Special ecological fermented feed for procambarus clarkii and production method thereof

Abstract

The invention discloses a special ecological fermented feed for procambarus clarkii and a production method of the special ecological fermented feed, and relates to the technical field of aquaculture fermented feeds, the fermented feed is prepared by using a crayfish feed as a fermentation substrate and fermenting with a mixed bacterial liquid; wherein the mixed bacterial liquid is prepared by adding cutinase, phytase, sodium butyrate, a fermentation accelerant and a mixed strain composed of lactic acid bacteria, bacillus, saccharomycetes and aspergillus oryzae into water. When the ecological fermented feed provided by the invention is applied to feeding the procambarus clarkia, the quality of the procambarus clarkia can be promoted to be improved while the procambarus clarkia can be ensured to have relatively good growth performance, the hardness of shrimp shells is improved while the soft shell rate of the procambarus clarkia is reduced in the aspect of shrimp shells, and the shrimp meat is tender in the aspect of the quality of the shrimp meat; the elasticity and the chewiness are improved, the meat quality is good, the eating quality is good, the market preference is favorably improved, and the breeding benefit is improved.

Description

Technical Field

[0001] The invention relates to the technical field of aquaculture fermented feed, in particular to a special ecological fermented feed for Procambarus clarkii and a production method thereof. Background Art

[0002] Procambarus clarkii, commonly known as crayfish, is loved by the market and consumers for its delicious and smooth meat. It is widely farmed in China because of its delicious meat. With the expansion of the scale of Procambarus clarkii farming, the demand for feed has also increased accordingly. Crayfish are omnivorous animals with a wide range of diets. However, the current freshwater aquaculture of crayfish mainly feeds on artificial compound feeds, and their food types are relatively single. This is mainly because there is a lack of research on the evaluation of the application effects of different types of feed in crayfish farming.

[0003] As a new type of environmentally friendly feed in recent years, bio-fermented feed is gradually being recognized by people. Bio-fermented feed can effectively improve the immunity and disease resistance of aquatic animals, which is beneficial to the production of green aquatic products and the protection of the breeding ecological environment. Since these microorganisms are rich in protein, they can also produce a variety of nutrients such as amino acids and vitamins, or secrete highly active decomposing enzymes and a variety of digestive enzymes. Therefore, adding fermented feed in appropriate amounts can improve the intestinal flora of animals, improve feed utilization and animal immunity, and thus promote animal growth.

[0004] At present, there are few studies on the effects of feeding with biological fermented feed on the growth and meat quality of crayfish. In order to improve the breeding effect of crayfish, promote its growth and improve its product quality, the present invention proposes a special ecological fermented feed for Procambarus clarkii and a production method thereof. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a special ecological fermented feed for Procambarus clarkii and a production method thereof.

[0006] The present invention is achieved by the following technical solution, which comprises the following steps:

[0007] The first aspect of the present invention provides an ecological fermented feed specifically for Procambarus clarkii, wherein the fermented feed is prepared by fermenting a mixed bacterial liquid using crayfish feed as a fermentation matrix; wherein the mixed bacterial liquid is prepared by adding cutinase, phytase, sodium butyrate, a fermentation promoter, and a mixed strain of lactic acid bacteria, Bacillus, yeast, and Aspergillus oryzae into water.

[0008] As a further optimization scheme of the present invention, the addition amount of the cutinase, phytase, sodium butyrate and fermentation promoter is 0.1-0.5% of the total mass of the mixed bacteria.

[0009] As a further optimized solution of the present invention, the fermentation promoter is sesame gum or guar gum.

[0010] As a further optimization scheme of the present invention, the viable count of the mixed strains is 2.5-3.0×10 8 cfu / g, and the live bacteria component ratio of the lactic acid bacteria, bacillus, yeast and Aspergillus oryzae is 1:2:1:0.05.

[0011] The second aspect of the present invention further provides a method for producing ecological fermented feed for Procambarus clarkii as described above, comprising the following steps:

[0012] (1) selecting a mixed strain consisting of lactic acid bacteria, bacillus, yeast and Aspergillus oryzae, stirring the mixed strain evenly and then letting it stand, placing the mixed strain after standing in water at 20-25° C., adding cutinase and a fermentation promoter, and stirring evenly to form a mixed bacterial liquid;

[0013] (2) Mixing the crayfish feed with the mixed bacterial solution obtained in step (1), adjusting the water content to 60-70%, and fermenting to obtain the ecological fermented feed dedicated to Procambarus clarkii.

