Method for improving growth performance and liver health of hexagrammos otakii

Abstract

The invention belongs to the technical field of aquatic animal nutrition and feed, and particularly relates to a method for improving the growth performance and liver health of Hexagrammos otakii, long-chain polyunsaturated fatty acid is added into feed and mixed, and the Hexagrammos otakii is fed with nutritional feed formed by mixing the feed and the long-chain polyunsaturated fatty acid. The long-chain polyunsaturated fatty acid is used for improving the growth performance and liver health of the hexagrammos otakii, the long-chain polyunsaturated fatty acid is composed of eicosapentaenoic acid and arachidonic acid, and the feed comprises the following components in parts by weight: 97-100 parts of the feed, 0-3 parts of the eicosapentaenoic acid and 0-3 parts of the arachidonic acid. By adjusting the adding proportion of the concentrated solution and optimizing the composition of essential fatty acids of the feed, the artificial high-yield healthy breeding of the hexagrammos otakii can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of aquatic animal nutrition and feed, and specifically relates to a method for improving the growth performance and liver health of Hexapod ocellaris otaki. Background Art

[0002] Hexagrammos otakii is a cold-temperate marine benthic fish without swim bladder. Its meat is tender and nutritious, and it has high economic benefits and aquaculture potential. However, in the process of artificial aquaculture, how to optimize its growth performance and liver health and improve aquaculture efficiency is an urgent problem to be solved.

[0003] Lipids are important energy substances and energy reserves in the growth and development of fish, and play a vital role in the growth and health of fish. Among them, essential fatty acids are a type of polyunsaturated fatty acids that fish cannot synthesize on their own or the amount synthesized cannot meet their own needs and must be obtained from external food. In the breeding process of Otaki six-line fish, ensuring an adequate supply of essential fatty acids has an important impact on promoting fish growth, improving immunity and maintaining liver health.

[0004] Eicosapentaenoic acid (EPA) and arachidonic acid (ARA) are two main essential fatty acids of Otaki hexapod, playing an important role in the formation of biological membranes, regulating membrane fluidity and permeability, etc. However, there are differences in the mechanism of action and demand ratio of the two in the body. Studies have found that the eicosanoids produced by EPA and ARA in the body have different physiological activities, among which the eicosanoids produced by ARA have stronger physiological activity, while the eicosanoids produced by EPA have weaker physiological activity. Therefore, adjusting the ratio of EPA and ARA in feed can affect the activity of eicosanoids in fish, and then affect their growth and health status.

[0005] At present, the ratio of EPA and ARA in marine fish feed has become one of the research hotspots. The appropriate EPA / ARA ratio can not only promote the growth of fish, but also improve their immunity and antioxidant capacity, and reduce the occurrence of diseases. However, the ratio of EPA and ARA in traditional marine fish feed is often difficult to meet the needs of bigeye mullet, resulting in poor breeding results.

[0006] Therefore, in order to solve the above problems, the present invention adopts eicosapentaenoic acid (EPA) and arachidonic acid (ARA) concentrates, adjusts their addition ratio in feed, optimizes the composition of essential fatty acids in feed, and develops a method for improving the growth performance and liver health of bigeye snapper. Summary of the invention

[0007] The purpose of the present invention is to provide a method for improving the growth performance and liver health of Hexagram otaki, and by adjusting the addition ratio of the concentrate and optimizing the essential fatty acid composition of the feed, the artificial high-yield and healthy breeding of Hexagram otaki can be improved.

[0008] The technical solution adopted by the present invention is as follows:

[0009] A method for improving the growth performance and liver health of Hexagram otaki, comprising adding long-chain polyunsaturated fatty acids to feed and mixing the feed, and feeding the nutritious feed formed by the mixture of the feed and the long-chain polyunsaturated fatty acids to Hexagram otaki, so as to improve the growth performance and liver health of Hexagram otaki;

[0010] The long-chain polyunsaturated fatty acid is composed of eicosapentaenoic acid and arachidonic acid, and the weight ratio of the feed, eicosapentaenoic acid and arachidonic acid is:

[0011] 97-100 parts of feed, 0-3 parts of eicosapentaenoic acid, and 0-3 parts of arachidonic acid.

