Special feed for juvenile abalone during seedling separation and transition period and application thereof

Abstract

The application discloses a kind of juvenile abalone divides special feed of seedling transition period and application thereof, belong to aquatic products breeding feed technical field.The feed includes Sargassum thunbergii powder 5-15%, kelp powder 10-25%, soybean meal powder 30-51%, high gluten flour 10-21%, gluten powder 5-10%, fish meal 3.6-5%, soybean oil 0.30-0.45%, fish oil 0.30-0.45% and abalone premix 3.8-5.2%, wherein Sargassum thunbergii powder and kelp powder are preferably 1:2 ratio.The feed can effectively alleviate the strong stress caused by dividing seedling operation to juvenile abalone through the synergism of specific proportion of active algal powder.The application results show that the feed can significantly improve the survival rate of juvenile abalone after dividing seedling (up to 84.17%), enhance the body antioxidant capacity, improve intestinal digestive enzyme activity, and regulate immune and cell apoptosis related gene expression, synergistically improve the stress resistance and health level of juvenile abalone from physiological and molecular level, suitable for feeding in the key transition stage after dividing seedling of juvenile abalone.

Description

Technical Field

[0001] This invention belongs to the field of aquaculture feed technology, specifically relating to a compound feed for the transition period of juvenile abalone seedlings, and particularly to a feed optimized from Sargassum fusiforme (…). Sargassum miyabei This is a functional feed composition that, when combined with kelp and verified through multiple dimensions, can significantly improve the survival rate of abalone, enhance antioxidant capacity, improve gut health, and regulate physiological metabolism. Background Technology

[0002] Abalone, as a valuable marine shellfish, plays a vital role in the healthy development of its aquaculture industry. In modern abalone farming, seedling separation is a crucial and indispensable step. After abalone seedlings reach a certain size, farmers can screen and sort them according to their size and growth status, transferring them from high-density nursery ponds / cages to low-density rearing cages. This process avoids competition for living space and food resources caused by excessively high stocking densities, ensuring balanced growth; it also allows for the timely removal of weak and diseased seedlings, preventing the spread of diseases and facilitating precise aquaculture management.

[0003] From juvenile abalone in a nursery to marketable adult abalone, the process typically involves 2-3 separations. However, while separation offers long-term management convenience, it also causes significant short-term stress for the abalone larvae. During separation, the larvae inevitably experience a series of physical and chemical stimuli, including removal from water, manual handling, mechanical friction, and sudden environmental changes (such as water temperature, salinity, and light), triggering a severe immune stress response. This manifests as an imbalance in the body's antioxidant system, disordered activity of immune-related enzymes, and a rapid decline in the body's resistance. The initial outdoor separation stage, particularly during the transfer from indoor nursery ponds to offshore aquaculture cages, is particularly stressful due to the drastic environmental changes, resulting in the highest mortality rate among all growth stages. This vulnerable period of the immune system, also known as the "transition phase" or "stress recovery period," usually lasts several days to half a month. During this time, abalone larvae are highly susceptible to opportunistic pathogens in the environment, leading to various diseases and ultimately a significantly increased mortality rate shortly after separation. Currently, abalone farmers primarily feed them conventional formulated feeds or natural algae after separation. These feeds have limitations. For example, seaweed is nutritionally unbalanced and lacks sufficient high-quality protein, essential fatty acids, and functional additives to support immune system repair and stress resistance. Furthermore, the formulation of conventional formulated feeds is mostly designed to promote growth, not to alleviate separation stress and reduce mortality. Their nutritional composition fails to precisely match the specific physiological needs of abalone during the stress recovery period.

[0004] Based on this, we developed a special formula feed based on a specific Sargassum species, suitable for the transitional stage after abalone seedling division. Through the synergistic effect of its specific active ingredients and other nutrients, it can effectively alleviate the immune stress of abalone and enhance its immunity, thereby significantly reducing the mortality rate during the critical period after seedling division. This is of great significance for improving the survival rate and economic benefits of abalone farming.

