Compound feed with effect of optimizing lipid composition of pseudosciaena crocea and application of compound feed
By regulating the lipid metabolism of large yellow croaker through algae-derived compound feed, the problem of excessive lipid deposition in existing technologies is solved, growth performance and muscle quality are significantly improved, and the optimization of lipid composition and regulation of gene expression are achieved.
Patent Information
- Application Number
- CN202510771333.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-10
- Publication Date
- 2025-09-19
AI Technical Summary
In the current large yellow croaker farming, the feed formula is not effective enough in regulating lipid metabolism, resulting in excessive lipid deposition, affecting growth performance and muscle quality, and there is a lack of effective lipid regulation methods.
An algae-derived compound feed is used, which is prepared by mixing a large yellow croaker basic compound feed, kelp, laver and fucoidan in a specific proportion. The preparation method is as follows: the large yellow croaker basic compound feed, kelp, laver and fucoidan are mixed in a mass ratio of (95.8-97.9): (1-2): (1-2): (0.1-0.2), then dried at 50°C for 12 hours, and vacuum-packed.
Significantly improve the growth performance of large yellow croaker, reduce muscle crude fat content, increase high-density lipoprotein cholesterol, reduce low-density lipoprotein cholesterol, regulate lipid composition, significantly upregulate cpt1 and lpl gene expression, and improve healthy breeding and quality.
Smart Images
Figure FT_1 
Figure FT_2 
Figure FT_3
Abstract
Description
Technical Field
[0001] The invention relates to a large yellow croaker compound feed, in particular to a compound feed capable of optimizing the lipid composition of the large yellow croaker and an application thereof, belonging to the technical field of feed processing. Background Art
[0002] Large yellow croaker (Larimichthys crocea) is an important economic fish in my country, mainly distributed in the coastal waters of the northwest Pacific Ocean. Large yellow croaker has a golden body surface, and its swim bladder has a complex branching structure, which can emit unique sonar signals for group communication. This species has attracted much attention due to its outstanding nutritional value, especially the n-3 polyunsaturated fatty acids (PUFA) rich in muscle tissue, which accounts for 28% to 35% in wild individuals, significantly better than other marine fish. These active ingredients have physiological functions such as cardiovascular protection and anti-inflammatory, making it attracting attention in the field of functional foods and health products. At present, my country has become the core production area of large yellow croaker farming in the world, and its sustainable utilization model provides an important example for the protection of marine biological resources.
[0003] In 2023, the national production of large yellow croaker has reached 280,000 tons. However, under the intensive farming model, the impact of feed formula on the growth performance and muscle quality of large yellow croaker has become increasingly prominent, among which lipid metabolism regulation is particularly critical. As an important energy reserve substance and biological membrane structural component of fish, lipids play multiple key roles in the physiological activities of fish: first, as the main form of energy storage, they provide energy to the body through the β-oxidation pathway; second, as an important component of the cell membrane, they participate in maintaining the integrity of cell structure and signal transduction processes; in addition, they also act as carriers of fat-soluble vitamins and precursors of steroid hormone synthesis, participating in the regulation of various physiological functions. The balance of lipid metabolism is directly related to the growth performance, immune function and antioxidant capacity of fish, which makes lipid metabolism regulation a key area of research in modern aquaculture.
[0004] Feed formulation is a key factor that directly affects lipid deposition. Studies have shown that optimizing the lipid content in feed can significantly reduce lipid deposition. In carp (Cyprinus carpio) farming, a feed lipid content in the range of 30-60g / kg can achieve optimal growth performance and lower lipid deposition, while a lipid content above 60g / kg will lead to increased lipid deposition in the liver and muscle. In addition, the addition of feed additives that promote lipid metabolism (such as xylose and arabinose) can also effectively reduce lipid deposition. Optimizing feed formulation to regulate lipid metabolism is of great significance to the healthy farming and quality improvement of large yellow croaker. First, reasonable lipid deposition can improve feed conversion rate and reduce farming costs; second, regulating muscle fatty acid composition can enhance the nutritional value and market competitiveness of the product; third, preventing excessive accumulation of liver lipids can reduce the occurrence of metabolic diseases and improve farming survival rate.