[0012] The technical effects achieved by the present invention are:

[0013] The invention adopts eicosapentaenoic acid (EPA) and arachidonic acid (ARA) concentrates, and optimizes the essential fatty acid composition of feed by adjusting the adding ratio of the concentrates, which can improve the artificial high-yield and healthy breeding of bigeye hexagram fish, and has important significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram showing the effect of dietary ARA / EPA of the present invention on liver histopathology of juvenile Otaki hexapod;

[0015] Figure 2 It is a schematic diagram of the scoring results of liver-related health status of young fish of Hexapoda otaki according to the degree of cavitation in the present invention;

[0016] Figure 3 Schematic diagram of the intestinal histopathological observation of the dietary ARA / EPA of the present invention on juvenile Hexagram otaki;

[0017] Figure 4 Schematic diagram of the effect of dietary ARA / EPA of the present invention on the intestinal tract of fry of Hexapod otaki. DETAILED DESCRIPTION

[0018] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present invention, and does not strictly limit the scope of protection of the specific claims of the present invention.

[0019] like Figure 1-4 As shown, a method for improving the growth performance and liver health of Hexagram otaki, comprising adding long-chain polyunsaturated fatty acids to feed and mixing them, and feeding the nutritious feed formed by the mixture of the feed and the long-chain polyunsaturated fatty acids to Hexagram otaki, so as to improve the growth performance and liver health of Hexagram otaki;

[0020] The feed raw material comprises the following components in weight proportions:

[0021] Fish meal 40 parts, soybean meal 30 parts, casein 15 parts, mixed vitamins 1 part, mixed minerals 1 part, sodium alginate 1 part, chromium oxide 1 part, corn starch 4 parts and fish oil 7 parts;

[0022] Fish meal and soybean meal, as the main protein sources, provide abundant essential amino acids, which are helpful for the muscle development and maintenance of normal physiological functions of the fish. Casein, as a high-quality protein supplement, further enhances the nutritional value of the feed.

[0023] The addition of mixed vitamins and mixed minerals ensures that the fish obtains comprehensive and balanced nutrition and enhances the fish's immune system.

[0024] The addition of sodium alginate brings additional health benefits. It is rich in polysaccharides, iodine and other bioactive substances, which help improve the digestion and immunity of the fish and also have certain antibacterial and antiviral effects.

[0025] As a feed additive, chromium oxide, although used in small amounts, has significant effects. It can increase the sensitivity of bigeye salmon to insulin, promote the metabolism and utilization of glucose, and thus improve the energy level and production performance of bigeye salmon.

[0026] Corn starch, as an energy source, provides the necessary carbohydrates for the bigeye mullet, ensuring the energy needs of animal activities.

[0027] And the fish meal includes 58% crude protein, 5.66% crude fat, and 36.34% crude ash;

[0028] Soybean meal includes 72.5% crude protein, 16.3% crude fat, and 11.2% crude ash;

[0029] The mixed vitamins provide VA7000IU, VE 50mg, VD3:2000IU, VK3:10mg, VB1:20mg, VB2:20mg, VB6:30mg, VB12:0.1mg, niacin 80mg, VC 100mg, calcium pantothenate 50mg, folic acid 6mg, inositol 80mg per kilogram of feed;

[0030] The mixed minerals provided per kg of feed: MgSO4·7H2O 5782mg, FeSO4·7H2O 1000mg, NaCl3000mg, ZnSO4·7H2O 150mg, MnSO4·4H2O 50.3mg, CuSO4·5H2O 15mg, CoCl2·6H2O 1.2mg, KI 1.5mg;

[0031] Corn starch contains 75% crude protein and 25% crude fat;

[0032] The above-mentioned feeds were all purchased from Dalian Yuelan Biotechnology Co., Ltd.

[0033] The long-chain polyunsaturated fatty acids consist of eicosapentaenoic acid and arachidonic acid;

[0034] The concentrations of eicosapentaenoic acid and arachidonic acid are both 38%-40%, which can effectively support the physiological functions of the otaki hexapod. Eicosapentaenoic acid, as a long-chain polyunsaturated fatty acid, can reduce the cholesterol and triglyceride levels in the blood, while arachidonic acid is an important component of the brain and retina, and is more important for the vision development of the otaki hexapod.

[0035] Eicosapentaenoic acid was purchased from Anhui Xinzhou Marine Biological Products Co., Ltd., and arachidonic acid was purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0036] The weight ratio of the feed, eicosapentaenoic acid and arachidonic acid is:

[0037] 97-100 parts of feed, 0-3 parts of eicosapentaenoic acid, and 0-3 parts of arachidonic acid.

