Regulator for improving nutritional value and utilization rate of hermetia illucens and preparation method and application thereof

Abstract

The application discloses a kind of regulation and preparation method and application for improving nutritional value and utilization of black soldier fly, and belongs to the field of aquaculture.The above-mentioned regulation includes the following components by weight parts: 450-480 parts of seaweed, 10-30 parts of schizochytrium, 5-20 parts of chitinase.For the nutritional deficiency of black soldier fly, such as lack of taurine and DHA, high chitin content and difficult degradation, etc., the application makes full use of the beneficial effects of seaweed, schizochytrium and chitinase, and scientifically matches them.Seaweed is rich in taurine, schizochytrium is rich in DHA, and chitinase can efficiently degrade chitin.Through further research, the suitable dosage and its regulation effect on improving the nutritional value of black soldier fly are mastered.Finally, combined with the growth and physicochemical index results of related breeding tests, it is proved that the above-mentioned regulation can significantly improve the nutritional value and utilization of black soldier fly.

Description

Technical Field

[0001] This invention belongs to the field of aquaculture, and particularly relates to a regulator for improving the nutritional value and utilization rate of black soldier fly larvae, its preparation method, and its application. Background Technology

[0002] The high fishmeal content in aquatic feeds leads to persistently high feed costs, hindering the sustainable development of aquaculture. Insect meal, on the other hand, is high in protein and fat, rich in amino acids, vitamins, and minerals, has good palatability, and is rich in immune-active substances, exhibiting antibacterial and antiviral effects, making it a significant potential substitute for fishmeal. Black soldier flies, with their rapid growth, high reproductive capacity, feeding on biological waste, high feed conversion rate, and ease of cultivation, can replace 10%-60% of the fishmeal in the feeds of several species, including Chinese mitten crab, whiteleg shrimp, and largemouth bass, thereby reducing feed costs and improving overall aquaculture efficiency.

[0003] Currently, the application of black soldier fly larvae in aquatic feed has some drawbacks. Studies have shown that while the essential amino acid composition of black soldier fly larvae meal is relatively balanced, even approaching that of fishmeal, its non-essential amino acid composition is unbalanced, with a severe deficiency of taurine. Furthermore, its fatty acid composition is poor, with a low content of n-3 polyunsaturated fatty acids, far from meeting the needs of aquatic animals. Additionally, the high chitin content in the black soldier fly shell makes it difficult for aquatic animals to degrade, leading to decreased feed digestibility and absorption. These factors result in a relatively low fishmeal substitution rate for black soldier fly larvae, further limiting its large-scale application in aquatic feed. Summary of the Invention

[0004] Purpose of the invention: The present invention aims to provide a regulator to improve the nutritional value and utilization rate of black soldier fly larvae, and the present invention also provides a method for preparing the above-mentioned regulator and its application.

[0005] Technical solution: The regulator provided by the present invention for improving the nutritional value and utilization rate of black soldier fly larvae comprises the following components by weight: 450-480 parts of laver, 10-30 parts of Schizochytrium, and 5-20 parts of chitinase, preferably 460-475 parts of laver, 16-25 parts of Schizochytrium, and 7-15 parts of chitinase, and more preferably 472 parts of laver, 20 parts of Schizochytrium, and 8 parts of chitinase.

[0006] Furthermore, the laver mentioned is laver residue, which is a byproduct generated during the laver processing.

[0007] The preparation method of the above-mentioned regulators that enhance the nutritional value and utilization rate of black soldier fly larvae is as follows: pre-crush laver, Schizochytrium, and chitinase separately and then mix them together to obtain the product.

[0008] Furthermore, the pre-crushed sieve has a mesh size of 100-120.

[0009] Furthermore, the conditions for the chitinase during pre-crushing and mixing are: light intensity < 800 lx and temperature < 60°C.

[0010] The above-mentioned regulators that enhance the nutritional value and utilization rate of black soldier flies are used as feed additives in aquaculture.

