Low-protein granular feed for green-silage and application thereof in grass carp breeding

Abstract

The application discloses a kind of low-protein sesbania green silage compound granular feed and its application in grass carp culture, by mass percentage, the feed includes the following components: protein premix 40~60%, corn 8~15%, wheat bran 10~20%, sesbania green silage feed 6~15% and rice bran 10~20%;The sum of the mass percentage of each component is 100%.According to the nutritional needs of grass carp, replace part of the protein premix with sesbania green silage feed and mix with other feed raw materials to make green silage compound granular feed, and raise grass carp.The results show that the low-protein sesbania green silage compound granular feed improves the digestive enzyme activity of grass carp, increases the content of functional amino acids such as brain gold DHA, threonine, valine, leucine, histidine, and kidney-tonifying and brain-strengthening lysine and / or phenylalanine in fresh meat, improves the digestion performance and muscle quality of grass carp, and reduces the feed breeding cost, and has great application value in production.

Description

Technical Field

[0001] This invention belongs to the field of aquaculture and feed processing technology, specifically relating to a low-protein sesame silage compound pellet feed and its application in grass carp farming. Background Technology

[0002] Sesbania, an annual leguminous herbaceous plant, is widely praised for its cold resistance, drought tolerance, salt and alkali tolerance, strong nitrogen-fixing ability, vigorous growth, and leaves rich in protein and low in fiber. Therefore, sesbania is not only suitable for soil improvement but also an ideal raw material for producing protein feed. In the process of using sesbania for soil improvement, farmers can harvest the sesbania and process it into protein-rich feed to feed animals. After about a month of regrowth, the sesbania is returned to the field for the next crop. This integrated crop-livestock method not only brings economic benefits from animal products but also ensures a bumper harvest of the next crop. Compared to the traditional method of directly returning all the sesbania to the field, this method yields a higher economic return.

[0003] Silage is an important method of forage preparation, processing, and storage, which can improve animal utilization and shelf life, thereby achieving stable and high-quality animal production throughout the year. For grass carp farming, sesbania serratifolia is typically not consumed by grass carp due to its pungent odor and poor palatability. However, silage may be an effective way to improve sesbania serratifolia consumption and utilization, but there are currently no reports on using sesbania serratifolia silage as a component of grass carp diets. Developing a method to convert sesbania serratifolia silage into a feed that grass carp readily consume is of significant research and practical value for ensuring high-quality grass carp farming throughout the year.

[0004] In order to improve efficiency, grass carp farming generally adopts intensive farming methods. Under this intensive farming model, the large input of feed is a key factor in increasing yield. Grass carp feed mainly relies on plant protein sources such as soybean meal, rapeseed meal, and cottonseed meal. However, these plant protein raw materials are also widely popular in the human food and livestock feed sectors, leading to fierce competition for these raw materials among humans, livestock farmers, and grass carp farmers. This competition largely restricts the healthy and sustainable development of grass carp farming. Therefore, finding new alternative sources of protein raw materials has become an urgent task.

[0005] Sesbania silage can serve as a protein source in grass carp diets, potentially improving their physique and meat quality. High-quality grass carp is rich in nutrients, meeting human needs for essential elements. For example, it contains essential fatty acids and amino acids such as DHA, threonine, valine, lysine, and phenylalanine. DHA, or docosahexaenoic acid, is known as "brain gold" and promotes brain cell development, slows aging, improves blood circulation, and lowers blood lipids; it is one of the essential polyunsaturated fatty acids for the human body. Threonine participates in the synthesis of immunoglobulins and collagen, maintaining a healthy intestinal mucosal barrier; it promotes fatty acid metabolism and assists in maintaining liver function. Valine promotes muscle repair and growth; regulates blood sugar and reduces insulin resistance; it enhances immunity and increases resistance to pathogens. Lysine can promote human growth and development, neurodevelopment, enhance immunity, resist viruses, promote fat metabolism, and alleviate anxiety. Phenylalanine participates in muscle growth and repair, maintaining normal human growth and development. It can be converted into tyrosine, which in turn synthesizes neurotransmitters such as dopamine, adrenaline, and noradrenaline, regulating the function of the nervous system and playing a role in nourishing the kidneys and brain. At the same time, phenylalanine can also participate in the metabolism of tyrosine in the blood, regulate creatine concentration, help improve athletic ability and endurance, and reduce fatigue.

[0006] To address the technical challenges of high grass carp farming costs and limited sustainable development due to intense competition for high-quality protein sources, and the waste of resources caused by the poor palatability of fresh sesbania silage, this invention provides a grass carp compound feed with sesbania silage as the core ingredient. This feed can fully utilize the potential of sesbania silage and significantly improve the quality of grass carp meat, especially increasing the content of functional nutrients essential for human health, such as DHA, threonine, valine, leucine, histidine, lysine, and / or phenylalanine, in the muscle. Summary of the Invention

[0007] The purpose of this invention is to address the technical problem of protein feed shortage in intensive grass carp farming by providing a low-protein sesame silage compound pellet feed and its application in grass carp farming. This invention uses sesame silage to replace a portion of traditional feed to produce a low-protein sesame silage compound pellet feed, which, when used in grass carp farming, can significantly improve the digestibility and quality of grass carp, reduce feed costs, and has significant application value in production.

[0008] The invention achieves the above objectives through the following technical solutions:

[0009] In a first aspect, the present invention claims protection for a low-protein sesame silage compound pellet feed, which comprises the following components by weight percentage: 40% to 60% protein premix, 8% to 15% corn, 10% to 20% wheat bran, 6% to 15% sesame silage and 10% to 20% rice bran; the sum of the weight percentages of each component is 100%.

