Breeding method of high-quality dazizi pig complete line

Abstract

The application discloses a breeding method of a high-quality type of Dawuzi pig complete set, which belongs to the technical field of livestock and poultry genetic breeding and animal nutrition regulation technology; Dawuzi pigs, Landrace pigs and Duroc pigs are selected to establish resource groups, Dawuzi sow and Landrace boar are crossbred to obtain Dawuzi-Longbaipig, and the Dawuzi-Longbaipig is crossbred with Duroc boar to produce commercial generation of fattening pigs; through determination of reproductive performance, production performance and meat quality indexes, combined with comprehensive selection index, closed population breeding is carried out, lauryl alcohol ferulate modified compound and eugenol succinic acid monoester compound are added in the stage from commercial generation weaning to the end of fattening, a three-level breeding system of core population, propagation population and commercial population is established, and the growth performance, feed utilization rate and meat quality stability of commercial pigs are improved.

Description

Technical Field

[0001] This invention belongs to the field of livestock and poultry genetic breeding and animal nutrition regulation technology, specifically relating to a breeding method for a high-quality large-bowled pig breeding system. Background Technology

[0002] my country boasts abundant local pig breeds, each possessing unique advantages in meat quality, flavor, disease resistance, adaptability, and reproductive stability. The Daweizi pig, as a local breed, is characterized by its tender meat, good flavor, and strong adaptability, making it suitable as a maternal resource for high-quality meat pig breeding systems. However, local pig breeds generally suffer from relatively slow growth rates, low feed conversion efficiency, insufficient lean meat percentage, and poor consistency in large-scale production. Relying solely on purebred breeding is insufficient to meet the comprehensive requirements of modern high-quality commercial pig production for growth performance, meat quality stability, and industrialized supply capacity. Therefore, how to maintain the meat quality advantages of the Daweizi pig while introducing the growth, reproductive, and carcass performance advantages of foreign pig breeds to establish a stable and sustainable high-quality breeding system is a crucial technological direction in the current development and utilization of local pig breed resources.

[0003] In current commercial pig breeding production, crossbreeding between different pig breeds is commonly used, combining the reproductive performance of maternal breeds, the meat quality advantages of local breeds, and the growth and carcass advantages of terminal sires. Landrace pigs typically have good reproductive performance, rapid growth, and high maternal utilization value, while Duroc pigs typically have fast growth rate, high feed utilization, and good carcass performance. Crossbreeding Landrace pigs with Large White pigs to obtain parental maternal lines, and then performing terminal crossbreeding with Duroc boars, can improve the production performance and carcass traits of commercial fattening pigs to some extent. However, current crossbreeding methods focus primarily on parental combination and performance improvement, with insufficient consideration given to maintaining the meat quality advantages of local breeds, ensuring meat quality consistency in commercial pigs, long-term breeding direction of the breeding population, and synergistic consideration of nutritional regulation during the fattening stage. This can easily lead to problems such as improved growth performance in commercial pigs but large fluctuations in meat quality, weakened flavor characteristics, and unstable breeding objectives.

[0004] Furthermore, in the production of high-quality meat pigs, the period from weaning to the end of fattening is a crucial time affecting growth rate, feed utilization, antioxidant status, meat deposition, and flavor formation. While conventional basal diets can meet basic nutritional needs, for commercial offspring of local pig breeds, conventional feeding and management alone are insufficient to adequately balance rapid fattening with stable meat quality. Plant phenolic active substances and their modified derivatives possess certain potential for antioxidant activity, flavor preservation, and nutritional regulation, and can be used to improve oxidative stress and meat quality retention during the fattening stage. However, existing technologies lack comprehensive and synergistic designs for closed-loop breeding of large-bred pigs, Landrace pigs, and Duroc pigs, commercial offspring performance and meat quality testing, and specialized feed systems using ferulic acid lauryl ester modified compounds and eugenol succinic acid monoester compounds. A breeding method for a high-quality large-bred pig breeding system that can simultaneously address the protection and utilization of local pig breeds, three-way crossbreeding for commercial production, continuous breeding stability, and meat quality regulation during the fattening stage is still needed. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a breeding method for a high-quality large-sized pig breeding system.

