A feed composition for fish farming and its application and farming method

Abstract

The application discloses a feed composition for fish culture and application and culture method thereof. The feed composition contains the following components in parts by weight: fish meal 20-40 parts, soybean meal 10-22 parts, food leaf grass 12-28 parts, gluten 1-8 parts, cassava starch 12-28 parts, secondary powder 3-12 parts, fish oil 2-10 parts, calcium dihydrogen phosphate 0.5-4 parts, vitamin and mineral premix 0.5-4 parts, and choline chloride 0.2-3 parts. The feed composition can be used for reducing fish earthy smell and improving fish quality. The culture method comprises the following steps: feeding the fish with the feed composition 6 weeks (preferably 4 weeks) before the fish go out of the pond, and no water hanging treatment is needed. The application can obtain high-quality fish without smell, compact meat and delicious flavor under the conditions of no feeding, no water hanging and pond changing and no facility increasing, meanwhile, the weight loss of the fish is avoided, and the economic effect is remarkable.

Description

Technical Field

[0001] This invention relates to the field of aquaculture feed, and in particular to a fish farming feed composition and its application and farming method. Background Technology

[0002] Currently, pond-farmed fish commonly suffer from a strong muddy taste and loose flesh after being harvested and sold, severely impacting consumer acceptance and market value. Research indicates that the main sources of this muddy taste are geosmin and 2-methylisoborneol (2-MIB). These odor compounds are produced by cyanobacteria and actinomycetes in the water, entering and accumulating in fish through their gills and digestive tract. Nutrition and taste are paramount factors for consumers when purchasing fresh fish. Therefore, reducing or eliminating the muddy taste and improving muscle quality have become urgent problems for the aquaculture industry.

[0003] Currently, the mainstream technology for solving the muddy taste problem is water treatment (also known as "slimming fish"), which adds a step between production and consumption by transferring marketable fish to clean or running water for 7-30 days without feeding. This starvation process depletes the fat accumulated in the fish's abdominal cavity, and the use of probiotics in the aquaculture water effectively removes muddy taste substances, achieving a removal rate of up to 80%. However, this technology has the following objective drawbacks:

[0004] (1) Significant economic losses: During the period of withholding food, the fish body consumes its own reserves, and the weight can decrease by 10%-30%, which directly causes economic losses to fish farmers. Taking grass carp as an example, every 10,000 catties of fish will lose 500-1000 catties of yield after being suspended from water.

[0005] (2) High biological risk: The process of changing ponds causes a strong stress response in fish, reduces their immunity, and makes them more susceptible to diseases. It has been reported that the incidence of fish diseases during the process of changing ponds is more than 30% higher than that of conventional aquaculture.

[0006] (3) The production cycle is long and unstable: affected by the season and water temperature, the fish metabolism is slow when the water temperature is low in winter, and the hanging cycle is prolonged; when the water temperature is high in summer, they are prone to die due to lack of oxygen, making it difficult to achieve stable production throughout the year.

[0007] (4) Large investment in facilities: It requires a special clear water pool, circulating water system or water tank, and the initial investment is high.

[0008] In recent years, the industry has seen technological improvements such as adding probiotics and using circulating water systems during the fish feeding process. However, these solutions have not solved the core problem: "the fish still need to go through a fasting period," and weight loss is inevitable. Some studies have also improved fish meat quality through functional feeds, but none of them have focused on the specific short window before harvesting, failing to achieve the technical goals of continuous feeding, no fish feeding, and no fishy smell. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a fish farming feed composition and its application and farming method, so as to obtain high-quality fish with no fishy smell, firm flesh and delicious flavor under the conditions of continuous feeding, no pond changing and no additional facilities, while avoiding weight loss, thereby overcoming the shortcomings of the existing technology.

[0010] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0011] In a first aspect, the present invention provides a fish farming feed composition comprising, by weight, the following components: 20-40 parts fish meal, 10-22 parts soybean meal, 12-28 parts leafy grass, 1-8 parts wheat gluten, 12-28 parts cassava starch, 3-12 parts wheat middlings, 2-10 parts fish oil, 0.5-4 parts calcium dihydrogen phosphate, 0.5-4 parts vitamin and mineral premix, and 0.2-3 parts choline chloride.