[0038] Specifically, the ratio of the feed, eicosapentaenoic acid and arachidonic acid is divided into six embodiments, and each embodiment is equipped with a batch of Otaki hexapods for breeding, and the breeding conditions are observed. The breeding experimental site and device are equipped as follows:

[0039] The feeds were prepared by using the feed formulas of Examples 1-6 respectively. The feeds were prepared in the feed room of the Liaoning Northern Fish Applied Biology and Aquaculture Laboratory of Dalian Ocean University. The fish meal and soybean meal were first crushed with a grinder and passed through an 80-mesh sieve. Then, they were mixed with casein, mixed vitamins, mixed minerals, sodium alginate, corn starch, chromium oxide, ARA concentrate, EPA concentrate, fish oil and 10% by weight of purified water. The mixture was stirred for 5 minutes using a stirrer, and then granulated using a granulator and a 4.0 mm mold. The granules were dried in an oven at 40° C. for 24 hours, and finally packaged in sealed bags and stored at -20° C.

[0040] This experiment was conducted in the live breeding room on the first floor of the No. 12 Sea Breeding Building of Dalian Ocean University. 360 fish of 30±5g in weight, 12cm in length, with no injuries on the surface and normal body development were purchased from Dalian Bay Commercial Fish Farm in Dalian. The experiment used 18 90L white light-transmitting rectangular beef tendon water tanks (20 fish per tank, three parallel groups per group), each tank was equipped with a 600L / h aquarium filter barrel, the water temperature was normal in spring (from 14℃ to 19℃), the salinity was 30, the dissolved oxygen was stable at 7mg / L, the pH was around 7.5, and the photoperiod was normal sunlight. Fingerlings of Otaki six-line fish were grouped and temporarily raised for one week and stopped eating for three days. They were then artificially fed with the experimental feed twice a day, at 9:30 a.m. and 4:30 p.m. The feeding method was small amounts and multiple times, and the feeding was stopped when the fish stopped eating. The bottom of each group of fish was sucked at 6:00 p.m. every day, and then 80% of the filtered seawater with no temperature difference was replaced for 8 weeks.

[0041] The detailed description of six embodiment feed formulas for breeding is as follows:

[0042] Embodiment 1:

[0043] This example is a traditional feed formula for Otaki hexapod, without using eicosapentaenoic acid (EPA) and arachidonic acid (ARA);

[0044] The feed raw materials of this embodiment are specifically composed of the following by mass percentage:

[0045] Fish meal 40 parts, soybean meal 30 parts, casein 15 parts, mixed vitamins 1 part, mixed minerals 1 part, sodium alginate 1 part, chromium oxide 1 part, corn starch 4 parts, fish oil 7 parts;

[0046] Embodiment 2:

[0047] This example is an experimental feed formula for Otaki hexapod, with arachidonic acid (ARA) concentrate added;

[0048] The weight ratio of the feed, eicosapentaenoic acid and arachidonic acid is:

[0049] 97 parts of feed, 0 parts of eicosapentaenoic acid, and 3 parts of arachidonic acid.

[0050] Specifically, the feed raw materials of this embodiment are composed of the following by mass percentage:

[0051] Fish meal 40 parts, soybean meal 30 parts, casein 15 parts, mixed vitamins 1 part, mixed minerals 1 part, sodium alginate 1 part, chromium oxide 1 part, corn starch 4 parts, fish oil 4 parts, ARA concentrate 3 parts.

[0052] Embodiment 3:

[0053] This example is an experimental feed formula for bigeye bream, in which eicosapentaenoic acid (EPA) and arachidonic acid (ARA) concentrates are added;

[0054] The weight ratio of the feed, eicosapentaenoic acid and arachidonic acid is:

[0055] 97 parts of feed, 1 part of eicosapentaenoic acid, and 2 parts of arachidonic acid.

[0056] Specifically, the feed raw materials of this embodiment are composed of the following by mass percentage:

[0057] Fish meal 40 parts, soybean meal 30 parts, casein 15 parts, mixed vitamins 1 part, mixed minerals 1 part, sodium alginate 1 part, chromium oxide 1 part, corn starch 4 parts, fish oil 4 parts, ARA concentrate 2 parts, EPA concentrate 1 part.

[0058] Embodiment 4:

[0059] This example is an experimental feed formula for bigeye bream, in which eicosapentaenoic acid (EPA) and arachidonic acid (ARA) concentrates are added;

[0060] The weight ratio of the feed, eicosapentaenoic acid and arachidonic acid is:

[0061] 97 parts of feed, 1.5 parts of eicosapentaenoic acid, and 1.5 parts of arachidonic acid.