[0005] Seaweed additives (such as kelp and laver) have shown promising potential in regulating fish lipid metabolism due to their rich content of polysaccharides, unsaturated fatty acids, and bioactive substances. Exploring the mechanisms by which different feed additives affect lipid deposition in large yellow croaker could provide a theoretical basis for developing functional feeds and achieving precise nutritional regulation, and has important practical value for promoting the sustainable development of large yellow croaker aquaculture. Summary of the Invention
[0006] The technical problem to be solved by the present invention is to address the deficiencies in the prior art and provide a compound feed having the function of optimizing the lipid composition of large yellow croaker and its application. The compound feed of the present invention can significantly improve the growth performance of large yellow croaker, has a significant lipid regulation effect, and has the function of upregulating the expression of cpt1 and lpl genes, which is of great significance to the healthy breeding and quality improvement of large yellow croaker.
[0007] In order to achieve the above object, the present invention adopts the following technical solutions:
[0008] One of the purposes of the present invention is to first provide a compound feed that has the function of optimizing the lipid composition of large yellow croaker. The compound feed is an algae-derived compound feed, which is composed of a large yellow croaker basic compound feed, kelp, laver and fucoidan; in the algae-derived compound feed, the mass composition ratio of the large yellow croaker basic compound feed, kelp, laver and fucoidan is (95.8-97.9): (1-2): (1-2): (0.1-0.2).
[0009] In the above technical solution, the large yellow croaker basic compound feed is a commercially available basic compound feed for breeding large yellow croaker in this field, preferably the large yellow croaker basic compound feed produced by Zhejiang Qiangpu Biotechnology Co., Ltd. in China.
[0010] In the above technical solution, in the composite algae-derived composite feed, the mass composition ratio of the large yellow croaker basic feed to kelp, laver, and fucoidan is preferably 95.8:2:2:0.2.
[0011] In the above technical solution, the kelp is kelp powder, which is obtained by low-temperature drying the kelp at 60°C and grinding it into 80-mesh fine powder using a grinder, or commercially available kelp powder (kelp powder produced by Xiangshan Xuwen Seaweed Co., Ltd.) is used.
[0012] In the above technical solution, the laver is Porphyra haitanensis powder, which is obtained by drying Porphyra haitanensis at 60°C and grinding it into 80 mesh fine powder using a crusher, or commercially available Porphyra haitanensis powder (kelp powder produced by Xiangshan Xuwen Seaweed Co., Ltd.) is used.
[0013] The second object of the present invention is to provide a method for preparing the compound feed having the effect of optimizing the lipid composition of large yellow croaker: large yellow croaker basic feed, kelp, laver and fucoidan are mixed in a mass ratio of (95.8-97.9): (1-2): (1-2): (0.1-0.2), then dried at 50°C for 12 hours, and finally the dried feed is vacuum-packed to obtain the compound feed having the effect of optimizing the lipid composition of large yellow croaker.
[0014] The present invention also provides an application of the compound feed having the function of optimizing the lipid composition of large yellow croaker in optimizing the lipid composition of large yellow croaker; when the compound feed is used to optimize the lipid composition of large yellow croaker, the daily feeding amount of each fish is 1-3% of the fish's body weight, and the feed is fed twice a day (5:00 a.m. and 5:00 p.m.).
[0015] Compared with the existing technology, it has the following characteristics:
[0016] (1) The compound feed with optimized lipid composition of large yellow croaker in the present invention can significantly improve the growth performance of large yellow croaker, and its terminal body weight, weight gain rate and specific growth rate are 1.24 times, 1.66 times and 1.47 times that of the control group, respectively.
[0017] (2) The composite algae-derived feed of the present invention has a significant lipid regulation effect: it reduces muscle crude fat content, increases high-density lipoprotein cholesterol (HDL-C) content, and reduces low-density lipoprotein cholesterol (LDL-C) content. The composite algae powder optimizes the lipid composition of large yellow croaker. The composite algae powder additive significantly reduces the relative abundance of phosphatidylcholine [PC (22:4_18:2), PC (18:1_14:1), PC (18:0_18:1), and PC (19:0_18:1)], phosphatidylserine (PS (18:0_20:5)), and triglycerides [TG (16:0_9:0_9:0) and TG (20:3e_18:1_18:2)].