[0011] Furthermore, the amount of the regulator used as a feed additive is 0.5-1% of the feed weight, which can be changed according to the growth stage, size and farming method of the aquatic animals.

[0012] Furthermore, applicable aquatic animals include fish, shrimp, and crab.

[0013] Invention Principle: In this invention, laver residue, a byproduct of laver processing, is rich in taurine, polysaccharides, and proteins, possessing various physiological functions such as tumor inhibition, lipid reduction, blood clotting inhibition, aging slowing, and immune regulation. Schizochytrium, in addition to being rich in DHA and protein, also contains many unique physiologically functional substances, such as polyunsaturated fatty acids, dietary fiber, and polysaccharides, exhibiting high nutritional value and development potential. Chitinase can efficiently degrade chitin in insect exoskeletons, thereby improving the digestibility and utilization rate of insect meal in aquatic animals. The scientific combination of these three components can compensate for the nutritional deficiencies of black soldier flies, improve their nutritional value and utilization rate, reduce the amount of fishmeal used in aquatic feed, and ultimately promote the healthy and sustainable development of aquaculture.

[0014] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The regulator of the present invention uses laver, schistocytic fungus and chitinase as raw materials, making full use of the beneficial effects of the three, making up for the shortcomings of black soldier fly lacking taurine and DHA, and having high chitin content and being difficult to degrade. Through in-depth research, the appropriate dosage and its regulatory effect and mechanism on improving the nutritional value of black soldier fly have been mastered, which has strong pertinence; (2) The present invention, combined with the growth performance, feed utilization rate and physicochemical index results of relevant breeding experiments, proves that the regulator can significantly improve the nutritional value and utilization rate of black soldier fly, increase its fishmeal substitution ratio in aquatic feed, and reduce the negative effect of fishmeal substitution on the growth performance and feed utilization rate of aquatic animals, ultimately promoting the healthy and sustainable development of aquaculture. Attached Figure Description

[0015] Figure 1 Figure showing the effect of different feeds on the weight gain rate of Chinese mitten crab; Figure 2 This is a graph showing the effect of different feeds on the feed conversion ratio of Chinese mitten crab; Figure 3 This is a graph showing the effect of different feeds on the total protein content of hemolymph in Chinese mitten crabs. Figure 4 This is a graph showing the effect of different feeds on the total protein content of the hepatopancreas of the Chinese mitten crab. Detailed Implementation

[0016] The technical solution of the present invention will be further described below with reference to the embodiments and accompanying drawings.

[0017] Example 1: The regulator for improving the nutritional value and utilization rate of black soldier fly larvae provided in this example includes the following components: 450 g of laver residue, 30 g of Schizochytrium, and 20 g of chitinase. The preparation method is as follows: Pulverized seaweed residue, Schizochytrium, and Streptomyces griseus chitinase were pulverized and passed through a 120-mesh sieve separately for later use. Then, 450 g of the sieved seaweed residue, 30 g of Schizochytrium, and 20 g of Streptomyces griseus chitinase were mixed evenly in a stepwise mixing process to ensure the uniformity and stability of the mixture, thus obtaining 500 g of regulator (as a feed additive).

[0018] Example 2: The regulator for improving the nutritional value and utilization rate of black soldier fly larvae provided in this example includes the following components: 480 g of laver residue, 10 g of Schizochytrium, and 10 g of chitinase. The preparation method is as follows: Pulverized seaweed residue, Schizochytrium, and Streptomyces griseus chitinase were pulverized and passed through a 120-mesh sieve separately for later use. Then, 480 g of the sieved seaweed residue, 10 g of Schizochytrium, and 10 g of Streptomyces griseus chitinase were mixed evenly in a stepwise mixing process to ensure the uniformity and stability of the mixture, thus obtaining 500 g of regulator (as a feed additive).

