. In recent years, the acceptance of extruded feed by farmers has gradually increased. .

How to further improve and enhance the level of feed processing technology to produce aquatic feed with good stability, strong palatability and higher feed conversion rate is still the future development goal and direction of the aquatic feed industry.