A method for increasing cholesterol in hippocampus, feed and preparation method thereof

Abstract

The invention discloses a method for increasing cholesterol in hippocampus, a feed and a preparation method, and belongs to the field of aquaculture. The invention provides a feed that is beneficial to cholesterol accumulation in hippocampus, including soybean meal, sodium alginate, vitamin premix, mineral premix, choline chloride, calcium dihydrogen phosphate, taurine, astaxanthin, soybean protein concentrate, soybean lecithin, fish meal, dextrin, fish oil, soybean oil, cellulose, wherein the lipid content is 3-15%, the sugar content is 15-30%, and the protein content is 30-45%. The preparation method comprises the following steps: S1, crushing; S2, mixing; S3, granulation. The invention uses the above-mentioned feed to feed hippocampus and thus increase the cholesterol content in hippocampus. The feed has a high conversion rate in hippocampus, solves the problems of water pollution and pathogen infection caused by feed deterioration, and improves the survival rate of hippocampus.

Description

Technical Field

[0001] The invention relates to the field of aquaculture, and in particular to a method for increasing cholesterol in a hippocampus, a feed and a preparation method thereof. Background Art

[0002] Seahorse (Hippocampus sp) belongs to the family Syngnathidae and the genus Hippocampus. It is a rare small marine fish with high ornamental and medicinal value. Seahorse likes to live in shallow bays with clean water and rich algae, water plants and corals. It is mainly distributed in tropical and subtropical shallow seas and is known as the "Southern Ginseng". Feed is the most important part of the artificial breeding process. Literature reports that inappropriate nutrient ratio in feed not only affects fish growth, but also leads to abnormal behavior and physiology of fish, and reduces resistance to adverse environments and diseases.

[0003] The main nutrients in feed are fat, protein and sugar. Studies have found that an appropriate fat level can promote growth and save protein. Too low a fat level will cause a lack of fat-soluble vitamins and essential fatty acids, while too high a fat level will cause excessive fat deposition in the liver, which will lead to slow growth or decreased disease resistance. If the protein content in the feed is insufficient, the growth rate and feed conversion rate of the fish will be reduced. On the contrary, when the protein content in the feed is too high, the protein will be decomposed and used only as energy, increasing the cost of feed, while increasing the metabolic burden of the fish body and causing the fish body to emit more ammonia nitrogen, resulting in a decrease in water quality. Sugar is the cheapest energy substance in the feed, and different fish have large differences in their utilization rate. Therefore, it is necessary to design targeted feeds with different nutritional ratios for different fish. As an animal raw material drug, modern Chinese medicine has confirmed that lipid substances in seahorses, including EPA, DHA and sterols (mainly cholesterol), are the main substances for seahorses to exert their pharmacological effects. Cholesterol is also the material basis for seahorses to have the effect of tonifying the kidney and strengthening yang, and has the effect of improving the quantity and quality of sperm in male mice. Therefore, the lipid content in seahorses is considered to be one of the main indicators of the quality of seahorse APIs. Therefore, the artificial feed for seahorse farming must not only ensure the normal growth and development of seahorses, but also promote the accumulation of medicinal ingredients in their bodies. Summary of the invention

[0004] The problem to be solved by the present invention is how to make the effective substances in the hippocampus accumulate effectively while the hippocampus grows normally.

[0005] To solve the above problems, the first aspect of the present invention provides a feed that is beneficial to the accumulation of cholesterol in hippocampus, characterized in that the feed that is beneficial to the accumulation of cholesterol in hippocampus comprises the following components: soybean meal, sodium alginate, vitamin premix, mineral premix, choline chloride, calcium dihydrogen phosphate, taurine, astaxanthin, soy protein concentrate, soy lecithin, fish meal, dextrin, fish oil, soybean oil, cellulose, wherein the lipid content in the feed is 3-15%.

[0006] Preferably, the feed that is beneficial to the accumulation of cholesterol in seahorses has a carbohydrate content of 15-30% and a protein content of 30-45%.