[0005] The primary objective of this invention is to provide a formulated feed for juvenile abalone during the transition period after hatching. This feed improves survival rates by optimizing the ratio of Sargassum fusiforme to kelp. Another objective of this invention is to elucidate the application of the aforementioned feed in enhancing the antioxidant levels of abalone, improving intestinal digestive function, and regulating the expression of metabolic genes related to immunity. Summary of the Invention

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A compound feed for abalone after seedling separation, characterized in that, on a dry weight basis, its raw materials include the following components: Sargassum fusiforme powder, kelp powder, protein source, starch source, vitamin premix and mineral premix; wherein, in the algae powder component, the ratio of Sargassum fusiforme powder to kelp powder is between 0:30 and 30:0, preferably 10:20.

[0008] Furthermore, the total mass percentage of Sargassum fusiforme powder and kelp powder in the compound feed is 20% to 35%.

[0009] Furthermore, the protein source is fish meal or soybean meal, and the starch source is wheat starch.

[0010] This invention addresses current aquaculture needs by developing a formulated feed for abalone with Sargassum fusiforme as the main algal component. When this feed is used to feed abalone seedlings, it can significantly improve the survival rate of abalone and help reduce the abalone farming cost.

[0011] The technical solution adopted by the present invention to achieve the above-mentioned objective is: a stress-resistant abalone compound feed, which is composed of the following components in weight percentage: Sargassum fusiforme powder 5-15%, kelp powder 10-25%, soybean meal powder 30-51%, high-gluten flour 10-21%, wheat gluten powder 5-10%, fish meal 3.6-5%, soybean oil 0.30-0.45%, fish oil 0.30-0.45%, and abalone premix 3.8-5.2%, wherein the abalone premix includes minerals, vitamins, and amino acids.

[0012] Furthermore, each kilogram of abalone premix contains 75,000-150,000 IU of vitamin A, 100-150 mg of vitamin B1, 100-150 mg of vitamin B2, 700-1000 mg of nicotinamide, 200-450 mg of D-pantothenic acid, 40-75 mg of vitamin B6, 25-45 mg of folic acid, 0.17-0.22 mg of vitamin B12, 2000-6000 mg of vitamin C, 1800-2400 IU of vitamin D3, 500-700 IU of vitamin E, and vitamin K3. 100-150mg, D-Biotin 19-25mg, Inositol 3500-5500mg, Sodium 300-600mg, Calcium 1200-1800mg, Zinc 120-220mg, Iron 500-1200mg, Magnesium 3600-8000mg, Copper 10-15mg, Manganese 55-78mg, Cobalt 0.35-0.80mg, Selenium 0.55-0.80mg, Iodine 0.5-2.0mg, Methionine 150-300mg, Lysine 150-250mg, Malic Acid 100-200mg, Shellfish Mixture 14000-20000mg, and Ethoxyquinoline 100-300mg.

[0013] Furthermore, the finished compound feed is in flake form.

[0014] A method for preparing a stress-resistant abalone compound feed includes the following steps:

[0015] Step 1: Take dried Sargassum fusiforme, kelp and soybean meal separately, remove impurities and grind them, then pass them through an 80-100 mesh sieve to obtain Sargassum fusiforme powder, kelp powder and soybean meal powder, and set them aside. Step 2: Weigh out the high-gluten flour, fish meal, gluten powder, abalone premix, and the Sargassum powder, kelp powder, and soybean meal powder obtained in Step 1 according to the above mass percentages. Mix them thoroughly to obtain the mixed powder for later use.

[0016] This invention discloses a stress-resistant abalone compound feed, developed using inexpensive, nutrient-rich, and high-biomass Sargassum fusiforme. By incorporating Sargassum fusiforme and kelp as algal-based components in the finished compound feed, it overcomes the technical deficiency of traditional abalone feeds' high dependence on kelp. Sargassum fusiforme / kelp, combined with compound soybean meal, high-gluten flour, wheat gluten, and fish meal, are scientifically formulated and synergistically combined to create a nutritionally rich, rationally proportioned, and balanced compound feed that meets the growth and development needs of abalone seedlings after separation. This improves the abalone's immunity and survival rate, reduces costs, and increases aquaculture efficiency.