[0062] Specifically, the feed raw materials of this embodiment are composed of the following by mass percentage:

[0063] Fish meal 40 parts, soybean meal 30 parts, casein 15 parts, mixed vitamins 1 part, mixed minerals 1 part, sodium alginate 1 part, chromium oxide 1 part, corn starch 4 parts, fish oil 4 parts, ARA concentrate 1.5 parts, EPA concentrate 1.5 parts.

[0064] Embodiment 5:

[0065] This example is an experimental feed formula for bigeye bream, in which eicosapentaenoic acid (EPA) and arachidonic acid (ARA) concentrates are added;

[0066] The weight ratio of the feed, eicosapentaenoic acid and arachidonic acid is:

[0067] 97 parts of feed, 2 parts of eicosapentaenoic acid, and 1 part of arachidonic acid.

[0068] Specifically, the feed raw materials of this embodiment are composed of the following by mass percentage:

[0069] Fish meal 40 parts, soybean meal 30 parts, casein 15 parts, mixed vitamins 1 part, mixed minerals 1 part, sodium alginate 1 part, chromium oxide 1 part, corn starch 4 parts, fish oil 4 parts, ARA concentrate 1 part, EPA concentrate 2 parts.

[0070] Embodiment 6:

[0071] This example is an experimental feed formula for bighead carp, in which eicosapentaenoic acid (EPA) concentrate is added;

[0072] The weight ratio of the feed, eicosapentaenoic acid and arachidonic acid is:

[0073] 97 parts of feed, 3 parts of eicosapentaenoic acid, and 0 parts of arachidonic acid.

[0074] Specifically, the feed raw materials of this embodiment are composed of the following by mass percentage:

[0075] Fish meal 40 parts, soybean meal 30 parts, casein 15 parts, mixed vitamins 1 part, mixed minerals 1 part, sodium alginate 1 part, chromium oxide 1 part, corn starch 4 parts, fish oil 4 parts, EPA concentrate 3 parts.

[0076] After the breeding is completed, the growth of the Otaki six-line fish is calculated according to the calculation formula of the growth index. The calculation formula of the growth index is shown in Table 1 below:

[0077]

[0078] In the above table, W in the weight gain formula t is the final total weight of fish, and W0 is the initial total weight of fish;

[0079] W in the liver-to-body ratio formula l is the liver weight, and W is the weight of a single fish;

[0080] W in the organ-to-body ratio formula g is the visceral mass weight, and W is the weight of a single fish;

[0081] In the fatness formula, W is the weight of a single fish, and L is the length of the fish;

[0082] W in the feed coefficient formula f is the total amount of feed ingested (dry matter basis, g), W t is the final total weight of fish, and W0 is the initial total weight of fish;

[0083] The test results in the above six embodiments are shown in Table 2 below:

[0084]

[0085] The above table shows the effects of adding ARA / EPA to feed on the growth performance and muscle composition of young fish of Otaki. In the same row, the same superscript letters or no letters indicate no significant difference (p>0.05), and different superscript letters indicate significant difference (p<0.05);

[0086] As shown in Table 1, the weight gain rate of the big six-line fish in Examples 2 and 4 is significantly higher than that in Example 1, and the bait coefficient is significantly lower than that in Example 1;

[0087] See Table 3 below, which shows the fatty acid composition (%) of the experimental feed, and the specific ratio of ARA / EPA in Examples 1 to 6;

[0088]

[0089] Note: The above data are all mean ± standard error, n = 9.

[0090] See attached Figure 1 As shown, the liver cells in Examples 2 and 6 were severely damaged, with obvious pathological changes such as cell vacuolization, cell wall rupture, and nuclear displacement, among which, Example 1: Control Example 2: ARA / EPA (3:0) Example 3: ARA / EPA (2:1) Example 4: ARA / EPA (1:1) Example 5: ARA / EPA (1:2) Example 6: ARA / EPA (0:3);

[0091] Note: Attached Figure 1-4 A, B, C, D, E and F in the description correspond to Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6 in the specification;

[0092] Red arrows represent fat vacuolation, green arrows represent cell wall rupture, blue arrows represent normal hepatocytes, and the ellipse represents the pancreas;

[0093] In the above table, the effects of ARA / EPA in the diet on the growth performance of young fish of Otaki six-line fish are shown in Tables 2-5. Compared with the group in Example 1, the increase in the HUFAS content in the diet increased the weight gain rate (WGR) and specific growth rate (SGR) of young fish of Otaki six-line fish. When the weight portion of ARA was 0.94 parts and the weight portion of EPA was 2 parts, the ARA / EPA ratio was 0.47 (Example 5), and the weight gain rate and specific growth rate were 57.68% and 0.81%, respectively, which were significantly higher than those of the group in Example 1 and the other experimental groups (p<0.05). The increase in HUFAS in the diet reduced the feed conversion rate and fatness of young fish of Otaki six-line fish;