[0012] Further, by weight, it contains the following components: 25-35 parts fish meal, 12-18 parts soybean meal, 16-24 parts leafy greens, 3-5 parts wheat gluten, 16-24 parts tapioca starch, 5-9 parts wheat bran, 4-8 parts fish oil, 1.5-2.5 parts calcium dihydrogen phosphate, 1.5-2.5 parts vitamin and mineral premix, and 0.8-1.2 parts choline chloride.

[0013] Further, by weight, it contains the following components: 30 parts fish meal, 15 parts soybean meal, 20 parts leafy greens, 4 parts wheat gluten, 20 parts tapioca starch, 7 parts wheat bran, 6 parts fish oil, 2 parts calcium dihydrogen phosphate, 2 parts vitamin and mineral premix, and 1 part choline chloride.

[0014] Secondly, the present invention also provides the application of the above-mentioned fish farming feed composition in the preparation of feed that reduces the muddy taste of fish.

[0015] Thirdly, the present invention also provides the application of the above-mentioned fish farming feed composition in the preparation of feed that improves the quality of fish meat.

[0016] Fourthly, the present invention also provides the application of the above-mentioned fish farming feed composition in reducing the muddy taste of fish.

[0017] Fifthly, the present invention also provides the application of the above-mentioned fish farming feed composition in improving fish meat quality.

[0018] Sixthly, the present invention also provides a method for reducing the muddy taste of fish and / or improving the quality of fish meat, using the above-mentioned fish farming feed composition, feeding the fish daily starting 6 weeks before harvesting, without the need for water treatment.

[0019] Furthermore, starting four weeks before the fish are harvested, they are fed daily without the need for water treatment.

[0020] Furthermore, feed them twice a day, once in the morning and once in the afternoon, until they appear to be satiated.

[0021] By adopting the above technical solution, the present invention has at least the following beneficial effects:

[0022] (1) Solving the contradiction of "reduced production and improved quality". This invention enables fish to grow normally without stopping feeding, changing ponds or adding facilities, and obtains high-quality fish with no fishy smell, firm flesh and delicious flavor. Moreover, while obtaining high quality, the yield does not decrease but increases, breaking through the bottleneck of difficulty in improving quality and increasing production in traditional aquaculture.

[0023] (2) A double breakthrough in technical effects. With the continuous effect of compound feed containing functional substances, the content of earthy taste substances in fish is effectively reduced, while the density of muscle fibers is increased, resulting in a significant improvement in the texture indicators such as the hardness and elasticity of the fish meat, and the overall quality is significantly better than that of conventionally farmed fish.

[0024] (3) Simplified production process and easy to promote. The operation is simple. It only requires changing the feed formula on the basis of conventional breeding. Farmers do not need to learn complicated techniques. It is easy to promote and apply quickly.

[0025] (4) Significant economic benefits. Production remains consistent throughout the entire process, the selling price is moderately higher than conventionally farmed fish, and market acceptance is high. Overall, the economic profit index increases by 1.92 (¥, fish). -1 ). Attached Figure Description

[0026] The above is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Figure 1 This refers to the final average weight of fish in different treatment groups in the application examples of this invention;

[0028] Figure 2 This refers to the weight gain rate of fish in different treatment groups in the application examples of this invention;

[0029] Figure 3 This refers to the content of essential, non-essential, and total amino acids in the muscles of different treatment groups in the application examples of this invention;

[0030] Figure 4 This refers to the content of geosmin in fish meat from different treatment groups in the application examples of this invention. Detailed Implementation

[0031] Example 1

[0032] The fish farming feed composition of this embodiment comprises the following components by weight: 30 parts fish meal, 15 parts soybean meal, 20 parts leafy grass, 4 parts wheat gluten, 20 parts cassava starch, 7 parts wheat middlings, 6 parts fish oil, 2 parts calcium dihydrogen phosphate, 2 parts vitamin and mineral premix, and 1 part choline chloride.

[0033] All raw materials are crushed and mixed before being extruded and granulated, with the pellet feed having a diameter of 3 mm.