[0017] Step 3: Weigh out soybean oil and fish oil according to the above mass percentages, and add them to the mixed powder prepared in Step 2. Add water to the mixture, which should be 25-30% of the mass of the mixed powder. Stir thoroughly to obtain the feed mixture for later use.

[0018] Step 4: Form the feed mixture obtained in Step 3 into flakes with a thickness of 1.6-2.3 mm and a size of (2-3) × (2-3) cm. 2 ,spare;

[0019] Step 5: Place the flake-shaped feed to be cooked obtained in Step 4 under steam at 80-90℃ for 10-20 minutes to cook it, thus obtaining cooked feed.

[0020] Step 6: Dry the cooked feed obtained in Step 5 to reduce its moisture content to below 10%, thus obtaining the finished stress-resistant abalone compound feed.

[0021] Beneficial effects of the present invention

[0022] This invention discloses a stress-resistant abalone compound feed, developed using inexpensive, nutrient-rich, and high-biomass Sargassum fusiforme. By incorporating Sargassum fusiforme and kelp as algal-based components in the finished compound feed, it overcomes the technical deficiency of traditional abalone feeds' high dependence on kelp. Sargassum fusiforme / kelp, combined with compound soybean meal, high-gluten flour, wheat gluten, and fish meal, are scientifically formulated and synergistically combined to create a nutritionally rich, rationally proportioned, and balanced compound feed that meets the growth and development needs of abalone seedlings after separation. This improves the abalone's immunity and survival rate, reduces costs, and increases aquaculture efficiency.

[0023] The preparation process of this invention is simple and easy to operate. The finished compound feed is in solid flake form, which is easily consumed by abalone and has a good breeding effect.

[0024] Compared with existing technologies, the feed of this invention can significantly improve the survival rate of abalone after seedling separation by using a specific ratio of Sargassum fusiforme and kelp synergistically. Examples confirm that the survival rate can be increased by more than 10% compared with the group without Sargassum fusiforme.

[0025] Abalone fed the feed of this invention showed a significant decrease in serum malondialdehyde (MDA) levels and an increase in proline levels, while maintaining stable total antioxidant capacity, indicating a substantial enhancement in the body's ability to resist oxidative damage. Furthermore, the feed of this invention significantly increased the activity of proteases and lipases in the abalone's midgut, promoting the digestion and absorption of nutrients.

[0026] Transcriptomic analysis of gill tissue revealed that the feed of this invention significantly regulated the expression of key immune-related genes in abalone gill tissue. This reveals at the molecular level the synergistic mechanism by which this invention promotes abalone survival by enhancing immunity. Attached Figure Description Figure 1 Feed production A. Raw material tableting; B. Raw material cutting; C. Dried and processed tablets Figure 2 Feed-based animal husbandry test AB: Abalone seedling separation; C: Raft culture; D: Test completed, samples collected and sent for testing. Figure 3 Transcriptome sequencing analysis of the immunomodulatory effects of Sargassum fusiforme formulated feed on abalone A. Volcano plot of differentially expressed genes; B. Heatmap of genome-wide transcriptional expression; C. Venn diagram of differentially expressed genes. Figure 4 GO enrichment and upregulation gene analysis Figure 5 GO enrichment downregulated gene analysis Figure 6 Heatmap of cell death and immune-related gene expression in the gills of abalone fed diets with different Sargassum contents. Figure 7 Quantitative real-time PCR to verify the transcriptional expression of relevant differentially expressed genes Detailed Implementation

[0027] To make the technical means, creative features, objectives, and beneficial effects of this invention clearer and more understandable, the invention is further described below in conjunction with specific embodiments:

[0028] Example 1: Formulation Composition

[0029] In this embodiment, the stress-resistant abalone feed formula consists of Sargassum fusiforme powder, kelp powder, soybean meal powder, high-gluten flour, wheat gluten, fish meal, abalone premix, soybean oil, and fish oil, with the following proportions:

