Preparation method of selenium-rich sea urchin fermented feed

Abstract

The invention discloses a preparation method of a selenium-rich sea urchin fermented feed, a sea urchin feed is obtained through fermentation of selenium-rich yeast and selenium-rich bifidobacterium, an inorganic selenium source is converted into organic selenium with higher biological activity by using a microbial fermentation method, the safety of a selenium supplement is improved, and after the selenium-rich sea urchin fermented feed is used for feeding sea urchin, the selenium content of the sea urchin is increased. The absorption utilization rate and palatability of the feed can be improved, and then the intestinal health of the sea urchins is improved. The selenium-rich sea urchin fermented feed prepared by the invention has the characteristics of sufficient selenium supplement and safe selenium supplement, is high in organic selenium content, good in safety and good in feed palatability, and also has the characteristics of being wide in raw material source, balanced in nutrition, high in feed coefficient, free of pathogenic bacteria and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of aquaculture, and particularly relates to a preparation method of a selenium-rich sea urchin fermented feed. Background Art

[0002] Sea urchins are economic marine organisms with high edible value, medicinal value, and research and teaching value. Their gonads are extremely delicious and nutritious, and are deeply loved by Chinese consumers. Among the sea urchins discovered in China, there are less than 10 important economic species, mainly including: Hemicentrotus pulcherrimus, Strongylocentrotus nudus, Anthocidaris crassispina, Tripneustes gratilla, etc. Sea urchins are regarded as precious seafood delicacies at home and abroad, and the supply is scarce in the Chinese market at present. With the improvement of people's requirements for the quality of life in recent years and the high economic background, the demand for sea urchins has been increasing continuously, and the price has also been rising continuously. The limited natural sea urchin resources can no longer meet the market demand, and artificial breeding of sea urchins has gradually emerged, and it is timely to develop artificial sea urchin breeding.

[0003] At present, the main sources of bait for breeding sea urchins are large algae such as kelp and wakame, but the protein content in algae is extremely low and cannot meet the growth requirements. Moreover, the growth cycle of large algae is long, the utilization period is short, and it is easily polluted by heavy metal enrichment and nuclear radiation. With the vigorous development of China's aquaculture industry and the continuous development and utilization of industry and agriculture, it has also led to a shortage of resources, and the prices of large algae such as kelp and wakame have also increased day by day. Therefore, it is necessary to find substitutes for natural sea urchin bait. In order to improve the growth rate of sea urchins, the present invention designs a preparation method of an artificial fermented feed. The feed of the present invention is nutritionally balanced, has a high protein content, and is rich in vitamins and minerals, which can meet the healthy growth requirements of sea urchins, and at the same time solves the problem of the shortage of natural bait resources.

[0004] Moreover, the present invention uses the microbial fermentation method to decompose the macromolecular nutrients in the feed into absorbable small molecules. The fermentation process endows the feed with a special sour and fragrant flavor, which can improve the palatability of the feed and the feeding amount of sea urchins. The growth activities of microorganisms can also produce active factors, balance the intestinal flora of sea urchins, regulate the gastrointestinal ecology of sea urchins, improve the digestive tract microbial environment, promote the digestion, absorption and utilization of nutrients, and improve the body immunity and disease resistance of sea urchins. Therefore, the fermentation process can significantly improve the utilization rate of the feed, not only save feed raw materials, reduce feed costs, but also promote the growth of sea urchins and improve the quality of seafood products.