[0006] This invention provides a breeding method for a high-quality large-bowl pig breeding line, comprising the following steps:

[0007] S1. Select large-boar sows and large-boar boars as the large-boar maternal base group; select Landrace boars and Landrace sows as the Landrace resource group; select Duroc boars and Duroc sows as the Duroc resource group; crossbreed with large-boar sows as the first maternal line and Landrace boars as the first paternal line to produce large-boar F1 generation sows; select sows from the large-boar F1 generation sows as parent maternal lines;

[0008] S2. Duroc boars were used as terminal sires and mated with Landrace F1 generation sows to obtain commercial fattening pigs. The reproductive and production performance of the Landrace, Duroc, and F1 generation sows were measured, and the production performance and meat quality of the commercial fattening pigs were measured. Individual selection was carried out on the Landrace, Duroc, and F1 generation sows using the comprehensive selection index method, and boars and sows were selected in each generation.

[0009] S3. From weaning of commercial piglets to the end of fattening, ferulic acid lauryl ester modified compound and eugenol succinic acid monoester compound are added to the basal diet; closed-group breeding is carried out; production performance is tested and meat quality is evaluated to establish a high-quality three-way crossbreeding system of large-scale pig × Landrace pig × Duroc pig, and then a three-level breeding system of core group, propagation group and commercial group is established. The commercial group is combined with ferulic acid lauryl ester modified compound and eugenol succinic acid monoester compound for standardized fattening production.

[0010] In this invention, the breeding method for a high-quality Daweizi pig breeding system combines the utilization of local pig breed resources, the introduction of exogenous pig breed performance, continuous measurement and selection, and nutritional regulation of commercial pigs. Daweizi sows and boars constitute the Daweizi maternal base group, used to maintain the meat quality, adaptability, and local genetic characteristics of Daweizi pigs; Landrace boars and sows constitute the Landrace resource group, used to provide maternal reproductive and growth performance; Duroc boars and sows constitute the Duroc resource group, used to provide the growth performance, carcass traits, and fattening performance required for the terminal sire. Daweizi sows are used as the first maternal line and Landrace boars as the first sire line for crossbreeding to form the F1 generation of Daweizi-Landrace sows. Sows are then selected from the F1 generation of Daweizi-Landrace sows to serve as parent sows, combining the meat quality of local pig breeds with the maternal performance of Landrace pigs. Duroc boars were used as terminal sires and mated with Landrace F1 sows to produce commercial fattening pigs, ensuring that the commercial generation simultaneously inherited the genetic resources of Landrace, Duroc, and Large White pigs. Reproductive and production performance were assessed in the Large White sow breeding stock, Landrace resource stock, Duroc resource stock, and Landrace F1 sows. Production performance and meat quality indicators were assessed in the commercial fattening pigs. Individual selection was conducted using a comprehensive selection index method to ensure that the breeding direction of the closed breeding group corresponded to the production results of the commercial generation. From weaning to the end of fattening, ferulic acid lauryl ester modified compound and eugenol succinic acid monoester compound were added to the basal diet to regulate antioxidant status, feed utilization, and meat quality maintenance during the fattening stage. Through a three-tiered breeding system of core group, propagation group, and commercial group, a high-quality Large White pig breeding system was formed, linking genetic selection, commercial generation verification, and standardized fattening production.

[0011] According to a preferred embodiment of the present invention, in step S1, 190-210 large-breasted sows and 22-28 large-breasted boars are selected; 18-22 Landrace boars and 140-160 Landrace sows are selected; 13-17 Duroc boars and 95-105 Duroc sows are selected; and 190-210 sows are selected from the F1 generation of large-breasted sows.

[0012] According to a preferred embodiment of the present invention, in step S2, the production performance indicators include: birth weight, weaning weight, body weight at 30 days of age, age at 100kg body weight, feed conversion ratio, backfat thickness, and eye muscle area; the meat quality indicators include: carcass weight, lean meat percentage, intramuscular fat content, meat color, pH value, drip loss, and shear force; the proportion of boars selected per generation is 8-12%, and the proportion of sows is 22-28%.

[0013] According to a preferred embodiment of the present invention, in step S3, the target of the closed-group breeding is the large-scale breeding sow base group, the Landrace pig resource group, the Duroc pig resource group, and the F1 generation of Landrace sows; the proportion of ferulic acid lauryl ester modified compound added to the basal diet is 0.08-0.18%, and the proportion of eugenol succinic acid monoester compound is 0.10-0.25%; closed-group breeding is carried out continuously for 4-5 generations.