[0030] Formula 1: 30% kelp powder, 40.8% soybean meal powder, 15.0% high-gluten flour, 7.0% wheat gluten, 3.0% fish meal, 0.1% soybean oil, 0.1% fish oil, 4.0% abalone premix;

[0031] Formula 2: 10% Sargassum powder, 20% kelp powder, 40.8% soybean meal powder, 15.0% high-gluten flour, 7.0% wheat gluten, 3.0% fish meal, 0.1% soybean oil, 0.1% fish oil, 4.0% abalone premix;

[0032] Formula 3: 15% Sargassum powder, 15% kelp powder, 40.8% soybean meal powder, 15.0% high-gluten flour, 7.0% wheat gluten, 3.0% fish meal, 0.1% soybean oil, 0.1% fish oil, 4.0% abalone premix;

[0033] Formula 4: 30% Sargassum powder, 40.8% soybean meal powder, 15.0% high-gluten flour, 7.0% wheat gluten, 3.0% fish meal, 0.1% soybean oil, 0.1% fish oil, and 4.0% abalone premix; the abalone premix contains vitamins, amino acids, and minerals.

[0034] The abalone premix composition described in the formula is as follows: per kilogram of premix, it contains 130,000 IU of Vitamin A, 100 mg of Vitamin B1, 110 mg of Vitamin B2, 800 mg of Nicotinamide, 350 mg of D-pantothenic acid, 620 mg of Vitamin B6, 33 mg of Folic acid, 0.18 mg of Vitamin B12, 4500 mg of Vitamin C, 2200 IU of Vitamin D3, 550 IU of Vitamin E, and 100 mg of Vitamin K3. 110mg, D-Biotin 19mg, Inositol 3500mg, Sodium 350mg, Calcium 1500mg, Zinc 180mg, Iron 700mg, Magnesium 4800mg, Copper 12mg, Manganese 60mg, Cobalt 0.65mg, Selenium 0.65mg, Iodine 1.5mg, Methionine 200mg, Lysine 200mg, Malic Acid 150mg, Shellfish Mixture 14000mg, Ethoxyquinoline 200mg.

[0035] Example 2: Feed Preparation

[0036] The preparation process of the above-mentioned stress-resistant abalone compound feed specifically includes the following steps:

[0037] (1) Raw material pretreatment: The dried Sargassum fusiforme powder, kelp powder, soybean meal powder, high gluten flour and fish meal were initially screened to remove other solid impurities; then they were crushed and passed through an 80-100 mesh sieve.

[0038] (2) First mixing: Weigh each raw material according to the mass ratio of 0%-30% Sargassum powder, 0%-30% kelp powder, 40.8% soybean meal powder, 15.0% high gluten flour, 7.0% wheat gluten powder, 3.0% fish meal, and 4.0% abalone premix, and mix them as the base feed.

[0039] (3) Secondary mixing: Add 0.1% soybean oil, 0.1% fish oil and 25-30% water by weight of the resulting solids to the mixed powder in step (2) above, stir and mix well to obtain feed mixture;

[0040] (4) Take out the prepared feed mixture and make it into flakes (e.g. Figure 1 A), wherein the sheet material is made by pressing and slicing, and the thickness of the sheet material to be cooked is 1.6-2.3mm, and the size is (2-3)×(2-3)cm. 2 (like Figure 1 B).

[0041] (5) The material to be cooked in step (4) is cooked by steam cooking at 80-90℃ for 10-20 minutes.

[0042] (6) The cooked flake feed from step (5) is dried by forced air drying until the moisture content is maintained below 10%, thus obtaining the finished growth-promoting abalone compound feed (e.g. Figure 1 C).