[0034] Example 2

[0035] The fish farming feed composition of this embodiment comprises the following components by weight: 20 parts fish meal, 10 parts soybean meal, 12 parts leafy grass, 1 part wheat gluten, 12 parts cassava starch, 3 parts wheat bran, 2 parts fish oil, 0.5 parts calcium dihydrogen phosphate, 0.5 parts vitamin and mineral premix, and 0.2 parts choline chloride.

[0036] All raw materials are crushed and mixed before being extruded and granulated, with the pellet feed having a diameter of 3 mm.

[0037] Example 3

[0038] The fish farming feed composition of this embodiment comprises the following components by weight: 40 parts fish meal, 22 parts soybean meal, 28 parts leafy grass, 8 parts wheat gluten, 28 parts cassava starch, 12 parts wheat middlings, 10 parts fish oil, 4 parts calcium dihydrogen phosphate, 4 parts vitamin and mineral premix, and 3 parts choline chloride.

[0039] All raw materials are crushed and mixed before being extruded and granulated, with the pellet feed having a diameter of 3 mm.

[0040] Example 4

[0041] The fish farming feed composition of this embodiment comprises the following components by weight: 25 parts fish meal, 12 parts soybean meal, 16 parts leafy grass, 3 parts wheat gluten, 16 parts cassava starch, 5 parts wheat bran, 4 parts fish oil, 1.5 parts calcium dihydrogen phosphate, 1.5 parts vitamin and mineral premix, and 0.8 parts choline chloride.

[0042] All raw materials are crushed and mixed before being extruded and granulated, with the pellet feed having a diameter of 3 mm.

[0043] Example 5

[0044] The fish farming feed composition of this embodiment is characterized by comprising the following components by weight: 35 parts fish meal, 18 parts soybean meal, 24 parts leafy grass, 5 parts wheat gluten, 24 parts cassava starch, 9 parts wheat bran, 8 parts fish oil, 2.5 parts calcium dihydrogen phosphate, 2.5 parts vitamin and mineral premix, and 1.2 parts choline chloride.

[0045] All raw materials are crushed and mixed before being extruded and granulated, with the pellet feed having a diameter of 3 mm.

[0046] The vitamin and mineral premix in Examples 1-5 above is composed of a 1:1 mixture of vitamin premix and mineral premix. The vitamin premix contains vitamins A, D3, E, K3, C, and B vitamins; the mineral premix contains ferrous sulfate, zinc sulfate, manganese sulfate, copper sulfate, potassium iodide, cobalt chloride, sodium selenide, and sodium chloride to supplement trace elements.

[0047] Application examples

[0048] This application example uses the fish farming feed composition of Example 1 (hereinafter referred to as compound feed containing leafy grass) as an example for illustration:

[0049] I. Experimental Design

[0050] 1. Experimental animals and grouping

[0051] Two thousand healthy, disease-free largemouth bass of the same batch and uniform size (average weight 398.2 ± 6.4 g) were randomly assigned to 12 aquaculture cages, with 200 fish per cage. Three cages formed one experimental group. The grouping and feeding schemes are as follows:

[0052] 1) Control group: fed commercial feed throughout the entire period

[0053] 2) Experimental Group 1: Two weeks before harvesting, the animals were fed a formulated feed containing leafy grass.

[0054] 3) Experimental Group 2: Four weeks before harvest, the animals were fed a formulated feed containing leafy grass.

[0055] 4) Experimental Group 3: Six weeks before harvest, the animals were fed a formulated feed containing leafy grass.

[0056] 2. Experimental Feed

[0057] Commercial feed: Commercially available largemouth bass compound feed (47% crude protein and 10% crude fat).

[0058] The fish farming feed composition (a compound feed containing leafy grass) in Example 1 has a crude protein content of 47% and a crude fat content of 10%, which is the same as the basic nutrition of the commercial feed in the control group.

[0059] 3. Feeding and Management

[0060] The aquaculture trial lasted for 6 weeks. All groups of fish were managed under the same environmental conditions (same water temperature, dissolved oxygen, and photoperiod). The daily management of all experimental groups was the same as that of the control group, and they were fed twice a day (8:00 am and 5:00 pm) until they appeared to be satiated.