[0014] According to a preferred embodiment of the present invention, the method for preparing the ferulic acid lauryl ester modified compound includes:

[0015] A1. By weight, 14.0-16.0 parts of ferulic acid, 60.0-75.0 parts of 1-dodecyl alcohol, 0.8-1.2 parts of p-toluenesulfonic acid monohydrate and 170-190 parts of toluene are mixed and reacted under nitrogen protection at 110-112℃. The generated water is removed by a water separator, cooled to room temperature, and distilled under reduced pressure to obtain crude ferulic acid lauryl ester intermediate.

[0016] A2. Mix 8.0-10.0 parts of crude crude ferulic acid lauryl ester intermediate with 100-120 parts of ethyl acetate, stir, wash successively with sodium bicarbonate aqueous solution and saturated brine, dry with anhydrous sodium sulfate, filter to obtain filtrate, add 0.05-0.08 parts of 2,6-di-tert-butyl-4-methylphenol to filtrate, distill under reduced pressure, purify by silica gel column chromatography, concentrate under reduced pressure, and dry.

[0017] In this invention, the formation of the ferulic acid lauryl ester modified compound is based on an acid-catalyzed esterification reaction between the carboxyl group of ferulic acid and the hydroxyl group of 1-dodecyl alcohol. The ferulic acid molecule simultaneously contains a carboxyl group, a phenolic hydroxyl group, and an unsaturated side chain, with the carboxyl group being the active site for the esterification reaction. p-Toluenesulfonic acid monohydrate acts as an acidic catalyst, protonating the carbonyl oxygen in the ferulic acid carboxyl group, thus enhancing the electrophilicity of the carbonyl carbon. The hydroxyl group of 1-dodecyl alcohol then undergoes a nucleophilic attack on this carbonyl carbon, forming a tetrahedral intermediate. Subsequently, through proton transfer and dehydration, a water molecule is removed, forming an ester bond to generate the crude intermediate ferulic acid lauryl ester. Toluene, as the reaction medium, forms an azeotrope with the water generated during the reaction under reflux conditions. A water separator continuously removes water from the system, shifting the esterification equilibrium towards ester formation. Nitrogen protection is used to reduce the oxidation of the phenolic hydroxyl group and the unsaturated side chain of ferulic acid during heating. After the reaction, the mixture is cooled and the toluene is removed by vacuum distillation to obtain the crude intermediate ferulic acid lauryl ester. The crude product contained unreacted ferulic acid, excess 1-dodecyl alcohol, p-toluenesulfonic acid monohydrate, and a small amount of polar impurities. Ethyl acetate was used to dissolve and transfer the crude product. Sodium bicarbonate aqueous solution was used to neutralize and remove residual acidic substances. Saturated brine was used to reduce the water content of the organic phase. Anhydrous sodium sulfate was used for further drying. The desiccant was removed by filtration. 2,6-Di-tert-butyl-4-methylphenol was added after washing and drying with water and before vacuum concentration. It played an antioxidant role during vacuum concentration and drying. After purification by silica gel column chromatography, vacuum concentration, and drying, the ferulic acid lauryl ester modified compound was obtained.

[0018] According to a preferred embodiment of the present invention, in step A1, the reflux reaction at 110-112°C is carried out for 13-15 hours.

[0019] According to a preferred embodiment of the present invention, in step A2, the stirring temperature is 25-30°C.

[0020] According to a preferred embodiment of the present invention, the method for preparing the eugenol succinate monoester compound includes:

[0021] B1. By weight, 10.0-12.0 parts of eugenol, 7.5-8.5 parts of succinic anhydride, 0.3-0.5 parts of 4-dimethylaminopyridine, 7.5-9.0 parts of triethylamine, and 140-160 parts of anhydrous dichloromethane are mixed and stirred at 0-5°C under nitrogen protection; then the temperature is raised to 25-30°C and the mixture is stirred to obtain a reaction solution; 140-160 parts of deionized water are added to the reaction solution for separation, and the organic phase is collected. The organic phase is washed successively with hydrochloric acid, deionized water, and saturated brine, dried over anhydrous sodium sulfate, purified by vacuum distillation, purified by silica gel column chromatography, and concentrated under vacuum to obtain crude eugenol succinic acid monoester.