[0018] (3) In terms of gene expression, the composite algae-derived feed of the present invention can upregulate the expression of cpt1 and lpl genes, which is of great significance to the healthy breeding and quality improvement of large yellow croaker. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 To verify the content of T-CHO, HDL-C and LDL-C in the muscle of yellow croaker after feeding different feeds to yellow croaker in Example 3; wherein: Figure 1 a is the total cholesterol (T-CHO) content of large yellow croaker muscle, Figure 1 b is the content of high-density lipoprotein cholesterol (HDL-C), Figure 1c is a graph of low-density lipoprotein cholesterol (LDL-C) content; in the figure, (*) indicates a significant difference between the two groups (P < 0.05), and (**) indicates an extremely significant difference between the two groups (P < 0.01) TG > PC > PE;
[0020] Figure 2 To verify the total ion chromatogram of large yellow croaker muscle after feeding large yellow croaker with different feeds in Example 4; wherein: Figure 2 a is the Positive mode graph, Figure 2 b is the Negative mode diagram;
[0021] Figure 3 To verify the number of lipid subclasses in the muscle of large yellow croaker after feeding large yellow croaker with different feeds in Example 4;
[0022] Figure 4 To verify the pie chart of muscle lipid classification of large yellow croaker after feeding large yellow croaker with different feeds in Example 4; wherein: Figure 4 a is the lipid classification pie chart of the CKM group, Figure 4 b is the lipid classification pie chart of the FNK1M group, Figure 4 c is the pie chart of lipid classification of FNK2M group;
[0023] Figure 5 To verify the PLS-DA score diagram and loading diagram of the large yellow croaker muscle in Example 5; wherein: Figure 5 A is the PLS-DA score graph, Figure 5 B is the PLS-DA loading diagram;
[0024] Figure 6 To verify the differential lipid volcano map of large yellow croaker muscle in Example 5;
[0025] Figure 7 To verify the differential lipid clustering heat map of large yellow croaker muscle in Example 5;
[0026] Figure 8 To verify the difference in lipid profiles of large yellow croaker muscle in Example 5; (*) indicates a significant difference between the two groups (P < 0.05), and (**) indicates an extremely significant difference between the two groups (P < 0.01);
[0027] Figure 9 To verify the lipid structure characteristics of large yellow croaker muscle in Example 6
[0028] Figure 10 This is a diagram to verify the expression results of lipid metabolism genes in large yellow croaker in Example 7; (*) indicates a significant difference between the two groups (P < 0.05), and (**) indicates an extremely significant difference between the two groups (P < 0.01). DETAILED DESCRIPTION
[0029] The specific implementation of the technical solution of the present invention is described in detail below, but the present invention is not limited to the following description:
[0030] The purpose of the present invention is to provide a compound feed with optimized lipid composition of large yellow croaker and application thereof, thereby making up for the deficiencies of the prior art.
[0031] The present invention first provides a compound feed with an optimized lipid composition of large yellow croaker, wherein the compound feed is an algae-derived compound feed, which is composed of a large yellow croaker basic feed, kelp, laver and fucoidan in a certain proportion;
[0032] The composite algae-derived feed provided by the present invention significantly improved the growth performance of large yellow croaker after being fed for 8 weeks. The final body weight, weight gain rate, and specific growth rate of large yellow croaker were 1.24 times, 1.66 times, and 1.47 times that of the control group, respectively. In terms of lipid metabolism, the composite algae-derived feed significantly regulates lipid metabolism, reducing muscle crude fat content, increasing high-density lipoprotein cholesterol (HDL-C) content, and reducing low-density lipoprotein cholesterol (LDL-C) content. It also optimizes the lipid composition of large yellow croaker, significantly reducing the relative abundance of phosphatidylcholine (PC(22:4_18:2), PC(18:1_14:1), PC(18:0_18:1), and PC(19:0_18:1)), phosphatidylserine (PS(18:0_20:5)), and triglycerides (TG(16:0_9:0_9:0) and TG(20:3e_18:1_18:2)). It also has the effect of upregulating the expression of cpt1 and lpl genes.
[0033] The solutions of the present invention are specifically described through embodiments.
[0034] In the following examples of the present invention, the large yellow croaker basic feed used was provided by Zhejiang Qiangpu Biotechnology Co., Ltd.; the fucoidan (purity>85%) used was purchased from Shandong Jiejing Group Co., Ltd.; the porphyra haitanensis and kelp powder raw materials used were purchased from Xiangshan Xuwen Seaweed Co., Ltd. (Ningbo, Zhejiang, China). The algae raw materials were respectively dried at 60° C. and ground into 80-mesh fine powder using a pulverizer for later use.