[0005] Selenium is one of the essential trace elements for the human body. It is a component of glutathione peroxidase and can improve the body's immunity. Selenium also plays an important physiological role in marine organisms. Selenium is an antioxidant that can increase reproduction, immune response, and thyroid hormone metabolism, and can improve the antioxidant capacity, immune function, and production performance of marine animals. Moreover, selenium has a strong detoxification function. Selenium can antagonize heavy metal elements and accelerate the elimination of heavy metal elements in the body. However, inorganic selenium has certain toxicity and a relatively narrow safety range, so it cannot be an ideal selenium source. Microorganisms have the function of enriching selenium and converting inorganic selenium into organic selenium. At the same time, organic selenium has a higher absorption rate, lower toxicity, and is safer than inorganic selenium. Therefore, organic selenium feed can not only improve the growth rate of marine animals, enhance the immunity of marine organisms, and increase their disease resistance, but also reduce the heavy metal content in marine animals. Summary of the Invention

[0006] To solve the above technical problems, the present invention provides a preparation method of selenium-rich sea urchin fermented feed.

[0007] The technical solution adopted by the present invention is as follows: A preparation method of selenium-rich sea urchin fermented feed, the steps are as follows:

[0008] Mix 8-25 parts of fish meal, 10-15 parts of kelp powder, 10-15 parts of seaweed powder, 15-25 parts of wheat flour, 5-25 parts of corn starch, 4-8 parts of spirulina algal mud, 6-15 parts of soybean meal, 2-4 parts of sea mud, and 0.5-1 part of multi-vitamin and multi-mineral evenly to obtain dry powder raw materials;

[0009] Mix 1-2 parts of soybean oil, 2-4 parts of fish oil, and 1-5 parts of lecithin evenly to form oil raw materials; and add the oil raw materials to the dry powder raw materials and mix evenly to obtain mixed raw materials;

[0010] Add water to the mixed raw materials at a material-liquid mass ratio of 1:0.15-0.3, stir evenly and then perform sterilization treatment to obtain a fermentation substrate;

[0011] Inoculate 0.12-0.5 parts of selenium-rich yeast and 0.12-0.5 parts of selenium-rich bifidobacterium into the fermentation substrate, and ferment at 20-38 °C for 2-3 days to obtain selenium-rich sea urchin fermented feed.

[0012] Preferably, the spirulina algal mud, soybean meal, and sea mud are respectively pulverized, sieved through 80-200 meshes together with fish meal, kelp powder, seaweed powder, wheat flour, corn starch, and multi-vitamin and multi-mineral, and then the components are mixed.

[0013] Preferably, the screened selenium-enriched yeast and selenium-enriched Bifidobacterium are added to warm water at a temperature of 36°C - 40°C, glucose is added thereto, and after being fully dissolved, it is left standing to obtain activated selenium-enriched mixed bacteria; wherein, by weight, 3 - 5 parts of selenium-enriched yeast powder, 3 - 4 parts of selenium-enriched Bifidobacterium powder, 60 - 85 parts of warm water, and 7 - 12 parts of glucose; the selenium-enriched mixed bacteria are used for inoculating the fermentation substrate.

[0014] Preferably, the mixture after fermentation is pulverized twice, then the mixture is subjected to low-temperature puffing and pressed into flakes;

[0015] The flaky feed is dried at 37 - 45°C until the water content is 8 - 10%, and made into a form suitable for storage.

[0016] The selenium-enriched sea urchin fermented feed prepared by the preparation method of the selenium-enriched sea urchin fermented feed.

[0017] The application of the selenium-enriched sea urchin fermented feed in feeding sea urchins.

[0018] The advantages and positive effects of the present invention are: the selenium-enriched sea urchin fermented feed combines the probiotic activity and the biological activity of organic selenium. Under the dual action of probiotics and organic selenium, the sea urchins fed with the present invention have stronger immunity, larger shell diameter, sufficient weight, higher gonad index, better flavor, and higher economic value;

[0019] The inoculated mixed ferment has strong selenium enrichment ability, good safety, and high biological utilization rate of organic selenium. Through the enrichment and transformation of selenium-enriched probiotics, the content of organic selenium in the sea urchin feed has been significantly improved; special flavors are produced during the fermentation process, improving the feed taste, enhancing the palatability of the feed, and increasing the feeding amount of sea urchins. At the same time, the activities of microorganisms decompose nutrients into smaller molecules that are more easily absorbed, and produce active factors to improve the intestinal health of sea urchins, increasing the absorption and utilization rate of nutrients in the feed by sea urchins;

