A kind of compound feed for blue crab and preparation method thereof

Abstract

The invention discloses a compound feed for blue crabs and a preparation method thereof, and belongs to the technical field of aquaculture. The main raw material of the compound feed for blue crabs is soybean meal with anti-nutritional factors removed. When the pretreated soybean meal prepared by the specific anti-nutritional factor removal method of the soybean meal of the invention is further prepared into a compound feed for blue crabs, the compound feed is used to feed blue crabs, which can reduce the cost of the compound feed on the one hand, and improve the growth performance and survival rate of blue crabs on the other hand, so as to achieve the purpose of increasing production, improve the economic benefits of farmers, and have good prospects for promotion and application.

Description

Technical Field

[0001] The invention belongs to the technical field of aquaculture, and particularly relates to a compound feed for blue crabs and a preparation method thereof. Background Art

[0002] The blue crab, also known as the blue crab, has the characteristics of fast growth, large size, strong adaptability and disease resistance, easy transportation, delicious meat, rich nutrition and good breeding benefits. It is favored by producers and consumers at home and abroad and is one of the important marine economic aquaculture crabs.

[0003] Since the natural biological baits used in blue crab farming are small fish, shrimps and shellfish, the use of these natural biological baits will not only destroy marine fishery resources, but also have the disadvantages of limited resources, unable to guarantee timely and sufficient supply, inconvenient to use (need to be frozen for storage), single nutritional structure, easy to rot and decompose after feeding, deteriorating water quality, causing the spread of diseases, etc., it is difficult to adapt to the growing demand for bait in the crab farming industry, so it is imperative to study artificial compound feeds.

[0004] At present, the raw material price of mud crab compound feed on the market is still high (generally containing a high proportion of high-quality fish meal), which in turn pushes up the breeding cost and reduces the economic benefits of farmers; and if the low-priced soybean meal is used as the main raw material, the anti-nutritional factors in the soybean meal with a high content will affect the growth of mud crabs. Therefore, finding a new compound feed with low cost and no impact on the growth performance of mud crabs is a technical problem that needs to be solved in this field. Summary of the invention

[0005] To solve the above problems, the present invention provides a compound feed for blue crabs and a preparation method thereof. By selecting pretreated soybean meal as the main raw material, the cost of the compound feed for blue crabs is greatly reduced and the economic benefit is improved. The main purpose of pretreatment is to reduce the anti-nutritional factors in soybean meal and improve the palatability of soybean meal.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One of the technical solutions of the present invention is to provide a method for preparing a compound feed for blue crabs, wherein the pretreated soybean meal accounts for 40-50% of the total weight of the raw materials;

[0008] The processing steps of pre-treating soybean meal include:

[0009] (1) firstly, uniformly mix soybean meal, ammonia water and sodium chloride, and then soak them to separate the solid and liquid;

[0010] (2) heating and drying of solid components;

[0011] (3) Calcium chloride is first added to the liquid component, and then ferric chloride is added after stirring. After stirring, the concentrated solution is heated and concentrated to remove solid precipitates in the concentrated solution. The liquid portion is mixed with the soybean meal dried in step (2), and heated to evaporate the water to obtain pretreated soybean meal.

[0012] The present invention first soaks soybean meal with ammonia water and sodium chloride. The alkaline environment provided by the ammonia water is conducive to the dissolution of anti-nutritional factors and nutrients in the soybean meal. The addition of sodium ions can form soluble sodium phytate with phytate, an anti-nutritional factor that is difficult to dissolve (most of the phytic acid in the soybean meal exists in the form of insoluble phytate except free phytic acid). Therefore, the addition of ammonia water and sodium chloride can dissolve most of the anti-nutritional factors in the soybean meal.