[0043] Figure 1 Feed production A. Raw material tableting; B. Raw material cutting; C. Dried and processed tablets

[0044] Example 3: Feed-based animal husbandry test

[0045] Using the four types of compound feeds prepared above as test subjects, a marine raft aquaculture test was conducted in the waters of Sandu Bay, Ningde, Fujian Province. Figure 2 The test subjects were green abalone larvae with shell lengths of 2.8-3.5 cm, with 120 abalone per group and 3 replicates for each group. The abalone were fed the test feed for one month, followed by a regular growth feed for the next three months. All abalone fed with the four feeds exhibited a bright green color. The survival rate results are shown in Table 1. Formula 2 (Sargassum powder: kelp powder ratio of 10:20) showed the highest survival rate and specific growth rate, significantly higher than formulas 1, 3, and 4. Regarding shell length growth, there was no significant difference between formula 2 and the control group, but formula 2 was higher than formulas 3 and 4.

[0046] Figure 2 Feed farming test AB: Abalone seedling separation; C: Raft culture; D: Test completed, samples collected and sent for testing.

[0047] Table 1. Survival rate and growth indicators of abalone tested Formula 1 <![CDATA[72.50±2.50 c ]]> <![CDATA[1.81±0.01 a ]]> <![CDATA[119.45±3.95 ab ]]> Formula 2 <![CDATA[84.17±2.89 a ]]> <![CDATA[1.84±0.03 a ]]> <![CDATA[123.08±4.71 a ]]> Formula 3 <![CDATA[80.00±4.33 ab ]]> <![CDATA[1.74±0.05 b ]]> <![CDATA[115.48±3.67 b ]]> Formula 4 <![CDATA[77.50±5.00 b ]]> <![CDATA[1.57±0.07 c ]]> <![CDATA[112.84±5.12 b ]]> Note: Different superscript letters in the same column indicate significant differences (P<0.05), and the same applies below.

[0048] Serum antioxidant indicators: Compared with the control group (formula 1), formula feed 2 helped maintain normal redox levels in abalone blood. The content of malondialdehyde (MDA), a lipid peroxidation stressant, was significantly reduced, while the level of proline, an osmotic balance-related substance, was increased. The total antioxidant level was comparable to the control group. With increasing proportions of Sargassum fusiforme, the MDA content in abalone blood gradually increased, while the proline content and total antioxidant capacity gradually decreased. This indicates that an appropriate proportion of Sargassum fusiforme helps maintain redox levels in abalone blood.

[0049] Table 2. Tests on non-specific immune indicators of abalone Formula 1 <![CDATA[0.94±0.09 ab ]]> <![CDATA[23.48±2.08 c ]]> <![CDATA[14.86±2.23 a ]]> Formula 2 <![CDATA[0.56±0.12 d ]]> <![CDATA[43.40±3.35 a ]]> <![CDATA[13.75±1.11 ab ]]> Formula 3 <![CDATA[0.70±0.07 c ]]> <![CDATA[29.51±2.65 b ]]> <![CDATA[11.43±0.71 b ]]> Formula 4 <![CDATA[0.97±0.12 a ]]> <![CDATA[14.14±1.11 d ]]> <![CDATA[9.81±0.47 c ]]>

[0050] Intestinal digestive enzyme activity: Among the four tested formulations, formulation 2 can most comprehensively enhance the complex enzyme activity of abalone digestive glands, especially showing significant advantages in cellulase and trypsin; formulation 3 has a specific effect on enhancing trypsin activity; in contrast, when Sargassum fusiforme completely replaces seaweed (formulation 4), the digestive indicators of the treated abalone are lower than those of the other formulation groups.

[0051] Table 3. Test indicators of abalone digestibility Formula 1 <![CDATA[26.65±3.73 b ]]> <![CDATA[76.23±11.74 b ]]> <![CDATA[26.22±1.49 a ]]> Formula 2 <![CDATA[38.02±1.42 a ]]> <![CDATA[137.43±8.5 a ]]> <![CDATA[26.45±0.65 a ]]> Formula 3 <![CDATA[21.48±1.30 c ]]> <![CDATA[142.25±15.23 a ]]> <![CDATA[25.48±3.04 a ]]> Formula 4 <![CDATA[17.91±0.95 d ]]> <![CDATA[43.35±5.43 c ]]> <![CDATA[18.06±1.92 b ]]>

