A low feed coefficient compound feed for large yellow croaker and a preparation method thereof

Abstract

The present application relates to a kind of low feed conversion ratio compound feed of large yellow croaker, raw material components include by weight parts: base feed 90~110 parts and rare earth polysaccharide chelate 0.005~0.02 parts.The present application adds low dose of rare earth polysaccharide chelate in base feed under the premise of not changing conventional nutrition framework, the chelate can improve the biological availability of large yellow croaker to the nutrient in base feed, thereby improving feed utilization efficiency, effectively reducing feed conversion ratio;On the other hand, it can enhance the immunity of fish body, realize the double promotion of growth performance and health level, significantly improve the economic benefit of large yellow croaker culture.

Description

Technical Field

[0001] This invention relates to the field of aquaculture feed technology, and in particular to a low feed conversion ratio compound feed for large yellow croaker and its preparation method. Background Technology

[0002] As a dominant species in my country's marine aquaculture, the high-density, factory-style farming of large yellow croaker places higher demands on feed. Currently, commercial feeds generally employ high-protein, high-fat nutritional formulas, with trace minerals primarily added in the form of inorganic salts. However, the bioavailability of these minerals is easily affected by phytic acid, fiber, pH, and gut microbiota, resulting in extremely low absorption efficiency. This not only leads to overfeeding to meet the fish's trace mineral requirements, causing protein and energy waste and keeping the feed conversion ratio (FCR) of large yellow croaker feed hovering between 1.4 and 1.6 for a long time, but also exacerbates the risk of eutrophication in the water bodies due to unabsorbed nutrients being excreted in feces.

[0003] To address these issues, some studies have attempted to add functional additives such as enzymes and probiotics to feed in order to improve the utilization rate of trace minerals and nutrients. However, these additives are easily affected by environmental and processing conditions, resulting in unstable activity and fluctuating application effects. Other studies have used coating and microencapsulation technologies to reduce the loss of trace minerals in water, but these methods are complex and cannot fundamentally improve the absorption efficiency of trace minerals in the intestines.

[0004] Therefore, it is necessary to further improve the existing compound feed for large yellow croaker. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a low feed conversion ratio compound feed for large yellow croaker and its preparation method.

[0006] The technical solution adopted in this invention is as follows: This invention provides a low feed conversion ratio compound feed for large yellow croaker, the raw material components of which include, by weight: 90-110 parts of basic feed and 0.005-0.02 parts of rare earth polysaccharide chelate.

[0007] Preferably, the raw material composition of the basic feed includes, by weight: 65-75 parts protein source, 12-15 parts carbohydrate, 8-11 parts fat source, 2-4 parts compound premix, 2-3 parts functional additives, and 1-2 parts binder.

[0008] Preferably, the rare earth polysaccharide chelate is present in 0.01 parts by weight.

[0009] Preferably, the rare earth element in the rare earth polysaccharide chelate is selected from lanthanum and / or cerium, and the polysaccharide is selected from one or a combination of two or more of chitosan oligosaccharide, fucoidan and mannan.

[0010] Preferably, the protein source comprises, by weight: 45-50 parts fish meal and 20-25 parts soybean meal; The fat source includes, by weight: 6-8 parts fish oil and 2-3 parts soy lecithin.

[0011] Preferably, the carbohydrate is high-gluten flour.

[0012] Preferably, the composite premix is ​​composed of vitamin premix and mineral premix in a weight ratio of 1:4 to 4:1.

[0013] Preferably, the functional adjuvant is selected from one or a combination of two or more of bile acids, calcium dihydrogen phosphate, and choline chloride.

[0014] Preferably, the adhesive is α-starch.

[0015] Another aspect of the present invention provides a method for preparing a low feed conversion ratio compound feed for large yellow croaker as described in the above technical solution, comprising the following steps: S1. Mix rare earth polysaccharide chelates with a portion of basic feed to obtain functional premix; S2. The functional premix is ​​mixed with the remaining basic feed, and then successively crushed, conditioned, expanded, dried, cooled and sieved to obtain the final product.