[0014] As a further optimization scheme of the present invention, in step (2), the fermentation process is divided into two stages. The fermentation conditions of the first stage are 25-30°C, pH 3.5-5.0, and fermentation for 72 hours. The fermentation conditions of the second stage are 28-32°C, pH 6.5-7.5, and fermentation for 48 hours.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] (1) The present invention proposes an ecological fermented feed for the cultivation of Procambarus clarkii, which is prepared by fermenting a mixed bacterial liquid with crayfish feed as a fermentation matrix. The mixed bacterial liquid is prepared by adding cutinase, phytase and sodium butyrate, a fermentation promoter and a mixed bacterial species consisting of lactic acid bacteria, Bacillus, yeast and Aspergillus oryzae into water. The prepared ecological fermented feed is beneficial to improving the activity of digestive enzymes in shrimps, promoting growth and weight gain, and improving the economic benefits of Procambarus clarkii cultivation.

[0017] (2) The quality of the crayfish fed with the ecological fermented feed provided by the present invention is improved, which is specifically reflected in the shrimp shell and shrimp meat. In terms of the shrimp shell quality, the soft shell rate of the crayfish is reduced and the hardness of the shrimp shell is improved. In terms of the shrimp meat quality, the shrimp meat is tender, and the elasticity and chewiness of the shrimp meat are improved, and the edible quality is good, which helps to improve its market preference.

[0018] (3) The time required for the new shell to harden completely after molting of the crayfish fed with the ecological fermented feed provided by the present invention is shortened, which shortens the single molting cycle and increases the number of molting times of the shrimp during the breeding period to a certain extent, which helps to increase the weight of the shrimp and improve the breeding efficiency. In addition, the time for the new shell to harden after the shrimp molts is shortened, which can reduce the risk of invasion by pathogens, toxins or other organisms caused by a long molting period to a certain extent, and also has a certain positive significance for improving the survival rate of the shrimp. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below. It is necessary to point out that the following specific implementation methods are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Technicians in this field can make some non-essential improvements and adjustments to the present invention based on the above application content.

[0020] 1. Reagents and Materials

[0021] Unless otherwise specified, the reagents and materials used below are commercially available.

[0022] The following strains were purchased from Mingzhou Biotechnology:

[0023] Lactobacillus, product number is BMZ133551; Bacillus, product number is BMZ339683; Saccharomyces, product number is BMZ126481; Aspergillus oryzae, product number is BMZ135265; Aspergillus niger, product number is BMZ135480.

[0024] Cutinase, with an enzyme activity of 5000 U / mL, was purchased from Jiangsu Yihaotian Biotechnology.

[0025] 2. Methods

[0026] Unless otherwise specified, the following methods are conventional methods known to those skilled in the art.

[0027] 1. Preparation of mixed bacterial solution

[0028] Mixed bacterial solution A: Select a mixed bacterial strain consisting of lactic acid bacteria, Bacillus, yeast and Aspergillus oryzae, stir evenly and let stand, the number of viable bacteria is 2.5×10 8cfu / g, the ratio of the live bacteria components of lactic acid bacteria, bacillus, yeast and Aspergillus oryzae is 1:2:1:0.05, the mixed bacteria after standing is put into water at 20-25°C, cutinase, phytase, sodium butyrate and a fermentation promoter are added, and the mixture is stirred evenly to form a mixed bacterial liquid, wherein the addition amounts of the cutinase and the fermentation promoter are respectively 0.5% of the total mass of the mixed bacteria, and the fermentation promoter is sesame gum.

[0029] Mixed culture liquid B: The difference from mixed culture liquid A is that the fermentation promoter is guar gum.

[0030] Mixed culture liquid C: The difference from mixed culture liquid A is that the fermentation promoter is soybean polysaccharide.

[0031] Mixed bacterial solution D: The difference from mixed bacterial solution A is that Aspergillus niger is used instead of Aspergillus oryzae.

[0032] Mixed bacterial solution E: The difference from mixed bacterial solution A is that the mixed bacterial species are selected from lactic acid bacteria, Bacillus and yeast. After being stirred evenly, the number of viable bacteria is 2.5×10 8 cfu / g, and the ratio of the live bacteria components of the lactic acid bacteria, bacillus and yeast is 1:2:1.