[0052] Transcriptome analysis of gill tissue: RNA-Seq sequencing was performed on the gill tissue of abalone from the above four treatments. Figure 3 (A-3B). Analysis revealed that, compared to formulation 1, formulation 2 abalone had 1153 differentially expressed genes, including 384 upregulated genes and 769 downregulated genes (|log2FC|>1, Padj<0.05, the same below), with the upregulated genes being the most prominent. Formulation 3 abalone had 1626 differentially expressed genes, including 629 upregulated genes and 997 downregulated genes. Formulation 4 abalone had 1711 differentially expressed genes, including 259 upregulated genes and 1452 downregulated genes. Figure 3 A).

[0053] Figure 3 Transcriptome sequencing analysis of the immunomodulatory effects of Sargassum fusiforme formulated feed on abalone A. Volcano plot of differentially expressed genes; B. Heatmap of genome-wide transcriptional expression; C. Venn diagram of differentially expressed genes.

[0054] Transcriptome analysis of gill tissue: RNA-Seq sequencing was performed on the gill tissue of abalone from the above four treatments. Figure 3 (A-3B). Analysis revealed that, compared to formulation 1, formulation 2 abalone had 1153 differentially expressed genes, including 384 upregulated genes and 769 downregulated genes (|log2FC|>1, Padj<0.05, the same below), with the upregulated genes being the most prominent. Formulation 3 abalone had 1626 differentially expressed genes, including 629 upregulated genes and 997 downregulated genes. Formulation 4 abalone had 1711 differentially expressed genes, including 259 upregulated genes and 1452 downregulated genes. Figure 3 A).

[0055] Venn diagram ( Figure 3C) Analysis revealed 1153, 1626, and 1711 DEGs in formulas 2, 3, and 4, respectively. Among these, 177 genes were differentially expressed across the three groups (core intersection), suggesting they may be involved in basal gill regulation. Formula 4 had the most DEGs (1169), indicating a potentially more unique metabolic response. Furthermore, formulas 2 and 3 shared 595 genes, and formulas 3 and 4 shared 442 genes, suggesting that formulas 2 and 3, and formulas 3 and 4, may share certain specific regulatory pathways.

[0056] GOBP enrichment analysis was performed on differentially expressed genes (DEGs) in abalone treated with formulation 1 and two or three other formulations. Figures 4-5 A total of 36 significantly enriched terms were obtained, with formulations 2, 3, and 4 enriching 6, 28, and 2 terms respectively. These mainly involved tumor necrosis factor, Wnt, apoptosis, cell necrosis, TLR signaling pathway, inflammatory response factors, and antibacterial responses. The most significant biological processes were concentrated in formulation 3 for "nitric oxide production in the inflammatory response" (GO:0002673) and "negative regulation of the exogenous apoptosis pathway through death domain receptors" (GO:1902042). When the Sargassum content was increased to 15% of the total feed (formulation 2), on the one hand, the inflammatory response in abalone was activated, accompanied by the production of effector molecules such as nitric oxide, which exacerbated cell necrosis; on the other hand, the cells simultaneously initiated resistance programs against exogenous death signals to avoid apoptosis. This pattern is similar to the characteristics of classic pathological models, such as the tumor microenvironment or chronic inflammatory diseases.

[0057] Figure 4 GO enrichment and upregulation gene analysis

[0058] In the downregulated gene enrichment analysis, a total of 38 significantly downregulated terms were obtained from the three treatment groups. Figure 5 The main focus was on abalone fed with Formula 4 (36 items), involving life processes such as apoptosis, immune-related genes, B lymphocyte activation / immune regulation, immunoglobulins, and T-lymphocyte activation / differentiation. The most significantly downregulated biological process was "regulation of humoral immune responses mediated by circulating immunoglobulins (GO0002925)". When Sargassum fusiforme was the sole algal source (Formula 4), the "regulatory capacity" of the abalone's humoral immune response decreased, and the immune feedback regulatory network centered on antibodies was generally suppressed or weakened, failing to effectively initiate or maintain normal immunity.