[0016] The beneficial effects of this invention are: This invention adds a low dose of rare earth polysaccharide chelate to the basic feed without changing the conventional nutritional framework. On the one hand, the chelate can improve the bioavailability of nutrients in the basic feed for large yellow croaker, thereby improving feed utilization efficiency and effectively reducing the feed conversion ratio; on the other hand, it can enhance the fish's immunity, achieving a dual improvement in growth performance and health level, and significantly improving the economic benefits of large yellow croaker farming. Detailed Implementation

[0017] The technical solution of the present invention will be further explained and described below through specific embodiments.

[0018] This invention provides a low feed conversion ratio compound feed for large yellow croaker, the raw material components of which include, by weight: 90-110 parts of basic feed and 0.005-0.02 parts of rare earth polysaccharide chelate.

[0019] This invention uses a low-dose rare earth polysaccharide chelate (0.0045%~0.0222% of the weight of the basic feed) as the core synergistic component. At this dosage, the rare earth polysaccharide chelate promotes nutrient utilization and enhances immune regulation. Specifically, this chelate effectively activates digestive enzymes in the intestines, improving the breakdown and absorption of macronutrients (protein and fat) in the basic feed. Furthermore, it helps mitigate the adverse effects of anti-nutritional factors such as phytic acid and regulates the intestinal microecology, providing a better physiological basis for the absorption of essential trace elements such as iron and zinc, thus improving the bioavailability of these trace elements. This eliminates the need for fish to overfeed to compensate for insufficient absorption, reducing protein and energy waste and ultimately improving overall feed utilization efficiency, thereby reducing the feed conversion ratio. In addition, the polysaccharide components in the rare earth polysaccharide chelate can improve intestinal health and enhance the fish's immunity. Compared to existing technologies that rely on a combination of multiple immune enhancers, probiotics, and traditional Chinese medicines, this invention features a simpler formula. The single core synergistic component, a rare-earth polysaccharide chelate, exhibits stable performance, effectively avoiding potential antagonistic effects between different functional synergistic components, resulting in more uniform and stable product quality. Furthermore, due to the significantly improved feed utilization efficiency, the formulated feed of this invention can noticeably reduce the ammonia nitrogen and total phosphorus emissions from aquaculture wastewater, alleviating eutrophication at its source and aligning better with the strategic direction of green and sustainable aquaculture.

[0020] In a preferred embodiment, the basic feed composition includes, by weight: 65-75 parts protein source, 12-15 parts carbohydrates, 8-11 parts fat source, 2-4 parts compound premix, 2-3 parts functional additives, and 1-2 parts binder. This invention selects the above-mentioned raw material composition to form the basic feed system, providing a good nutritional foundation for rare earth polysaccharide chelates to fully exert their core functions of improving feed utilization efficiency and reducing the feed conversion ratio.

[0021] In a preferred embodiment, the rare earth polysaccharide chelate is present in a weight fraction of 0.01 parts. When the rare earth polysaccharide chelate is present in a weight fraction of 0.01 parts, the feed conversion ratio can be significantly reduced, immune indicators improved, and survival rate increased, resulting in excellent overall economic benefits for aquaculture.

[0022] In a preferred embodiment, the rare earth element in the rare earth polysaccharide chelate is selected from lanthanum and / or cerium, and the polysaccharide is selected from one or a combination of two or more of chitosan oligosaccharide, fucoidan, and mannan. This invention selects the above-mentioned rare earth element to chelate with the polysaccharide, which has good compatibility. The resulting rare earth polysaccharide chelate has a stable structure and can effectively improve feed utilization efficiency and reduce the feed conversion ratio at low doses. For example, an embodiment of this invention provides a method for preparing a rare earth polysaccharide chelate, comprising the following steps: adding a rare earth salt solution with a concentration of 0.05~0.5mol / L dropwise to a polysaccharide solution with a concentration of 1~5% w / v; stirring and reacting at pH=5~6 and a temperature of 40~60℃ for 2~6 hours; cooling to room temperature after the reaction; and then precipitating with alcohol, filtering, washing, and drying to obtain the final product.