[0007] There is a close connection between the biological clock system and the physiological metabolism in the organism. When the expression of the biological clock gene is disordered due to environmental factors, the corresponding metabolic pathways will also change or even be disordered, thereby causing various metabolic diseases. Therefore, the normal operation of the biological clock system and physiological metabolism can be guaranteed by changing the external environmental conditions. When the ingredients (content, ratio, etc.) in the feed are unreasonable, it will directly affect the operation of the biological clock of the cultured organism, thereby affecting its metabolism. Therefore, the biological clock can be used as a tool to judge the rationality of the ingredients in the feed by the expression of the biological clock and nutrient metabolism genes, thereby preparing an artificial feed suitable for the growth of hippocampus and the accumulation of effective substances. The feed that is beneficial to the accumulation of cholesterol in hippocampus provided by the present invention can make the biological clock gene expression environment of hippocampus reach the best, thereby ensuring the accumulation of cholesterol in the hippocampus and improving the quality of hippocampus.

[0008] Furthermore, the second aspect of the present invention provides a method for preparing a feed that is beneficial to cholesterol accumulation in the hippocampus, comprising the following steps:

[0009] S1. Grinding: soybean meal, sodium alginate, vitamin premix, mineral premix, choline chloride, calcium dihydrogen phosphate, taurine, astaxanthin, soybean protein concentrate, fish meal, dextrin, and cellulose are mixed and then ultrafinely ground to obtain crushed material;

[0010] S2, mixing: adding soybean lecithin, fish oil and soybean oil to the crushed material, adding the mixture into a mixer after mixing, adding water and mixing evenly to form a crude feed;

[0011] S3. Granulation: Use a granulator to make the crude feed into granular feed, heat and mature it to obtain feed that is beneficial to the accumulation of cholesterol in the seahorse.

[0012] Preferably, in parts by mass, in step S1, the soybean meal is 100-160 parts, the sodium alginate is 30-40 parts, the vitamin premix is ​​5-15 parts, the mineral premix is ​​10-15 parts, the choline chloride is 1-3 parts, the monocalcium phosphate is 10-15 parts, the taurine is 10-25 parts, the astaxanthin is 0.1-1 parts, the soy protein concentrate is 100-150 parts, the fish meal is 200-220 parts, the dextrin is 210-230 parts, and the cellulose is 60-100 parts.

[0013] Preferably, in step S2, the amount of soybean lecithin is 10 to 50 parts, the amount of fish oil is 20 to 40 parts, and the amount of soybean oil is 20 to 40 parts.

[0014] Preferably, in step S1, the particle size of soybean meal, sodium alginate, vitamin premix, mineral premix, choline chloride, calcium dihydrogen phosphate, taurine, astaxanthin, soybean protein concentrate, fish meal, dextrin and cellulose is 40 mesh to 120 mesh.

[0015] Preferably, in step S3, the particle size of the pellet feed is 0.5-2 mm and the length is 1-6 mm.

[0016] Preferably, in step S3, the moisture content of the feed that is beneficial to the accumulation of cholesterol in the seahorses is 10%.

[0017] The third aspect of the present invention provides a method for increasing the cholesterol content in a hippocampus, wherein the method uses the aforementioned feed that is conducive to cholesterol accumulation in the hippocampus to feed the hippocampus.

[0018] Preferably, when raising seahorses, the raising conditions are: salinity 25, temperature 23-26°C, photoperiod L:D=16:8, light intensity 800-1300 lux, feeding time 2 hours after the start of illumination, feeding once a day, and the feed weight of the seahorse is 5-10% of the body weight.