[0020] The selenium-enriched sea urchin fermented feed prepared by the present invention has the characteristics of sufficient selenium supplementation and safe selenium supplementation, high organic selenium content, good safety, good feed palatability, and at the same time has the characteristics of wide raw material sources, balanced nutrition, high bait coefficient, and no pathogenic bacteria. Description of the Drawings

[0021] Figure 1 Statistics of the number of sea urchins in each group in Example 3;

[0022] Figure 2 Average body weight of sea urchins in each group in Example 3;

[0023] Figure 3 Average gonad mass of sea urchins in each group in Example 3;

[0024] Figure 4The gonad indices of each group in Example 3. Detailed implementation mode

[0025] The embodiments of the present invention will be described below with reference to the accompanying drawings.

[0026] The present invention discloses a preparation method of a selenium-rich sea urchin fermented feed. The prepared selenium-rich sea urchin fermented feed can be used for feeding sea urchins. An artificial feed with a more balanced nutrition replaces the natural bait of sea urchins. By inoculating a screened probiotic with high selenium-rich ability as a fermenting agent, inorganic selenium is converted into organic selenium, and a selenium-rich sea urchin fermented feed that can better meet the healthy growth needs of sea urchins, has a low production cost, strong safety, and a high organic selenium conversion rate is produced. The preparation method of the selenium-rich sea urchin fermented feed is as follows: 1. Prepare the fermentation base material:

[0027] A. Raw material pretreatment: The spirulina algae mud, soybean meal, and sea mud are respectively crushed and sieved through 80-200 meshes together with fish meal, kelp powder, seaweed powder, wheat flour, corn starch, and multi-vitamins and minerals. The storage environment of the raw materials should be kept ventilated and dry, and each material is stored separately in different containers.

[0028] B. Dry powder mixing: According to the weight parts, 8-25 parts of fish meal, 10-15 parts of kelp powder, 10-15 parts of seaweed powder, 15-25 parts of wheat flour, 5-25 parts of corn starch, 4-8 parts of spirulina algae mud, 6-15 parts of soybean meal, 2-4 parts of sea mud, 0.5-1 part of multi-vitamins and minerals are mixed evenly to obtain a dry powder raw material;

[0029] C. Oil mixing: According to the weight parts, 1-2 parts of soybean oil, 2-4 parts of fish oil, and 1-5 parts of lecithin are mixed evenly, and then the oil mixture is slowly added to the powdery raw material, stirring while adding until evenly mixed;

[0030] D. Pasteurization: Water is added to the above mixed raw material at a material-liquid mass ratio of 1:0.15-0.3, stirred evenly, and then pasteurized in a sterilization box to obtain the fermentation base material.

[0031] 2. Prepare the strain liquid medium:

[0032] The medium includes 5.0 g of soy peptone, 5.0 g of tryptone, 10.0 g of yeast powder, 10.0 g of glucose, 120 mg of sodium selenite, 40.0 ml of salt solution, 0.5 g of L-cysteine hydrochloride (added after the medium is boiled), 15.0 g of agar, 1.0 L of distilled water, the pH is adjusted to 7.0, and autoclaved at 121 °C for 20 min;

[0033] Among them, the above salt solution formula: CaCl 2 0.2 g, MgSO 4 ·7H2 O 0.48 g, K 2 HPO 4 1.0 g, KH 2 PO 4 1.0 g, NaHCO 3 10.0 g, NaCl 2.0 g, mix evenly in 300 ml of distilled water until dissolved. 3 Inoculate with selenium-rich fermentation strains:

[0034] A. Activation of selenium-rich mixed strains: Add the screened selenium-rich yeast and selenium-rich bifidobacterium to warm water at a temperature of 36°C - 40°C, add glucose to it, and make it dissolve fully, then let it stand for 1 h; among them, by weight, 3 - 5 parts of selenium-rich yeast powder, 3 - 4 parts of selenium-rich bifidobacterium powder, 60 - 85 parts of warm water, 7 - 12 parts of glucose; among them, the selenium content of the selenium-rich bifidobacterium powder is 631.65 μg / g;