[0022] B2. Add 8.0-10.0 parts of crude eugenol succinate monoester to a mixed solvent of 50.0-70.0 parts of ethanol and water, stir at 60-70℃, add 0.02-0.04 parts of 2,6-di-tert-butyl-4-methylphenol, stir, filter, and obtain filtrate; cool the filtrate, recrystallize, filter, purify by silica gel column chromatography, concentrate under reduced pressure, and dry.

[0023] In this invention, the formation of eugenol succinate monoester is based on a nucleophilic catalytic ring-opening esterification reaction between the phenolic hydroxyl group of eugenol and succinic anhydride. The eugenol molecule contains a phenolic hydroxyl group, a methoxy group, and an allyl group, with the phenolic hydroxyl group being the active site for the esterification reaction. 4-Dimethylaminopyridine undergoes a nucleophilic attack on the carbonyl carbon of succinic anhydride, causing the succinic anhydride to ring-open and form an N-acylpyridinium intermediate with high acyl transfer activity. The phenolic hydroxyl group of eugenol then undergoes a nucleophilic attack on the acyl carbon of this intermediate, forming an ester bond and retaining the free carboxyl group at the end of the succinic acid residue. The 4-dimethylaminopyridine is subsequently regenerated. Triethylamine acts as an acid-binding agent, accepting protons generated during the reaction and maintaining the reactivity of the phenolic hydroxyl group of eugenol. Anhydrous dichloromethane is used as the reaction medium to keep eugenol, succinic anhydride, 4-dimethylaminopyridine, and triethylamine homogeneous. Low-temperature stirring was used to control the initial ring-opening and acyl transfer processes of succinic anhydride. Subsequent heating and stirring ensured complete ester bond formation, yielding eugenol succinate monoester containing free carboxyl groups. After the reaction, deionized water was added for liquid-liquid separation, with the target product retained in the organic phase. Hydrochloric acid washing transferred residual 4-dimethylaminopyridine and triethylamine into the aqueous phase. Deionized water washing removed residual acidic and water-soluble impurities, followed by washing with saturated brine to reduce the water content of the organic phase. Anhydrous sodium sulfate was used for further drying. After removing anhydrous dichloromethane under reduced pressure and purification by silica gel column chromatography, crude eugenol succinate monoester was obtained. This crude product was dissolved in a mixed solvent of ethanol and water upon heating. 2,6-Di-tert-butyl-4-methylphenol was used to reduce oxidation during recrystallization. The mixture was then filtered while hot, cooled, recrystallized, purified by silica gel column chromatography, concentrated under reduced pressure, and dried to obtain the eugenol succinate monoester compound.

[0024] According to a preferred embodiment of the present invention, in step B1, the stirring time at 0-5°C is 1-2 hours; the stirring reaction time at 25-30°C is 10-12 hours.

[0025] According to a preferred embodiment of the present invention, in step B2, the filtrate is cooled to 0-5°C.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) This invention is based on the Daweizi pig maternal base group, the Landrace pig resource group, and the Duroc pig resource group. First, Daweizi pig sows are crossed with Landrace boars to form the F1 generation of Daweizi-Landrace sows. Then, Duroc boars are used as terminal sires to mate with the F1 generation of Daweizi-Landrace sows to obtain commercial fattening pigs. This method makes full use of the meat quality and adaptability base of the Daweizi pig maternal base group, the reproductive performance source of the Landrace pig resource group, and the growth performance and carcass performance source of the Duroc pig resource group. This method clarifies the roles of the Daweizi pig maternal base group, the Landrace pig resource group, the Duroc pig resource group, the F1 generation of Daweizi-Landrace sows, and the commercial fattening pigs in the breeding system. It is beneficial to reduce the phenotypic segregation caused by the continued breeding of commercial fattening pigs and maintain the production stability of the Daweizi × Landrace × Duroc three-way crossbred high-quality breeding line.