[0019] The present invention has the beneficial effects as follows: the feed provided by the present invention that is beneficial to the accumulation of cholesterol in the hippocampus ensures the accumulation of cholesterol in the hippocampus from the gene level. The feed provided by the present invention determines the synergy between the central and peripheral clock systems and between the clock genes and metabolic genes through comparative analysis of the expression cycle, expression phase and expression amount of clock genes in the central biological clock system and the peripheral biological clock system, as well as the expression analysis between clock genes and metabolic genes, and determines the formula of the compound feed with the lipid, protein and carbohydrate levels that is most suitable for the growth and development of the hippocampus and the accumulation of effective ingredients;

[0020] At the same time, the feed provided by the present invention that is beneficial to the accumulation of cholesterol in the hippocampus is a compound feed, the conversion rate of the feed in the hippocampus is high, and the ingredients have little impact on the environment, which solves the problems of water pollution and pathogen infection caused by feed deterioration and improves the survival rate of the hippocampus. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Comparison of the total cholesterol content of lipid substances in the body tissues of hippocampi cultured in different treatments at the first and seventh weeks;

[0022] Figure 2 Comparison of the free fatty acid content of lipid substances in the body tissues of hippocampi cultured in different treatments at the first and seventh weeks;

[0023] Figure 3 Comparison of the differences in DHA content in the body tissues of hippocampi cultured in different treatments at the first and seventh weeks;

[0024] Figure 4 Comparison of the content of lipid EPA in body tissues of hippocampi cultured in different treatments at the first and seventh weeks. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below. It should be noted that the following embodiments are only used to illustrate the implementation method and typical parameters of the present invention, and are not used to limit the parameter range described in the present invention. Reasonable changes derived therefrom are still within the scope of protection of the claims of the present invention.

[0026] It should be noted that the endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this article.

[0027] The present invention provides a feed conducive to cholesterol accumulation in a hippocampus, a preparation method thereof, and a method for increasing the cholesterol content in a hippocampus. Specifically, the feed consists of 100-160 parts of soybean meal, 30-40 parts of sodium alginate, 5-15 parts of vitamin premixes, 10-15 parts of mineral premixes, 1-3 parts of choline chloride, 10-15 parts of calcium dihydrogen phosphate, 10-25 parts of taurine, 0.1-1 part of astaxanthin, 100-150 parts of soybean protein concentrate, 200-220 parts of fish meal, 210-230 parts of dextrin, 60-100 parts of cellulose, 10-50 parts of soybean lecithin, 20-40 parts of fish oil, and 20-40 parts of soybean oil, which can ensure the accumulation of cholesterol in the hippocampus from a genetic level. In a specific embodiment of the present invention, the effect of the hippocampus feed on the accumulation of cholesterol in the hippocampus is mainly achieved by adjusting the ratio of lipids, proteins, and carbohydrates.

[0028] In some embodiments, the lipid content in the feed is 3-15%.

[0029] In the most preferred embodiment, the lipid content is 8.8%.

[0030] In some embodiments, the content of carbohydrates in the feed is 15-30%.

[0031] In the most preferred embodiment, the content of carbohydrates is 19.10% to 23.52%.

[0032] In some embodiments, the protein content in the feed is 30-45%.

[0033] In the most preferred embodiment, the protein content is 38.67-42.34%.

[0034] In actual production and breeding, a compound feed containing 8.5% lipids, 39.89% protein and 22.14% carbohydrates is more conducive to the accumulation of cholesterol in the hippocampus.

[0035] At the same time, the present invention also provides a method for preparing the feed for cholesterol accumulation in the hippocampus, comprising the following steps:

[0036] S1. Grinding: Soybean meal, sodium alginate, vitamin premix, mineral premix, choline chloride, calcium dihydrogen phosphate, taurine, astaxanthin, soybean protein concentrate, fish meal, dextrin and cellulose are mixed and then ultrafinely ground to obtain crushed material. By weight, the soybean meal is 100-160 parts, the sodium alginate is 30-40 parts, the vitamin premix is ​​5-15 parts, the mineral premix is ​​10-15 parts, the choline chloride is 1-3 parts, and the calcium dihydrogen phosphate is 10-15 parts. The amount of the raw material is 10-15 parts, the amount of taurine is 10-25 parts, the amount of astaxanthin is 0.1-1 parts, the amount of soy protein concentrate is 100-150 parts, the amount of fish meal is 200-220 parts, the amount of dextrin is 210-230 parts, the amount of cellulose is 60-100 parts, and the particle size of soybean meal, sodium alginate, vitamin premix, mineral premix, choline chloride, calcium dihydrogen phosphate, taurine, astaxanthin, soy protein concentrate, fish meal, dextrin, and cellulose is 40 meshes to 120 meshes;