[0035] Example 1: A compound feed having the effect of optimizing the lipid composition of large yellow croaker
[0036] According to the total amount of feed required to be fed to large yellow croaker daily, the large yellow croaker basic compound feed was mixed with kelp, laver and fucoidan in different proportions to prepare a composite algae-derived feed, wherein the mass composition ratio of the large yellow croaker basic compound feed, kelp, laver and fucoidan was 97.9:1:1:0.1; the composite feed group 1 in Example 1 was named FNK1M, and its crude component composition is shown in Table 1; the large yellow croaker basic compound feed was used as the control group feed, named CKM, and its crude component composition is shown in Table 1.
[0037] Example 2: A compound feed having the effect of optimizing the lipid composition of large yellow croaker
[0038] This embodiment is basically the same as Example 1, except that in the composite algae-derived feed, the large yellow croaker basic feed is mixed with kelp, laver, and fucoidan in a ratio of 95.8:2:2:0.2. The composite feed group 2 in Example 2 is named FNK2M, and its crude component composition is shown in Table 1.
[0039] Table 1 Crude ingredients of composite algae-derived feed for large yellow croaker
[0040] control group Compound feed 1 group Compound feed group 2 Approximate composition (% dry weight) CKM FNK1M FNK2M crude protein 49.18 47.98 47.00 crude fat 14.27 13.23 12.68 ash content 13.07 13.36 13.61 Moisture 7.10 7.12 7.24
[0041] Verification example:
[0042] The feeds of Example 1, Example 2 and the control group were fed and fed. 1 g of feed binder and an appropriate amount of water were added to each kg of the algae mixed feed, stirred thoroughly, and fed in time after drying. The feeding amount was determined each time and the number of times per day. The performance indicators of the large yellow croaker after feeding were shown in the following verification examples:
[0043] Verification Example 1: Effects of composite algae-derived feed on growth performance and crude components of large yellow croaker
[0044] After eight weeks of feeding, body length, weight, and other parameters were measured in the different groups. As shown in Table 2, growth performance was improved in group 1 (FNK1M) and group 2 (FNK2M) compared to the control group (CKM). The body weight, weight gain rate, and specific growth rate of the large yellow croaker in the group 1 (FNK1M) were significantly higher than those in the control group (P < 0.05), reaching approximately 1.24, 1.66, and 1.47 times those in the control group, respectively. There were no significant differences in fatness, organ-to-body ratio, or liver-to-body ratio among the three feed groups (P > 0.05). However, fatness decreased in both groups (94% and 92% of the control group, respectively) in the compound algae-based feed group, with the decrease in the compound feed group being even greater. The body length / height ratio in the compound feed group 2 was significantly higher (P < 0.05) than in the control group and the compound feed group 1 group, reaching approximately 1.06 and 1.04 times that in the compound feed group. The crude fat content of large yellow croaker muscle in FNK1M and FNK2M groups was significantly lower than that in the control group (P<0.05), reaching approximately 72.13% and 75.80% of that in the control group, respectively. There was no significant difference in the water content of large yellow croaker muscle among the three groups (P>0.05).
[0045] Table 2 Growth performance of yellow croaker fed with different feeds
[0046]
[0047]
[0048] Note: Different lowercase letters in the same row indicate significant differences (P < 0.05).
[0049] Verification Example 2: Effects of composite algae-derived feed on moisture and crude fat content of large yellow croaker
[0050] After 8 weeks of feeding, the water content and crude fat content of large yellow croaker in different groups were measured. According to Table 3, the crude fat content of large yellow croaker in compound feed group 1 (FNK1M) and compound feed group 2 (FNK2M) was significantly reduced, and the water content in each group had little effect.
[0051] Table 3 Muscle crude fat and water content of yellow croaker fed with different feeds
[0052] Group Crude fat (%) Moisture (%) CKM 15.25±1.32a 71.82±4.48a FNK1M 11.00±1.18b 66.54±4.73a FNK2M 11.56±1.51b 68.54±2.85a
[0053] Note: Different lowercase letters in the same column indicate significant differences (P < 0.05).