[0035] Among them, the selenium-rich yeast and selenium-rich bifidobacterium can be commercially available products or prepared by existing experimental methods;

[0036] B. Strain culture: Inoculate the activated selenium-rich yeast and selenium-rich bifidobacterium into a liquid medium and culture in a shaker for 48 - 60 hours;

[0037] C. Inoculation: Inoculate the mixed strains including selenium-rich yeast and selenium-rich bifidobacterium into the fermentation substrate according to an inoculation amount of 5 - 8%.

[0038] 4 Feed fermentation:

[0039] Put the fermentation substrate and the mixed selenium-rich strains into a fermentation device for fermentation, control the fermentation temperature within the range of 20 - 38°C, and the fermentation time is 2 - 3 days. The fermentation device needs to have a certain air permeability and dust-proof property to improve the quality of the fermented feed.

[0040] 5 Product forming:

[0041] Perform secondary pulverization on the fermented mixture, then import it into the interior of an extruder using a transmission device, perform low-temperature extrusion (≤60°C) on the mixture using the extruder, and press it into flakes.

[0042] 6 Drying:

[0043] Import the flaky feed into a drying device and dry it at 37 - 45°C until the water content is 8 - 10%, remove the moisture in the flaky feed, and then perform air-cooling and temperature reduction treatment on the dried and formed flaky feed, that is, obtain the selenium-rich sea urchin feed. The flaky feed after the temperature reduction treatment should be quantitatively stored and kept in a dry storage environment.

[0044] The prepared selenium-rich sea urchin fermented feed can be used to feed sea urchins. The selenium content in the fermented feed reaches more than 1.7 mg / kg, and the feed can be fed in appropriate amounts according to the feeding and defecation conditions of sea urchins. Yeasts and bifidobacteria with high selenium-rich ability are screened out and inoculated into sea urchin feed, and fermented in an environment containing inorganic selenium salt solution. Not only can the macromolecular nutrients in the feed be effectively decomposed into absorbable small molecules, improving the nutritional value of the feed, but also special flavors are produced during the fermentation process, improving the feed taste, enhancing the palatability of the feed and the feeding amount of animals. The activities of selenium-rich probiotics can also produce active factors to improve the intestinal health of animals, significantly enhancing the body immunity and disease resistance of sea urchins and improving the quality of sea urchins.

[0045] Selenium-rich probiotics have the ability to enrich and transform organic selenium. The organic selenium content in the feed is significantly increased through the microbial fermentation process. Moreover, this method has good safety and high bioavailability of organic selenium. The selenium-rich fermented feed combines the activities of probiotics and the biological activities of organic selenium. Under the dual actions of probiotics and organic selenium, the sea urchins fed with the selenium-rich sea urchin fermented feed have strong immunity, low prevalence, sufficient weight, high gonad index, good quality and high selenium content. An artificial feed that is more nutritionally balanced, has a higher protein content, is rich in vitamins and minerals, and can better meet the healthy growth needs of sea urchins replaces the natural bait of sea urchins, not only solving the problem of shortage of algal resources, but also promoting the development of the artificial sea urchin aquaculture industry.

[0046] The following further illustrates the solution of the present invention in conjunction with specific embodiments.

[0047] Example 1:

[0048] This example provides a production method of selenium-rich sea urchin fermented feed, which specifically includes the following steps:

[0049] (1) Prepare the fermentation base material:

[0050] A. Raw material pretreatment: The spirulina algal mud, soybean meal and sea mud are respectively crushed, and then sieved through 150 meshes together with fish meal, kelp powder, seaweed powder, wheat flour, corn starch and vitamins and minerals. The storage environment of the raw materials should be kept ventilated and dry, and each material is stored separately in different containers.