[0037] S2, mixing: adding soybean lecithin, fish oil and soybean oil to the crushed material, adding the mixture into a mixer after mixing, adding water and mixing evenly to form a crude feed, wherein the soybean lecithin is 10 to 50 parts by weight, the fish oil is 20 to 40 parts by weight, and the soybean oil is 20 to 40 parts by weight;

[0038] S3. Granulation: Use a granulator to make the crude feed into granular feed with a particle size of 0.5 to 2 mm and a length of 1 to 6 mm. Heat and mature the granular feed to obtain feed that is beneficial to the accumulation of cholesterol in the hippocampus.

[0039] In addition, the present invention also provides a method for increasing the cholesterol content in a hippocampus, wherein the method uses the aforementioned feed that is beneficial to the accumulation of cholesterol in the hippocampus to feed the hippocampus. During the feeding process, the conditions that are most beneficial to the accumulation of cholesterol in the hippocampus are: salinity 25, temperature 23-26°C, photoperiod L:D=16:8, light intensity 800-1300 lux, feeding time 2 hours after the start of illumination, feeding once a day, and the feed mass being 5-10% of the hippocampus body weight.

[0040] Example 1

[0041] In this embodiment, fish oil and soybean oil are used as fat sources, soybean protein concentrate, fish meal and soybean meal are used as protein sources, and dextrin is used as a sugar source to prepare compound feeds with different lipid concentrations, protein concentrations and sugar concentrations. The preparation method is as follows:

[0042] Before preparation, the raw material components of soybean meal, sodium alginate, vitamin premix, mineral premix, choline chloride, calcium dihydrogen phosphate, taurine, astaxanthin, soybean protein concentrate, fish meal, dextrin, and cellulose are crushed by a crusher through an 80-mesh sieve, mixed evenly according to the proportions in the table, and ultrafinely crushed once; then, oil and lecithin are added and mixed again, and all the mixed raw materials are poured into the mixer, and water is added while mixing. Then, a granulator is used to make a compound feed with a particle size of 1 mm, and it is cut into particles with a length of 2-3 mm. Then, it is placed in a 90°C oven for aging for 30 minutes, taken out and naturally air-dried until the moisture content is about 10%, and finally placed in a marked sealable bag and placed in a -20°C freezer for standby use.

[0043] The theoretical concentration gradients of lipids are 4.00%, 8.00%, and 12.00%, respectively. The measured values ​​are 4.84%, 8.80%, and 12.59%, respectively. The components in the relevant feed are shown in Table 1:

[0044] Table 1 Contents of various components in feeds with different lipid levels

[0045]

[0046]

[0047] The theoretical concentration gradients of protein are 34.00%, 38.00%, and 42.00%, respectively. The measured values ​​are 34.58%, 38.67%, and 42.34%, respectively. The components in the relevant feed are shown in Table 2:

[0048] Table 2 Content of each component in feeds with different protein levels

[0049]

[0050] The theoretical concentration gradients of sugars are 18.00%, 22.00%, and 26.00%, respectively. The measured values ​​are 19.10%, 23.52%, and 27.02%, respectively. The components in the relevant feed are shown in Table 2:

[0051] Table 3 Content of each component in feed with different sugar levels

[0052]

[0053] Example 2

[0054] 120 seahorse larvae (weight 0.6±0.1 g, body length 50.±1.0 cm) were randomly divided into three groups, with 40 larvae in each group.

[0055] The feed prepared in Example 1 was used, and the measured values ​​of the content of each component in each group of feed were shown in the following table:

[0056] Table 4 Measured values ​​of each component in each group of feed

[0057]

[0058]

[0059] The feeds of groups G1, G2, and G3 were used to feed the three groups of seahorses in this example. The culture environment was as follows: salinity 25, temperature 25°C, light cycle L:D 16:8, and light intensity 1000 lux. The feeding time was set to two hours after the lights were turned on, and the feeding was once a day. The feeding amount each time was about 8% of the total weight of the seahorses in the group, and the feeding was continued for four weeks.