[0054] Verification Example 3: Effect of composite algae-derived feed on T-CHO, HDL-C and LDL-C levels in large yellow croaker muscle
[0055] After 8 weeks of feeding, total cholesterol (T-CHO), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) in muscle of different groups of large yellow croaker were measured. Figure 1 As shown, significant differences were observed in HDL-C and LDL-C levels in large yellow croaker muscle samples from the different algae-based composite feed groups. T-CHO showed no significant differences, with only a downward trend. HDL-C levels in the FNK1M and FNK2M groups were significantly elevated (P < 0.05), reaching 1.46 and 1.32 times that of the CKM group, respectively. LDL-C levels in the FNK1M and FNK2M groups were significantly decreased (P < 0.05), reaching 82.12% and 72.43% of those in the CKM group, respectively.
[0056] Verification Example 4: Effect of composite algae-derived feed on lipid classification of large yellow croaker
[0057] After feeding with different ratios of compound algae-derived feed for 8 weeks, the muscle tissue of yellow croaker was analyzed by UPLC-MS. The total ion current of lipid metabolites of yellow croaker is shown in Figure 2 A total of 3120 lipid molecules were identified in the muscle lipids extracted from large yellow croaker fed with mixed algae meal feed at different ratios, which were divided into 61 lipid subclasses ( Figure 3 The top ten lipid classes and their molecular species in the muscles of the CKM, FNK1M and FNK2M groups were as follows: 763 triglycerides (TGs), 470 phosphatidylcholines (PCs), 268 phosphatidylethanolamines (PEs), 202 diacylglycerols (DGs), 157 methylphosphatidylcholines (MePCs), 127 Hex1Cers, 1124 ceramides (Cers), 112 phosphatidylserines (PSs), 103 sphingomyelins (SMs) and 96 phosphatidylinositols (PIs). These classes accounted for 77.63% of the total lipid molecular species. Among all the lipids identified, the different lipid subclass compositions (taking the top 10 lipids in each group) are shown in Table 1. Figure 4 As can be seen from the figure, the main lipid subclasses in the CKM, FNK1M and FNK2M groups are TG, PC and PE, and the proportion of the main lipid subclasses in each group is TG>PC>PE.
[0058] Verification Example 5: Analysis of the Effect of Composite Algae-Source Feed on Differential Lipids in Large Yellow Croaker Muscle
[0059] In order to further explore the lipid changes in large yellow croaker muscle under the influence of different ratios of compound algae-derived feed and verify the reliability of the results, partial least squares discriminant analysis (PLS-DA) was used to simulate and visualize the results. This method effectively extracted the differences between groups, reduced the influence of multicollinearity between variables, and enhanced the discrimination between groups. Figure 5As shown in A, the PLS-DA score plot shows cluster differences between muscle samples from different algae meal feed groups, highlighting the impact of feed differences on lipid profiles. The CKM group, FNK1M group, and FNK2M group were clearly separated, especially the FNK2M group and the CKM group, indicating significant changes in lipid profiles. PLS-DA loading plot ( Figure 5 B) Shows the relationship between each lipid and the principal component, and labels the top 20 lipids with the highest contribution, including SM (d38_4), TG (16:0_9:0:9:0), PC (22:5_20:4), PI (35:1) and MePC (44:11).
[0060] The volcano plot analysis of the differential lipid profiles between CKM and FNK1M, and between CKM and FNK2M was performed. Figure 6 As shown in the figure, in the comparison between CKM and FNK1M groups, PS (18:0_20:3) and CKM were significantly downregulated relative to the FNK1M group, while PS (18:0_20:5), MePC (32:5), PS (20:1_18:2) and MePC (31:2) were significantly upregulated; in the comparison between CKM and FNK2M, WE (2:0_19:4) and CKM were significantly downregulated relative to the FNK2M group, while MGDG (18:1_18:1) and ZyE (36:5) were significantly upregulated. Figure 7 As shown, the cluster heat map shows the overall intensity changes of lipid classes. Lipid molecules in muscle samples from the same group clustered together, while samples from different groups were clearly separated. The lipid molecule intensities of the FNK1M and CKM groups showed some similarity. Most lipid classes had reduced intensities in the FNK2M group, while they were higher in CKM and FNK1M. The FNK2M group had reduced intensities of PG, PS, Cer, GM3, PI, and PA.