[0019] Example 3: The regulator for improving the nutritional value and utilization rate of black soldier fly larvae provided in this example includes the following components: 472 g of laver residue, 20 g of Schizochytrium, and 8 g of chitinase. The preparation method is as follows: Pulverized seaweed residue, Schizochytrium, and Streptomyces griseus chitinase were pulverized and passed through a 120-mesh sieve separately for later use. Then, 472 g of the sieved seaweed residue, 20 g of Schizochytrium, and 8 g of Streptomyces griseus chitinase were mixed evenly in a stepwise mixing process to ensure the uniformity and stability of the mixture, thus obtaining 500 g of regulator (as a feed additive).

[0020] Example 1: Culture Experiment and Results Analysis of Chinese Eriocheir sinensis (50-150 g): The aquaculture experiment was conducted at the Aquatic Teaching and Research Base of Nanjing Agricultural University (Pukou District, Nanjing). After temporary rearing, 200 robust and uniformly sized Chinese mitten crabs (initial weight: 54.63±0.08 g) were randomly divided into 5 groups. The groups were: 1) Control group: fed with basal feed; 2) Black soldier fly group: fed with black soldier fly replacing 50% of the fishmeal feed; 3) Black soldier fly + laver group: fed with black soldier fly replacing 50% of the fishmeal feed + laver as described in Example 1; 4) Black soldier fly + laver + chitinase group: fed with black soldier fly replacing 50% of the fishmeal feed + laver and chitinase as described in Example 1; 5) Black soldier fly + regulator group: fed with black soldier fly replacing 50% of the fishmeal feed + 0.5% of the regulator prepared in Example 1. A total of 20 cement pools (1.0×1.0×0.8 m in size) were used, with 4 replicates per group and 10 animals per pool. The feed formula is shown in Table 1.

[0021] The experiment lasted for 10 weeks, from early July to early October. During the experiment, the feeding and growth of the Chinese mitten crab were observed. After the experiment, growth performance was statistically analyzed, and hemolymph and hepatopancreas samples were collected for further analysis. Specific results are as follows: Figures 1-4 As shown in Tables 2-4.

[0022] Table 1 Experimental feed formulations

[0023] Table 2. Effects of different feeds on the growth and feed utilization of Chinese mitten crab.

[0024] Note: Data from the same peer group containing the same letter in the superscript does not show significant differences.

[0025] Table 3. Effects of different feeds on hemolymphatic biochemical parameters of Chinese mitten crab.

[0026] Note: Data from the same peer group containing the same letter in the superscript does not show significant differences.

[0027] Table 4. Effects of different diets on the hepatopancreas biochemical parameters of Chinese mitten crab.

[0028] Note: Data from the same peer group containing the same letter in the superscript does not show significant differences.

[0029] Depend on Figure 1 , Figure 2 As shown in Table 2, the weight gain rate, final weight, specific growth rate, hepatopancreatic index, and molting rate of the black soldier fly group were significantly lower than those of the control group. P <0.05, and the feed conversion ratio was significantly higher than that of the control group ( P<0.05). Compared with the black soldier fly group, the black soldier fly + laver group and the black soldier fly + laver + chitinase group all showed significantly higher weight gain rate, final weight, specific growth rate, hepatopancreas index, and molting rate. P <0.05, and the feed conversion ratio decreased significantly ( P <0.05). Meanwhile, compared to the control group, the black soldier fly group, the black soldier fly + laver group, and the black soldier fly + laver + chitinase group, the black soldier fly + regulator group showed significantly higher weight gain rate, final weight, specific growth rate, and molting rate than the other groups. P <0.05, the feed conversion ratio was significantly lower than that of the other groups ( P <0.05). This indicates that feeding black soldier fly larvae to replace 50% fishmeal feed has a certain negative impact on the growth performance of Chinese mitten crabs. Adding a certain amount of laver, laver + chitinase composition, and the regulatory composition prepared in Example 1 to this feed can improve the growth performance of Chinese mitten crabs to a certain extent. Among them, adding the regulatory composition prepared in Example 1 has the best effect.

