Low-carbon grass carp feed based on dietary fiber regulation and control and preparation method of low-carbon grass carp feed

Abstract

The invention relates to a low-carbon grass carp feed based on dietary fiber regulation and a preparation method thereof. The low-carbon feed for the grass carp comprises the following components in parts by weight: 10-15 parts of a functional premix, 20-80 parts of an animal protein source, 120-400 parts of cottonseed meal, less than or equal to 100 parts of a high-fiber raw material, 30-40 parts of a conventional premix, 40-80 parts of grease, 200-400 parts of an energy feed and 90-300 parts of a balancing protein source. The dietary fiber load of the grass carp is reduced by increasing the animal protein and grease level in the compound feed; by improving the cottonseed meal level and limiting the use amount of high-fiber raw materials, the types of dietary fibers in daily ration are regulated and controlled, and the loading amount of the dietary fibers with a relatively strong anti-nutrition effect is reduced; the beet pulp is used for replacing part of rice bran meal, so that the food calling and lipid metabolism regulating effects of betaine in the beet pulp are exerted; the taurine, the glycine, the taurocholic acid, the choline and the lysine are added, so that the interference of dietary fibers on the homeostasis of bile acid is blocked, the balance of amino acids is improved, and the utilization efficiency of proteins is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of low-carbon aquaculture, and in particular relates to a low-carbon grass carp feed based on dietary fiber regulation and a preparation method thereof. Background Art

[0002] As global climate change intensifies, reducing greenhouse gas emissions and responding to climate change have become the consensus of the international community. There are also a lot of greenhouse gas emissions in the aquaculture process. It is estimated that in 2022, greenhouse gas emissions from aquaculture activities in my country will reach more than 33 million tons. Therefore, carbon emission reduction has become one of the important tasks for the development of aquaculture. A three-year study showed that the feed-derived carbon footprint of rainbow trout cultured in cement ponds accounted for 61.76% of the total carbon footprint of the aquaculture process; a study on salmon cultured in cages showed that the feed-derived carbon footprint accounted for 85% of the total carbon footprint of the aquaculture process; most studies show that the feed-derived carbon footprint accounts for more than 60% of the carbon footprint of the aquaculture process. Therefore, reducing the feed-derived carbon footprint is one of the important ways to achieve low-carbon aquaculture.

[0003] For aquatic products, feed-derived carbon footprint is not only related to the carbon footprint of raw materials in compound feed, but also to feed processing and feed efficiency. Generally, the carbon footprint of plant protein sources is smaller than that of animal protein sources. Therefore, the research and development of environmentally friendly compound feeds in the past mainly replaced animal protein sources with plant protein sources. However, replacing animal protein sources with plant protein sources is often not conducive to fish growth and leads to decreased feed efficiency. The feed carbon footprint per ton of fish produced (feed carbon footprint per ton of fish products) is not necessarily low. Therefore, the research and development of low-carbon feeds should not only control the carbon footprint of the compound feed itself, but also pay attention to feed efficiency and feed coefficient.

[0004] The key intrinsic factor affecting feed efficiency is dietary fiber. As we all know, dietary fiber cannot be digested and absorbed by monogastric animals, and it also hinders the digestion and absorption of other nutrients, thus leading to a decrease in feed efficiency. In previous studies, the inventors were the first to discover that excessive intake of dietary fiber can also cause bile acid metabolism disorders and tissue damage in fish, which is an important cause of fish bleeding, enteritis, cholestasis, fatty liver and death. Disease and death will greatly increase the feed carbon footprint of a ton of fish products. Therefore, controlling dietary fiber in feed is an important entry point for the research and development of low-carbon feed.

[0005] The impact of processing technology on the carbon footprint of farmed fish feed is also bidirectional. At present, the main fish feed processing technologies are puffing and hard pellet processing. The carbon footprint of puffing is about twice that of hard pellet processing, but the feed efficiency of compound feed using puffing is higher. Therefore, when the feed nutrition level is high (feed coefficient is low), puffing may be able to reduce the feed carbon footprint of ton fish products; but if the feed nutrition level is low, puffing is not suitable. In other words, it is necessary to evaluate which processing technology is suitable for the formula.