[0010] As a preferred technical solution, the feed comprises the following components by weight percentage: 45%~60% protein premix, 10%~15% corn, 10%~20% wheat bran, 9%~15% sesame silage, and 10%~20% rice bran.

[0011] Further preferably, the feed comprises the following components: 45%~55% protein premix, 10%~15% corn, 12%~18% wheat bran, 10%~15% sesame silage, and 13%~19% rice bran. Even more preferably, the feed comprises the following components: 45%~50% protein premix, 10%~15% corn, 13%~16% wheat bran, 10%~15% sesame silage, and 15%~18% rice bran. In a specific embodiment of the present invention, the feed comprises the following components: 45% protein premix, 10% corn, 15% wheat bran, 15% sesame silage, and 15% rice bran.

[0012] Furthermore, the above-mentioned sesame silage is obtained by the following steps: First, fresh sesame compound leaves are cut into short sections, and then a compound additive containing Lactobacillus plantarum and cellulase is added in proportion to start and optimize the fermentation process; next, sesame is mixed with wheat bran in proportion to adjust the moisture and nutrients; finally, the mixture is packaged and vacuum-sealed for storage, and finally sesame silage is obtained.

[0013] Furthermore, add Lactobacillus plantarum culture medium (1×10⁶ bacteria count) at 1% of the fresh weight of sesame. 11 ~10 12 The sesame seeds are prepared by adding 1g CFU / ml FM and cellulase at 1.5%~2% of their fresh weight; the sesame seeds and wheat bran are mixed at a weight ratio of 4:1~3:1 for silage. Storage is at room temperature (25~32℃). The fresh sesame seeds are cut into 1-2 cm short pieces; if the fermented sesame seeds and wheat bran silage does not meet the wheat bran ratio requirements in the formula, unfermented wheat bran is added directly to meet the requirements.

[0014] Secondly, the present invention seeks protection for the use of the above-mentioned low-protein sesame silage pellet feed in the preparation of products for the following purposes:

[0015] (1) Farming grass carp;

[0016] And / or,

[0017] (2) Improve the quality of grass carp, wherein the improvement in grass carp quality is reflected in at least one of the following indicators:

[0018] a) Increase the DHA content in grass carp muscle; b) Increase the content of functional amino acids in grass carp muscle; the functional amino acids are threonine, valine, leucine, histidine, lysine and / or phenylalanine.

[0019] Thirdly, this invention claims protection for a method to improve the quality of grass carp, which involves using the aforementioned low-protein sesame silage combined with pelleted feed for grass carp farming to improve the quality of the grass carp, wherein the improvement in grass carp quality is reflected in at least one of the following indicators:

[0020] a) Increase the DHA content in grass carp muscle; b) Increase the content of functional amino acids in grass carp muscle; the functional amino acids are threonine, valine, leucine, histidine, lysine, and / or phenylalanine. This method uses sesbania silage to replace a portion of traditional protein premixes to produce low-protein sesbania silage compound pellet feed for grass carp farming.

[0021] Fourthly, the present invention seeks protection for the use of sesame in the following (1) or (2):

[0022] (1) Preparation of low-protein sesame silage pellet feed for grass carp farming;

[0023] (2) Improve the quality of grass carp, wherein the improvement in grass carp quality is reflected in at least one of the following indicators:

[0024] a) Increase the DHA content in grass carp muscle; b) Increase the content of functional amino acids in grass carp muscle; the functional amino acids are threonine, valine, leucine, histidine, lysine, and / or phenylalanine. During the research, this invention provided three types of sesbania, specifically groups S1, S2, and S3. The sesbania and wheat bran mixed silage feed produced after mixing with wheat bran had a high lactic acid bacteria content. In a specific embodiment of this invention, the number of lactic acid bacteria exceeded 5.0 lg cfu / g FM, and the pH was below 4.8. Conventional silage preparation methods can be used, and it can be stored at room temperature.

[0025] The preparation method of the above-mentioned low-protein sesame silage compound pellet feed is as follows: Protein premix, corn, wheat bran, sesame silage, and rice bran are mixed in proportion and then pelleted into pellets with a moisture content of 15%. After air-drying for 24 hours, the pellets are placed in self-sealing bags and vacuum-sealed for storage. In the specific embodiment of this invention, the number of lactic acid bacteria in the fresh weight of the sesame silage compound pellet feed is higher than 5.44 lg CFU / g.

[0026] This invention aims to clarify the impact of adding compound lactic acid bacteria additives on the fermentation quality of sesame silage, and to obtain silage with good fermentation quality. Based on the nutritional requirements of adult grass carp, silage was used to replace part of the protein premix and formulated into compound silage pellets in proportion with other feed ingredients (corn, wheat bran, and rice bran, etc.). Grass carp were then raised in a factory-style recirculating aquaculture system. Results showed that the low-protein sesame silage pellets increased the activity of intestinal digestive enzymes in grass carp, and improved the content of DHA (a key amino acid for brain health) and functional amino acids such as threonine, valine, leucine, histidine, lysine (for kidney and brain health), and phenylalanine in the fresh meat. Furthermore, it reduced feed costs, demonstrating significant application value in production.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) Silage made from high-protein sesame can replace traditional protein feed, which is low-cost, safe, reliable and easy to use.