[0028] (2) This invention measures the reproductive and production performance of the Daweizi pig breeding stock, Landrace pig resource group, Duroc pig resource group, and F1 generation Daweizi pig sows, and measures the production performance and meat quality indicators of commercial fattening pigs. Individual selection is carried out based on the comprehensive selection index method to establish a correspondence between the closed-group breeding targets and the production results of commercial fattening pigs. By continuously selecting Daweizi pig breeding stock, Landrace pig resource group, Duroc pig resource group, and F1 generation Daweizi pig sows through closed-group breeding, the consistency of the core group and the propagation group can be improved, and the fluctuations in reproductive performance, production performance, and meat quality indicators between different generations can be reduced, which is conducive to the stable establishment and sustainable utilization of high-quality Daweizi pig breeding systems.

[0029] (3) In this invention, a modified compound of ferulic acid lauryl ester and a monoester of eugenol succinate are added to the basal diet of commercial piglets from weaning to the end of fattening. The modified compound of ferulic acid lauryl ester exerts its antioxidant effect through the phenolic hydroxyl group and conjugated structure of ferulic acid, and improves its compatibility in the dietary lipid phase and muscle lipid environment through the long-chain alkyl structure, which is beneficial to reduce lipid oxidation during the fattening stage, reduce intramuscular fat oxidation, and help maintain the stability of intramuscular fat; the monoester of eugenol succinate participates in antioxidant regulation through the phenolic hydroxyl group and methoxy group in the eugenol structure, and improves its polarity and dispersibility through the free carboxyl group at the end of the succinic acid residue, which is beneficial to improve feed utilization and meat water retention. The modified compound of ferulic acid lauryl ester and the compound of eugenol succinic acid monoester work together to form a synergistic regulatory effect on lipid-phase antioxidants, phenolic antioxidants, nutrient utilization, and meat quality maintenance. This allows commercial fattening pigs to maintain high growth performance while maintaining high intramuscular fat content, improving meat water retention, and enhancing the stability of pork quality. Through a three-tiered breeding system of core herd, propagation herd, and commercial herd, a production model that integrates breeding stock selection, propagation and supply, and commercial fattening production can be formed. Detailed Implementation

[0030] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0031] Example 1

[0032] This embodiment provides a breeding method for a high-quality large-bodied pig breeding line, including the following steps:

[0033] S1. Select 200 healthy, normal-condition, and genetically defect-free Daweizi sows and 25 Daweizi boars as the Daweizi maternal base group; select 20 Landrace boars and 150 Landrace sows as the Landrace resource group; and select 15 Duroc boars and 100 Duroc sows as the Duroc resource group. Crossbreed with Daweizi sows as the first maternal line and Landrace boars as the first paternal line. After mating, record the sow's ear tag, boar's ear tag, mating date, farrowing date, litter size, and number of weaned piglets to produce the Landrace-Landrace F1 generation sows. From the Landrace-Landrace F1 generation sows, select 200 sows as parent sows based on body condition, breeding records, weaning weight, 30-day-old weight, and health status.

[0034] S2. Duroc boars were used as terminal sires and mated with Landrace F1 sows to obtain commercial fattening pigs. Reproductive and production performance were measured in the Landrace sow breeding group, Duroc sow breeding group, and Landrace F1 sows. Production performance and meat quality indicators were measured in the commercial fattening pigs. Production performance indicators included birth weight, weaning weight, 30-day body weight, age at 100kg body weight, feed conversion ratio, backfat thickness, and eye muscle area. Meat quality indicators included carcass thickness. Body weight, lean meat percentage, intramuscular fat content, meat color, pH value, drip loss, and shear force were measured. Individual selection was conducted on the main breeding herd of Landrace pigs, Duroc pigs, and F1 generation Landrace sows using a comprehensive selection index method. The comprehensive selection index method involved converting each measured indicator into a standardized score within the same generation, group, and sex, with a maximum score of 100 points. Birth weight, weaning weight, 30-day-old body weight, eye muscle area, carcass weight, and lean meat percentage were also measured. The selection index for the Landrace pig breeding stock was determined by a positive evaluation of intramuscular fat content and a negative evaluation of age at 100kg body weight, feed conversion ratio, backfat thickness, drip loss, and shear force. The comprehensive selection index for the Landrace sow breeding stock consisted of reproductive performance, production performance, and meat quality indicators, with weights of 35%, 25%, and 40%, respectively. The comprehensive selection index for the Duroc pig breeding stock consisted of reproductive performance, production performance, and carcass traits, with weights of 45%, 40%, and 15%, respectively. The comprehensive selection index for the Duroc pig breeding stock consisted of reproductive performance, production performance, and carcass traits, with weights of 20%, 55%, and 25%, respectively. The comprehensive selection index for the Landrace F1 generation sows consisted of reproductive performance, production performance, and meat quality indicators, with weights of 40%, 35%, and 25%, respectively. The sows were ranked from highest to lowest based on their comprehensive selection index. The proportion of boars selected in each generation was 10%, and the proportion of sows selected was 25%. Individuals that did not meet the selection requirements were not included in the next generation breeding stock.