[0030] Depend on Figure 3 As shown in Table 3, the levels of total protein, albumin, total amino acids, and urea nitrogen in the hemolymph of the black soldier fly group were significantly lower than those of the control group. P <0.05%, and the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were significantly higher than those in the control group ( ). P <0.05). Compared with the black soldier fly group, the total protein, albumin, total amino acid, and urea nitrogen contents of the black soldier fly + laver group and the black soldier fly + chitinase group were significantly increased ( P <0.05), while there was no significant difference in the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). P >0.05). However, after adding the regulatory composition prepared in Example 1, compared to the other groups, the black soldier fly + regulator group showed significantly increased levels of total protein, total amino acids, albumin, and urea nitrogen in the hemolymph, and significantly decreased activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). P <0.05). By Figure 4 As shown in Table 4, the total protein, albumin, and total amino acid content, as well as the activities of trypsin, aspartate aminotransferase, and alanine aminotransferase in the hepatopancreas of the black soldier fly group were significantly lower than those in the control group. P <0.05%. Compared with the black soldier fly group, the total protein, albumin, and total amino acid contents, as well as the trypsin, aspartate aminotransferase, and alanine aminotransferase activities in the hepatopancreas of the black soldier fly + laver group and the black soldier fly + chitinase group were significantly increased. P <0.05), while after adding the regulatory composition prepared in Example 1, compared with the other groups, the total protein, total amino acid and albumin content, as well as the activities of aspartate aminotransferase and alanine aminotransferase in the hepatopancreas of the black soldier fly + regulator group were significantly increased ( P<0.05). The above results indicate that feeding black soldier fly larvae with 50% fishmeal has a certain negative impact on the protein metabolism and hepatopancreas of Chinese mitten crab. Adding a certain amount of laver, laver + chitinase combination, and the regulatory composition prepared in Example 1 to this feed can promote protein metabolism and reduce liver damage to a certain extent. Among them, the regulatory composition prepared in Example 1 has the best effect.

[0031] Experiment Example 2: California bass farming experiment and results analysis: The aquaculture experiment was conducted at the Aquaculture Teaching and Research Base of Nanjing Agricultural University (Pukou District, Nanjing). After temporary rearing, 400 healthy and uniformly sized fish (initial weight: 22.16±0.08 g) were randomly divided into 5 experimental groups. The groups were: 1) Control group: fed a basal diet; 2) Black soldier fly group: fed with black soldier fly replacing 80% of the fishmeal diet; 3) Black soldier fly + laver group: fed with black soldier fly replacing 80% of the fishmeal diet + the amount of Schizochytrium used in Example 2; 4) Black soldier fly + laver + Schizochytrium group: fed with black soldier fly replacing 80% of the fishmeal diet + the amount of laver and Schizochytrium used in Example 2; 5) Black soldier fly + regulator group: fed with black soldier fly replacing 80% of the fishmeal diet + 0.5% of the regulator prepared in Example 2. Each group consisted of 4 net cages (size: 2.0 × 1.0 × 1.0 m), with 20 fish per cage. The feed formula is shown in Table 5. After 8 weeks of cage culture, growth performance was statistically analyzed and blood and intestinal samples were collected for index determination. The results are shown in Tables 6 and 7.

[0032] Table 5 Experimental feed formulations

[0033] Table 6. Effects of different diets on growth performance and blood biochemical parameters of largemouth bass.

[0034] Note: Data from the same peer group containing the same letter in the superscript does not show significant differences.

[0035] Table 7. Effects of different diets on the intestinal digestive enzyme activity of largemouth bass

[0036] Note: Data from the same peer group containing the same letter in the superscript does not show significant differences.