[0029] (2) Sesbania silage has a long shelf life, high nutritional value, and good palatability, and can be used extensively in the aquaculture industry.

[0030] (3) The mixed pellet feed used in this invention improves the digestibility and meat quality of grass carp. Detailed Implementation

[0031] The present invention will be further described below with reference to specific embodiments. These descriptions are merely preferred embodiments of the invention and are not intended to limit the invention in any other way. Any person skilled in the art may make equivalent modifications to the disclosed technical content to create similar embodiments. Any modifications or equivalent changes made to the following embodiments based on the technical essence of the present invention without departing from the scope of the invention are all within the protection scope of the present invention.

[0032] Example 1: Production of low-protein sesame silage pellets

[0033] 1. Materials and Methods

[0034] 1.1 Sources of Silage Materials

[0035] Sesbania seeds were purchased from Beijing Zhengdao Seed Industry Co., Ltd., Zhengzhou Century Tianyuan Biotechnology Co., Ltd., and Sichuan Huafeng Seed Industry Co., Ltd., and were numbered S1, S2, and S3 respectively. They were planted at the Baima Teaching and Research Practice Base of Nanjing Agricultural University. The sesbania seeds were harvested and ensiled after reaching the initial flowering stage. The ensilion treatments were set as follows: a control group (without additives, referred to as the CON group) and a group treated with compound lactic acid bacteria additive [1% Lactobacillus plantarum MTD-1; Ecosyl Products Ltd, Stokesley, North Yorkshire, UK] culture medium (1×10⁶ bacteria count). 11 ~10 12 [1g CFU / ml FM) and 2% cellulase (Cangzhou Xiasheng Enzyme Biotechnology Co., Ltd.), abbreviated as BB group]. After silage, the group with the best fermentation quality was selected for the preparation of mixed pellet feed.

[0036] 1.2 Preparation of Mixed Pellet Feed

[0037] The formula for low-protein sesame silage pellet feed, based on mass percentage, is as follows:

[0038] SF1 formulation (formula one): 45% protein premix (commercially available product, Haid Group, 36% protein), 10% corn, 15% wheat bran, 15% S1 sesbania silage and 15% rice bran.

[0039] SF2 formulation (formula 2): 45% protein premix, 10% corn, 15% wheat bran, 15% S2 sesbania silage and 15% rice bran.

[0040] SF3 formulation (formula 3): 45% protein premix, 10% corn, 15% wheat bran, 15% S3 sesbania silage and 15% rice bran.

[0041] Formula without added sesame (CK): 60% protein premix, 10% corn, 15% wheat bran, and 15% rice bran.

[0042] Corn, wheat bran, rice bran, and protein premix are commercially available raw materials.

[0043] Preparation process of low-protein sesame silage compound pellet feed:

[0044] Preparation of S1, S2, and S3 sesbania silage: Sesbania compound leaves were cut into 1-2 cm segments and mixed evenly. Depending on fresh weight, no additives were added (CON, control group) or compound lactic acid bacteria additives were added (BB group). 160 g of sesbania + 40 g of wheat bran, 16 kg of sesbania, and 4 kg of wheat bran were packaged into laboratory silage bags, forming small and large packages respectively. A vacuum sealing environment was then created using a vacuum sealer, and the silage was stored at room temperature (25-32℃) for 60 days before use. Fermentation quality is shown in Table 1. All sesbania silages with added BB showed good fermentation quality and were suitable for preparing low-protein sesbania silage pellets.

[0045] Preparation of low-protein sesame silage pellets (SF1, SF2, and SF3): After silage fermentation, the pellets were mixed with other dietary ingredients according to the formula and made into 1-2 cm pellets with a moisture content of approximately 15% using a pellet mill (model 125, Xingbai Agricultural Machinery Factory, Zhengzhou). The pellets were then placed in self-sealing bags and vacuum-sealed for storage. The lactic acid bacteria content in the SF1 mixed pellets was 6.38 lg cfu / g FM, the lactic acid bacteria content in the SF2 mixed pellets was 8.87 lg cfu / g FM, and the lactic acid bacteria content in the SF3 mixed pellets was 6.68 lg cfu / g FM.

[0046] Among them, the low-protein sesame silage compound pellet feed formula one uses S1 group sesame and wheat bran mixed silage (I); formula two uses S2 group sesame and wheat bran mixed silage (II); formula three uses S3 group sesame and wheat bran mixed silage (III).

[0047] During the study, three groups were designated: S1 (prepared with low-protein sesame silage pellets), S2 (prepared with low-protein sesame silage pellets), and S3 (prepared with low-protein sesame silage pellets), with no sesame silage added (CK) and no commercially available feed added (SC). Table 2 shows the composition and nutritional components of the pelleted feed for grass carp.

[0048] Table 1. Fermentation quality of silage made from sesame seeds and wheat bran from different sources

[0049]

[0050] Note: S1, S2, and S3 represent sesbania from different sources; CON is the control group without compound lactic acid bacteria additive BB; BB is the treatment group with compound lactic acid bacteria additive; standard error SEM is the standard error of the mean; different lowercase letters next to the standard deviation indicate significant differences between groups (P < 0.05).

[0051] Table 2. Composition and nutritional components (% fresh weight) of sesame silage from different sources

[0052]

[0053] Note: All nutrient components are actual measured values. The market feed mentioned is 32% protein grass carp feed, purchased from Tongwei Group Co., Ltd. S1 silage, S2 silage, and S3 silage correspond to mixed silage of sesbania and wheat bran from different sources. When the fermented sesbania and wheat bran mixed silage does not meet the wheat bran ratio requirements in the formula, unfermented wheat bran is added directly to meet the requirements.