[0013] Furthermore, the present invention performs solid-liquid separation on the soaked soybean meal, and the separated solid soybean meal portion is heated and dried to completely volatilize the ammonia in the soybean meal. The liquid portion is firstly added with calcium chloride to precipitate the anti-nutritional factors in the liquid component (the anti-nutritional factors are easily chelated with calcium to form a precipitate), and then ferric chloride is added to form phytic iron precipitate with iron ions and phytic acid to completely remove the anti-nutritional components in the liquid component. The purpose of the subsequent heating and concentration treatment is to remove ammonia in the solution, and then filter after concentration. The remaining part in the filtrate is a beneficial nutritional component, which is then mixed with the soybean meal dried in the previous step, and the water is evaporated to obtain the pretreated soybean meal.

[0014] The invention comprises multiple heating steps in the pretreatment process of soybean meal, and the multiple heating processes can completely remove the beany smell of the soybean meal, so that the compound feed for blue crabs prepared by using the soybean meal as a raw material has good palatability, increases the feed intake of blue crabs, and achieves the purpose of increasing production.

[0015] Preferably, the pH of the ammonia water in step (1) is 9-10; the solid-liquid ratio of the soybean meal to the ammonia water is 1 g:5-6 mL; the amount of sodium chloride added is 3-5% of the mass of the soybean meal; and the soaking time is 2-3 h.

[0016] Preferably, the temperature of the heating and drying in step (2) is 60-80°C.

[0017] Preferably, in step (3), the amount of calcium chloride added is 1-2% of the mass of the soybean meal; and the amount of ferric chloride added is 1-2% of the mass of the soybean meal.

[0018] Preferably, in step (3), the stirring time after adding calcium chloride is not less than 60 minutes; and the stirring time after adding ferric chloride is not less than 60 minutes.

[0019] The stirring step of the present invention is to allow calcium and iron to react with the anti-nutritional components in the solution, and the time selection only needs to achieve a sufficient reaction effect, so the minimum limit is retained and no upper limit is set.

[0020] Preferably, the temperature of the heating and concentration in step (3) is 60-80° C., and the concentration is performed until no ammonia gas escapes.

[0021] More preferably, the ammonia gas released during the heating and concentration process can be collected and used as ammonia water for subsequent soaking of soybean meal, thereby achieving the purpose of recycling.

[0022] Preferably, the temperature for heating to evaporate the water in step (3) is 60-80°C.

[0023] The temperature selected in the process of pretreating soybean meal in the present invention does not exceed 80° C., so as not to destroy the nutrient components in the soybean meal that are not resistant to high temperatures.

[0024] Preferably, other components of the compound feed for blue crabs include 17-22% shrimp head meal, 17-22% fish meal, 13-15% fish oil, 1.5-2% bentonite, 0.5-1% complex vitamins, 0.5-1% potassium dihydrogen phosphate, 0.5-1% calcium dihydrogen phosphate, 1-2% trace elements, 0.1-0.15% preservatives and 0.1-0.2% choline chloride.

[0025] The shrimp head powder selected by the present invention is the crayfish heads discarded after the shrimp tails are separated in the crayfish tail production process, which can provide a new high resource utilization channel for the discarded crayfish heads.

[0026] More preferably, the complex vitamins include vitamin A, vitamin B2, vitamin B6, vitamin C, vitamin D3, vitamin E, niacin and folic acid; and the trace elements include zinc, copper, manganese and selenium.

[0027] The second technical solution of the present invention is to provide a method for preparing the above-mentioned compound feed for blue crabs, comprising the following steps:

[0028] The pretreated soybean meal is mixed evenly with other raw material components, extruded into granules, and then crushed to a particle size not exceeding 5 mm to obtain a compound feed for blue crabs.

[0029] The beneficial technical effects of the present invention are as follows:

[0030] The invention prepares a compound feed for blue crabs by using pretreated soybean meal as a raw material. The pretreatment process removes anti-nutritional factors in the soybean meal, while retaining the nutrients in the soybean meal to the greatest extent. Using the pretreated soybean meal as the main raw material can greatly save the amount of high-priced fish meal in traditional blue crab compound feeds, thereby achieving the purpose of improving economic benefits.