[0035] S3. From weaning of commercial piglets to the end of fattening, add 1.3g of ferulic acid lauryl ester modified compound and 1.75g ​​of eugenol succinic acid monoester compound to 1000.0g of basal diet. First, mix the 1.3g ferulic acid lauryl ester modified compound and 1.75g ​​eugenol succinic acid monoester compound, then premix it with 100.0g of basal diet to obtain a premix. Then, add the premix to 900.0g of basal diet and mix evenly to obtain a special diet for commercial fattening pigs. The closed-group breeding target is the large-encircled piglet sow. Four generations of closed-loop breeding were conducted using the foundation herd, Landrace pig resource herd, Duroc pig resource herd, and Landrace F1 generation sows. Each generation underwent repeated parental testing, commercial generation testing, individual selection using the comprehensive selection index method, and selection and retention operations. Production performance and meat quality were also assessed to establish a high-quality three-way crossbreeding system of Landrace × Duroc pigs. A three-tiered breeding system of core herd, propagation herd, and commercial herd was then established. The commercial herd was used for standardized fattening production by combining ferulic acid lauryl ester modified compound and eugenol succinic acid monoester compound.

[0036] Preparation steps of ferulic acid lauryl ester modified compounds:

[0037] A1. Add 15.0g ferulic acid, 70.0g 1-dodecyl alcohol, 1.0g p-toluenesulfonic acid monohydrate, and 180.0g toluene to a reaction vessel equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet. First, add toluene, then add ferulic acid, 1-dodecyl alcohol, and p-toluenesulfonic acid monohydrate in sequence. Purge the air in the reaction vessel with nitrogen for 15 minutes and maintain nitrogen protection during the reaction. Start stirring to form a homogeneous reaction system of ferulic acid, 1-dodecyl alcohol, p-toluenesulfonic acid monohydrate, and toluene. Heat to 111°C and maintain reflux for 14 hours. Remove the generated water using a water separator. During the reaction, the condensate is continuously refluxed back into the reaction vessel. After the reaction is completed, stop heating and cool to 25°C. Distill off the toluene under reduced pressure of 0.08MPa until no obvious fraction is distilled off to obtain crude ferulic acid lauryl ester intermediate.

[0038] A2. Take 9.0 g of crude ferulic acid lauryl ester intermediate, add 110.0 g of ethyl acetate, and stir at 27.5°C until the crude ferulic acid lauryl ester intermediate is fully dissolved to obtain the ethyl acetate phase; add 50.0 g of 5% sodium bicarbonate aqueous solution to the ethyl acetate phase for washing, shake to mix, and allow to stand for layering, collect the organic phase, repeat the washing once with 5% sodium bicarbonate aqueous solution, and then wash the organic phase with 50.0 g of saturated brine, allow to stand for layering, and collect the organic phase; add 10.0 g of anhydrous sodium sulfate to the organic phase and dry for 1 h, filter to remove anhydrous sodium sulfate, and obtain the filtrate; add 0.065 g of 2,6-di-tert-butyl-4-methylphenol to the filtrate, and evaporate the ethyl acetate under reduced pressure of 0.08 MPa. The obtained residue is purified by silica gel column chromatography with petroleum ether-ethyl acetate mixed solvent in a volume ratio of 5:1. Collect the target product component, concentrate under reduced pressure, and dry at 40°C until the mass is constant to obtain the ferulic acid lauryl ester modified compound.