[0054] Example 2: Experiment on feeding grass carp with low-protein sesame silage and pelleted feed

[0055] 1. Materials and Methods

[0056] Grass carp were reared in a factory-style recirculating aquaculture system. Five tanks were used, each containing 30 grass carp. Each tank was fed a combination of feed from Example 1 and commercially available feeds (SF1 group feed, SF2 group feed, SF3 group feed, feed without sesbania and commercially available feed), labeled SF1, SF2, SF3, CK, and SC, respectively. The rearing experiment lasted 60 days, with sampling every 15 days. Grass carp selected were those with golden-yellow body color, robust physique, normal appetite, and an initial weight of 700 ± 50 g. One aerator was used for centralized oxygenation. The fish were fed the above feeds twice daily, each time at 2% of their body weight. During the experiment, the water temperature was 18-26℃, dissolved oxygen ≥ 5.00 mg / L, pH 6.60-7.10, nitrite < 0.1 mg / L, and nitrate 0.05-0.13 mg / L.

[0057] 2. Grass carp sampling steps and methods

[0058] After the experiment, without starvation, the number of surviving fish in each experimental area was measured and counted. Fish were removed from each area and placed in a 40 L tank pre-treated with ethyl m-aminobenzoate methanesulfonate anesthetic (MS-222, 400 mg / L) to minimize injury during removal. After anesthesia, body length and final body weight were measured. Subsequently, six fish from each experimental formulation group were randomly selected for live dissection on ice, measuring visceral weight, liver weight, and total intestinal length and weight. Dorsal muscle, liver, and midgut were then harvested, with 1 cm of tissue taken from each fish. 3 The dorsal muscle was used for muscle texture determination; another 10 g of muscle was used for amino acid and fatty acid determination; the liver was used for liver digestive enzyme activity determination; and the midgut was used for intestinal digestive enzyme activity determination. Except for the muscle, all other samples were stored at -20℃.

[0059] 3. Methods for determining grass carp indicators

[0060] The formulas for calculating growth and morphological indicators are as follows:

[0061] W WGR =(m t –m0) / m0×100%

[0062] K SGR =(lnm t –lnm0) / t×100%

[0063] D CF =100m / L 3

[0064] W VSI = m v / m×100%

[0065] W HSI = m h / m×100%

[0066] W RGW = m G / m×100%

[0067] I = L G / L

[0068] R S = n t / n0×100%

[0069] In the formula, W WGR K represents the quality increase rate (%). SGR CF represents the specific growth rate (% / d), W represents the condition factor, and CF represents the condition factor. VSI The organ index (%), W HSI Liver body index (%), W RGW The intestinal body index (%) is given by I, where I is the length of the intestine and R is the intestinal length. S Survival rate (%), t is the number of days of rearing (d), m0 is the initial weight (g), m t For the final mass (g), m v Visceral mass (g), m h Liver mass (g), m G For intestinal mass (g), L G Let m be the intestinal length (cm), m be the body mass (g), L be the body length (cm), and n0 and n t The numbers represent the number of fish (tails) at the beginning and end of each group of experiments.

[0070] A 1 cm × 1 cm × 0.5 cm piece of back muscle was collected and analyzed using a texture analyzer (TMS-Pro, FTC, USA). The measured parameters included hardness, adhesiveness, cohesiveness, springiness, gumminess, chewiness, and resilience. A 25 mm × 25 mm cylindrical probe was used, with a contact force of 5 gf, a testing speed of 1 mm / s, a target mode of deformation, a deformation of 50%, and a testing time of 2.5 s. Each sample was measured twice, and the average value was taken.

[0071] Intestinal and liver digestive enzyme activity assays: Under freezing conditions, take 0.10-0.20 g of sample and mix it with physiological saline (0.69%) at a ratio of 1:9 (by mass). Homogenize thoroughly in an ice-water bath. Centrifuge the homogenate at 4 ℃ and 3000 r / min for 15 min. Use the supernatant to determine the activities of protease, amylase, and lipase. Protease, amylase, and lipase assay kits were purchased from Nanjing Wanqing Biotechnology Co., Ltd. Use a UV spectrophotometer to measure absorbance according to the instructions. Determine digestive enzyme activity using a standard curve.

[0072] Serum biochemical index determination: After anesthetizing the experimental fish, blood was collected from the tail vein using a 2 mL sterile syringe (pre-lubricated with heparin sodium anticoagulant). The blood was immediately centrifuged at 3500 r / min for 10 min, and the supernatant was collected and frozen at -20℃. The assay kits for aspartate aminotransferase (AST), alanine aminotransferase (ALT), and glucose (GLU) were purchased from Nanjing Wanqing Biotechnology Co., Ltd.

[0073] Method for detecting fatty acids in fish meat: Fatty acids were detected using gas chromatography. Chromatographic conditions: TRACE GC gas chromatograph; Agilent HP-88 column (100 mm × 0.25 mm); helium as carrier gas; injection volume 40 μL; split ratio 100:1; injection port temperature 270℃; detector temperature 280℃; detector auxiliary gas hydrogen flow rate 30 mL·min. -1 Airflow rate: 30 mL / min -1 Temperature program: 100℃ for 4 minutes, then at 15℃ / min. -1 After heating to 180℃ and maintaining the temperature for 6 minutes, then increase the temperature by 1℃·min. -1 After rapidly heating to 200°C and maintaining that temperature for 15 minutes, the temperature was increased at a rate of 8°C / min. -1 Heat to 230℃ and maintain for 10 minutes.

