Shrimp Feed Formulation and Manufacturing Process

The quality of shrimp feed determines the development of shrimp grounds. Shrimp feed cost accounts for about 50% of the overall cost in shrimp fishery! Due to the information being site-specific and proprietary, it is not an easy thing to provide shrimp production cost data. In accordance with one review of hatchery operating costs, we summarized a sketchy production cost data:

Typically, shrimp feed expenses represented at least 40 percent of total nursery production costs. Investment costs for grow-out facilities have been cited as ranging from USD 400/ha (yielding 600 kg/ha/yr) in India to nearly USD 64,000/ha (yielding 2,270 kg/ha/yr) in the USA. Similarly, grow-out operating costs from less than USD 2 to more than USD 15 kg/yr have been cited. The average cost split was 30 percent feeding, 20 percent seed, 15 percent labor, and 35 percent other expenses.

What should shrimp farmers do to improve the return on the feed investment?
• Industry education – farmer
– What to look for in a feed
– How to feed
• Improve feeding methods
– Deliver feed to meet nutrient requirements
• Increase the cost-effectiveness of feeds

– Refine nutrient requirements
– Reduce the use of exotic ingredients
– Stop over formulation
– Manufacture extruded shrimp feed pellets rather than hard pellets

Classification of Shrimp Feed Pellets

At present, there are 2 kinds of feed pellets on the market, hard shrimp feed pellets and extruded food pellets.

Pros and cons of hard pellets

Commercial hard shrimp feed pellets are mainly produced by ring die pellet mills. In the production process, after the raw material is crushed and mixed, the starch gelatinized, and the protein denaturation in steam conditioning functions, the viscous force is enhanced, and the materials are close to each other under the action of die and roller pressing, rubbing, and finally forming through the die hole.

The advantages of hard shrimp feed pellets:

1. The feed formula could be optimized combination to both meet the nutritional needs and reduce the cost;
2. In the process of tempering granulation, feeds are ripened under the effect of steam and loop die, which is conducive to shrimp digestion and absorption.
3. In the granulator suppression effect, all components are bonded with each other, improving the density of the feed, The obtained product is sinking, and it is adapted to the shrimp benthic lifestyle.
4. According to the need to add nutrients and medicine, enhance physical fitness and immunity of shrimp.
5. Simple feeding, The shape and size of bait are suitable for shrimp eating.
6. The feed is convenient for preservation and transportation, less affected by natural conditions, and can be produced in large quantities.

But there is a disadvantage of the hard particles shrimp feed, if the starch gelatinization degree is low in the production process, the product will have poor water resistance.

Increasing demand for extruded shrimp feed pellets in the near future

With the increase of the shrimp farming scale, the yield of shrimp feed also continued to increase, many livestock feed processing plants and some traditional aquatic feed processing plants have turned to produce shrimp feed. However, the quality of shrimp feed requirements is relatively high. If only in accordance with the traditional production process of aquatic feed, it is difficult to achieve the quality requirements of shrimp feed, especially in water resistance. With the improvement of living standards, food quality, and safety problems are paid more and more attention. The security problem of shrimp food must start from the source. Therefore, the shrimp culture has to be developed in healthy and pollution-free aquaculture. Can not use a lot of antibiotics in feed, one of the difficult problems is using ripeners to prevent disease. Shrimp feed is a key factor affecting the shrimp culture, and have to develop the direction of safety and environmental protection. In the production process of hard pellet feed, if the starch gelatinization degree is low in the production process, the product will have poor water resistance. While the requirements of shrimp feed on the water resistance is relatively high, so it is very important to improve the water-resistance of shrimp feed. During the process, the change of various factors will affect the quality of feed, especially water resistance. Study on the influence of various factors on the sinking and water resistance of the final product from the feed processing can provide technical guidance for the actual production process, so as to improve the process conditions and the quality of the shrimp feed, it is also conducive to promoting the healthy and sustainable development of shrimp aquaculture, improve breeding efficiency. Compared with the hard pellets, the biggest difference with extrusion feed is that material is directly into the extrusion machine after quenching and tempering, high-temperature high pressure made by rubbing, shearing, and heating, then suddenly released into the normal temperature and pressure through the die hole, so as the material formed and produced a series of changes in the physical and chemical properties. During the extrusion process, the high-intensity hydrothermal can remove most of the harmful factors, improving the safety of shrimp feed. Therefore, shrimp feed produced by fish feed extrusion granulating machines will occupy a heavier market share.

Shrimp Feed Formulation Directly Affecting Quality of Feed Pellets

High-quality shrimp feed is characterized by good water stability, good hygienic control of raw materials for optimum FCR and health of prawns, good attractability and feed palatability, and rich in nutrition to produce healthy and strong prawns. In recent years, pond-reared shrimp have developed rapidly. While farmers know little about the shrimp feed production and feeding method. Some of them don’t care about what kind of shrimp feed they are feeding their prawn, while others take no notice of the dose rate, thereby increasing shrimp feed costs increasing, production efficiency. Shrimp feed pellets should be formulated to meet the shrimp’s nutritional requirements of essential amino acids, fatty acids, vitamins, minerals, and molting accelerating substances. To solve those problems, Fish Feed Machinery introduced some shrimp feed formulas and hopes they will help farmers earn more profits.