[0061] To further analyze the details of the differential lipid subclasses of CKM, FNK1M and FNK2M, the VIP values of the PLS-DA model were used for screening, and the top 20 differential lipids with the highest VIP values were selected for relative abundance analysis. The bar graph is shown in Figure 2. Figure 8As shown, the results showed that in the FNK1M group, the relative abundance of WE (2:0_19:4) was significantly higher than that in the CKM group (P < 0.05), which was 1.04 times that of the control group, and the relative abundance of PS (18:0_20:5) and MGDG (18:1_18:1) was significantly lower than that in the CKM group, which were 97.12% and 96.84% of the CKM group, respectively (P < 0.01); in the FMK2M group, only the relative abundance of WE (2:0_19:4) was significantly higher than that in the CKM group (P < 0.001), which was 1.07 times that of the CKM group, and the relative abundance of the other lipid subclasses was significantly lower than that in the CKM group (P < 0.05), which was approximately 82.78% to 98.14% of the CKM group. It is worth noting that the relative abundance of most lipids in the FNK2M group was significantly reduced compared with the FNK1M group (P < 0.05), especially TG (16:0_9:0_9:0) and TG (20:3e_18:1_18:2), which decreased significantly by 5.34% and 10.85%.
[0062] Verification Example 6: Analysis of the Effect of Composite Algae-Source Feed on the Lipid Structure Characteristics of Large Yellow Croaker Muscle
[0063] According to lipid types, the effects of different concentrations of composite algae-derived feed additives on the lipid structure characteristics of large yellow croaker muscle were studied from the perspective of lipid acid carbon number and saturation. Figure 9Among glycerophospholipids, PC, PE, and PG (with carbon atoms ranging from 35 to 45 and double bonds ranging from 0 to 6) were significantly higher in the CKM group than in the FNK1M group, while MePC and dMePE levels were increased in the FNK1M group. In the FNK1M group, TG (with double bonds greater than 5) increased, while TG (with double bonds from 0 to 4) decreased. Furthermore, DG (with carbon atoms greater than 45 and double bonds from 0 to 2) was significantly lower in the FNK1M group than in the CKM group. Hex1Cer (with low double bonds (0 to 2) and SM (with carbon atoms from 35 to 45) was significantly higher in the CKM group than in the FNK1M group. Compared with the CKM group, the FNK2M group showed a significant decrease in PC, PE, PS, and PI (with carbon atoms from 35 to 45), while PC (with double bonds greater than 5) increased significantly. The content of long-chain polyunsaturated lipids (TG), with more than 50 carbon atoms and more than 5 double bonds, increased, while that with 0 to 2 double bonds decreased. The content of DG in FNK2M increased compared to the CKM group, specifically long-chain polyunsaturated lipids with 35 to 45 carbon atoms and more than 5 double bonds. FNK2M, however, concentrated on long-chain saturated lipids (Cer), with 0 to 3 double bonds and 30 to 45 carbon atoms, and decreased the content of long-chain polyunsaturated lipids (SM), compared to CKM. These results suggest that the algae-based composite diet influences the lipid composition of large yellow croaker muscle by regulating the abundance of unsaturated lipid molecules. The FNK1M group promoted the expression of polyunsaturated lipids, while the FNK2M group enhanced the expression of low-unsaturated lipids with 0 to 2 double bonds and suppressed the expression of high-unsaturated lipids.
[0064] Verification Example 7: Analysis of the Effect of Composite Algae-derived Feed on the Expression of Lipid Metabolism Genes in Large Yellow Croaker Muscle
[0065] The expression of lipid metabolism genes in large yellow croaker muscle was analyzed. Figure 10 As shown, there were no significant differences in aco, pparα, and srebp1 between the compound diet and control groups (P>0.05). Among other genes involved in fatty acid oxidation, cpt1 and pgc1-α were significantly more expressed in the FNK1M and FNK2M groups than in the CKM group, ranging from 1.40 to 9.74 times higher than in the CKM group. Among genes involved in fatty acid synthesis, fas was significantly lower in the FNK1M group than in the CKM group (P<0.001), decreasing by 46.13%. Its expression also showed a downward trend in FNK2M. The lpl gene expression in the FNK1M and FNK2M groups was significantly higher than in the CKM group (P<0.0001), reaching 1.50 and 3.17 times higher, respectively.