[0060] After four weeks of feeding, all treatment groups were sampled at six times: ZT2 (Zeitgeber time), ZT6, ZT10, ZT14, ZT18, and ZT22. At each sampling time point, four hippocampal individuals were randomly selected and their brain and liver tissues were quickly collected for the relative expression of circadian clock genes (Clock, Bmal1, Per1, Per2, Per3, Cry1, Cry2) and lipid metabolism genes (Hmgcr, Mvk, Mvd, Lss, Fdps, Cetp, Scap, Srebp1, Srebp2).

[0061] The obtained raw data of expression were analyzed using Acro circadian rhythm analysis software to determine whether the expression of the target gene conforms to the cosine function and to determine the time of its peak value.

[0062] The relevant experimental results are shown in Table 5:

[0063] Table 5 Effects of feeds with different lipid contents on hippocampal circadian clock genes (showing apical phase time)

[0064]

[0065]

[0066] After analyzing the central clock genes in the hippocampus and the peripheral clock genes and metabolic genes in the liver (Table 5), it was found that different lipid contents had a significant effect on the expression of clock genes and lipid metabolism genes. Within 24 hours, except for Cry2, the expression of central clock genes had a complete cycle, and the apex time appeared at 9 o'clock, except for the Clock gene in G1 and G2; the expression of peripheral clock genes varied greatly among different treatments. In G1, only the apex of Clock and Per3 genes appeared at 9 o'clock, and the rest of the genes were at 13 o'clock. Compared with the central clock genes, the time of apex expression was significantly delayed. In addition, the expression of lipid metabolism genes was similar to that of clock genes. Except for Srebp1 and Scap, which reached the apex at 9 o'clock, the rest were at 13 o'clock. This phenomenon shows that low-fat diet causes the peripheral clock system to be separated from the central clock system and lose synchronization. The reason may be that the lipid intake of the hippocampus is too low. In order to maintain normal operation, the relevant lipid synthesis pathways will be inhibited, which is manifested as the expression of key enzymes in the lipid synthesis pathway being affected, and then indirectly affecting the expression of clock genes. The expression of peripheral clock genes and central clock genes in G2 showed perfect synchronization, and most of the lipid metabolism genes in the liver also peaked at 9 o'clock, indicating that the lipid content of 8.80% in the feed is suitable for the growth and development of hippocampus. The expression of peripheral clock genes in G3 completely lost its rhythmicity, and the corresponding lipid metabolism genes were also disordered, indicating that high lipid content destroyed the expression rhythm of peripheral clock genes and metabolic genes.

[0067] Example 3

[0068] 120 seahorse larvae (weight 0.6±0.1 g, body length 50.±1.0 cm) were randomly divided into three groups, with 40 larvae in each group.

[0069] The feeds of groups G4, G5 and G6 were used to feed the three groups of seahorses in the present embodiment. The culture environment was as follows: salinity 25, temperature 25°C, light cycle L:D 16:8, and light intensity 1000 lux. The feeding time was set to two hours after the lights were turned on, and the feeding was once a day. The feeding amount each time was about 8% of the total weight of the seahorses in the group, and the feeding was continued for four weeks.

[0070] After four weeks of feeding, all treatment groups were sampled at six times: ZT2 (Zeitgeber time), ZT6, ZT10, ZT14, ZT18, and ZT22. At each sampling time point, four hippocampal individuals were randomly selected and their brain and liver tissues were quickly collected for the relative expression of circadian clock genes (Clock, Bmal1, Per1, Per2, Per3, Cry1, Cry2) and lipid metabolism genes (Hmgcr, Mvk, Mvd, Lss, Fdps, Cetp, Scap, Srebp1, Srebp2).

[0071] The obtained raw data of expression were analyzed using Acro circadian rhythm analysis software to determine whether the expression of the target gene conforms to the cosine function and to determine the time of its peak value.