[0031] The compound feed for blue crabs prepared by the present invention can improve the growth performance and survival rate of blue crabs, achieve the purpose of increasing production, increase the economic benefits of breeders, and has a good prospect for promotion and application. DETAILED DESCRIPTION

[0032] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0033] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0034] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0035] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0036] The contents of each vitamin in the multivitamin used in the examples and comparative examples of the present invention are as follows:

[0037] Vitamin A 200g / kg, vitamin B2 15g / kg, vitamin B6 15g / kg, vitamin C 100g / kg, vitamin D3 3.5g / kg, vitamin E 0.5g / kg, niacin 50g / kg, folic acid 5g / kg.

[0038] The content of zinc in the trace elements used in the examples and comparative examples of the present invention is 3000 ppm, the content of copper is 500 ppm, the content of manganese is 1500 ppn, and the content of selenium is 200 ppm.

[0039] The shrimp head powder used in the embodiments of the present invention and the comparative examples is crayfish head powder.

[0040] Example 1

[0041] Preparation of compound feed for blue crab:

[0042] (1) Take 50 kg of dried soybean meal, add 250 L of ammonia water with pH=10 and 1.5 kg of sodium chloride, stir evenly, soak for 2.5 hours, then suck out the supernatant, use a plate and frame filter press to press out water from the lower layer, spread out the filter residue, and place it in a blast drying oven at 65° C. to dry; combine the aqueous solution filtered out with the sucked out supernatant, add 0.5 kg of calcium chloride, stir for 60 minutes, then add 0.5 kg of ferric chloride, continue to stir for 60 minutes, and then heat and concentrate at 80° C. until no ammonia gas escapes, and the ammonia gas escaped during the concentration process is collected with water as ammonia water for soaking the soybean meal next time; the concentrated solution is evenly mixed with the soybean meal after blast drying, and the water is evaporated at 80° C. to obtain pretreated soybean meal;

[0043] (2) Take 44.25 kg of pretreated soybean meal, 18 kg of shrimp head meal, 18 kg of fish meal, 15 kg of fish oil, 2 kg of bentonite, 0.5 kg of multivitamins, 0.5 kg of potassium dihydrogen phosphate, 0.5 kg of calcium dihydrogen phosphate, 1 kg of trace elements, 0.1 kg of potassium sorbate (preservative) and 0.15 kg of choline chloride, stir evenly, extrude granules, and then crush them and pass through a sieve with a pore size of 5 mm to obtain a compound feed for blue crabs.

[0044] Comparative Example 1

[0045] Preparation of compound feed for blue crab:

[0046] (1) taking 50 kg of dried soybean meal, spreading it out, and drying it at 80° C. for 10 h to obtain pretreated soybean meal;

[0047] (2) Take 44.25 kg of pretreated soybean meal, 18 kg of shrimp head meal, 18 kg of fish meal, 15 kg of fish oil, 2 kg of bentonite, 0.5 kg of multivitamins, 0.5 kg of potassium dihydrogen phosphate, 0.5 kg of calcium dihydrogen phosphate, 1 kg of trace elements, 0.1 kg of potassium sorbate (preservative) and 0.15 kg of choline chloride, stir evenly, extrude granules, and then crush them and pass through a sieve with a pore size of 5 mm to obtain a compound feed for blue crabs.

[0048] Comparative Example 2

[0049] Preparation of compound feed for blue crab:

[0050] Compared with Example 1, the only difference is that no sodium chloride is added in step (1).

[0051] Comparative Example 3

[0052] Preparation of compound feed for blue crab:

[0053] Compared with Example 1, the only difference is that calcium chloride is not added in step (1).

[0054] Comparative Example 4

[0055] Preparation of compound feed for blue crab:

[0056] Compared with Example 1, the only difference is that ferric chloride is not added in step (1).

[0057] The yields of the mud crab compound feeds prepared in Example 1 and Comparative Examples 1 to 4 in the culture of mud crabs were compared.