[0061] 4. Sample collection and index determination

[0062] After the experiment, the fish in each group were weighed. Four experimental fish were randomly selected from each net cage, and the dorsal muscle of each fish was collected to test routine nutritional components (such as protein, fat, amino acids, fatty acids, etc.), muscle texture characteristics, muscle microstructure, muscle color, and muscle flavor.

[0063] In addition, three fish were randomly selected from each group for sensory evaluation.

[0064] 5. Test Results

[0065] After the experiment, the fish in each group were weighed to assess their growth performance. Statistical results showed that, compared with the control group, the average final weight of all experimental groups was significantly higher (P < 0.05), with the highest average final weight observed in groups fed for 4 weeks (experimental group 2) and 6 weeks (experimental group 3). Figure 1 The trend of weight gain rate was basically consistent with that of final average weight. Figure 2 The weight gain rate of fish in each experimental group was higher than that in the control group (P < 0.05), with experimental groups 2 and 3 showing the most significant increases. This indicates that the formulated feeds in all experimental groups can effectively promote fish growth, and under the conditions of this experiment, feeding for 4 to 6 weeks yields the best results, providing a reference for optimizing the aquaculture cycle.

[0066] After the experiment, the conventional nutritional components in the fish muscle of each group were detected and analyzed (Table 1). The results showed that, compared with the control group, the crude protein content in the fish muscle of the experimental groups generally increased with the extension of feeding time (P < 0.05). Notably, the crude protein content in the fish muscle after 4 weeks of feeding (experimental group 2) and 6 weeks of feeding (experimental group 3) became similar, indicating that crude protein deposition may have entered a plateau phase after 4 weeks of feeding. Regarding crude fat, the muscle crude fat content was lowest after 4 weeks of feeding (experimental group 2). This result, combined with the trend of crude protein changes, suggests that the addition of functional substances in the experimental formula not only helps to improve muscle protein deposition but also effectively controls fat accumulation, thereby improving fish meat quality.

[0067] Table 1. Routine nutrient composition (%, wet weight) of muscle in different treatment groups

[0068]

[0069] To further investigate the nutritional quality of fish meat, an automated amino acid analyzer was used to detect the amino acid composition of fish muscle in each group. After classifying and statistically analyzing the amino acids according to their nutritional characteristics, it was found that compared with the control group, the contents of non-essential amino acids (NEAA) and total amino acids (TAA) in the fish muscle of each experimental group were significantly increased (P < 0.05). Among them, experimental group 3, fed for 6 weeks, showed the best performance in all amino acid indicators, reaching the highest values. Figure 3 The results of this experiment show that the formulated feed in the experimental group not only significantly increased the accumulation of total amino acids in fish meat, but also optimized the composition ratio of essential and non-essential amino acids, further confirming its positive role in improving the protein quality of fish meat.

[0070] To further evaluate the physical quality of the fish meat, a texture analyzer was used to test the textural properties of the fish muscle in each group. The results (Table 2) show that, compared with the control group, each experimental group exhibited varying degrees of improvement in muscle firmness, cohesion, and shear force. Specifically, in terms of firmness (reflecting muscle compactness) and shear force (characterizing muscle tenderness), experimental groups 2 (fed for 4 weeks) and 3 (fed for 6 weeks) showed significant improvements compared to the control group (P < 0.05), indicating that appropriately extending the feeding period can effectively improve the texture and chewiness of the fish meat. Regarding cohesion, a significant improvement was observed after only 2 weeks of feeding (experimental group 1) (P < 0.05), indicating that the formulated feed can enhance the binding force of the internal muscle structure in a short period, helping to maintain the integrity of the fish meat during processing or cooking. In summary, the formulated feed in the experimental groups can improve the textural properties of fish meat from multiple dimensions, especially with more significant improvements in firmness and shear force during feeding from 4 to 6 weeks. This provides strong support for optimizing the taste of fish meat and increasing the added value of the product.