[0006] Grass carp is the freshwater farmed fish with the highest production in my country, with a production of 5.94 million tons in 2023. The development of low-carbon feed for grass carp has a decisive impact on carbon emissions from freshwater aquaculture in my country, and has practical urgency and important ecological significance, but there is currently little related research, and there is no low-carbon compound feed based on fish products. Summary of the invention

[0007] To solve the above technical problems, the present invention provides a low-carbon feed for grass carp based on dietary fiber regulation and a preparation method thereof, and specifically relates to a low-carbon feed formula based on the carbon footprint of fish products per unit mass and a preparation method thereof.

[0008] The present invention is achieved through the following technical solutions:

[0009] The first object of the present invention is to provide a low-carbon feed for grass carp based on dietary fiber regulation, which comprises the following components by weight: 10-15 parts of functional premix, 20-80 parts of animal protein source, 120-400 parts of cottonseed meal, ≤100 parts of high-fiber raw materials, 30-40 parts of conventional premix, 40-80 parts of oil, 200-400 parts of energy feed, 90-300 parts of protein source for balance, and granulation by puffing processing technology; preferably, the high-fiber raw materials are ≤80 parts.

[0010] In one embodiment of the present invention, the functional premix comprises taurine, glycine, taurocholic acid, choline and lysine.

[0011] In one embodiment of the present invention, the mass ratio of taurine, glycine, taurocholic acid, choline (content is 50%) and lysine added is 5-10: 0.1-0.2: 0.2-0.6: 2-4: 2-4.

[0012] In one embodiment of the present invention, the animal protein source comprises one or more of fish meal, pork meal, beef meal, chicken meal and meat and bone meal; the protein content of the animal protein source is greater than 55%. Preferably, the amount of fish meal added in the total formula is not less than 2%.

[0013] In one embodiment of the present invention, the high-fiber raw material is a raw material with a dietary fiber content of >40%.

[0014] In one embodiment of the present invention, the high-fiber raw material is one or more of beet pulp, bran, palm pulp, soybean hulls, alfalfa meal and their fermented products, preferably one or more of beet pulp fermented products, bran fermented products, palm pulp fermented products and alfalfa meal fermented products; more preferably beet pulp fermented products.

[0015] The fermented product of high-fiber raw materials refers to the product obtained by mixing and fermenting high-fiber raw materials after crushing them. The fermented bacterial agent is composed of liquid bacteria (mainly lactic acid bacteria, accounting for about 2%) and solid bacteria (Bacillus and yeast, 250mg / kg), and the fermentation reaction system is: 1kg raw material + 1g solid bacteria + 10mL liquid bacteria + 500mL water, the reaction temperature is 37°C, and the fermentation time is 7d. Alfalfa powder can be prepared without fermentation treatment.

[0016] In one embodiment of the present invention, the oil comprises soybean oil and lecithin.

[0017] In one embodiment of the present invention, the mass ratio of soybean oil to phospholipid is 3-7: 1. Adding a higher level of soybean oil is to reduce the feed coefficient, thereby reducing the carbon footprint of feed per ton of fish product.

[0018] In one embodiment of the present invention, the conventional premix comprises multivitamin for freshwater fish, calcium dihydrogen phosphate and salt. The multivitamin for freshwater fish is produced by Wuxi Sanzhi Biotechnology Co., Ltd. or Beijing Sangpu Biochemical Technology Co., Ltd.

[0019] In one embodiment of the present invention, the multivitamin and multimineral for freshwater fish includes vitamin A, vitamin D3, vitamin E, vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin C, vitamin K, pantothenic acid, folic acid, magnesium, iron, copper, zinc, manganese, and selenium.

[0020] In one embodiment of the present invention, the energy feed comprises fine rice bran, rice bran meal, wheat and / or second flour. Wheat and / or second flour are used to supplement energy and ensure the stability of feed in water.