[0023] In a preferred embodiment, the protein source comprises, by weight: 45-50 parts fish meal and 20-25 parts soybean meal; The fat sources include, by weight: 6-8 parts fish oil and 2-3 parts soy lecithin.

[0024] This invention uses a blend of fish meal and soybean meal as a protein source. Fish meal provides high-quality animal protein and essential amino acids, while soybean meal supplements plant protein and complements fish meal in amino acids. Together, they meet the high protein requirements and growth performance of large yellow croaker. The invention also uses a blend of fish oil and soybean lecithin as a fat source. Fish oil provides large yellow croaker with essential high-unsaturated fatty acids, while soybean lecithin acts as a natural emulsifier to promote lipid emulsification, dispersion, and absorption, while also improving the processing performance of compound feed pellets.

[0025] In a preferred embodiment, the carbohydrate is high-gluten flour. The present invention selects high-gluten flour as the carbohydrate, which on the one hand provides easily digestible carbohydrates for the growth of large yellow croaker, meeting its energy requirements; on the other hand, it plays a skeletal support and binding role in the pelleting and extrusion process, improving the integrity and water stability of the compound feed pellets.

[0026] In a preferred embodiment, the compound premix is ​​composed of vitamin premix and mineral premix in a weight ratio of 1:4 to 4:1. This invention uses vitamin premix and mineral premix as the compound premix to supplement the micronutrients required for the normal growth and metabolism of large yellow croaker. This invention does not particularly limit the specific composition of the compound premix; commercially available large yellow croaker-specific or aquatic-general-purpose vitamin premix and mineral premix can be used. For example, the vitamin premix may include: inositol, nicotinamide, calcium pantothenate, folic acid, biotin, vitamin A, vitamin E, vitamin C phosphate, vitamin K3, vitamin B2, vitamin B6, vitamin D3, vitamin B1, vitamin B12, and the remainder being corn starch; the mineral premix may include sodium selenite, magnesium sulfate, zinc sulfate, manganese sulfate, calcium iodate, yeast selenium, ferrous sulfate, copper sulfate, cobalt chloride, and the remainder being zeolite powder.

[0027] In a preferred embodiment, the functional adjuvant is selected from one or a combination of two or more of bile acids, calcium dihydrogen phosphate, and choline chloride. This invention promotes the efficient utilization of nutrients by large yellow croaker by adding functional adjuvants. Bile acids help promote fat digestion and absorption, calcium dihydrogen phosphate supplements the calcium and phosphorus nutrients required by large yellow croaker, and choline chloride helps maintain fat metabolism and liver health.

[0028] In a preferred embodiment, the binder is α-starch. The present invention uses α-starch as a binder, which has good adhesive properties and can improve the pelleting properties and water stability of compound feed.

[0029] Another aspect of the present invention provides a method for preparing a low feed conversion ratio compound feed for large yellow croaker as described above, comprising the following steps: S1. Mix rare earth polysaccharide chelates with a portion of basic feed to obtain functional premix; S2. Mix the functional premix with the remaining basic feed, and then process it in sequence through crushing, conditioning, puffing, drying, cooling, and sieving to obtain the final product.

[0030] This invention pre-mixes and disperses rare earth polysaccharide chelates with a portion of the basic feed to avoid excessively high local concentrations or uneven distribution when low doses of rare earth polysaccharide chelates are directly added to the basic feed, thus ensuring the quality stability of the finished compound feed between batches.

[0031] Example 1 A low feed conversion ratio compound feed for large yellow croaker, the raw material components include, by weight: 99.99 parts of basic feed and 0.01 parts of rare earth polysaccharide chelate; The basic feed consists of the following raw materials by weight: 72.2 parts protein source (50 parts fish meal, 22.2 parts soybean meal), 13.39 parts carbohydrates (high gluten flour), 8.9 parts fat source (6.7 parts fish oil, 2.2 parts soybean lecithin), 2.2 parts compound premix (1.1 parts vitamin premix, 1.1 parts mineral premix), 2.2 parts functional additives (0.6 parts bile acids, 1.3 parts calcium dihydrogen phosphate and 0.3 parts choline chloride), and 1.1 parts binder (α-starch). Rare earth polysaccharide chelates were prepared by the following steps: a 0.1 mol / L lanthanum chloride solution was added dropwise to a 2% w / v chitosan oligosaccharide solution (molecular weight 2000 Da), and the mixture was stirred for 2 h at pH 5 and 50 °C. After the reaction was completed, the mixture was cooled to room temperature, and then subjected to alcohol precipitation, filtration, washing, and drying to obtain lanthanum-chitosan oligosaccharide chelates.