[0071] Table 2. Muscle texture indices in different treatment groups

[0072]

[0073] Free amino acids are essential building blocks for fish meat flavor, and their composition and content directly influence the taste characteristics of fish. We categorized the flavor characteristics of various free amino acids into three groups: umami, sweet, and bitter amino acids, and conducted a statistical analysis (Table 3). The results showed that compared with the control group, the content of umami amino acids (mainly glutamic acid, etc.) in the muscle of each experimental group was significantly increased (P < 0.05). Regarding sweet amino acids, the total amount of sweet amino acids in experimental group 2 (fed for 4 weeks) and experimental group 3 (fed for 6 weeks) was significantly higher than that in the control group (P < 0.05), which was mainly related to the increase in glycine content. Glycine is one of the main sources of sweetness in fish meat, and its increased content helps improve the palatability of fish meat. The total amount of bitter amino acids in each experimental group was also significantly higher than that in the control group (P < 0.05), mainly due to the increase in histidine content. In summary, feeding the experimental groups with the formulated feed for 4 or 6 weeks significantly increased the content of umami and sweet amino acids in fish meat, thereby enhancing the flavor of the muscle, but there was no significant difference between the two feeding durations. Therefore, from a flavor perspective, feeding for 4 weeks is sufficient to achieve a relatively ideal effect.

[0074] Table 3. Free amino acid content in muscle of different treatment groups

[0075]

[0076] Geosmin, produced by the metabolism of microorganisms such as actinomycetes and cyanobacteria in aquaculture water, is easily absorbed by the gills and intestines of fish and deposited in muscle tissue, making it the main substance that causes the earthy taste of fish meat. Humans have a very low taste threshold for geosmin, usually 0.9-1.0 μg / kg; exceeding this threshold will result in a noticeable off-flavor.

[0077] To assess the effect of functional compounds on the earthy taste of fish, this study used gas chromatography-mass spectrometry to detect the content of geosmin in muscle. Figure 4 The results showed that the content of geosmin in the muscle of fish fed commercial feed throughout the entire feeding period was as high as 7.63 μg / kg, far exceeding the human taste threshold. In contrast, the content of geosmin in the muscle of fish fed the formulated feed in the experimental groups was significantly reduced (P < 0.05). The contents in experimental groups 1 (fed for 2 weeks), 2 (fed for 4 weeks), and 3 (fed for 6 weeks) were 0.746 μg / kg, 0.402 μg / kg, and 0.185 μg / kg, respectively, all below the lower limit of the taste threshold of 0.9 μg / kg.

[0078] To comprehensively evaluate the overall impact of the compound feed of this invention on the edible quality of fish, this study further conducted sensory evaluation experiments. Fish from each group were steamed without any added seasonings and then submitted to a sensory evaluation panel composed of trained professional tasters. The panel quantitatively scored the fish based on five dimensions: color, aroma, texture, taste, and overall acceptability (Table 4).

[0079] Sensory evaluation results showed that, compared with the control group, the formulated feed in each experimental group significantly improved the sensory quality of the fish meat. In terms of the two key indicators of color and taste, the scores of experimental group 2 (fed for 4 weeks) and experimental group 3 (fed for 6 weeks) were significantly higher than those of the control group (P < 0.05). This result is highly consistent with the physicochemical tests described earlier: the improvement in color may be related to the improvement in muscle quality, while the significant improvement in taste directly confirms our previous findings of increased umami and sweet amino acid content and a significant reduction in off-flavor substances such as geosmin.

[0080] The results of the comprehensive sensory evaluation show that feeding the experimental feed for 4 to 6 weeks can synergistically improve the palatability of fish meat in terms of color, flavor, texture, and other aspects. This has been verified not only by objective physicochemical indicators but also by subjective sensory experience.

[0081] Table 4 Sensory evaluation of fish meat in different treatment groups

[0082]

[0083] The economic benefits of this aquaculture program were evaluated by calculating the economic conversion rate and economic profit index (Table 5). The results showed that the control group had the highest economic conversion rate, which was related to its higher feed costs. The experimental group's compound feed cost was 639 yuan per ton lower than the control group's. Furthermore, the economic profit index of each experimental group was higher than that of the control group, although the numerical differences were not significant.