[0094] When the weight portion of ARA was 0.94 parts and the weight portion of EPA was 2 parts, and the ARA / EPA ratio was 0.47, and when the weight portion of ARA was 1.01 parts and the weight portion of EPA was 1 part, and the ARA / EPA ratio was 1.01, and when the weight portion of ARA was 2.66 parts and the weight portion of EPA was 1 part, and the ARA / EPA ratio was 2.66 (in Example 5, Example 4, and Example 2), the feed coefficient and fatness were significantly lower than those of Example 1 (p<0.05), and the lowest feed coefficient was 1.40;

[0095] However, when the weight portion of ARA was 1.34 and the weight portion of EPA was 1, the ARA / EPA ratio was 1.34, and when the weight portion of ARA was 0.19 and the weight portion of EPA was 1, the ARA / EPA ratio was 0.19 (Examples 3 and 6), the feed conversion rate and fatness were not significantly different from those of the control group (p>0.05).

[0096] The results of liver-body ratio and organ-body ratio showed that when ARA / EPA was added to the diet, the weight portion of ARA was 1.01, the weight portion of EPA was 1, and the ARA / EPA ratio was 1.01, and the weight portion of ARA was 0.94, and the weight portion of EPA was 2, and the ARA / EPA ratio was 0.47 (Examples 4 and 5), there was no significant difference compared with the control group of Example 1 (p>0.05), but it was significantly lower than the other experimental groups with the ratio of ARA and EPA (p<0.05);

[0097] The antioxidant capacity of serum and liver was determined by using the following Table 4. Referring to the following Table 4, in order to evaluate the effect of dietary ARA / EPA on the antioxidant capacity of liver and serum of juvenile Otaki six-line fish, superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT) and total antioxidant capacity (T-AOC) activities were used as antioxidant indicators. The results are shown in Table 4. Effect of dietary ARA / EPA on the antioxidant capacity of liver and serum of juvenile Otaki six-line fish;

[0098] As shown in Table 4 below:

[0099]

[0100] In Table 4 above, the effects of ARA / EPA addition to feed on the antioxidant capacity of liver and serum of juvenile Otaki hexapods are shown;

[0101] As can be seen from the table above, the malondialdehyde content in serum and liver in Example 5 is significantly lower than that in other examples, the SOD and CAT content in liver and serum reaches the highest level, and the total antioxidant in serum is significantly higher than that in other examples. It can be seen that the eicosapentaenoic acid (EPA) and arachidonic acid (ARA) in Example 5 are the most valuable addition ratios;

[0102] In Table 4 above, compared with the group in Example 1, increasing the content of HUFAS in the diet showed different effects on the SOD, MDA, CAT and T-AOC activities in the liver and serum of the juvenile fish of Otaki six-line fish. As the ARA / EPA ratio in the diet decreased, the activities of SOD, CAT and T-AOC first decreased, then increased and then decreased, and the activity of MDA first increased, then decreased and then increased. When the weight of ARA was 2.66 parts and the weight of EPA was 1 part, the ARA / EPA ratio was 2.66, and when the weight of ARA was 1.34 parts and the weight of EPA was 1 part, the ARA / EPA ratio was 1.34, and when the weight of ARA was 0.19 parts and the weight of EPA was 1 part, the ARA / EPA ratio was 0.19 (Examples 2, 3 and 6), the activities of SOD and T-AOC in the liver of the juvenile fish of Otaki six-line fish, and the activities of SOD, CAT and T-AOC in the serum were significantly lower than those in the group in Example 1;

[0103] When the weight portion of ARA was 1.01 and the weight portion of EPA was 1, and the ARA / EPA ratio was 1.01, and when the weight portion of ARA was 0.94 and the weight portion of EPA was 2, and the ARA / EPA ratio was 0.47 (in Example 4 and Example 5), the SOD, CAT and T-AOC activities in the liver of young Otaki hexapod fish, and the SOD and CAT in the serum were significantly higher than those in Example 1 and the other experimental groups (p<0.05);

[0104] When the weight portion of ARA was 2.66 parts and the weight portion of EPA was 1 part, and the ARA / EPA ratio was 2.66 (Example 2), the MDA activity in the liver of the juvenile fish of Otaki was significantly higher than that of the group in Example 1 and the other experimental groups;