[0021] In one embodiment of the present invention, the balancing plant protein source includes at least two of soybeans, puffed soybeans, soybean meal, fermented soybean meal, rapeseed meal, fermented rapeseed meal, peanut meal and DDGS, which are used to adjust the crude protein content of the compound feed to ensure that the protein content of the compound feed meets the relevant standards.

[0022] The second object of the present invention is to provide a method for preparing the grass carp low-carbon feed based on dietary fiber regulation, wherein the grass carp low-carbon feed is prepared by a puffing process, specifically comprising the following steps:

[0023] S1. Weigh the functional premix, animal protein source, cottonseed meal, oil, high-fiber raw material and balanced plant protein source according to the weight proportions of claim 1, add them to a mixer in batches for crushing and mixing to obtain a mixture;

[0024] S2. Tempering, puffing and granulating, and drying the mixture obtained in step S1 to obtain the grass carp low-carbon feed regulated by dietary fiber.

[0025] Among them, the water addition rate of the conditioner is 0.75kg / h-0.95kg / h; the conditioning temperature is 100℃-105℃, and the moisture content after conditioning is 27.0%-34.0%. The feeding frequency of the puffing granulation is 70Hz-80 Hz (Φ1.0mm, 1.5mm), 80Hz-88Hz (Φ2.0mm, 3.0mm, 4.0mm, 5.0mm, 6.0mm); the drying temperature is 80℃-95℃.

[0026] The expansion coefficient of the grass carp low-carbon feed is 1.5-1.9;

[0027] And / or, the particle bulk density of the grass carp low-carbon feed is 350g / L-430g / L;

[0028] And / or, the moisture content of the grass carp low-carbon feed is 7.0%-9.5%.

[0029] In one embodiment of the present invention, the higher the animal protein and fat content in the grass carp low-carbon feed, the lower the amount of the functional premix.

[0030] The above technical solution of the present invention has the following advantages compared with the prior art:

[0031] Due to the high amount of plant protein sources in commercial grass carp feed, grass carp is in a state of high dietary fiber load for a long time. The inability to digest and absorb dietary fiber is the main reason for the low feed utilization rate; high dietary fiber load also induces metabolic disorders and tissue damage, which in turn affects growth and increases the carbon footprint of the breeding process.

[0032] The present invention reduces the dietary fiber load of grass carp by increasing the levels of animal protein and oil in compound feed; regulates the types of dietary fiber in the diet by increasing the level of cottonseed meal and reducing the levels of soybean meal and rapeseed meal, thereby reducing the load of fermentable dietary fiber with strong anti-nutritional effect; uses beet meal to replace part of rice bran meal, exerts the feeding and lipid metabolism regulating effects of betaine in the beet meal, and limits the amount of high-fiber raw materials such as beet meal, bran, soybean hulls, alfalfa meal, palm meal, etc., so as to prevent excessive dietary fiber from inducing green liver, green stool, white stool, fatty liver and other diseases; adds taurine, glycine, taurocholic acid, choline and lysine, blocks the interference of dietary fiber on bile acid homeostasis, improves the balance of amino acids, and improves the utilization efficiency of protein. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0034] Figure 1 The fermentation process of beet pulp raw materials and photos before and after fermentation in the embodiment of the present invention;

[0035] Figure 2 is a process flow chart of a low-carbon grass carp feed regulated by dietary fiber according to an embodiment of the present invention;

[0036] Figure 3 It is a grass carp disease caused by the high-fiber feed in the embodiment of the present invention. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0038] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods, and the materials, reagents, etc. used are all available from commercial sources unless otherwise specified.

[0039] Example 1

[0040] This embodiment provides a low-carbon feed for grass carp regulated by dietary fiber, which specifically includes the following components by weight:

[0041] Functional premix 10 parts, fish meal 50 parts, cottonseed meal 200 parts, lecithin 10 parts, soybean oil 40 parts, fermented beet pulp 80 parts, calcium dihydrogen phosphate 25 parts, multivitamin for freshwater fish 10 parts, salt 5 parts, wheat 220 parts, fine rice bran 160 parts, soybean meal 60 parts, rapeseed meal 130 parts. The functional premix includes lysine, taurine, glycine, taurocholic acid, and choline. The mass ratio of taurine, glycine, taurocholic acid, choline (content 50%) and lysine is 10:0.2:0.4:3:3.