[0051] B. Dry powder mixing: According to the weight parts, 8 parts of fish meal, 15 parts of kelp powder, 15 parts of seaweed powder, 20 parts of wheat flour, 17 parts of corn starch, 4 parts of spirulina algal mud, 6 parts of soybean meal, 2 parts of sea mud, and 1 part of vitamins and minerals are mixed evenly to obtain a dry powder raw material;

[0052] C. Oil mixing: According to the weight parts, 2 parts of soybean oil, 4 parts of fish oil and 5 parts of lecithin are mixed evenly, and then the oil mixture is slowly added to the powdery raw material, stirring while adding until evenly mixed.

[0053] D. Pasteurization: Add water to the above-mentioned mixed raw materials at a material-liquid mass ratio of 1:0.15, stir evenly, and then perform Pasteurization treatment in a sterilization box to obtain a fermentation base material;

[0054] (2) Prepare the liquid medium for the strain:

[0055] 5.0 g of soy peptone, 5.0 g of tryptone, 10.0 g of yeast powder, 10.0 g of glucose, 120 mg of sodium selenite, 40.0 ml of salt solution, 0.5 g of L-cysteine hydrochloride (added after the medium is boiled), 15.0 g of agar, 1.0 L of distilled water, adjust the pH to 7.0, and sterilize at 121 °C under high-pressure steam for 20 min.

[0056] Among them, the formula of the above salt solution: CaCl 2 0.2 g, MgSO 4 ·7H 2 O 0.48 g, K 2 HPO 4 1.0 g, KH 2 PO 4 1.0 g, NaHCO 3 10.0 g, NaCl 2.0 g, mix evenly in 300 ml of distilled water until dissolved.

[0057] (3) Inoculate the selenium-rich fermentation strain:

[0058] A. Activation of the selenium-rich mixed strain: Add the screened selenium-rich yeast and selenium-rich bifidobacterium to warm water at a temperature of 36 °C - 40 °C, add glucose to it, make it fully dissolve, and let it stand for 1 h; among them, by weight, 3 parts of selenium-rich yeast powder, 3 parts of selenium-rich bifidobacterium powder, 60 parts of warm water, and 7 parts of glucose; the selenium content of the selenium-rich bifidobacterium powder is 631.65 μg / g;

[0059] B. Strain culture: Inoculate the activated selenium-rich yeast and selenium-rich bifidobacterium into the liquid medium and culture in a shaker for 48 hours;

[0060] C. Inoculation: Inoculate the selenium-rich yeast and selenium-rich bifidobacterium into the fermentation base material according to an inoculation amount of 5%.

[0061] (4) Feed fermentation:

[0062] Put the raw materials and the mixed selenium-rich strain together into the fermentation equipment for fermentation. The fermentation temperature is controlled within the range of 20 - 38 °C, and the fermentation time is 2 - 3 days. Among them, the fermentation equipment needs to have a certain air permeability and dust prevention property to improve the quality of the fermented feed.

[0063] (5) Product forming:

[0064] The mixture after fermentation is pulverized for the second time, and then introduced into the interior of an extruder by means of a conveying device. The mixture is subjected to low-temperature extrusion (≤60 °C) using the extruder and pressed into flakes.

[0065] (6) Drying:

[0066] The flaky feed is introduced into a drying device and dried at 37 °C until the water content is 8-10%, removing the moisture in the flaky feed. After that, the dried and formed flaky feed is subjected to air-cooling for temperature reduction treatment, thus obtaining the selenium-rich sea urchin feed.

[0067] Example 2:

[0068] This example provides a method for producing a selenium-rich sea urchin fermented feed, which specifically includes the following steps:

[0069] (1) Preparation of fermentation base material:

[0070] A. Pretreatment of raw materials: The spirulina algal mud, soybean meal, and sea mud are respectively pulverized, and sieved through 100 meshes together with fish meal, kelp powder, seaweed powder, wheat flour, corn starch, and multi-vitamins and minerals. Among them, the storage environment of the raw materials should be kept ventilated and dry, and each material is stored separately in different containers.

