Producing feeds is a crucial aspect of fish farming because it is a source of well-balanced nutrition that the fish require. Fish feeds are available in many types, and the pellet or granule fish feed provides fish with nutritional stability in a concentrated manner, which increases in terms of efficiency and productivity of the fish. Pellet fish feed is numerous applications within fish farm.
Pellet Fish Feed Process
Pellet fish feed is produced by a standard fish feed pellet mills with no extrusion function , or a extruder for fish feed pellets. The feed for fish includes hard pellets that are produced by an ordinary fish feed pellet machine , and extruded pellet feed made by a fish feed extruder and the extruded feed pellets are increasingly being used in use to increase the production of fish.
Extrusion is the process of cooking the mixture of ingredients used in fish feed at high temperatures, high moisture , and high pressure conditions within the extruder. By adjusting the parameters of temperature, moisture , and pressure the producer of fish feed can produce pellets that fit various methods of farming fish including floating pellets for fish feed and sinking pellets for fish feed slow-sinking pellets for fish feed and so on.
In accordance with the processing technique extrusion of fish pellets is separated into wet-type extrusion as well as dry-type extrusion. The extruder with a wet type is equipped with a conditioner working on the steam produced by the boiler. its final products must be dried. The dry-type extruder is not equipped with a conditioner and works through friction, acting as a heat source to create pellets.
The purpose of extrusion processing
- To cook to achieve starch gelatinization as well as deactivating nutritionally harmful factors
- To sterilize the material to eliminate pathogens present in raw materials
- For expansion in order to improve quality of the feed
- Texturization is required to get an elongated structure
- For shaping the product into a pellets for fish feed, it is easy to do so.
The operation of pellets for fish feed extruding
1. Raw materials that are crushed
Size of the particle in the ingredient is vital The high-quality fish feed pellets are made by crushing ingredients into pieces with dimensions that are less than more than 1/3 the size of the die hole.
2. Conditioning and water addition:
Steam conditioning is essential to make floating extruded fish feed, as it improves the external and internal quality of feed, as well as reduce wear on the feed machinery and the loss of energy. The final feed pellet is top-quality when the temperature at which the conditioning process is 90 degrees.
In addition steam conditioning causes an increase in the size of feed which is an ideal ingredient for the production high-fat and high-protein fish feeds in floating form.
The adjustments of the water addition system at the feed inlet as well as the system for pressure release within the feed outlet is designed to regulate the spread and settleability in the end product. The reduction in the expansibility of feed and settleability could be accomplished by reducing the amount of steam added and supplying with conditioning water, and the reduction of pressure release.
Equipment to support extruding of pellets for fish feed
Feed conveyor for fish pellets
The freshly extruded feed for fish pellet is distinguished by its the high temperature, the excessive moisture, softness and the production of steam. Therefore, a correct conveyor is essential to prevent the pellet from being damaged. Positive pressure pneumatic conveying and belt conveying are among the most commonly used methods.
Drying equipment for feeding fish pellets
The purpose of product drying is to stop pellets from becoming mildewed. The time for drying is dependent on the drying rate, time and temperature must be managed and coordinated, in addition, a proper pellet layer and proper turning pellets must be maintained during the drying. Multi-layer mesh belt dryers as well as a high efficiency fluidized bed dryers work great for drying fish pellets.
Spraying of fish pellets and cooling machine
Post-spraying with fat/oil following drying pellets is designed to improving the water resistance and the taste of the pellet fish feed. However, cooling pellets after the coating with oil and fat is crucial for ensuring that the pellets packed be stored in a safe manner that is free of fat oxidation surface water condensation , and mould.
Benefits of extruded fish feed pellet
- Palatability is important to avoid separation of feed ingredients to ensure an even distribution of nutrients within pellets that ensure a great performance of the fish’s feed intake.
- Extruding is a process that requires the use of fine particles from raw materials. At it’s same time it also gelatinizes the starch and breaks down protein, which leads to a high conversion of feed and utilization rates.
- Systematism and starch gelatinization increase the caking properties of feed so as to increase the stability of feed water that can extend for 12-36 hours. A higher water resistance equals greater retention of nutrients as well as less pollution from water.
- Certain fish species require high-fat feed and the fat contained in the extruded pellets for fish feed has a stable and uniform penetration of pellets, making the feed more attractive for increasing intake of fish for food.
- By using high-pressure and high-temperature process, many pathogens present in the materials are eliminated, and digestive tract infections are diminished by extruding pellets of fish feed.
- Extruded fish food can be produced in a variety of types, including flotation feeds, sinking food and slow-sinking food, etc. to accommodate various methods of fish farming reduce waste feed as well as water contamination.
- Extruded feeds can be perceived as a magnet for fish by changing its shape according to the preferences of fish.
- The fish are young and able to eat and absorb pellets of extruded feed to get an outstanding growth.
- To enhance the quality of fish feed Extrusion can be utilized to create additional feed ingredients like high-fat soybean meal, feathers blood powder, and so on.
- It is simple to check and regulate the conditions of feeding fish to ensure optimum production of fish.
- The moisture content is low in the extruded pellets of fish feed that allows for long-term storage.