1. Current status of domestic and foreign aquatic feed

Aquatic products are one of the most important agricultural products. About 7.5% of the world's total food comes from oceans, lakes and rivers. The animal protein ingested by people in developing countries mainly comes from aquatic products. Shrinking, people will become more and more dependent on aquaculture. The aquaculture industry is growing at a rate of about 10% per year, but the production of aquatic feed is limited by the original production process conditions and equipment. Most of the produced aquatic feed is hard pellet feed, and extruded pellet feed only accounts for a small part Part, the development of extruded feed is imperative.

2. Advantages of wet extruder in aquatic feed production

2.1 The current aquatic feed processing enterprises are facing special challenges

On the one hand, the special feed required by aquaculture farmers must be provided, and on the other hand, the aquatic feed produced must be competitive in terms of quality and price. The above needs can be solved by wet extruding processing. This processing method can not only reduce the cost of feed production and increase efficiency, but also enable farmers to obtain considerable economic benefits from the use of extruded feed.

2.2 The aquatic feed processed by extruding equipment has the following advantages

It can produce a wide variety of products; improve the conversion rate of feed; improve the stability of feed in water; facilitate the control of feed density; the mechanical properties of finished feed are good; the lowest cost formula can be used to reduce feed production costs; feed is more hygienic.

2.2.1 A wide variety of products can be produced For aquatic feed, feeds that can be processed include: shrimp, crab, eel, catfish, carp, frogs, etc., and can also produce full-fat soybeans, cat and dog feed, pet feed, and ornamental products Animal feed and other specialty feeds.

2.2.2 Improving feed conversion rate Due to the high temperature transient (HTST) processing of materials, the gelatinization degree of starch in the feed is improved, which can reach 80-99%, which is more beneficial to animals, especially aquatic animals (because the intestinal tract of aquatic animals Short and thin) digestion and absorption of feed.

2.2.3 Improve feed stability in water Stability is an important indicator for aquatic feed, especially for slow-feeding animals, such as shrimp and crab. Because the water stability is not good, the feed will be decomposed in the water before the aquatic animals can eat it in the future, which not only wastes the feed, but also pollutes the water quality, which is not conducive to environmental protection and the sustainable development of the aquaculture industry, and the stability of the extruded feed in water Reach; 12 hours, the highest can reach more than 24 hours, which is enough time to wait for animals to eat, and the stability of shrimp feed in water is required to be 4 hours on average.

2.2.4 It is easy to control the feed density. It can produce floating feed, sinking feed and slow-sinking feed (the process parameters are difficult to control in the processing of slow-sinking feed), which is more conducive to the feed demand of animals in different water layers. Using floating feed, it allows farmers to observe the feeding situation of fish, so as to adjust feed feeding and save feed.

2.2.5 Extruded feed has good mechanical properties and is not easy to break because any crushing and decomposition of finished feed before use will produce dust, which not only increases the waste of feed, but also pollutes water quality and air.

2.2.6 Feed is more hygienic. The material is processed by high temperature transient (HTST), which is equivalent to the pasteurization process. All harmful bacteria in the feed are killed, thereby reducing the impact of feed on aquatic animals and the impact of harmful bacteria on water quality. pollute.

In recent years, the wet extruder developed for aquatic feed has been gradually developed to produce feeds of various specifications. Due to the different design formulas, it can be produced on the same equipment with only a few changes. Due to its wide range of uses, wet-process extruding equipment has become the tool of choice for the production of aquatic feed. With the application of computer technology in the control of wet-process extruders, the control of wet-process extruders will become easier and easier, which will greatly affect the quality of wet-process extruders. Application of machine in aquafeed production.