[0037] As shown in Table 6, the weight gain rate, liver-to-body ratio, protein efficiency ratio, and total protein and albumin content of the black soldier fly group were significantly lower than those of the control group. P <0.05, and the feed conversion ratio was significantly higher than that of the control group ( P<0.05. Compared with the black soldier fly group, the black soldier fly + Schizochytrium group and the black soldier fly + Porphyra + Schizochytrium group all showed significantly higher weight gain rate, liver-to-body ratio, protein efficiency ratio, total protein and albumin content. P <0.05, and the feed conversion ratio decreased significantly ( P <0.05. Meanwhile, compared to the control group, black soldier fly group, Schizochytrium group, and black soldier fly + Porphyra + Schizochytrium group, the black soldier fly + regulator group showed significantly higher weight gain rate, liver-to-body ratio, protein efficiency ratio, total protein, and albumin content than the other groups. P <0.05, the feed conversion ratio was significantly lower than that of the other groups ( P <0.05). This indicates that feeding black soldier fly larvae with 80% fishmeal has a certain negative impact on the growth performance of largemouth bass. Adding a certain amount of Schizochytrium and the combination of laver and Schizochytrium, as well as the regulatory composition prepared in Example 2, to this feed can improve the growth performance of largemouth bass to a certain extent. Among them, the regulatory composition prepared in Example 2 has the best effect.

[0038] Table 7 shows that the levels of trypsin, lipase, amylase, creatine kinase, and Na+ in the black soldier fly group were... + -K +- ATPase activity was significantly lower than that of the control group. P >0.05). Compared to the black soldier fly group, the black soldier fly + Schizochytrium group and the black soldier fly + Porphyra + Schizochytrium group showed higher levels of protease, lipase, amylase, creatine kinase, and Na+. + -K +- ATPase activity was significantly increased ( P <0.05). After adding the regulatory composition prepared in Example 2, compared with the black soldier fly group, the Schizochytrium group, and the black soldier fly + Porphyra + Schizochytrium group, the black soldier fly + regulator group showed higher levels of trypsin, lipase, amylase, creatine kinase, and Na+. + -K + - The activity of ATPase was significantly increased ( P <0.05. The alkaline phosphatase activity in both the black soldier fly group and the replacement group was significantly higher than that in the control group ( P <0.05). The above results indicate that feeding black soldier fly larvae with 80% fishmeal has a certain negative impact on the intestinal digestive function of largemouth bass. Adding a certain amount of Schizochytrium and a combination of Porphyra + Schizochytrium and the regulatory composition prepared in Example 2 to this feed can improve this situation to a certain extent, increase the activity of intestinal digestive enzymes, and promote digestion and absorption. Among them, the regulatory composition prepared in Example 2 has the best effect.

[0039] Example 3: Culture Experiment and Results Analysis of Litopenaeus vannamei: The aquaculture experiment was conducted at the Aquaculture Teaching and Research Base of Nanjing Agricultural University (Pukou District, Nanjing). After temporary rearing, 1250 healthy and robust Litopenaeus vannamei shrimp (initial weight: 1.03±0.02 g) were randomly divided into 5 experimental groups. The groups were: 1) Control group: fed a basal diet; 2) Black soldier fly group: fed with black soldier fly replacing 60% of the fishmeal diet; 3) Black soldier fly + chitinase group: fed with black soldier fly replacing 60% of the fishmeal diet + chitinase as described in Example 3; 4) Black soldier fly + Schizochytrium + chitinase group: fed with black soldier fly replacing 60% of the fishmeal diet + Schizochytrium and chitinase as described in Example 3; 5) Black soldier fly + regulator group: fed with black soldier fly replacing 60% of the fishmeal diet + 0.5% of the regulator prepared in Example 3. Each group had 4 replicates, with 50 shrimp per replicate, and all shrimp were cultured in a 500 L recirculating aquaculture system. The feed formulation is shown in Table 8. After 8 weeks of cage culture, growth performance was statistically analyzed and hepatopancreas samples were collected for index determination. The results are shown in Tables 9 and 10.

[0040] Table 8 Experimental Feed Formulations

[0041] Table 9 Effects of different feeds on the growth performance of Litopenaeus vannamei.

[0042] Note: Data from the same peer group containing the same letter in the superscript does not show significant differences.

[0043] Table 10 Effects of different diets on biochemical parameters of hepatopancreas in Litopenaeus vannamei.

[0044] Note: Data from the same peer group containing the same letter in the superscript does not show significant differences.