[0042] The fermented beet pulp used in this example was prepared by the following method:

[0043] The fermentation agent is provided by Sanzhi Biotechnology Co., Ltd., and includes liquid bacteria (mainly lactic acid bacteria, accounting for about 2%) and solid bacteria (Bacillus and yeast) 250mg / kg. The beet pulp raw material is crushed, and the strain and beet pulp are mixed evenly and put into a fermentation bag with a one-way exhaust valve. The fermentation reaction system is: 1kg beet pulp + 1g solid bacteria + 10mL liquid bacteria + 500mL water. The temperature is 37℃ and the fermentation time is 7d. Shake and release the air every day. The status before and after fermentation is shown in the figure. Figure 1 .

[0044] The number of microorganisms and pH in the fermented material are shown in Table 1 below:

[0045] Table 1

[0046]

[0047] The processing flow of the preparation method of the grass carp low-carbon feed based on dietary fiber regulation in this embodiment is as follows: Figure 2 shown.

[0048] The method for preparing the grass carp low-carbon feed based on dietary fiber regulation is characterized by comprising the following steps:

[0049] S1. Processing with GPS128 unit. Weigh functional premix, fish meal, cottonseed meal, lecithin, soybean oil, fermented beet pulp, calcium dihydrogen phosphate, multivitamin for freshwater fish, salt, wheat, fine rice bran, soybean meal, rapeseed meal by weight. Grind, mix, condition, granulate, and dry the above ingredients. Among them, the crushing particle size requires more than 96% to pass 80 mesh, the mixing uniformity requires CV<7%, the water addition amount of the conditioner is 0.90kg / h, the conditioning temperature is 105℃, and the moisture content after conditioning is 30%. The feeding frequency during granulation is 80Hz (Φ1.0mm); the drying temperature is 90℃.

[0050] The expansion coefficient of the finished grass carp low-carbon feed obtained in this embodiment is about 1.9, the bulk density of the expanded granulated particles is 390g / L, the floating rate is 100%, and the moisture content of the finished product is about 8.5%.

[0051] Example 2

[0052] Functional premix 15 parts, fish meal 80 parts, cottonseed meal 300 parts, lecithin 10 parts, soybean oil 50 parts, fermented beet pulp 80 parts, calcium dihydrogen phosphate 25 parts, multivitamin for freshwater fish 10 parts, salt 5 parts, wheat 220 parts, fine rice bran 115 parts, soybean meal 40 parts, rapeseed meal 50 parts. Among them, the functional premix includes lysine, taurine, glycine, taurocholic acid, and choline. The mass ratio of taurine, glycine, taurocholic acid, choline (content 50%) and lysine is 10:0.2:0.4:3:3.

[0053] The preparation method of the low-carbon feed for grass carp based on dietary fiber regulation in this embodiment is the same as that in Example 1.

[0054] Example 3

[0055] The present embodiment provides a low-carbon feed for grass carp based on dietary fiber regulation, which specifically includes the following components by weight: 15 parts of functional premix, 50 parts of fish meal, 200 parts of cottonseed meal, 10 parts of phospholipids, 40 parts of soybean oil, 80 parts of fermented beet pulp, 25 parts of calcium dihydrogen phosphate, 10 parts of multivitamin for freshwater fish, 5 parts of salt, 220 parts of wheat, 155 parts of fine rice bran, 60 parts of soybean meal, and 130 parts of rapeseed meal. Among them, the functional premix includes lysine, taurine, glycine, taurocholic acid, and choline. The mass ratio of taurine, glycine, taurocholic acid, choline (content 50%) and lysine added is 10:0.2:0.4:3:3.

[0056] The preparation method of the low-carbon feed for grass carp based on dietary fiber regulation in this embodiment is the same as that in Example 1.