[0071] B. Dry powder mixing: According to the weight parts of the pulverized raw materials, 15 parts of fish meal, 10 parts of kelp powder, 10 parts of seaweed powder, 20 parts of wheat flour, 10 parts of corn starch, 8 parts of spirulina algal mud, 12 parts of soybean meal, 3 parts of sea

[0072] mud, 1 part of multi-vitamins and minerals are mixed evenly to obtain a dry powder raw material;

[0073] C. Oil mixing: According to the weight parts, 2 parts of soybean oil, 4 parts of fish oil, and 4 parts of lecithin are mixed evenly, and then the oil mixture is slowly added to the powdery raw material, stirring while adding until evenly mixed.

[0074] D. Pasteurization: Water is added to the above-mentioned mixed raw materials at a material-liquid mass ratio of 1:0.3, stirred evenly, and then subjected to Pasteurization treatment in a sterilization box to obtain the fermentation base material;

[0075] (2) Preparation of the strain liquid medium:

[0076] 5.0 g of soy peptone, 5.0 g of tryptone, 10.0 g of yeast powder, 10.0 g of glucose, 120 mg of sodium selenite, 40.0 ml of salt solution, 0.5 g of L-cysteine hydrochloride (added after the medium is boiled), 15.0 g of agar, 1.0 L of distilled water, adjust the pH to 7.0, and sterilize at 121 °C under high-pressure steam for 20 min.

[0077] Among them, the above salt solution formula: CaCl2 0.2 g of MgSO 4 ·7H 2 O 0.48 g of K 2 HPO 4 1.0 g of KH 2 PO 4 1.0 g of NaHCO 3 10.0 g of NaCl 2.0 g, mix evenly in 300 ml of distilled water until dissolved.

[0078] (3) Inoculate selenium-rich fermentation strains:

[0079] A. Activation of selenium-rich mixed strains: Add the screened selenium-rich yeast and selenium-rich bifidobacterium to warm water at a temperature of 36°C - 40°C, add glucose to it, make it dissolve completely, and let it stand for 1 h;

[0080] Among them, by weight, 5 parts of selenium-rich yeast powder, 4 parts of selenium-rich bifidobacterium powder, 85 parts of warm water, and 12 parts of glucose;

[0081] B. Strain culture: Inoculate the activated selenium-rich yeast and selenium-rich bifidobacterium into a liquid medium and culture in a shaker for 60 hours;

[0082] C. Inoculation: Inoculate selenium-rich yeast and selenium-rich bifidobacterium into the fermentation substrate according to an inoculation amount of 8%.

[0083] (4) Feed fermentation:

[0084] Put the raw materials and the mixed selenium-rich strains into a fermentation equipment for fermentation. Control the fermentation temperature within the range of 20 - 38°C, and the fermentation time is 2 - 3 days.

[0085] (5) Product forming:

[0086] Perform secondary pulverization on the fermented mixture, then introduce it into the interior of an extruder using a transfer device, perform low-temperature extrusion (≤60°C) on the mixture using the extruder, and press it into flakes;

[0087] (6) Drying:

[0088] Put the flaky feed into a drying equipment and dry it at 45°C until the water content is 8 - 10%, remove the water in the flaky feed, and then perform air-cooling and temperature reduction treatment on the dried and formed flaky feed, thus obtaining the selenium-rich sea urchin feed.

[0089] Example 3:

[0090] A. Test grouping

[0091] Select 60 sea urchins with similar sizes (shell diameter (36.21 ± 0.34) mm, shell height (18.66 ± 0.55) mm), close weights (initial weight 18.86 ± 0.55 g), good growth conditions, and similar physiological conditions in the nursery. Randomly divide them into three groups, with 20 sea urchins in each group. Among them, the experimental groups are: the control group, the selenium-rich fermented feed group 1, and the selenium-rich fermented feed group 2. The control group is fed with ordinary non-selenium non-fermented feed on the market. The selenium-rich fermented feed group 1 is fed according to the feed formula in Example 1, and the selenium-rich fermented feed group 2 is fed according to the feed formula in Example 2.