[0032] The above-mentioned low feed conversion ratio compound feed for large yellow croaker is prepared by the following method, including the following steps: S1. Mix rare earth polysaccharide chelates with some carbohydrates to obtain functional premix; S2. Mix the protein source, remaining carbohydrates, compound premix, functional additives and binder to obtain the base powder, then mix it with the above functional premix, then spray the fat source and mix evenly, and then crush, condition, expand, dry, cool and sieve in sequence to obtain a low feed coefficient compound feed for large yellow croaker containing 100mg / kg (based on the weight of finished feed) of rare earth polysaccharide chelates.

[0033] Example 2 The main difference between this embodiment and Example 1 is that the weight percentage of the rare earth polysaccharide chelate is adjusted from 0.01 parts to 0.005 parts, and the weight percentage of carbohydrates is adjusted from 13.39 parts to 13.395 parts, resulting in a low feed conversion ratio compound feed for large yellow croaker containing 50 mg / kg (based on the weight of the finished feed). The remaining steps remain unchanged.

[0034] Example 3 The main difference between this embodiment and Example 1 is that the weight percentage of the rare earth polysaccharide chelate is adjusted from 0.01 parts to 0.02 parts, and the weight percentage of carbohydrates is adjusted from 13.39 parts to 13.38 parts, resulting in a low feed conversion ratio compound feed for large yellow croaker containing 200 mg / kg (based on the weight of the finished feed). The remaining steps remain unchanged.

[0035] Example 4 The main difference between this embodiment and Example 1 is that the rare earth polysaccharide chelate is changed from lanthanum-chitosan oligosaccharide chelate to cerium-brown algae polysaccharide chelate. Its preparation includes the following steps: a 0.1 mol / L cerium sulfate solution is added dropwise to a 3% w / v brown algae polysaccharide solution (molecular weight 8000 Da), and the mixture is stirred and reacted for 6 hours at pH 6 and 55°C. After the reaction is complete, the mixture is cooled to room temperature, precipitated with alcohol, filtered, washed, and dried to obtain the final product. The remaining steps remain unchanged.

[0036] In this embodiment, the finished compound feed pellets of 1-4 have a diameter of 3mm, a crude protein content of not less than 45%, and a crude fat content of not less than 8%.

[0037] Comparative Example 1 This comparative example uses commercially available high-end compound feed for large yellow croaker, which does not contain rare earth polysaccharide chelates and uses yeast polysaccharides and probiotics to enhance its effects.

[0038] Comparative Example 2 The main difference between this comparative example and Example 1 is that the rare earth polysaccharide chelate is not added, and the weight parts of carbohydrates are adjusted from 13.39 parts to 13.4 parts. The remaining steps remain unchanged.

[0039] Comparative Example 3 The main difference between this comparative example and Example 1 is that the weight percentage of the rare earth polysaccharide chelate was adjusted from 0.01 parts to 0.05 parts, and the weight percentage of carbohydrates was adjusted from 13.39 parts to 13.35 parts, resulting in a large yellow croaker compound feed containing 500 mg / kg (based on the weight of the finished feed). The remaining steps remained unchanged.

[0040] Comparative Example 4 The main difference between this comparative example and Example 1 is that the weight percentage of the rare earth polysaccharide chelate was adjusted from 0.01 parts to 0.1 parts, and the weight percentage of carbohydrates was adjusted from 13.39 parts to 13.3 parts, resulting in a large yellow croaker compound feed containing 1000 mg / kg (based on the weight of the finished feed) of rare earth polysaccharide chelate. The remaining steps remained unchanged.