[0033] Mixed bacterial solution F: The difference from mixed bacterial solution C is that Aspergillus niger is used instead of Aspergillus oryzae.

[0034] Mixed bacterial solution G: The difference from mixed bacterial solution A is that no cutinase is added.

[0035] 2. Preparation of ecological fermented feed for Procambarus clarkii

[0036] The mixed bacterial liquid AG is used to ferment crayfish feed at the same addition amount. The specific fermentation process is to mix the crayfish feed with the mixed bacterial liquid, adjust the water content to 60-70%, and ferment. The fermentation is divided into two stages: the first stage fermentation conditions are 25-30℃, pH 3.5-5.0, and fermentation is 72h; the second stage fermentation conditions are 28-32℃, pH 6.5-7.5, and fermentation is 48h. After the fermentation is completed, the fermented feed AG is obtained.

[0037] The ingredients of crayfish feed are as follows: fish meal 16%, soybean meal 12%, rapeseed meal 15%, corn starch 28%, wheat flour 19%, fish oil 3%, soybean oil 4%, calcium dihydrogen phosphate 1.4%, premix 1.5% and mildew inhibitor 0.1%; the premix provides copper 7.2mg, zinc 59.5mg, iron 71.5mg, iodine 0.35mg, manganese 55.5mg, selenium 0.8mg, vitamin A 7300IU, vitamin D 32750IU, vitamin E 30mg, vitamin B1 1.8mg, vitamin B2 2.8mg, vitamin B6 2.4mg, vitamin B 12 0.01mg, vitamin K 32.5mg, folic acid 0.72mg, biotin 1.45mg.

[0038] The nutritional level of crayfish feed is: crude protein 32%, crude fat 6%, ash 18%, crude fiber 8%, lysine 1.5% and moisture 10%.

[0039] In order to illustrate the feeding and breeding effect of the fermented feed provided by the present invention on Procambarus clarkii, in addition, commercially available fermented lobster feed was used as control group 1, and unfermented crayfish feed was used as control group 2.

[0040] The formula of commercially available lobster fermented feed is 70% soybean meal, 10% corn starch, 18.13% bacterial solution (Bacillus licheniformis, Enterococcus faecalis, yeast, butyric acid bacteria), 0.00125% vitamin A, 0.00035% vitamin D, 0.0175% vitamin E, 0.0004% vitamin K, 0.00075% vitamin B1, 0.002% vitamin B2, 0.006% niacin, 0.00375% pantothenic acid, 0.001% vitamin B6, and 0.002% vitamin B6. 12 0.00025%, folic acid 0.00025%, biotin 0.00375%, copper sulfate 0.0005%, ferrous sulfate 0.0085%, zinc sulfate 0.003%, manganese sulfate 0.0032%, 1% sodium iodate 0.0003%, 1% calcium iodate 0.0055%, 1% cobalt chloride 0.0025% and dihydrogen calcium 1.8%. The lobster fermentation feed can be fermented for 72 hours at 30°C and a pH value below 4, and has a distinct mellow aroma.

[0041] 3. Experimental animals and breeding management

[0042] The crayfish with healthy appendages and good vitality were selected for breeding. The initial weight of the crayfish was 5±0.5g, and they were taken from the breeding base of the Quanjiao Crayfish Breeding Cooperative. They were all cultured in the crayfish pond of the Fisheries Research Institute of Anhui Academy of Agricultural Sciences in June. Nine crayfish ponds with the same size and an area of ​​about 0.20hm were selected. 2The experimental ponds were kept with the same water source and the number of fish was 60,000 / hm2. 2 The stocking density of the crayfish was randomly assigned, and the culture period was 60 days. Feed was given once at 7:00 and 18:00 every day, and the daily feed amount was about 4% of the shrimp body weight. At the same time, daily water quality management was carried out.

[0043] 4. Effects on the growth performance of Procambarus clarkii

[0044] After the rearing period, 10 fish were randomly selected from the mouths of the 9 experimental ponds. Three replicates were taken from each experimental treatment group. The weight was weighed using an electronic balance to calculate the weight gain rate and specific growth rate. The results were averaged and retained to two decimal places. The specific calculation formula is as follows:

[0045] Weight gain rate (WGR, %) = [(m t -m0) / m0]×100%;

[0046] Specific growth rate (SGR, %·d -1 )=[(lnm t -lnm0) / d]×100%;

[0047] Where: m0 is the initial body weight of the culture (g); m t is the body weight at the end of breeding (g); d is the number of feeding days.