Adult freshwater shrimp feed formulation

◇ Formulation of raw materials

◇ Premix formula (g)

◇ Vitamins and mineral elements
Vitamins: (IUs=international units)

Mineral elements(mg./kg):

Macrobrachium nipponense feed formulation

Macrobrachium nipponense is one kind of freshwater shrimp with high economic value and large cultivation potential. It is rich in nutrition, and grows fast, deeply loved by people. Macrobrachium nipponense culture has been popularized in large areas till now.
◇ Adult shrimp feed formulation (%)

◇ Juvenile prawn feed formulation (%)

Shrimp Feed Manufacturing Process

A. Grinding technology
The raw material grinding is a basic process, particle size should be above 40-60 mesh. Research shows that the digestion and absorption rate of protein in peanut oil-cake powder that passes the sieve with 40 – 100 mesh has no obvious difference. Considering from the processing energy consumption, The energy consumption of the hammer mill in 100 mesh is three times higher than that in 40 mesh. Therefore, the fineness of raw material could be not less than 40 mesh, but the finer the grinding degree is, the better the water resistance of shrimp feed pellets is. In addition, the fine material can improve the mixing uniformity of ingredients and the compaction quality of pellet feed, and it is easy for digestive enzymes to contact with the feed to promote digestion. Grinding raw material needs two processes, the first is coarse grinding, like peanut cake and shrimp head capsule. A fish Feed Hammer Mill is needed. It should be equipped with a 3mm sieve piece to crush raw materials into coarse powder. The second process is fine crushing, needing a Droplet Fish Feed Crusher with a sieve of 0.5mm pore. The crushing degree must reach the requirement that all pass 40 mesh, and 80% material passes 60 mesh.

B. Batching technology
The raw materials must be cleaned up before crushing and cleaning our debris, such as paper, wood, stones, and others. Before the second process, the ingredients, like peanut oil-cake powder, fish meal, spray-dried blood cells, and squid powder, should be mixed in accordance with the proportion of ingredients, then crushed into more than 40 mesh powder, then stirred well with the standard flour and additive-the coefficient of variation is not more than 10%.

C. Granulation technology
After being crushed, the moisture content of raw materials is 13 %, which makes it not easy to soften up and gelatinize, so it is an important condition to add the appropriate amount of water to ensure powder bonding and starch gelatinization. At first, in the mixing process, shrimp feed manufacturers should squirt water with a high-pressure hydraulic pump to keep the moisture content of raw materials remain about 18%, followed by adding steam. By this means, raw materials are with uniform moisture content and reach softening requirements. After adding steam, the material temperature increases rapidly, extending the material gelatinization time. Only with starch fully gelatinized does the working temperature of dies to decrease and the service life of the die improve. When raw material temperature, after steam treatment, reaches 90 – 105oC, it is the right time to process the materials. Fish Feed Extruder is used to manufacture delicious and nutritional shrimp feed pellets.

D. Drying technology
The particles come from the host having high moisture content and need to be dried, the most common fish feed pellet drying equipment is a net Mesh-belt type fish feed dryer. Its role is to reduce the water content, water content is usually below 10%, and this can ensure the feed won’t deteriorate for more than 2 months; The second role is promoting gelatinization, ripening, and adhesion. The general drying temperature is 90oC for 20 minutes, if beyond this standard, the feed may be burned and the vitamin destroyed, which can affect the shrimp’s appetite and feed prices, while the steam drying temperature can relatively increase to 105oC.

E. Cooling technology
Shrimp feed pellet cooling is usually in the Counter-flow type fish feed cooler, In this process cool air will take away some hot energy and water, and pellets can be packaged when they stay at room temperature. If the pellet makes cooling progress without drying, a large number of small cracks will appear on the surface and extend to the deep due to the internal of the pellet having rapid cooling and dewatering, even good gelatinization fines will also have the phenomenon. In the feeding, the particles along the crack into several pieces because of being soaked in water, but the phenomenon will reduce a lot after drying. The water content is 17% – 18% from the feed extruder, 12％—13% after drying, and 10% – 11% after cooling.

F. Classifying Screener
After granulating, drying, and cooling, unfinished products, including particles, powder, and residue, should be screened by a classifying screener. Powder and pieces are filtered out from the bottom of the machine. Large particles and residue are screened from the top of this machine. Finished materials are packaged in a feed column from the interlayer. Shrimp feed is classified into four types from juvenile prawn to adult shrimp. Since the nutritional ingredient is different, there are different feed size and length. Little shrimp needs feed 0.3-1.5mm in diameter; prawn, 2mm; adult shrimp, 2.7mm. With the growth of little shrimp, the length of granules increases to a few centimeters. In this way, to keep it tidy, pure, and beautiful, the interlayer of the classifying screener can be changed accordingly. The raw materials should be crushed, screened, and packaged once or twice.

G. Packaging
Taking Penaeus Orientalis for example, the feed is stored and fed in shrimp ponds along the coast, easy to be affected by dampness because of the humid coastal air, so Penaeus Orientalis feed pellets must be packaged by paper and plastic syntactic bags. Weight of per package is better to be 20 kg or 25 kg, which is beneficial to transport.