[0041] Performance testing The formulated feeds obtained in Examples 1-4 and Comparative Examples 1-4 were used in comparative experiments on the culture of large yellow croaker. The experiments were conducted under standard salinity seawater culture conditions, with the water temperature controlled at 25±1℃. Uniformly sized and healthy juvenile large yellow croaker were selected, and three independent replicates were set up for each group. The feeding period was 8 weeks, with daily feeding at 3-4% of the fish's body weight. Before the experiment, the initial average body weight and initial number of fish were measured. During the experiment, feed intake, growth, and survival were recorded. After the experiment, the final average body weight, final number of fish, serum lysozyme activity, and liver HSP70 expression were measured, and the weight gain rate and feed conversion ratio were calculated. The test results are recorded in Table 1.

[0042] Table 1

[0043] Compared with Comparative Example 2, which did not contain rare earth polysaccharide chelates, Examples 1-4 of this invention significantly improved feed conversion efficiency, with corresponding reductions in feed conversion ratios of 17.8%, 14.5%, 15.8%, and 17.1%, respectively. Example 1 (100 mg / kg lanthanum-chitosan oligosaccharide chelate) showed the largest reduction. Simultaneously, the introduction of low-dose rare earth polysaccharide chelates also achieved a simultaneous improvement in the growth performance and health of large yellow croaker. Furthermore, Examples 1-4 of this invention, using rare earth polysaccharide chelates as the core synergistic component, showed superior performance across all indicators compared to Comparative Example 1, which used a combination of multiple additives, fully demonstrating the synergistic enhancing effect of low-dose rare earth polysaccharide chelates in nutrient absorption and metabolic regulation. Comparative Examples 3-4, however, showed that the synergistic effect of high-dose rare earth polysaccharide chelates was actually weakened.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low feed conversion ratio formulated feed for large yellow croaker, characterized in that, The raw material components include, by weight: 90-110 parts of basic feed and 0.005-0.02 parts of rare earth polysaccharide chelate.

2. The low feed conversion ratio compound feed for large yellow croaker as described in claim 1, characterized in that, The raw material composition of the basic feed includes, by weight: 65-75 parts protein source, 12-15 parts carbohydrate, 8-11 parts fat source, 2-4 parts compound premix, 2-3 parts functional additives, and 1-2 parts binder.

3. The low feed conversion ratio formulated feed for large yellow croaker as described in claim 1, characterized in that, The rare earth polysaccharide chelate has a weight fraction of 0.01 parts.

4. The low feed conversion ratio formulated feed for large yellow croaker as described in claim 1 or 3, characterized in that, The rare earth elements in the rare earth polysaccharide chelate are selected from lanthanum and / or cerium, and the polysaccharides are selected from one or a combination of two or more of chitosan oligosaccharides, fucoidan, and mannan.

5. The low feed conversion ratio compound feed for large yellow croaker as described in claim 2, characterized in that, The protein source includes, by weight: 45-50 parts fish meal and 20-25 parts soybean meal; The fat source includes, by weight: 6-8 parts fish oil and 2-3 parts soy lecithin.

6. The low feed conversion ratio compound feed for large yellow croaker as described in claim 2, characterized in that, The carbohydrate is high-gluten flour.

7. The low feed conversion ratio compound feed for large yellow croaker as described in claim 2, characterized in that, The compound premix is ​​composed of vitamin premix and mineral premix in a weight ratio of 1:4 to 4:

1.

8. The low feed conversion ratio compound feed for large yellow croaker as described in claim 2, characterized in that, The functional additive is selected from one or a combination of two or more of bile acids, calcium dihydrogen phosphate, and choline chloride.

9. The low feed conversion ratio compound feed for large yellow croaker as described in claim 2, characterized in that, The adhesive is α-starch.

10. A method for preparing a low feed conversion ratio compound feed for large yellow croaker as described in claim 1, characterized in that, Includes the following steps: S1. Mix rare earth polysaccharide chelates with a portion of basic feed to obtain functional premix; S2. The functional premix is ​​mixed with the remaining basic feed, and then successively crushed, conditioned, expanded, dried, cooled and sieved to obtain the final product.

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