[0058] In an agricultural breeding base in Taishan, Guangdong, 15 experimental plots were enclosed with polyethylene mesh, each with an area of ​​67±2m 2 , dig a U-shaped ditch 1.5m away from the edge of the test plot, the ditch width is 1m, the depth is 0.8-1.2m, set up a water supply and drainage system, select healthy, vigorous, uniform, disease-free and uninjured crab seedlings to put into each test plot, put 100 crab seedlings into each test plot in spring, and divide the 15 test plots into 3 groups, respectively feed with the blue crab compound feed prepared in Example 1 and Comparative Examples 1-4, and harvest collectively after four months of cultivation, count the number and average weight of blue crabs in each test plot, and compare the actual effect of the blue crab compound feed in each group. The statistical results are shown in Table 1.

[0059] Table 1 Feeding results of each group of blue crabs with compound feed

[0060]

[0061] It can be seen from the data in Table 1 that after the soybean meal is treated by the pretreatment method of the present invention, the growth performance and survival rate of the blue crab are significantly improved when it is used as a raw material to prepare a compound feed for blue crabs compared with the untreated soybean meal. The reason is that the pretreatment method of the present invention can remove the anti-nutritional factors in the soybean meal to the greatest extent. By comparing the data of Comparative Examples 2 to 4 with Example 1, it can be seen that when the pretreatment method is changed, resulting in a decrease in the amount of anti-nutritional factors of the soybean meal removed by pretreatment, the compound feed prepared with the pretreated soybean meal as a raw material has an adverse effect on the growth performance and survival rate of blue crabs.

[0062] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A compound feed for blue crabs, characterized in that: Pretreated soybean meal accounts for 40-50% of the total raw material weight; The processing steps of pre-treating soybean meal include: (1) First, mix the soybean meal, ammonia water and sodium chloride evenly, soak them and separate the solid and liquid; (2) Heating and drying of solid components; (3) adding calcium chloride to the liquid component, stirring and then adding ferric chloride, stirring and then heating and concentrating, removing solid precipitates in the concentrate, mixing the liquid portion with the soybean meal dried in step (2), heating and evaporating the water to obtain pretreated soybean meal; The pH of the ammonia water in step (1) is 9-10; the material-liquid ratio of the soybean meal to the ammonia water is 1 g:5-6 mL; the amount of sodium chloride added is 3-5% of the mass of the soybean meal; and the soaking time is 2-3 h; The heating and drying temperature in step (2) is 60-80°C; In step (3), the amount of calcium chloride added is 1-2% of the mass of the soybean meal; the amount of ferric chloride added is 1-2% of the mass of the soybean meal; The temperature for heating to evaporate the water in step (3) is 60-80°C.

2. The compound feed for blue crab according to claim 1, characterized in that: In step (3), the stirring time after adding calcium chloride is not less than 60 minutes; the stirring time after adding ferric chloride is not less than 60 minutes.

3. The compound feed for blue crab according to claim 1, characterized in that: The heating and concentration in step (3) is carried out at a temperature of 60-80° C., and the mixture is concentrated until no ammonia gas escapes.

4. The compound feed for blue crab according to claim 1, characterized in that: Other components of the blue crab feed include 17-22% shrimp head meal, 17-22% fish meal, 13-15% fish oil, 1.5-2% bentonite, 0.5-1% complex vitamins, 0.5-1% potassium dihydrogen phosphate, 0.5-1% calcium dihydrogen phosphate, 1-2% trace elements, 0.1-0.15% preservatives and 0.1-0.2% choline chloride.

5. The compound feed for blue crab according to claim 4, characterized in that: The complex vitamins include vitamin A, vitamin B2, vitamin B6, vitamin C, vitamin D3, vitamin E, niacin and folic acid; the trace elements include zinc, copper, manganese and selenium.

6. A method for preparing the compound feed for blue crabs according to any one of claims 1 to 5, characterized in that: The following steps are involved: The pretreated soybean meal is mixed evenly with other raw material components, extruded into granules, and then crushed to a particle size not exceeding 5 mm to obtain a compound feed for blue crabs.

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