[0066] As mentioned above, the effects of feeding large yellow croaker with a composite algae-based feed (fucoid: kelp: porphyra = 0.1:1:1 and 0.2:2:2, compound feed 1 and compound feed 2) for 8 weeks on growth performance and lipid metabolism were systematically evaluated. The results showed that compound feed 2 significantly improved the growth performance of large yellow croaker, with terminal body weight, weight gain rate, and specific growth rate 1.24, 1.66, and 1.47 times that of the control group, respectively. Regarding lipid metabolism, both composite algae-based feeds exhibited significant lipid-regulating effects: reduced muscle crude fat content, increased high-density lipoprotein cholesterol (HDL-C), and decreased low-density lipoprotein cholesterol (LDL-C). Lipidomic analysis showed that the composite algae-based feed treatment optimized the lipid composition of large yellow croaker. A total of 3120 lipid molecules were identified in the control and composite algae-based feed groups, classified into 61 lipid subclasses, with triglycerides, polyglycerides, and polyethylene glycols as the main components. The compound algae powder supplement significantly reduced the relative abundance of phosphatidylcholine (PC(22:4_18:2), PC(18:1_14:1), PC(18:0_18:1), and PC(19:0_18:1)), phosphatidylserine (PS(18:0_20:5)), and triglycerides (TG(16:0_9:0_9:0) and TG(20:3e_18:1_18:2)). Regarding gene expression, the compound feed groups upregulated cpt1 and lpl gene expression, with lpl expression reaching its highest level in compound feed group 2, while fas expression was downregulated in compound feed group 1, further improving mitochondrial β-oxidation capacity in large yellow croaker muscle. In summary, compound feed group 2 was the most effective in optimizing the lipid composition of large yellow croaker.
[0067] The above examples are only for illustrating the technical concept and technical features of the present invention and are not intended to limit the scope of protection of the present invention. Any equivalent transformation or modification made based on the essence of the present invention should be included in the scope of protection of the present invention.
Claims
1. A compound feed having the effect of optimizing the lipid composition of large yellow croaker, characterized in that: The compound feed is an algae-derived compound feed, which is composed of a large yellow croaker basic compound feed, kelp, laver and fucoidan; in the algae-derived compound feed, the mass composition ratio of the large yellow croaker basic compound feed, kelp, laver and fucoidan is (95.8~97.9): (1~2): (1~2): (0.1~0.2).
2. The compound feed according to claim 1, characterized in that The large yellow croaker basic compound feed is a commercially available basic compound feed used for breeding large yellow croaker in this field.
3. The compound feed according to claim 1, characterized in that In the composite algae-derived composite feed, the mass composition ratio of the large yellow croaker basic feed to kelp, laver, and fucoidan is 95.8:2:2:0.
2.
4. The compound feed according to claim 1, characterized in that The kelp is kelp powder, which is obtained by drying the kelp at a low temperature of 60°C and grinding it into 80-mesh fine powder using a crusher, or by using commercially available kelp powder.
5. The compound feed according to claim 1, characterized in that The laver is Porphyra haitanensis powder, which is obtained by drying the Porphyra haitanensis at a low temperature of 60° C. and then grinding the Porphyra haitanensis into 80-mesh fine powder using a pulverizer, or commercially available Porphyra haitanensis powder.
6. A method for preparing a compound feed having the function of optimizing the lipid composition of large yellow croaker according to any one of claims 1 to 5, characterized in that: The following steps are involved: The large yellow croaker basic compound feed, kelp, laver and fucoidan are mixed in a mass ratio of (95.8~97.9):(1~2):(1~2):(0.1~0.2), and then dried at 50°C for 12 hours. Finally, the dried feed is vacuum-packed to obtain the compound feed having the effect of optimizing the lipid composition of the large yellow croaker.
7. Use of the compound feed having the effect of optimizing the lipid composition of large yellow croaker according to any one of claims 1 to 5 in optimizing the lipid composition of large yellow croaker.
8. The use according to claim 6, characterized in that When the compound feed is used to optimize the lipid composition of large yellow croaker, the daily feeding amount for each fish is 1-3% of the fish's body weight, and the feed is fed twice a day.