[0074] The amino acid content of muscle was determined using a fully automated amino acid analyzer (L-8900, Japan).

[0075] Acid hydrolysis method: 0.1 g of muscle is placed in a hydrolysis flask, and 6 mol·L⁻¹ is added. -1 10 mL of hydrochloric acid solution was placed at -20℃ for 2–3 min, and nitrogen gas was purged through it for 2 min using a nitrogen evaporator (YDCY-12AL, Shanghai). The solution was then sealed with an explosion-proof gas cylinder. The hydrolysis flask was placed at 110℃ for 22–24 h, and the solution was transferred to a 50 mL volumetric flask and diluted to volume with ultrapure water. 1 mL of the solution was transferred to a 5 mL centrifuge tube, dried with a nitrogen evaporator, and 0.02 mol·L⁻¹ was added. -1 The residue was dissolved in 2 mL of hydrochloric acid and filtered through a 0.22 µm pore size filter. The amino acid content of the resulting clear liquid was determined using a fully automated amino acid analyzer.

[0076] Alkaline hydrolysis method: Place 0.1 g of muscle into a hydrolysis flask, add 4 mol·L⁻¹ -1 10 mL of hydrochloric acid solution was placed at -20℃ for 2–3 min, and nitrogen gas was purged through it for 2 min using a nitrogen evaporator (YDCY-12AL, Shanghai). The solution was then sealed with an explosion-proof gas cylinder. The hydrolysis flask was placed at 110℃ for 22–24 h, and the solution was transferred to a 50 mL volumetric flask and diluted to volume with ultrapure water. 1 mL of the solution was transferred to a 5 mL centrifuge tube, dried with a nitrogen evaporator, and 0.02 mol·L⁻¹ was added. -1 The residue was dissolved in 2 mL of hydrochloric acid and filtered through a 0.22 µm pore size filter. The amino acid content of the resulting clear liquid was determined using a fully automated amino acid analyzer.

[0077] Data were organized using Excel and analyzed using SPSS version 22 statistical analysis software. Based on one-way ANOVA, Tukey's test was used to test whether there were significant differences between groups. P < 0.05 was considered to be significant.

[0078] 4 Results Analysis

[0079] 4.1 Effects of low-protein sesame silage compounded with pelleted feed on the growth performance of grass carp

[0080] Table 3 shows that the rearing time had a significant impact on the body weight, weight gain rate, specific growth rate, and carcass percentage of grass carp (P < 0.05). Different formulated pelleted feeds also had a significant impact on the body weight, weight gain rate, specific growth rate, and carcass percentage of grass carp (P < 0.05). The interaction between the rearing time and different formulated pelleted feeds also had a significant impact on the body weight, weight gain rate, specific growth rate, and carcass percentage of grass carp (P < 0.05).

[0081] When the rearing time encompassed different formulated pellet feed factors, the body weight, weight gain rate, and specific growth rate of grass carp increased with increasing rearing time (P < 0.05). Carcass percentage decreased with increasing time (P < 0.05). When different formulated pellet feeds encompassed the rearing time factor, compared with the control group (CK), the SC group significantly increased the body weight, weight gain rate, and specific growth rate of grass carp (P < 0.05); the SF2 group significantly increased the body weight and weight gain rate of grass carp (P < 0.05).

[0082] The interaction between rearing time and different formulated pelleted feeds was considered. Grass carp body weight was highest in the SC group on day 60 and lowest in the CK group on day 15 (P < 0.05). Weight gain rate was highest in the SC group on day 60 and lowest in the CK group on day 15 (P < 0.05). Specific growth rate was highest in the SC group on day 60 and lowest in the CK group on day 15 (P < 0.05). Carcass percentage was highest in the CK group on day 15 and lowest in the SF2 group on day 60 (P < 0.05).

[0083] Table 3. Effects of feeding low-protein sesame silage pelleted feed on growth performance indicators of grass carp

[0084]

[0085] Note: SF1 refers to grass carp fed with S1 group sesame silage and pelleted feed, SF2 refers to grass carp fed with S2 group sesame silage and pelleted feed, SF3 refers to grass carp fed with S3 group sesame silage and pelleted feed, CK is the control group, grass carp fed with pelleted feed without sesame silage, and SC is grass carp raised on commercially available feed; different lowercase letters indicate significant differences (P < 0.05).

[0086] 4.2 Effects of low-protein sesame silage compounded with pelleted feed on morphological parameters of grass carp

[0087] Table 4 shows that the rearing time had a significant impact on the condition factor, specific intestine length, hepatobody ratio, and viscera ratio of grass carp (P < 0.05). Different formulated pelleted feeds also had significant impacts on the condition factor, specific intestine length, hepatobody ratio, and viscera ratio of grass carp (P < 0.05). The interaction between the rearing time and different formulated pelleted feeds also had significant impacts on the condition factor, specific intestine length, hepatobody ratio, and viscera ratio of grass carp (P < 0.05).

[0088] Table 4. Effects of feeding low-protein sesame silage pelleted feed on morphological parameters of grass carp

[0089]

[0090] Note: SF1 refers to grass carp fed with S1 group sesame silage and pelleted feed, SF2 refers to grass carp fed with S2 group sesame silage and pelleted feed, SF3 refers to grass carp fed with S3 group sesame silage and pelleted feed, CK is the control group, grass carp fed with pelleted feed without sesame silage, and SC is grass carp raised on commercially available feed; different lowercase letters indicate significant differences (P < 0.05).