[0105] When the weight portion of ARA was 0.94 and the weight portion of EPA was 2, and the ARA / EPA ratio was 0.47 (Example 5), the MDA activity in the liver and serum was significantly lower than that in the Example 1 group and the other experimental groups (p<0.05);

[0106] See attached Figure 2 As shown in the figure, the red arrows represent fat vacuolization; the green arrows represent cell wall rupture; the blue arrows represent normal hepatocytes. The effects of dietary ARA / EPA on the liver tissue pathology of juvenile otaki hexapods are shown in the figure. Figure 2HE staining results showed that compared with Example 1, the cavitation area in the liver of the juvenile fish of Example 2 was enlarged, the cavitation rate of hepatocytes was increased, and cell wall rupture occurred. However, there was no obvious pathological phenomenon in the liver of the juvenile fish of Example 4 and Example 5. The liver health status was scored by the cavitation area of ​​the liver using IMAGE j software;

[0107] like Figure 3 The results showed that increasing the HUFAS content in the diet had different effects on the liver. When the weight of ARA was 2.66 parts and the weight of EPA was 1 part, and the ARA / EPA ratio was 2.66 (Example 2), the liver health score was the worst;

[0108] When the weight of ARA is 1.01 parts and the weight of EPA is 1 part, and the ARA / EPA ratio is 1.01 (Example 4), the liver health score is the best, which is consistent with the results of microscopic observation. Figure 3 In the middle, 0-20: severe damage; 20-40: moderate damage; 40-60: mild damage; 60-80: slight damage; 80-100: normal. Letters with different superscripts above the bars indicate significant differences, the same below (p < 0.05);

[0109] Effects of dietary ARA / EPA on intestinal histopathology of juvenile Hexagramminnow fish Figure 4 As shown. When the weight portion of ARA is 2.66 parts and the weight portion of EPA is 1 part, the ARA / EPA ratio is 2.66, and when the weight portion of ARA is 1.34 parts and the weight portion of EPA is 1 part, the ARA / EPA ratio is 1.34, and when the weight portion of ARA is 0.19 parts and the weight portion of EPA is 1 part, the ARA / EPA ratio is 0.19 (in Example 2, Example 3 and Example 6), the villi in the intestinal cavity of the fry of Otaki six-line fish fell off, and a large number of vacuoles appeared in the mucosal layer. Compared with the group in Example 1, the number of villi in the intestinal cavity of the fry of Otaki six-line fish increased with the addition of HUFAS content in the diet, and the addition of HUFAS increased the number of villi in the intestinal cavity of the fry of Otaki six-line fish. Figure 4 The explanations in are: villus length (VL), villus width (VW) and myometrial thickness (MT);

[0110] Effects of dietary ARA / EPA on the intestinal villus length (VL), villus width (VW) and muscularis thickness (MT) of juvenile ocellaris Figure 4When the weight portion of ARA is 1.01 and the weight portion of EPA is 1, and the ARA / EPA ratio is 1.01, and when the weight portion of ARA is 0.94 and the weight portion of EPA is 2, and the ARA / EPA ratio is 0.47 (in Example 4 and Example 5), VL is significantly greater than that of the other experimental groups and Example 1 group (p<0.05);

[0111] When the weight portion of ARA was 0.19 and the weight portion of EPA was 1, and the ARA / EPA ratio was 0.19 (Example 6), the villus length was not significantly different from that of the Example 1 group (p>0.05), but was significantly smaller than that of the experimental groups with other ratios (p<0.05); the addition of ARA or EPA in the diet and the change of the ratio had no significant effect on VW;

[0112] When the weight portion of ARA was 1.01 and the weight portion of EPA was 1, and the ARA / EPA ratio was 1.01 (Example 4), the MT of juvenile Otaki hexapod fish was significantly thicker than that of the experimental groups with other ratios and the group in Example 1 (p<0.05);

[0113] In order to evaluate the effect of dietary ARA / EPA on the antioxidant capacity of liver and serum of juvenile bigeye snapper, superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT) and total antioxidant capacity (T-AOC) activities were used as antioxidant indicators. The results are shown in Table 4.

[0114] Compared with the group in Example 1, increasing the HUFAS content in the diet showed different effects on the SOD, MDA, CAT and T-AOC activities in the liver and serum of fry of Otaki hexapoda. As the ARA / EPA ratio in the diet decreased, the activities of SOD, CAT and T-AOC first decreased, then increased, and then decreased, while the activity of MDA first increased, then decreased, and then increased.