[0045] As shown in Table 9, the weight gain rate, feed conversion ratio, specific growth rate, and protein efficiency ratio of the black soldier fly group were significantly lower than those of the control group. P <0.05, and the feed conversion ratio was significantly higher than that of the control group ( P <0.05). Compared with the black soldier fly group, the black soldier fly + chitinase group and the black soldier fly + Schizochytrium + chitinase group all showed significantly higher weight gain, feed conversion ratio, specific growth rate, and protein efficiency ratio. P <0.05, and the feed conversion ratio decreased significantly ( P <0.05). Meanwhile, compared to the control group, the black soldier fly group, the black soldier fly + chitinase group, and the black soldier fly + Schizochytrium + chitinase group, the black soldier fly + regulator group showed significantly higher weight gain rate, feed conversion ratio, specific growth rate, and protein efficiency ratio than the other groups. P <0.05, the feed conversion ratio was significantly lower than that of the other groups ( P<0.05). This indicates that feeding black soldier fly larvae with 60% fishmeal feed has a certain negative impact on the growth performance of Litopenaeus vannamei. Adding a certain amount of chitinase and the combination of Schizochytrium + chitinase and the regulatory composition prepared in Example 3 to this feed can improve the growth performance of Litopenaeus vannamei to a certain extent. Among them, the regulatory composition prepared in Example 3 has the best effect.

[0046] As shown in Table 10, the activities of protease, lipase, and amylase in the black soldier fly group were significantly lower than those in the control group. P <0.05%. Compared to the black soldier fly group, the activities of protease, lipase, and amylase were significantly increased in the black soldier fly + chitinase group and the black soldier fly + Schizochytrium + chitinase group. P <0.05%. After adding the regulatory composition prepared in Example 3, compared with the control group, black soldier fly group, black soldier fly + chitinase group and black soldier fly + Schizochytrium + chitinase group, the activities of protease, lipase and amylase in the black soldier fly + regulatory composition group were significantly increased. P <0.05). This indicates that directly feeding black soldier fly larvae with 60% fishmeal feed has a certain negative impact on the digestive and absorptive capacity of Litopenaeus vannamei. Adding a certain amount of chitinase and a combination of Schizochytrium + chitinase and the regulatory composition prepared in Example 3 to the feed can improve this situation, enhance the protein metabolism of Litopenaeus vannamei, and promote digestion and absorption. Among them, adding the regulatory composition prepared in Example 3 has the best effect.

[0047] In summary, this invention provides a regulator for improving the nutritional value and utilization rate of black soldier fly larvae, along with its preparation method and application. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A regulator for improving the nutritional value and utilization rate of black soldier fly larvae, characterized in that, By weight, it includes the following components: 450-480 parts laver, 10-30 parts Schizochytrium, and 5-20 parts chitinase.

2. The regulator according to claim 1, characterized in that, By weight, it includes the following components: 460-475 parts laver, 16-25 parts Schizochytrium, and 7-15 parts chitinase.

3. The regulator according to claim 1, characterized in that, By weight, it includes the following components: 472 parts laver, 20 parts Schizochytrium, and 8 parts chitinase.

4. The regulator according to claim 1, characterized in that, The laver mentioned is laver residue, which is a byproduct generated during the laver processing.

5. A method for preparing the regulator for improving the nutritional value and utilization rate of black soldier fly larvae as described in claim 1, characterized in that, The steps are as follows: pre-crush the laver, Schizochytrium, and chitinase separately, and then mix them together to obtain the final product.

6. The preparation method according to claim 5, characterized in that, The pre-crushed sieve has a mesh size of 100-120.

7. The preparation method according to claim 5, characterized in that, The conditions for the chitinase during pre-crushing and mixing are: light intensity < 800 lx and temperature < 60 ℃.

8. The application of the regulator of claim 1, which enhances the nutritional value and utilization rate of black soldier fly, as a feed additive in aquaculture.

9. The application according to claim 8, characterized in that, The amount of the regulator used as a feed additive is 0.5-1% of the feed weight.

10. The application according to claim 8, characterized in that, Applicable aquatic animals include fish, shrimp, and crab.

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