[0091] When the rearing time encompassed different formulated pelleted feed factors, the condition factor and specific intestinal length of grass carp increased with increasing rearing time (P < 0.05); the hepatobiliary ratio initially increased and then decreased (P < 0.05); and the visceral ratio initially decreased and then increased (P < 0.05). When different formulated pelleted feed factors encompassed the rearing time factor, compared with the control group, the SF3 group significantly increased condition factor (P < 0.05), followed by the SF2 group (P < 0.05). The SC group significantly increased specific intestinal length (P < 0.05). The SF3 group significantly decreased the hepatobiliary ratio (P < 0.05). The SC group significantly increased the maximum visceral ratio (P < 0.05).

[0092] The interaction between rearing time and different formulated pelleted feeds was considered. The condition factor of grass carp was highest on day 60 in the SC group and lowest on day 15 in the SF1 group (P < 0.05). The specific intestinal length was highest on day 15 in the CK group and lowest on day 15 in the SF2 group (P < 0.05). The liver-to-body ratio was highest on day 15 in the CK group and lowest on day 45 in the SF1 group (P < 0.05). The viscera-to-body ratio was highest on day 15 in the SC group and lowest on day 15 in the SF3 group (P < 0.05).

[0093] 4.3 Effects of low-protein sesame silage pelleted feed on the activity of intestinal digestive enzymes in grass carp

[0094] Table 5 shows that the rearing time significantly affected the activities of proteases, amylases, lipases, and cellulases in the intestines of grass carp (P < 0.05). Different formulated pelleted feeds significantly affected the activities of amylases and lipases in the intestines of grass carp (P < 0.05). The interaction between rearing time and different formulated pelleted feeds significantly affected the activities of proteases, amylases, lipases, and cellulases in the intestines of grass carp (P < 0.05).

[0095] When the rearing time encompassed different formulated pellet feed factors, the intestinal protease activity of grass carp initially increased, then decreased, and then increased again with increasing time (P < 0.05). The intestinal amylase and lipase activities of grass carp initially increased and then decreased (P < 0.05). Cellulase activity increased (P < 0.05). When different formulated pellet feed factors encompassed the rearing time, compared with the control group, the SF2 group showed a significant increase in protease activity, reaching the highest level (P < 0.05), indicating high protein utilization efficiency; the SC group significantly increased amylase and lipase content (P < 0.05); and the SF3 group significantly decreased cellulase content (P < 0.05).

[0096] The interaction between rearing time and different formulated pelleted feed was considered. The intestinal protease content of grass carp was highest in the SF2 group on day 30 and lowest in the SF1 group on day 45 (P < 0.05). The amylase content was highest in the SC group on day 30 and lowest in the CK group on day 15 (P < 0.05). The lipase content was highest in the SF2 group on day 60 and lowest in the CK group on day 60 (P < 0.05). The cellulase content was highest in the SF2 group on day 60 and lowest in the SF3 group on day 15 (P < 0.05).

[0097] 4.4 Effects of low-protein sesame silage compounded with pelleted feed on the muscle texture of grass carp

[0098] Table 6 shows that the rearing time significantly affected the muscle hardness, viscosity, chewiness, and resilience of grass carp (P < 0.05). Different formulated pellet feeds also significantly affected the muscle hardness, cohesion, elasticity, viscosity, chewiness, and resilience of grass carp (P < 0.05). The interaction between rearing time and different formulated pellet feeds also significantly affected the muscle hardness, cohesion, elasticity, cohesion, viscosity, chewiness, and resilience of grass carp (P < 0.05).

[0099] When the rearing time encompassed different formulated pellet feed factors, the following results were observed: Grass carp muscle hardness increased with time (P < 0.05). Muscle adhesion initially increased and then decreased (P < 0.05). Muscle elasticity showed no significant difference (P > 0.05). Muscle cohesion increased (P < 0.05). Muscle viscosity increased (P < 0.05). Muscle chewiness initially increased, then decreased, and then increased again (P < 0.05). Muscle recovery increased (P < 0.05). When different formulated pellet feeds encompassed the rearing time factor, compared with the control group, the SF2 group significantly increased muscle hardness (P < 0.05) and muscle adhesion (P < 0.05), while the SF2 and SF3 groups significantly increased muscle elasticity (P < 0.05).

[0100] Table 5. Effects of feeding low-protein sesame silage pelleted feed on intestinal digestive enzymes in grass carp.

[0101]

[0102] Note: SF1 refers to grass carp fed with S1 group sesame silage and pelleted feed, SF2 refers to grass carp fed with S2 group sesame silage and pelleted feed, SF3 refers to grass carp fed with S3 group sesame silage and pelleted feed, CK is the control group, grass carp fed with pelleted feed without sesame silage, and SC is grass carp raised on commercially available feed; different lowercase letters indicate significant differences (P < 0.05).

[0103] The interaction between rearing time and different formulated pellet feeds was considered. Grass carp muscle firmness was highest in the SC group on day 60 and lowest in the CK group on day 15 (P < 0.05). Adhesion was highest in the SF2 group on day 30 and lowest in the SF1 group on day 15 (P < 0.05). Elasticity was highest in the SF3 group on day 45 and lowest in the SF1 group on days 15 and 30 (P < 0.05). Cohesion was highest in the SF2, SF1, and CK groups on day 60 and lowest in the SC group on day 15 (P < 0.05). Stickiness was highest in the SF2 group on day 60 and lowest in the CK group on day 15 (P < 0.05). Chewiness was highest in the SF3 group on day 30 and lowest in the SC group on day 15 (P < 0.05). Resilience was highest in the SC group on day 60 and lowest in the SC group on day 15 (P < 0.05).