[0057] Example 4

[0058] The present embodiment provides a low-carbon feed for grass carp based on dietary fiber regulation, which specifically includes the following components by weight: 10 parts of functional premix, 80 parts of fish meal, 300 parts of cottonseed meal, 10 parts of phospholipids, 50 parts of soybean oil, 80 parts of fermented beet pulp, 25 parts of monocalcium phosphate, 10 parts of multivitamin for freshwater fish, 5 parts of salt, 220 parts of wheat, 120 parts of fine rice bran, 40 parts of soybean meal, and 50 parts of rapeseed meal. Among them, the functional premix includes lysine, taurine, glycine, taurocholic acid, and choline. The mass ratio of taurine, glycine, taurocholic acid, choline (50%) and lysine added is 10:0.2:0.4:3:3.

[0059] The preparation method of the low-carbon feed for grass carp based on dietary fiber regulation in this embodiment is the same as that in Example 1.

[0060] Comparative Example 1

[0061] The present comparative example provides a commercially available grass carp feed, which specifically comprises the following components by weight: 20 parts of fish meal, 20 parts of cottonseed meal, 10 parts of phospholipids, 25 parts of calcium dihydrogen phosphate, 10 parts of multivitamin for freshwater fish, 5 parts of salt, 220 parts of wheat, 250 parts of fine rice bran, 140 parts of soybean meal, and 300 parts of rapeseed meal.

[0062] The preparation method of the grass carp feed in this comparative example is the same as that in Example 1.

[0063] Comparative Example 2

[0064] This comparative example provides a grass carp feed regulated by dietary fiber, the ingredients of which are similar to those of Example 3, except that the feed is prepared by using a hard granule process.

[0065] Comparative Example 3

[0066] This comparative example provides a grass carp feed regulated by dietary fiber, the ingredients of which are similar to those of Example 4, except that the feed is prepared by using a hard granule process.

[0067] The preparation method of the grass carp feed in this comparative example is the same as that of comparative example 2.

[0068] Application Examples

[0069] The breeding experiment was conducted in an outdoor cement pool at the Yangzhong Base of Jiangsu Freshwater Fisheries Research Institute. Grass carp with an average tail weight of 6.7g were fed with the above-mentioned compound feed for 10 weeks. The grass carp were fed at 7:30 and 17:00 every day to show that they were full. The remaining bait was collected 1 hour after each feeding to accurately calculate the feed coefficient and carbon footprint of feed per ton of fish. The fish were weighed after 10 weeks to calculate the weight gain rate, feed coefficient and carbon footprint of feed per ton of fish products. The results are shown in Table 2 below:

[0070] Table 2

[0071]

[0072] Table 3

[0073]

[0074] Note: The same data of Examples 1-4 and Comparative Example 1 with different lowercase letters indicate significant differences (AONVA, P<0.05). The same data of Experimental Examples 3-4 and Comparative Examples 2-3 with different uppercase letters indicate significant differences (ANOVA, P<0.05).

[0075] As can be seen from Tables 2 and 3, the carbon footprint per ton of fish feed in Examples 2 and 4 is lower than that in Examples 1 and 3, respectively (t-test, P<0.05), indicating that increasing the levels of animal protein, oil and cottonseed meal can significantly reduce the carbon footprint per ton of fish feed; the carbon footprint per ton of fish feed in Example 3 is lower than that in Example 1, indicating that appropriately increasing the amount of functional premix has the effect of reducing the carbon footprint of ton of fish products, but when the content of animal protein, oil and cottonseed meal is high (Examples 2 and 4), increasing the amount of functional premix no longer has an obvious carbon reduction effect; the weight gain rate of grass carp in all example groups is significantly higher than that in Comparative Example 1 (P<0.05), and the feed coefficient, carbon footprint per ton of fish product feed and feed cost are significantly lower than those in Comparative Example 1 (P<0.05). It can be seen that increasing the levels of animal protein and oil, adding appropriate amounts of functional premix and beet meal, and increasing the amount of cottonseed meal can reduce the carbon footprint of ton of fish feed.