[0092] Among them, the feed formula of the control group:

[0093] Extruded soybean meal 29%, fish meal 12%, kelp powder 20%, flour 14%, corn flour: 10%, sargassum powder: 7.8%, bentonite 2%, fish oil 1%, compound vitamin 1%, aquatic yeast 0.5%, lactic acid bacteria 0.5%, bacillus: 1%, oligosaccharide 0.7%, squid paste 0.3%, immune enhancer 0.1%, N-carbamylglutamic acid 0.1%.

[0094] B. Feeding conditions

[0095] After random grouping, put them into 60 disinfected cages (15 cm × 15 cm × 35 cm), and stock 1 sea urchin in each cage for single-cage culture. Feed the feed twice a day (09:00 and 17:00). The next day, suck out the feces and residual bait at the bottom of the water tank. The daily average water change volume is 30% of the water tank volume. The test period is 42 days. During the test period, the water temperature is 9 - 15 °C, the dissolved oxygen is 9.5 - 10.0 mg / L, the salinity is 30‰, the pH is 8.0 ± 0.1, and aeration is carried out for 24 hours.

[0096] C. Experimental data collection

[0097] Feed the feed according to 5% - 8% of the sea urchin weight. The feed feeding amount fluctuates accordingly according to the sea urchin's feeding and defecation conditions, and record the feeding amount; the sea urchin weight is recorded every 7 experimental days. Correspondingly, the sea urchin feed feeding amount is adjusted every 7 experimental days and recorded. The feeding management is carried out according to the routine. The experimental period is 42 days. Record the survival, development, and health status of the sea urchins in each experimental group on the 0th, 7th, 14th, 21st, 28th, 35th, and 42nd days of the test period, and measure the shell diameter and weight of the sea urchins in each experimental group. Stop feeding 24 hours before the end of the test. Take the gonads of the sea urchins, collect and weigh them, and then detect their selenium content according to the "National Food Safety Standard - Determination of Selenium in Foods" (GB5009.93 - 2010).

[0098] D. Experimental data processing

[0099]

[0100]

[0101]

[0102] Specific growth rate (% / d) = (lnW f - lnW i ) / Number of experimental days × 100

[0103] Where: N f and N i are the final number and initial number of sea urchins (pcs); W f and W i are the final weight and initial weight of sea urchins (g); G is the gonad weight of sea urchins (g).

[0104] The data were analyzed using SPSS 22.0 software. On the basis of performing a significance test using the one-way analysis of variance (One-way ANOVA) method, the Duncan's multiple comparison method was used to test the significance of differences between groups. The experimental data were expressed as mean ± standard error (mean ± SE), and P < 0.05 was considered significantly different.

[0105] E. Experimental results

[0106] After statistics, the initial number and final number of sea urchins in each group during the experimental period are shown in Table 1 and Figure 1 as follows.

[0107] Table 1 Statistical results of the number of sea urchins in each group during the experimental period (pcs)

[0108]

[0109] The average weight (g) of sea urchins in each group during the experimental period is shown in Table 2 and Figure 2 as follows.

[0110] Table 2 Average weight (g) of sea urchins in each group during the experimental period

[0111]

[0112] The weight gain rate (%) and specific growth rate (% / d) of sea urchins in each group during the experimental period are shown in Table 3.

[0113] Table 3 Weight gain rate (%) and specific growth rate (% / d) of sea urchins in each group during the experimental period

[0114] Group Weight gain rate (%) Specific growth rate (% / d) Control group 18.82 0.41 Se-enriched sea urchin fermented feed group 1 23.75 0.51 Se-enriched sea urchin fermented feed group 2 21.193 0.47

[0115] From Table 1 - 3 and Figure 1-2Data shows that the selenium-rich sea urchin fermented feed is beneficial to maintaining a high survival rate of sea urchins, improving the immunity of sea urchins, and can further promote the growth of sea urchins under the dual action of probiotics and organic selenium. The weight gain rate and specific growth rate of sea urchins fed with the selenium-rich sea urchin fermented feed are higher than those of the control group fed with ordinary feed.