[0048] The results are shown in Table 1.

[0049] Table 1 Effects of different feeds on the growth performance of Procambarus clarkii

[0050]

[0051] As can be seen from Table 1, compared with the use of unfermented crayfish feed for feeding, the use of fermented feed for feeding Procambarus clarkii can improve the weight gain rate and specific growth rate of shrimp to a certain extent, because fermented feed can stimulate intestinal peristalsis, and various digestive enzymes are improved to promote the decomposition and absorption of feed, and the utilization rate of feed is improved, which is beneficial to the growth and weight gain of shrimp. In addition, it can be seen from the table that compared with the commercially available fermented lobster feed, the use of the fermented feed provided by the present invention for feeding Procambarus clarkii can improve the weight gain rate and specific growth rate of Procambarus clarkii, which is beneficial to improve the breeding efficiency of Procambarus clarkii.

[0052] 5. Effects on the digestive enzyme activity of Procambarus clarkii

[0053] After the rearing period, 10 fish were randomly selected from the mouths of 9 experimental ponds, and 3 samples were taken from each experimental treatment group as replicates. The hepatopancreas and intestines were collected and stored in ice. They were immediately brought back to the laboratory for determination of digestive enzyme activity. Strictly according to the instructions of the commercially available kit, all samples were mixed with an appropriate amount of physiological saline, homogenized at 4°C, separated and the supernatant was collected, and the activities of trypsin, amylase, lipase and cellulase were determined. The results were averaged and rounded to two decimal places.

[0054] The results are shown in Table 2.

[0055] Table 2 Effects of different feeds on digestive enzyme activity of Procambarus clarkii (unit: U / mg)

[0056]

[0057]

[0058] It can be seen from Table 2 that compared with unfermented crayfish feed, the digestive enzyme activities in the hepatopancreas and intestine of Procambarus clarkii are improved to a certain extent when fermented feed is fed to Procambarus clarkii, which has a promoting effect on the growth of Procambarus clarkii. In addition, it can be seen from the table that different fermented feeds have different effects on the digestive enzyme activities in the hepatopancreas and intestine of shrimp. Compared with commercially available fermented lobster feed, the fermented feed obtained by fermenting crayfish feed with the mixed bacterial liquid provided by the present invention can improve the digestive enzyme activity index of Procambarus clarkii when fed to Procambarus clarkii.

[0059] 6. Effect on the shell quality of Procambarus clarkii

[0060] After the breeding period, 1000 shrimps were randomly selected from the ponds of 9 experimental ponds, and the shrimps with soft shell problems were picked out and the number was recorded to calculate the soft shell rate. Ten shrimps with normal shell hardness were randomly selected from the 9 experimental ponds, and the third section of the shrimp shell was cut into two pieces along the back to measure the shell hardness. The test parameters of the texture analyzer were set as follows: the probe selected was a P50 blade probe, the maximum pressure value of the induction element probe was 60N, the mode was TPA, the trigger force was 0.6N, the probe running speed was 60mm / s, and the deformation was 100%. Three copies were taken for each experimental treatment group as replicates, and the results were averaged, with two decimal places retained.

[0061] Table 3 Effects of different feeds on shell quality of Procambarus clarkii

[0062]

[0063] As can be seen from Table 3, feeding different fermented feeds to Procambarus clarkii has an effect on the quality of shrimp shells. From the data on the soft shell rate of Procambarus clarkii, it can be seen that compared with feeding Procambarus clarkii with unfermented crayfish feed, fermented feed AG can reduce the number of soft-shell shrimps and has a positive effect on reducing the soft shell rate of shrimps. By comparing fermented feed AC, it can be seen that when sesame gum is selected as the fermentation promoter, the effect on improving the quality of shrimp shells is the best. In addition, by comparing fermented feed A, fermented feed D and fermented feed F, it can be seen that Aspergillus oryzae and sesame gum have a synergistic effect on improving the quality of shrimp shells. Finally, by comparing fermented feed A with fermented feed G, it can be seen that the addition of cutinase has a positive effect on improving the hardness of shrimp shells.