[0076] When the puffing process is used, the weight gain rate of grass carp (Examples 3 and 4) is significantly higher than that of the hard granule process (Comparative Examples 2 and 3), and the feed coefficient, carbon footprint per ton of fish feed, and cost per ton of fish feed are all significantly reduced (P<0.05). It can be seen that the low-carbon feed formula of the present invention is suitable for the puffing process.

[0077] Comparative Example 4

[0078] The present comparative example provides a grass carp feed, which specifically includes the following components by weight: 220 parts of wheat, 244 parts of fine rice bran, 140 parts of soybean meal CP46%, 300 parts of rapeseed meal, 20 parts of cottonseed meal, 20 parts of fish meal, 25 parts of monocalcium phosphate, 10 parts of phospholipids, 10 parts of multivitamin minerals for freshwater fish, 3 parts of lysine, 3 parts of choline, and 5 parts of salt.

[0079] The preparation method of grass carp feed is the same as that of comparative example 1, the main difference being that two components of choline and lysine in the functional premix are added, but taurine, glycine and taurocholic acid are not added.

[0080] After feeding grass carp with the obtained feed, the weight gain rate of grass carp was 271±10%, the feed coefficient was 1.86±0.11, the carbon footprint per ton of fish product was 1701±102kg·CO2, and the feed cost per ton of fish product was 8296±491 yuan.

[0081] Comparative Example 5

[0082] The present comparative example provides a grass carp feed, which specifically includes the following components by weight: 80 parts of fish meal, 100 parts of cottonseed meal, 30 parts of soybean oil, 160 parts of soybean meal, 70 parts of rapeseed meal, 160 parts of flour, 40 parts of rice bran, 10 parts of rice bran meal, 10 parts of multivitamin for freshwater fish, 15 parts of monocalcium phosphate, 5 parts of salt, and 300 parts of high-fiber raw materials (bran or soybean husk or palm meal or beet meal or their fermented products).

[0083] Although the amount of fish meal used in this comparative example was high, due to the high amount of high-fiber raw materials added, symptoms such as green liver, green stool, and white stool were observed during the feeding process ( Figure 3 ) and death.

[0084] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A low-carbon feed for grass carp based on dietary fiber regulation, characterized in that: The invention comprises the following components by weight: 10-15 parts of functional premix, 20-80 parts of animal protein source, 120-400 parts of cottonseed meal, ≤100 parts of high-fiber raw materials, 30-40 parts of conventional premix, 40-80 parts of oil, 200-400 parts of energy feed, 90-300 parts of balanced protein source, and is granulated by puffing processing technology.

2. The grass carp low-carbon feed according to claim 1, characterized in that: The functional premix comprises taurine, glycine, taurocholic acid, choline and lysine.

3. The grass carp low-carbon feed according to claim 2, characterized in that: The added mass ratio of taurine, glycine, taurocholic acid, choline and lysine is 5-10: 0.1-0.2: 0.2-0.6: 2-4: 2-4.

4. The grass carp low-carbon feed according to claim 1, characterized in that: The animal protein source comprises one or more of fish meal, pork meal, beef meal, chicken meal and meat and bone meal; the protein content of the animal protein source is greater than 55%.

5. The grass carp low-carbon feed according to claim 1, characterized in that: The high-fiber raw material is a raw material with a dietary fiber content of more than 40%.

6. The grass carp low-carbon feed according to claim 1, characterized in that: The oils and fats include soybean oil and lecithin.

7. The low-carbon feed for grass carp according to claim 6, characterized in that: The mass ratio of the soybean oil to the phospholipid is 3-7:

1.

8. The low-carbon feed for grass carp according to claim 1, characterized in that: The conventional premix includes multivitamin for freshwater fish, calcium dihydrogen phosphate and salt.

9. The low-carbon feed for grass carp according to claim 1, characterized in that: The energy feed comprises fine rice bran, rice bran meal, wheat and / or wheat flour.

10. The low-carbon feed for grass carp according to claim 1, characterized in that: The balancing plant protein source comprises at least two of soybeans, puffed soybeans, soybean meal, fermented soybean meal, rapeseed meal, fermented rapeseed meal, peanut meal and DDGS.

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