[0115] When the weight portion of ARA is 2.66 and the weight portion of EPA is 1, the ARA / EPA ratio is 2.66, and when the weight portion of ARA is 1.34 and the weight portion of EPA is 1, the ARA / EPA ratio is 1.34, and when the weight portion of ARA is 0.19 and the weight portion of EPA is 1, the ARA / EPA ratio is 0.19 (in Examples 2, 3 and 6), the activities of SOD and T-AOC in the liver of young Otaki hexapod fish and SOD, CAT and T-AOC in the serum are significantly lower than those in the Example 1 group;

[0116] When the weight portion of ARA was 1.01 and the weight portion of EPA was 1, and the ARA / EPA ratio was 1.01, and when the weight portion of ARA was 0.94 and the weight portion of EPA was 2, and the ARA / EPA ratio was 0.47 (Example 4, Example 5), the SOD, CAT and T-AOC activities in the liver of young Otaki hexapod fish, and the SOD and CAT in the serum were significantly higher than those in Example 1 and the other experimental groups (p<0.05);

[0117] When the weight portion of ARA was 2.66 parts and the weight portion of EPA was 1 part, and the ARA / EPA ratio was 2.66 (Example 2), the MDA activity in the liver of the juvenile fish of Otaki was significantly higher than that of the group in Example 1 and the other experimental groups;

[0118] When the weight portion of ARA is 0.94 and the weight portion of EPA is 2, and the ARA / EPA ratio is 0.47 (Example 5), when the dietary ARA / EPA is 0.47, the MDA activity in the liver and serum is significantly lower than that in Example 1 and the other experimental groups (p<0.05).

[0119] Referring to Table 5 below, the effects of dietary ARA / EPA on the body composition of juvenile Otaki hexapods are shown;

[0120]

[0121] In the above table, the effect of dietary ARA / EPA on the body composition of young fish of Hexagram otaki is shown in Table 5. Compared with the group in Example 1, the increase in the HUFAS content in the diet increased the crude ash content of young fish of Hexagram otaki, decreased the crude protein content, and increased or decreased the crude fat content in some cases, but there was no significant difference in the crude protein, crude fat and crude ash content between the experimental group and the group in Example 1 (p>0.05). At the same time, there was no significant difference between different ratios of ARA / EPA in the diet, indicating that the increase in the HUFAS content in the diet and the different ratios of ARA / EPA had no significant effect on the body composition of young fish of Hexagram otaki;

[0122] Referring to Table 6 below, the effect of dietary ARA / EPA on the fatty acid composition of muscle of juvenile Otaki hexapod fish is shown;

[0123]

[0124] The effects of dietary ARA / EPA on the fatty acid composition of muscle of juvenile Otaki hexapod are shown in Table 6. The increase of dietary HUFAS content had different effects on the MUFAS content in muscle. The increase of dietary HUFAS content significantly reduced the SFAS content in muscle of juvenile Otaki hexapod (p<0.05).

[0125] When the weight of ARA is 1.34 parts, the weight of EPA is 1 part, and the ARA / EPA ratio is 1.34 (Example 3), the SFA content in muscle is the lowest;

[0126] When the weight portion of ARA was 0.19 parts and the weight portion of EPA was 1 part, and the ARA / EPA ratio was 0.19 (Example 6), the MUFAS content in the muscle was significantly higher than that of the Example 1 group and the other experimental groups;

[0127] When the weight portion of ARA was 2.66 and the weight portion of EPA was 1, and the ARA / EPA ratio was 2.66 (Example 2), the MUFAS content in the muscle was significantly lower than that in the Example 1 group (p<0.05).

[0128] The increase of HUFAS in the diet significantly increased the HUFAS content in the muscle of fry of Otaki hexapod. When the weight portion of ARA was 1.34 and the weight portion of EPA was 1, and the ARA / EPA ratio was 1.34 (Example 3), the HUFAS content in the muscle was significantly higher than that of the experimental groups with other ratios (p<0.05).

[0129] In the experimental group, the ARA / EPA ratio of the muscle of the juvenile Otaki hexapod decreased as the ARA / EPA ratio in the diet decreased. When the weight portion of ARA was 0.94 and the weight portion of EPA was 2, and the ARA / EPA ratio was 0.47 (Example 5), the muscle ARA / EPA ratio was not significantly different from that of the Example 1 group (p<0.05).