[0072] The relevant experimental results are shown in Table 6:

[0073] Table 6 Effects of feeds with different protein contents on hippocampal circadian clock genes (showing apical phase time)

[0074]

[0075] As can be seen from Table 6, the expression of circadian clock genes and metabolic genes in the hippocampus is also different when fed with feeds with different protein contents. Among them, except for Cry2, the expression of circadian clock genes has obvious rhythmicity, with a complete cycle within 24 hours, but the difference in the top phase is large. In G4, Clock, Bmal1 and Per3 appeared at 9 o'clock, while Per1, Per2 and Cry1 reached their peak at 13 o'clock; in G5 and G6, the top phase was reached at 9 o'clock, indicating that low-protein feed will affect the expression of central clock genes, and this effect will disappear above a certain content. In addition, it can be seen from the table that the expression of peripheral clock genes in G4 is still rhythmic, but it loses synchronization with the central clock genes, and the expression rhythmicity of lipid metabolism genes is also lost. This shows that low-protein feed affects the expression of peripheral clock genes and the lipid metabolism genes regulated by them.

[0076] Example 4

[0077] 120 seahorse larvae (weight 0.6±0.1 g, body length 50.±1.0 cm) were randomly divided into three groups, with 40 larvae in each group.

[0078] The feeds of groups G7, G8, and G9 were used to feed the three groups of hippocampi in the present embodiment. The culture environment was as follows: salinity 25, temperature 25°C, light cycle L:D 16:8, and light intensity 1000 lux. The feeding time was set to two hours after the lights were turned on, and the feeding was once a day. The feeding amount each time was about 8% of the total weight of the hippocampi in the group, and the feeding was continued for four weeks.

[0079] After four weeks of feeding, all treatment groups were sampled at six times: ZT2 (Zeitgeber time), ZT6, ZT10, ZT14, ZT18, and ZT22. At each sampling time point, four hippocampal individuals were randomly selected and their brain and liver tissues were quickly collected for the relative expression of circadian clock genes (Clock, Bmal1, Per1, Per2, Per3, Cry1, Cry2) and lipid metabolism genes (Hmgcr, Mvk, Mvd, Lss, Fdps, Cetp, Scap, Srebp1, Srebp2).

[0080] The obtained raw data of expression were analyzed using Acro circadian rhythm analysis software to determine whether the expression of the target gene conforms to the cosine function and to determine the time of its peak value.

[0081] The relevant experimental results are shown in Table 7:

[0082] Table 7 Effects of feeds with different sugar contents on hippocampal circadian clock genes (showing apical phase time)

[0083]

[0084]

[0085] The expression peaks of the central clock genes of high-sugar G9 all appeared at 9 o'clock, while the peaks of its peripheral clock genes, Clock, Bmal1 and Per3, were only at 9 o'clock, and the rest were at 13 o'clock; among its lipid metabolism genes, only Srebp1 and Scap had peaks at 9 o'clock, while Hmgcr, Mvk and Mvd were at 13 o'clock, and Lss, Fdps and Cetp were not rhythmic, indicating that high sugar content affected the expression of peripheral clock genes and lipid metabolism genes in the hippocampus. Low-sugar and normal-sugar diets did not affect the expression of clock genes and lipid metabolism genes, and the central and peripheral clock systems were well synchronized.

[0086] According to the experimental results of Examples 2 to 4, it can be seen that a compound feed containing 8.80% lipids, 38.67%-42.34% protein and 19.10%-23.52% carbohydrates is more conducive to the growth of hippocampus.