[0059] Figure 5 GO enrichment downregulated gene analysis

[0060] Based on this, this patent analyzed the transcriptome expression profiles of key genes related to cell necrosis, apoptosis, and immune regulation. Figure 6 Based on their expression patterns, these genes can be divided into two distinct response groups. The first group consists of genes that are initially induced and then repressed, including immune signaling hubs. NF-κB and MYD88 Core apoptosis executive genes Caspase-7 Apoptosis initiation genes Caspase-8 , CK1Lα-2 and apoptosis inhibitors IAP-3 Its expression level first increased and then decreased with the increase of the proportion of Sargassum in the feed, and the expression peak was found in formulation group 3 (50% Sargassum: 50% kelp). The second category is persistently repressive genes, including TLR-2, TNFSF-14, SULT1A1, FAT4-A, FAT4-B, SAMD9L as well as ITM2B The expression levels of these genes showed a dose-dependent and sustained significant downregulation with increasing Sargassum addition, eventually decreasing to the control group level. Figure 6 ).

[0061] Figure 6 Heatmap of cell death and immune-related gene expression in the gills of abalone in diets with different Sargassum contents

[0062] To verify the reliability of the sequencing results, this patent performed quantitative real-time PCR verification on the aforementioned key genes. Figure 7 In the first class of genes, with the increase of Sargassum content, immune signaling hub genes... NF-κB and MYD88 Core apoptosis executive genes Caspase-7 α isoform of cytokine-like factor 1 CK1Lα-1 and CK1Lα-2 Apoptosis inhibitors IAP-3 Exogenous detoxification enzymes SULT1A1 The transcriptional expression levels of 7 genes gradually increased. ， The relative expression level reached its highest (approximately 1.2-2.5-fold) in formulation 3 (Sargassum:kelp = 1:1) and its lowest in formulation 4. This expression pattern is consistent with the transcriptome heatmap data, indicating that an appropriate equiproportion (1 / 3 to 1 / 2 algal base) of Sargassum can effectively activate the innate immune response in the abalone gills. MyD88 / NF-κB It can induce controlled apoptosis and moderately enhance the stress defense response.

[0063] In the second type of genes, we also observed similar phenomena to those observed in the transcriptome. Figure 7 Compared to formulation 1, the pattern recognition receptor... TLR-2, Regulating the balance between cell proliferation and death FAT4-A, FAT4-BGene expression levels gradually decreased with increasing Sargassum content, indicating severe inhibition; in formulation group 4, the levels were only 20% of the control group. TLR-2 ), 10% FAT4-A ) and 17% FAT4-B In addition, it has cell-protective functions. ITM2B and SAMD9L Gene expression was also significantly impaired, decreasing to 40% and 15% of the control group (Formula 1) in Formula 4, respectively. This indicates that a high proportion (Formula 4) of Sargassum feed had a wide range of negative effects on the abalone gills. Long-term consumption of a diet consisting entirely of Sargassum (Formula 4) may lead to a shift in abalone gill cells from regulated apoptosis to uncontrolled necrosis or inflammatory cell death pathways, which may be a potential molecular mechanism by which high proportions of Sargassum induce tissue damage.

[0064] Figure 7 Quantitative real-time PCR to verify differentially expressed genes

[0065] In summary, the abalone feed prepared by optimizing the ratio of Sargassum fusiforme to kelp (1:2) in this invention exhibits significant synergistic effects in promoting the growth of abalone after seedling division, maintaining normal antioxidant function of blood, improving digestive function, and positively regulating the expression of immune genes, and has extremely high application value.

Claims

1. A special feed for the transition period of juvenile abalone seedlings, characterized in that, It is composed of the following components by weight percentage: Sargassum fusiforme 5-10%, kelp powder 10-20%, soybean meal powder 30-51%, high-gluten flour 10-21%, wheat gluten 5-10%, fish meal 3.6-5%, soybean oil 0.30-0.45%, fish oil 0.30-0.45%, and abalone premix 3.8-5.2%, wherein the abalone premix contains vitamins, amino acids, and minerals.