[0130] Refer to Table 7 below for the effects of dietary ARA / EPA on intestinal digestive enzyme activities in juvenile Otaki hexapods;

[0131]

[0132] The effects of dietary ARA / EPA on the activities of digestive enzymes in the intestine of juvenile Hexagram otaki are shown in Table 7. Compared with the group in Example 1, increasing the content of HUFAS in the diet showed different effects on the activities of trypsin, lipase and amylase in the intestine of juvenile Hexagram otaki.

[0133] When the weight portion of ARA was 2.66 parts and the weight portion of EPA was 1 part, and the ARA / EPA ratio was 2.66, when the weight portion of ARA was 1.01 parts and the weight portion of EPA was 1 part, and the ARA / EPA ratio was 1.01, when the weight portion of ARA was 0.94 parts and the weight portion of EPA was 2 parts, and the ARA / EPA ratio was 0.47 (in Example 2, in Example 4 and in Example 5), the trypsin and lipase activities were significantly higher than those in Example 1 and the other experimental groups (p<0.05);

[0134] When the weight portion of ARA was 1.34 and the weight portion of EPA was 1, and the ARA / EPA ratio was 1.34, and when the weight portion of ARA was 0.19 and the weight portion of EPA was 1, and the ARA / EPA ratio was 0.19 (Examples 3 and 6), the lipase activity was significantly lower than that of the control group and the other experimental groups, and the trypsin activity had no significant change compared with that of the Example 1 group and was significantly lower than that of the other experimental groups (p<0.05);

[0135] The results of the effect of increasing the ARA and EPA content in the diet on the intestinal amylase activity of young bigeye bass showed that when the weight portion of ARA was 1.01 parts and the weight portion of EPA was 1 part, and the ARA / EPA ratio was 1.01; when the weight portion of ARA was 0.94 parts and the weight portion of EPA was 2 parts, and the ARA / EPA ratio was 0.47 (in Examples 4 and 5), the amylase activity was significantly higher than that of the Example 1 group and the other experimental groups (p<0.05).

[0136] Therefore, the above data show that adding eicosapentaenoic acid (EPA) and arachidonic acid (ARA) to the feed of bigeye mullet can increase the weight gain rate. At the same time, adding 2% eicosapentaenoic acid (EPA) and 1% arachidonic acid (ARA) can effectively ensure the health of liver tissue and enhance the antioxidant capacity of liver and serum.

[0137] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. A method for improving the growth performance and liver health of Otaki hexapod, characterized in that: Adding long-chain polyunsaturated fatty acids to feed and mixing them, and feeding the mixture of the feed and the long-chain polyunsaturated fatty acids to the nutritious feed to improve the growth performance and liver health of the otaki hexapod; The long-chain polyunsaturated fatty acid is composed of eicosapentaenoic acid and arachidonic acid, and the weight ratio of the feed, eicosapentaenoic acid and arachidonic acid is: 97-100 parts of feed, 0-3 parts of eicosapentaenoic acid, and 0-3 parts of arachidonic acid.

2. The method according to claim 1, characterized in that: The weight ratio of the feed, eicosapentaenoic acid and arachidonic acid is: 97 parts of feed, 0 parts of eicosapentaenoic acid, and 3 parts of arachidonic acid.

3. The method according to claim 1, characterized in that: The weight ratio of the feed, eicosapentaenoic acid and arachidonic acid is: 97 parts of feed, 1 part of eicosapentaenoic acid, and 2 parts of arachidonic acid.

4. The method according to claim 1, characterized in that: The weight ratio of the feed, eicosapentaenoic acid and arachidonic acid is: 97 parts of feed, 1.5 parts of eicosapentaenoic acid, and 1.5 parts of arachidonic acid.

5. The method according to claim 1, characterized in that: The weight ratio of the feed, eicosapentaenoic acid and arachidonic acid is: 97 parts of feed, 2 parts of eicosapentaenoic acid, and 1 part of arachidonic acid.

6. The method according to claim 1, characterized in that: The weight ratio of the feed, eicosapentaenoic acid and arachidonic acid is: 97 parts of feed, 3 parts of eicosapentaenoic acid, and 0 parts of arachidonic acid.

7. The method according to claim 1, characterized in that: The concentrations of eicosapentaenoic acid and arachidonic acid are both 38%-40%.

8. The method according to claim 1, characterized in that: The feed raw material comprises the following components in weight proportions: Fish meal 40 parts, soybean meal 30 parts, casein 15 parts, mixed vitamins 1 part, mixed minerals 1 part, sodium alginate 1 part, chromium oxide 1 part, corn starch 4 parts and fish oil 7 parts.

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