[0116] The average gonad mass (g) and gonad index (%) of sea urchins in each group during the experimental period are shown in Table 4 Figure 3-4 as follows.

[0117] Table 4 Average gonad mass (g) and gonad index (%) of sea urchins in each group during the experimental period

[0118]

[0119] The average selenium content in the gonad tissue of sea urchins is shown in Table 5.

[0120] Table 5 Average selenium content (mg / Kg) in the gonad tissue of sea urchins

[0121]

[0122] From Table 4 - 5 and Figure 3-4 the data shown, for sea urchins fed with the selenium-rich sea urchin fermented feed, the gonad development is better, the gonad mass and the selenium content in the gonad are significantly higher than those of the control group, the gonad index of sea urchins can be improved, and the sea urchins obtained by feeding have a better flavor and higher economic value.

[0123] The above has described the embodiments of the present invention in detail, but the content described is only the preferred embodiments of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the present invention application should still fall within the scope covered by the patent of the present invention.

Claims

1. A preparation method of selenium-rich sea urchin fermented feed, characterized in that: The steps are as follows: Mix 8-25 parts of fish meal, 10-15 parts of kelp powder, 10-15 parts of seaweed powder, 15-25 parts of wheat flour, 5-25 parts of corn starch, 4-8 parts of spirulina algal mud, 6-15 parts of soybean meal, 2-4 parts of sea mud, and 0.5-1 part of multi-vitamin and multi-mineral evenly to obtain dry powder raw materials; Mix 1-2 parts of soybean oil, 2-4 parts of fish oil and 1-5 parts of lecithin evenly to form oil raw materials; and add the oil raw materials to the dry powder raw materials and mix evenly to obtain mixed raw materials; Add water to the mixed raw materials at a material-liquid mass ratio of 1:0.15-0.3, stir evenly and then sterilize to obtain a fermentation base material; Inoculate 0.12-0.5 parts of selenium-rich yeast and 0.12-0.5 parts of selenium-rich bifidobacterium into the fermentation base material, and ferment at 20-38°C for 2-3 days to obtain selenium-rich sea urchin fermented feed after fermentation.

2. The preparation method of selenium-rich sea urchin fermented feed according to claim 1, characterized in that: Crush spirulina algal mud, soybean meal and sea mud respectively, sieve them through 80-200 meshes together with fish meal, kelp powder, seaweed powder, wheat flour, corn starch and multi-vitamin and multi-mineral, and then mix the components.

3. The preparation method of selenium-rich sea urchin fermented feed according to claim 1, characterized in that: Add the screened selenium-rich yeast and selenium-rich bifidobacterium to warm water at a temperature of 36°C - 40°C, add glucose to it, fully dissolve and then let it stand to obtain activated selenium-rich mixed bacteria; among them, by weight, 3-5 parts of selenium-rich yeast powder, 3-4 parts of selenium-rich bifidobacterium powder, 60-85 parts of warm water, and 7-12 parts of glucose; the selenium-rich mixed bacteria are used for inoculating the fermentation base material.

4. The preparation method of selenium-rich sea urchin fermented feed according to any one of claims 1-3, characterized in that: Perform secondary crushing on the mixture after fermentation is completed, then perform low-temperature puffing on the mixture, and press it into flakes; dry the flaky feed at 37-45°C until the water content is 8-10%, and make it into a form suitable for storage.

5. The selenium-rich sea urchin fermented feed prepared by the preparation method of the selenium-rich sea urchin fermented feed according to any one of claims 1-4.

6. Application of the selenium-rich sea urchin fermented feed according to claim 5 in feeding sea urchins.

Images