[0064] 7. Effects on the quality of Procambarus clarkii meat

[0065] Ten crayfish were randomly selected from the mouths of nine experimental ponds and the hardness, elasticity and chewiness of crayfish meat were measured using a P / 36R probe in TPA mode according to the methods described by Huang Chunhong et al. (2020) and Li Gaoshang et al. (2019). Each sample was measured three times and the average was taken, with two decimal places retained.

[0066] The results are shown in Table 4.

[0067] Table 4 Effects of different feeds on the quality of Procambarus clarkii meat (unit: g)

[0068]

[0069] It can be seen from Table 4 that feeding different fermented feeds to Procambarus clarkii has an effect on the quality of shrimp meat. Comparing fermented feeds AC, it can be seen that when sesame gum is selected as the fermentation promoter, the hardness of shrimp meat can be reduced, the elasticity and chewiness of shrimp meat can be improved, and the meat quality and edible quality of shrimp meat can be comprehensively improved. In addition, comparing fermented feeds A, D and F, it can be seen that Aspergillus oryzae and sesame gum have a synergistic effect in improving the quality of shrimp meat.

[0070] 8. Effects on the molting of Procambarus clarkii

[0071] Ten crayfish with sound appendages and good vitality were selected from each of the nine experimental ponds. A breeding area was isolated in each experimental pond to ensure that the size of the breeding area was adapted to the stocking density of the entire pond. Each crayfish was marked and then the breeding management described above was carried out. At the same time, daily water quality management was carried out. When the crayfish in each experimental pond was undergoing the second molting, the molting observation was carried out in turn. The specific method was to take the completion of the second molting as the starting time, record the time required for the new shell of the crayfish to harden completely, and take the average value of the results, retaining two decimal places.

[0072] The results are shown in Table 5.

[0073] Table 5 Effects of different feeds on molting of Procambarus clarkii (unit: h)

[0074]

[0075] As can be seen from Table 5, compared with feeding with unfermented crayfish feed, feeding with fermented feed can improve the utilization of feed by Procambarus clarkii, shorten the time required for the new shell to harden completely after molting, shorten the single molting cycle, and increase the number of molting times during the breeding period, which helps the weight gain of shrimp and improves the breeding efficiency. In addition, the shortened hardening time of the new shell after molting can reduce the risk of invasion by pathogens, toxins or other organisms caused by the long molting period, which also has a certain positive significance for improving the survival rate of shrimp.

[0076] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A special ecological fermented feed for Procambarus clarkii, characterized in that: The fermented feed is prepared by fermenting crayfish feed as a fermentation matrix through mixed bacterial liquid; The mixed bacterial liquid is prepared by adding cutinase, phytase, sodium butyrate, a fermentation accelerator and a mixed bacterial species consisting of lactic acid bacteria, bacillus, yeast and Aspergillus oryzae into water.

2. The special ecological fermented feed for Procambarus clarkii according to claim 1, characterized in that: The added amounts of the cutinase, phytase, sodium butyrate and fermentation promoter are 0.1-0.5% of the total mass of the mixed bacteria.

3. The special ecological fermented feed for Procambarus clarkii according to claim 1, characterized in that: The fermentation accelerator is sesame gum or guar gum.

4. The special ecological fermented feed for Procambarus clarkii according to claim 1, characterized in that: The viable count of the mixed strains is 2.5-3.0×10 8 cfu / g, and the live bacteria component ratio of the lactic acid bacteria, bacillus, yeast and Aspergillus oryzae is 1:2:1:0.

05.

5. A method for producing ecological fermented feed for Procambarus clarkii according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) selecting a mixed strain consisting of lactic acid bacteria, bacillus, yeast and Aspergillus oryzae, stirring the mixed strain evenly and then letting it stand, placing the mixed strain after standing in water at 20-25° C., adding cutinase and a fermentation promoter, and stirring evenly to form a mixed bacterial liquid; (2) Mixing the crayfish feed with the mixed bacterial solution obtained in step (1), adjusting the water content to 60-70%, and fermenting to obtain the ecological fermented feed dedicated to Procambarus clarkii.

6. The method for producing a special ecological fermented feed for Procambarus clarkii according to claim 5, characterized in that: In step (2), the fermentation process is divided into two stages. The fermentation conditions of the first stage are 25-30°C, pH 3.5-5.0, and fermentation for 72 hours. The fermentation conditions of the second stage are 28-32°C, pH 6.5-7.5, and fermentation for 48 hours.

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