[0104] Table 6. Effects of feeding low-protein sesame silage pelleted feed on the muscle texture of grass carp.

[0105]

[0106] Table 6 (Continued) Effects of feeding low-protein sesame silage pelleted feed on the muscle texture of grass carp

[0107]

[0108] Note: SF1 refers to grass carp fed with S1 group sesame silage and pelleted feed, SF2 refers to grass carp fed with S2 group sesame silage and pelleted feed, SF3 refers to grass carp fed with S3 group sesame silage and pelleted feed, CK is the control group, grass carp fed with pelleted feed without sesame silage, and SC is grass carp raised on commercially available feed; different lowercase letters indicate significant differences (P < 0.05).

[0109] Overall, the improved firmness, elasticity, and cohesion of the SF2 group's fish meat, along with the optimized adhesion, collectively improved the texture of the fish meat: it is firmer, more bouncy, chewier, less likely to fall apart, and does not stick to the teeth, significantly enhancing the eating quality and making the fish meat taste better.

[0110] 4.5 Effects of low-protein sesame silage compounded with pelleted feed on serum biochemical parameters of grass carp

[0111] Table 7 shows that the rearing time had a significant effect on aspartate aminotransferase (AST) in grass carp (P < 0.05). Different formulated pelleted feeds had a significant effect on blood glucose in grass carp (P < 0.05). The interaction between rearing time and different formulated pelleted feeds had a significant effect on AST and blood glucose in grass carp (P < 0.05).

[0112] Table 7. Effects of feeding low-protein sesame silage pelleted feed on serum biochemical parameters of grass carp.

[0113]

[0114] Note: SF1 refers to grass carp fed with S1 group sesame silage and pelleted feed, SF2 refers to grass carp fed with S2 group sesame silage and pelleted feed, SF3 refers to grass carp fed with S3 group sesame silage and pelleted feed, CK is the control group, grass carp fed with pelleted feed without sesame silage, and SC is grass carp raised on commercially available feed; different lowercase letters indicate significant differences (P < 0.05).

[0115] When the rearing time covered different formulated pelleted feed factors, the serum aspartate aminotransferase (AST) levels of grass carp initially increased and then decreased with increasing time (P < 0.05), the serum alanine aminotransferase (ALT) levels initially increased and then decreased (P > 0.05), and the serum glucose levels of grass carp increased (P > 0.05). When different formulated pelleted feed factors covered the rearing time factor, compared with the control group, the SF2 group showed a significant increase in serum glucose levels (P < 0.05).

[0116] Considering the interaction between rearing time and different formulated pelleted feed, the serum aspartate aminotransferase (AST) level of grass carp was highest on day 45 in the SC group and lowest on day 15 in the CK group (P < 0.05). The serum glucose level was highest on day 30 in the SC group and lowest on day 30 in the CK group (P < 0.05).

[0117] 4.6 Effects of low-protein sesame silage pelleted feed on amino acids in fish meat

[0118] As shown in Table 8, for fresh grass carp muscle on day 60, the SF2 group had the highest aspartic acid content (P < 0.05), followed by threonine, serine, and histidine (P < 0.05); the SF3 group had the highest aspartic acid content (P < 0.05); compared with the CK and SC groups, the contents of aspartic acid, threonine, serine, alanine, cysteine, valine, leucine, tyrosine, phenylalanine, lysine, histidine, arginine, and total amino acids in SF1, SF2, and SF3 were all significantly increased (P < 0.05).

[0119] Table 8. Amino acid analysis of grass carp muscle after feeding with low-protein sesame silage pelleted feed.

[0120]

[0121] Note: SF1 refers to grass carp fed with S1 group sesame silage and pelleted feed, SF2 refers to grass carp fed with S2 group sesame silage and pelleted feed, SF3 refers to grass carp fed with S3 group sesame silage and pelleted feed, CK is the control group, grass carp fed with pelleted feed without sesame silage, and SC is grass carp raised on commercially available feed; different lowercase letters indicate significant differences (P < 0.05).

[0122] 4.7 Effects of low-protein sesame silage pelleted feed on fatty acids in fish meat

[0123] Table 9 shows that 14 fatty acids were detected in the fresh grass carp muscle on day 60, including 4 saturated fatty acids and 10 unsaturated fatty acids. Compared with the CK and SC groups, eicosapentaenoic acid (EPA) was detected in SF1 and SF3, erucic acid in SF2 and SF3, and docosahexaenoic acid (DHA) in SF1, SF2, and SF3. The levels of heptadecanoic acid and non-beta-dependent trans-linolenic acid (BLA) in SF2 were significantly lower than in other groups (P < 0.05), while non-beta-dependent dodecanoic acid (DOA) and docosahexaenoic acid (DHA) were not detected in SF2. The nutmeg oil content in the SF2 group was significantly higher than that in the SF1, SF3, CK, and SC groups (P < 0.05). The nervonic acid content in the SF3 group was significantly higher than that in other groups (P < 0.05). Compared with the CK group, the SF1, SF3 and SC groups significantly increased the total fatty acid content (P < 0.05); the SF2 group significantly decreased the saturated fatty acid content (P < 0.05); and the SF3 group significantly increased the unsaturated fatty acid content (P < 0.05).