[0084] Table 5 Economic Conversion Rate and Economic Profit Index

[0085]

[0086] As shown above, feeding the largemouth bass with the formulated feed provided by this invention for 4 or 6 weeks before harvesting can significantly improve muscle quality: increase protein and amino acid content, optimize nutritional composition; enhance muscle firmness and shear strength, improving palatability; increase flavor amino acids and reduce geosmin, effectively enhancing flavor. Since the effects of 4 weeks and 6 weeks are comparable, from a farming efficiency perspective, it is recommended to feed the largemouth bass with this patented feed continuously for 4 weeks before harvesting to achieve the goal of optimizing muscle palatability and taste.

[0087] The difference between Examples 2-5 and Example 1 lies only in the fact that the content of each component is routinely adjusted within the scope of protection of this invention, without changing the core mechanism of action of the composition. Based on this, those skilled in the art can reasonably expect that Examples 2-5 can achieve substantially the same aquaculture effects when applied to fish farming.

[0088] In summary, this invention, by feeding fish with a formulated feed containing leafy grass during a specific window period before harvesting, allows for the production of high-quality fish with no fishy smell, firm flesh, and delicious flavor, without the need for continuous feeding, pond refilling, or additional facilities, while simultaneously preventing weight loss. This overcomes the common problems of pond-farmed fish having a strong earthy smell and loose flesh upon harvest, severely impacting consumer acceptance and market value. It also avoids the issues of existing methods that, while effectively removing odors through water refilling, result in up to 30% weight loss during the feeding freeze period, significantly increasing selling prices and making the products unaffordable for ordinary consumers.

[0089] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, or alterations made by those skilled in the art using the disclosed technical content shall fall within the protection scope of the present invention.

Claims

1. A fish farming feed composition, characterized in that, By weight, it contains the following components: 20-40 parts fish meal, 10-22 parts soybean meal, 12-28 parts leafy greens, 1-8 parts wheat gluten, 12-28 parts tapioca starch, 3-12 parts wheat middlings, 2-10 parts fish oil, 0.5-4 parts calcium dihydrogen phosphate, 0.5-4 parts vitamin and mineral premix, and 0.2-3 parts choline chloride.

2. The fish farming feed composition according to claim 1, characterized in that, By weight, it contains the following components: 25-35 parts fish meal, 12-18 parts soybean meal, 16-24 parts leafy greens, 3-5 parts wheat gluten, 16-24 parts tapioca starch, 5-9 parts wheat middlings, 4-8 parts fish oil, 1.5-2.5 parts calcium dihydrogen phosphate, 1.5-2.5 parts vitamin and mineral premix, and 0.8-1.2 parts choline chloride.

3. The fish farming feed composition according to claim 2, characterized in that, By weight, it contains the following components: 30 parts fish meal, 15 parts soybean meal, 20 parts leafy greens, 4 parts wheat gluten, 20 parts tapioca starch, 7 parts wheat middlings, 6 parts fish oil, 2 parts calcium dihydrogen phosphate, 2 parts vitamin and mineral premix, and 1 part choline chloride.

4. The use of the fish farming feed composition according to any one of claims 1-3 in the preparation of feed that reduces the muddy taste of fish.

5. The use of the fish farming feed composition according to any one of claims 1-3 in the preparation of feed that improves fish meat quality.

6. The use of the fish farming feed composition according to any one of claims 1-3 in reducing the muddy taste of fish.

7. The use of the fish farming feed composition according to any one of claims 1-3 in improving fish meat quality.

8. A method for aquaculture that reduces the muddy taste of fish and / or improves the quality of fish meat, characterized in that, The fish farming feed composition according to any one of claims 1-3 is used, and the fish are fed daily starting 6 weeks before harvest, without the need for water treatment.

9. The aquaculture method for reducing the muddy taste of fish and / or improving the quality of fish meat according to claim 8, characterized in that, Starting four weeks before the fish are harvested, feed them daily without needing to suspend their water supply.

10. The aquaculture method for reducing the muddy taste of fish and / or improving the quality of fish meat according to claim 8 or 9, characterized in that, Feed twice a day, once in the morning and once in the afternoon, until the animal appears to be full.

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