[0087] After regression analysis and combined with comprehensive considerations such as cost, it was concluded that the artificial compound feed with 8.50% lipid, 39.89% protein and 22.14% carbohydrate is most suitable for the growth and cholesterol accumulation of hippocampus. The feed formula is shown in Table 8:

[0088] Table 8 The most suitable diet formula for the growth and cholesterol accumulation of hippocampus

[0089]

[0090] Example 5

[0091] 60 seahorses (average body weight of 0.7±0.1g, average body length of 7.3±1.0cm) were selected and divided into two groups, with three replicates in each group. They were raised in 80L plastic drums, and the seawater was changed regularly every day. The salinity of the seawater was 25, the temperature was 25℃, and the light intensity was 1000lux. The feeding time was set to two hours after the lights were turned on, and the feeding was once a day, with about 8g of feed each time. The setting conditions for treatment 1 (G10) were: the photoperiod was L:D=16:8, and the bait was the above-mentioned optimized compound feed (including: lipid level of 8.50%, protein level of 39.89%, carbohydrate level of 22.14%, and taurine of 2%); the setting conditions for treatment 2 (G11) were: the photoperiod was L:D=16:8, and the bait was frozen adult mysid shrimp. They were raised for seven weeks under their respective conditions.

[0092] During the feeding experiment, the weight and length of all seahorses in each treatment were measured in the first, third, fifth and seventh weeks. At the same time, the food intake of the seahorses in each treatment was quantitatively analyzed every day. The data obtained from the experiment were calculated according to the following formula and then compared and analyzed.

[0093] Weight specific growth rate = [(LnWt-LnW0) / t]*100%

[0094] Body length specific growth rate = [(LnLt-LnL0) / t]*100%

[0095] Feed conversion rate = (Wt-W0) / F*100%

[0096] Fullness = (Wt / Lt3)*100%

[0097] Where Wt and Lt are the final weight (g) and body length (cm) of the hippocampus at the end of the feeding experiment, respectively; W0 and L0 are the initial weight (g) and body length (cm) of the hippocampus at the beginning of the experiment, respectively.

[0098] After seven weeks of feeding, seahorse samples were taken and stored in a -80°C refrigerator, and then used to detect the total fat content, cholesterol content, DHA and EPA content in the hippocampus. The experimental results are shown in Table 9.

[0099] Table 9 Analysis of hippocampal growth characteristics after seven weeks of feeding

[0100]

[0101]

[0102] By comparison, except for fatness, the seahorses in different treatments showed significant differences in final body length, final body weight, specific body weight growth rate, specific body length growth rate and feed conversion rate (p<0.05). The above indicators of seahorses in G10 treatment were higher than those in G11 treatment, indicating that the artificial compound feed in this study is more suitable for the growth of seahorses, and is more convenient in operation, storage and transportation.

[0103] Figure 1 Comparison of total cholesterol content in lipid tissues of hippocampi cultured in different treatments at the first and seventh weeks.

[0104] Figure 2 Comparison of free fatty acid content in lipid tissues of hippocampi cultured in different treatments at the first and seventh weeks.

[0105] Figure 3 Comparison of the differences in DHA content in the body tissues of hippocampi cultured in different treatments at the first and seventh weeks.

[0106] Figure 4 Comparison of the content of lipid EPA in body tissues of hippocampi cultured in different treatments at the first and seventh weeks.

[0107] from Figure 1 to Figure 4 As can be seen from the results, at the beginning of cultivation (the first week), there was no significant difference between the total cholesterol, free fatty acids, DHA and EPA of the seahorses in the two treatments. Combined with the data of the growth index of the seahorses (Table 9), it is shown that the seahorses in each treatment are adapting to the new environment in the first week, and there is no obvious difference in growth and accumulation of body substances (effective substances). After the cultivation of seahorses gradually adapts to the environment, the difference in the cultivation effect caused by the feed gradually manifests itself. By the seventh week, it can be seen from the data of the two treatments that the seahorses (G1) fed with artificial formula feeds are significantly higher than the seahorses fed with frozen mysid shrimp in total cholesterol, free fatty acids, DHA and EPA. It shows that compared to the cultivation method of traditional mysid shrimp feeding, the artificial formula feed configured by the present invention is indeed more suitable for the growth of seahorses, and is more likely to promote the accumulation of lipid substances in seahorses. This does not mean that the nutritional value of mysid shrimp is not high, but shows that the content and proportion of the three nutritional components (lipid, protein, sugar) in the feed formula of the seahorses of this study are more suitable for seahorses.

