Avoiding the segregation of feed ingredients during the process of mixing, people use the pelleting process to increase the gelatinization and digestibility of feed so that fish is more apt to receive a totally mixed nutrition. Just as its name implies, fish feed pelleting refers to the process of compressing, pelleting, and molding feed ingredients into the shape of pellets under the action of heat, moisture, and pressure. Pelleted and extruded feed produced by fish feed pellet mills and fish feed extruders have become the mainstream feed for most fish because of their high digestibility, abundant nutrition, and floating properties.
Why Pelleting the Feed Ingredients?
- The purpose of pelleting is to make fish feed pellets with healthy nutrition and delicious taste for fish by high heat, moisture, and pressing, replacing the dusty, unpalatable, and difficult-to-handle feed material.
- Fish feed pellets produced by our pellet mill have homogenous nutritional value after the uniform mixture and extrusion process, increasing gelatinization and digestibility of feed pellet, so that each fish can absorb a well-balanced diet, also saving feed pellets and lowering the fish farming cost.
- After pelleting, feed pellets would be less influenced by moisture, oxidation, and other external factors. It is easier and more convenient to handle, transfer, and store the pelleted fish feed.
- The most important feature of the pellet is durability, crushing strength, and water resistance, feed pelleted through our machine can float on the water surface for 12 hours.
- Adopting the pelleting process can kill pathogenic bacteria and reduce the occurrence of fish disease. Pellets would be processed under high temperatures up to 70-100 Celsius, which can kill parasites and pathogenic microorganisms, obviously reducing fish disease.
Pelleting Process of Fish Feed
Pelleting is processing the mixture of feed ingredients under high temperature, moisture, and high pressure within a fish feed pellet mill – raw materials are pressed through a die mold. According to lots of experience, too little or too much steam and heat added to the ingredients would produce pellets with poor quality while insufficient temperature and uneven mixing could not kill the dangerous pathogenic micro-organisms existing in feed pellets. The path to the perfect fish feed pellet requires top processing technology and an advanced pellet mill and fish feed extruder. In partnership with the feed industry, we continually strive for pelleting process technology and fish feed machines so as to improve the feed conversion rates and nutrition of fish feed. Now let’s discuss the detailed processing of making fish feed pellets.
1. Fish Feed Grinding In order to accelerate the mixing process and increase nutritional utilization, people need to grind raw materials of fish feed into small particles, which always requires a crushing machine – droplet fish feed crusher. In the meantime, the particle sizes of materials have a great effect on feed size and quality in the next pelleting process. Generally speaking, the grinding degree for most freshwater adult fish is about 40 mesh (420um), while for juvenile fish, it is around 60 mesh (250um).
2. Fish Feed Mixing: The daily feeding amount of fish is small, hence, feed ingredients should be mixed uniformly after the grinding process in order to make sure fish can get complete nutrition from the daily feed. The mixing degree of blender is very important in feed production processing because it can influence the quality of fish feed, so choosing a suitable mixing machine is quite significant. Here, we recommend a well-designed fish feed mixer 500 for equably blending powder or particle materials with good flow ability.
3. Fish Feed Pelleting: If fish farmers want to produce feed pellets that hit precise quality targets in terms of size, durability, density, and nutritional composition, they should choose a suitable pelleting machine according to their investment cost, production scale, and feeding characteristics and habits of different aquatic animals. Our pellet mill is able to produce high-quality feed pellets for fish and also for pets like dogs and cats. Moreover, it is not hard to produce feed pellets with different diameters (usually from 0.9mm to 15mm), just changing the size of the pellet mill die mold, which gives fish farmers more flexible choices according to fish type and growth situation.
Factors of Fish Feed Pellets Quality
Ø Fish feed formulation: Fish have their own characteristics at the nutrient requirement for feed, for instance, fish can make the most of protein and fat in feed, but cannot absorb carbohydrates very well, and it is hard for fish to digest cellulose. Moreover, fish with different feeding habits have various needs for nutrients. So it is necessary to make scientific and nutritional formulations according to various fish growing demands. Only the nutrients in feed pellets are consistent with fish needs and can promote digestion and absorption and lower feed coefficient.
Ø Quality of feed ingredients: If the types, origin, grade, foreign matter content, and storage conditions of feed ingredients are different, the difference in nutritional components will be large. Thus, feed ingredients have a direct effect on the nutrient composition and quality of fish feed pellets. Raw materials with good quality and high grade can be made into feed pellets achieving the perfect nutrition level, while the reverse is also true. In particular, the storing time of feed raw materials can greatly influence the nutrition of fish feed pellets.
Ø Processing technology of feed pellets: The particularity of fish feed has higher requirements on the processing technology, and the main indexes affecting processing quality include grinding particle sizes, steam pressure of tempering, and temperature. The thin particle size of raw material means a large surface area, which can acquire a better tempering effect. The high curing degree and full gelatinization lead to pellets with good cohesiveness that are not easy to lose after entering the water, all of which make feed pellets easier to digest and absorb.
Applications of Pelleting
In general, there are lots of raw materials for making fish feed pellets – from grains to wood and straw, such as corn, bean pulp, straw meal, soybean, peanut cake, rice bran, wheat bran, and so forth. Except for producing fish feed, the pelleting process also can be applied to produce animal feed(such as livestock and poultry feed), organic fertilizer pellets (with flat die pellet mill), and biomass industries.