[0124] Table 9. Effects of feeding low-protein sesame silage pelleted feed on fatty acids in fish meat.

[0125]

[0126] Note: SF1 refers to grass carp fed with S1 group sesame silage and pelleted feed, SF2 refers to grass carp fed with S2 group sesame silage and pelleted feed, SF3 refers to grass carp fed with S3 group sesame silage and pelleted feed, CK is the control group, grass carp fed with pelleted feed without sesame silage, SC is grass carp raised on commercially available feed; - indicates not detected or below the minimum detection limit; different lowercase letters indicate significant differences (P < 0.05).

[0127] 4.8 Economic Benefits of Replacing Grass Carp Protein Powder with Sesbania Silage

[0128] As shown in Table 10, the low-protein sesame silage compound pellet feed made by replacing 15% protein premix with sesame silage has a cost reduction of approximately 17.14% and 25.3% compared to the control group and the market feed group, respectively.

[0129] In summary, the low-protein sesame silage compound pellet feed made by replacing 15% protein premix with SF2 group sesame silage improved the growth performance, digestibility, muscle quality and probiotic effects of grass carp, while reducing feed costs.

[0130] Table 10. Aquaculture Cost Accounting

[0131]

[0132] Note: S1, S2, and S3 silages correspond to mixed silages of sesbania and wheat bran from different sources. SF1 represents grass carp fed with S1 group sesbania silage and pelleted feed, SF2 represents grass carp fed with S2 group sesbania silage and pelleted feed, SF3 represents grass carp fed with S3 group sesbania silage and pelleted feed, CK represents the control group fed with pelleted feed without sesbania silage, and SC represents grass carp raised on commercially available feed; different lowercase letters indicate significant differences (P < 0.05). When the fermented sesbania and wheat bran mixed silage does not meet the wheat bran ratio requirements in the formula, unfermented wheat bran is added directly to meet the requirements.

Claims

1. A low-protein sesame silage compound pellet feed, characterized in that, The feed contains the following components by weight percentage: 40%–60% protein premix, 8%–15% corn, 10%–20% wheat bran, 6%–15% sesame silage, and 10%–20% rice bran; the sum of the weight percentages of each component is 100%.

2. The low-protein sesame silage pellet feed according to claim 1, characterized in that, The feed comprises the following components by weight percentage: 45%~60% protein premix, 10%~15% corn, 10%~20% wheat bran, 9%~15% sesame silage, and 10%~20% rice bran.

3. The low-protein sesame silage pellet feed according to claim 2, characterized in that, The feed comprises the following components by weight percentage: 45%~55% protein premix, 10%~15% corn, 12%~18% wheat bran, 10%~15% sesame silage and 13%~19% rice bran.

4. The low-protein sesame silage pellet feed according to claim 3, characterized in that, The feed comprises the following components by weight percentage: 45%~50% protein premix, 10%~15% corn, 13%~16% wheat bran, 10%~15% sesame silage and 15%~18% rice bran.

5. The low-protein sesame silage pellet feed according to claim 1, 2, 3, or 4, characterized in that, The sesame silage is obtained by the following steps: First, fresh sesame compound leaves are cut into short sections, and then a compound additive containing Lactobacillus plantarum and cellulase is added in proportion to start and optimize the fermentation process; next, sesame is mixed with wheat bran in proportion to adjust the moisture and nutrients; finally, the mixture is packaged and vacuum-sealed for storage to obtain sesame silage.

6. The low-protein sesame silage pellet feed according to claim 5, characterized in that, Add Lactobacillus plantarum culture medium at 1% of the fresh weight of sesame and cellulase at 1.5% to 2% of the fresh weight of sesame; the sesame and wheat bran are mixed and ensiled at a weight ratio of 4:1 to 3:

1.

7. The low-protein sesame silage pellet feed according to claim 5, characterized in that, The fresh sesame seeds are cut into 1-2 cm short sections. When the fermented sesame seeds and wheat bran mixed into silage do not meet the wheat bran ratio requirements in the formula, unfermented wheat bran is added directly to meet the requirements.

8. The use of the low-protein sesame silage pellet feed according to any one of claims 1-7 in the preparation of products for the following purposes: (1) Farming grass carp; And / or, (2) Improve the quality of grass carp, wherein the improvement in grass carp quality is reflected in at least one of the following indicators: a) Increase the DHA content in grass carp muscle; b) Increase the content of functional amino acids in grass carp muscle; the functional amino acids are threonine, valine, leucine, histidine, lysine and / or phenylalanine.

9. A method for improving the quality of grass carp, characterized in that, Grass carp are raised using the low-protein sesame silage compound pelleted feed described in any one of claims 1-7 to improve the quality of the grass carp, wherein the improvement in grass carp quality is reflected in at least one of the following indicators: a) Increase the DHA content in grass carp muscle; b) Increase the content of functional amino acids in grass carp muscle; the functional amino acids are threonine, valine, leucine, histidine, lysine and / or phenylalanine.

10. Applications of sesame in the following (1) or (2): (1) Preparation of low-protein sesame silage pellet feed for grass carp farming; (2) Improve the quality of grass carp, wherein the improvement in grass carp quality is reflected in at least one of the following indicators: a) Increase the DHA content in grass carp muscle; b) Increase the content of functional amino acids in grass carp muscle; the functional amino acids are threonine, valine, leucine, histidine, lysine and / or phenylalanine.

Images