2. The special feed for the transition period of juvenile abalone seedlings according to claim 1, characterized in that, Each kilogram of the abalone premix contains the following components: Vitamin A 70,000-140,000 IU, Vitamin B1 90-140 mg, Vitamin B2 90-140 mg, Nicotinamide 600-9,000 mg, D-pantothenic acid 150-400 mg, Vitamin B6 40-70 mg, Folic acid 2-40 mg, Vitamin B12 0.15-0.20 mg, Vitamin C 2,000-5,500 mg, Vitamin D3 1,500-2,500 IU, Vitamin E 500-800 IU, and Vitamin K3. 90-140mg, D-Biotin 20-25mg, Inositol 3000-5000mg, Calcium 1100-1700mg, Sodium 200-550mg, Zinc 110-210mg, Iron 450-1100mg, Magnesium 3500-7500mg, Copper 9-14mg, Manganese 52-76mg, Cobalt 0.30-0.75mg, Selenium 0.50-0.75mg, Iodine 0.4-1.9mg, Methionine 140-290mg, Lysine 140-240mg, Malic Acid 90-190mg, Shellfish Mixture 13000-20000mg, Ethoxyquinoline 100-280mg.

3. The special feed for the transition period of juvenile abalone seedlings according to claim 2, characterized in that, Each kilogram of the abalone premix contains the following components: Vitamin A 120,000 IU, Vitamin B1 100 mg, Vitamin B2 100 mg, Nicotinamide 750 mg, D-pantothenic acid 300 mg, Vitamin B6 610 mg, Folic acid 32 mg, Vitamin B12 0.17 mg, Vitamin C 4400 mg, Vitamin D3 2100 IU, Vitamin E 540 IU, Vitamin K3 100 mg, D-Biotin 18 mg, Inositol 3400 mg, Sodium 330 mg, Calcium 1400 mg, Zinc 170 mg, Iron 680 mg, Magnesium 4700 mg, Copper 11 mg, Manganese 60 mg, Cobalt 0.64 mg, Selenium 0.64 mg, Iodine 1.2 mg, Methionine 200 mg, Lysine 200 mg, Malic acid 150 mg, Shellfish mixture 13500 mg, Ethoxyquinoline 200 mg.

4. The special feed for the transition period of juvenile abalone seedlings according to claim 1, characterized in that: The finished product of the compound feed is in flake form.

5. A method for preparing a special feed for the transition period of juvenile abalone seedlings according to any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Take dried Sargassum fusiforme, kelp and soybean meal separately, remove impurities and grind them separately, and pass them through an 80-100 mesh sieve to obtain Sargassum fusiforme powder, kelp powder and soybean meal powder for later use. Step 2: Weigh out the high-gluten flour, chicken powder, gluten powder, abalone premix according to the above mass percentages, and mix them with the Sargassum powder, kelp powder and soybean meal powder obtained in Step 1. After mixing thoroughly, a mixed powder is prepared and set aside. Step 3: Weigh out soybean oil and fish oil according to the stated mass percentages, add them to the mixed powder obtained in Step 2, add water, and mix thoroughly to obtain the feed mixture for later use. Step 4: Form the feed mixture obtained in Step 3 into flakes for cooking and set aside. Step 5: Cook the flake or granular feed obtained in Step 4 under steam at 80-90℃ for 10-20 minutes to obtain cooked feed for later use. Step 6: Dry the cooked feed obtained in Step 5 to reduce its moisture content to below 10%, thus obtaining the finished product of the stress-resistant abalone compound feed.

6. The preparation method according to claim 5, characterized in that, The high-gluten flour and chicken powder mentioned in step two should be sieved through a 60-100 mesh sieve before weighing.

7. The method for preparing a special feed for the transition period of juvenile abalone seedlings according to claim 5, characterized in that: The amount of water added in step three is 25-30% of the mass of the mixed powder.

8. The preparation method according to claim 5, characterized in that, In step four: The flaky feed is made by pressing and slicing the feed mixture, with a thickness of 1.6-2.3 mm and a size of (2-3) cm × (2-3) cm.

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