[0108] Unless otherwise defined, all terms, symbols and other scientific terms used herein are intended to have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. In some cases, terms with conventionally understood meanings are defined herein for the purpose of clarification or ease of reference, and such definitions herein should not be construed as indicating significant differences from conventional understandings in the art. The technical methods described or cited herein are generally well understood by those skilled in the art and are adopted by conventional methods. Unless otherwise stated, the use of commercially available kits, reagents and instruments is carried out in accordance with the protocols and parameters given by the manufacturer.

[0109] Although the disclosure is disclosed as above, the protection scope of the disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A feed that is beneficial to cholesterol accumulation in hippocampus, characterized in that: The feed that is beneficial to the accumulation of cholesterol in seahorses includes the following components by mass: 100-160 parts of soybean meal, 30-40 parts of sodium alginate, 5-15 parts of vitamin premix, 10-15 parts of mineral premix, 1-3 parts of choline chloride, 10-15 parts of calcium dihydrogen phosphate, 10-25 parts of taurine, 0.1-1 parts of astaxanthin, 100-150 parts of soybean protein concentrate, 10-50 parts of soybean lecithin, 200-220 parts of fish meal, 210-230 parts of dextrin, 20-40 parts of fish oil, 20-40 parts of soybean oil, and 60-100 parts of cellulose, wherein the lipid content in the feed is 3-15%.

2. The feed for promoting cholesterol accumulation in hippocampus according to claim 1, wherein: The carbohydrate content of feed that is beneficial to the accumulation of cholesterol in seahorses is 15~30% and the protein content is 30~45%.

3. A method for preparing a feed that is beneficial to cholesterol accumulation in hippocampus according to claim 1, characterized in that: The following steps are involved: S1. Grinding: by weight, 100-160 parts of soybean meal, 30-40 parts of sodium alginate, 5-15 parts of vitamin premix, 10-15 parts of mineral premix, 1-3 parts of choline chloride, 10-15 parts of calcium dihydrogen phosphate, 10-25 parts of taurine, 0.1-1 parts of astaxanthin, 100-150 parts of concentrated soy protein, 200-220 parts of fish meal, 210-230 parts of dextrin, and 60-100 parts of cellulose are mixed and then ultrafinely ground to obtain crushed material; S2, mixing: adding 10-50 parts of soybean lecithin, 20-40 parts of fish oil and 20-40 parts of soybean oil to the crushed material by weight, adding the mixture into a mixer after mixing, adding water and mixing evenly to form a crude feed; S3. Granulation: Use a granulator to make the crude feed into granular feed, heat and mature it to obtain feed that is beneficial to the accumulation of cholesterol in the seahorse.

4. The method for preparing a feed that is beneficial to cholesterol accumulation in hippocampus as claimed in claim 3, characterized in that: In the step S1, the particle sizes of soybean meal, sodium alginate, vitamin premix, mineral premix, choline chloride, calcium dihydrogen phosphate, taurine, astaxanthin, soybean protein concentrate, fish meal, dextrin and cellulose are 40 mesh to 120 mesh.

5. The method for preparing a feed that is beneficial to cholesterol accumulation in hippocampus according to claim 3, characterized in that: In step S3, the particle size of the pellet feed is 0.5-2 mm and the length is 1-6 mm.

6. The method for preparing a feed that is beneficial to cholesterol accumulation in hippocampus according to claim 3, characterized in that: In step S3, the moisture content of the feed that is beneficial to the accumulation of cholesterol in the seahorse is 10%.

7. A method for increasing the cholesterol content in hippocampus, characterized in that: The hippocampus is fed with the feed that is beneficial to cholesterol accumulation in the hippocampus according to claim 1 or 2.

8. The method for increasing the cholesterol content in the hippocampus according to claim 7, characterized in that: When raising seahorses, the breeding conditions are: salinity 25, temperature 23~26 ℃, photoperiod L:D=16:8, light intensity 800~1300 lux, feeding time is 2 hours after the start of lighting, feeding once a day, and the feed quality is 5~10% of the seahorse body weight.

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