[0039] Preparation steps of eugenol succinate monoester compound:

[0040] B1. Add 11.0g eugenol, 8.0g succinic anhydride, 0.4g 4-dimethylaminopyridine, 8.25g triethylamine, and 150.0g anhydrous dichloromethane to a reaction vessel equipped with a stirrer, temperature control device, and nitrogen inlet. First, add the anhydrous dichloromethane, then add eugenol, succinic anhydride, 4-dimethylaminopyridine, and triethylamine sequentially. Purge the air in the reaction vessel with nitrogen for 15 minutes, maintaining nitrogen protection throughout the reaction. Stir the reaction system at 2.5°C for 1.5 hours to ensure uniform dispersion of eugenol, succinic anhydride, 4-dimethylaminopyridine, and triethylamine in the anhydrous dichloromethane. Then, raise the temperature to 27.5°C and stir for 11 hours to obtain the reaction solution. Add the reaction solution... Add 150.0 g of deionized water to the solution for separation. After shaking and mixing, allow the layers to separate and collect the organic phase. Wash the organic phase once with 50.0 g of 1 mol / L hydrochloric acid, allow the layers to separate and collect the organic phase. Wash the organic phase once with 50.0 g of deionized water, allow the layers to separate and collect the organic phase. Wash the organic phase once with 50.0 g of saturated saline solution, allow the layers to separate and collect the organic phase. Add 10.0 g of anhydrous sodium sulfate to the organic phase and dry for 1 h. Filter to remove the anhydrous sodium sulfate. Distill off the anhydrous dichloromethane under reduced pressure of 0.08 MPa. Purify the crude product by silica gel column chromatography using a methanol-dichloromethane mixed solvent with a volume ratio of 1:8. Collect the main component and concentrate under reduced pressure to obtain crude eugenol succinic acid monoester.

[0041] B2. Take 9.0 g of crude eugenol succinate monoester and add it to a mixed solvent of 60.0 g ethanol and water, consisting of 45.0 g ethanol and 15.0 g water. Stir at 65°C until the crude eugenol succinate monoester is fully dissolved. Add 0.03 g of 2,6-di-tert-butyl-4-methylphenol and continue stirring for 20 min. Filter while hot to obtain the filtrate. Cool the filtrate to 2.5°C and recrystallize at this temperature for 4 h. Filter and collect the precipitated solid. Purify the obtained solid by silica gel column chromatography using a methanol-dichloromethane mixed solvent with a volume ratio of 1:15 as the eluent. Collect the target product fraction, concentrate under reduced pressure, and dry at 40°C until the mass is constant to obtain the eugenol succinate monoester compound.

[0042] Example 2

[0043] The difference between this embodiment and Embodiment 1 is that this embodiment provides a breeding method for a high-quality large-sized piglet breeding line, including the following steps:

[0044] S1. Select 190 sows and 22 boars of the Dawei pig as the Dawei pig maternal base group, select 18 boars and 140 sows of the Landrace pig as the Landrace pig resource group, and select 13 boars and 95 sows of the Duroc pig as the Duroc pig resource group. Crossbreed the Dawei pig sows as the first maternal line and the Landrace boars as the first paternal line to produce the F1 generation of Dawei pig sows. Select 190 sows from the F1 generation of Dawei pig sows as the parent maternal line.

[0045] S2. Duroc boars were used as terminal sires and mated with Landrace F1 generation sows to obtain commercial fattening pigs. Reproductive and production performance were measured in the Landrace, Duroc, and F1 generation sows. Production performance and meat quality indicators were measured in the commercial fattening pigs. Production performance indicators included birth weight, weaning weight, 30-day weight, age at 100kg, feed conversion ratio, backfat thickness, and eye muscle area. Meat quality indicators included carcass weight, lean meat percentage, intramuscular fat content, meat color, pH value, drip loss, and shear force. Individual selection was performed on the Landrace, Duroc, and F1 generation sows using a comprehensive selection index method. The proportion of boars selected in each generation was 8%, and the proportion of sows selected was 22%.

[0046] S3. From weaning of commercial piglets to the end of fattening, 0.8g of ferulic acid lauryl ester modified compound and 1.0g of eugenol succinic acid monoester compound are added to 1000.0g of basic diet. The closed-group breeding targets are the Daweizi pig maternal base group, Landrace pig resource group, Duroc pig resource group and Landrace F1 generation sows. Closed-group breeding is carried out for 4 consecutive generations, and production performance and meat quality are measured and evaluated to establish a high-quality three-way crossbreeding system of Daweizi pig × Landrace pig × Duroc pig. Then, a three-level breeding system of core group, propagation group and commercial group is established. The commercial group is combined with ferulic acid lauryl ester modified compound and eugenol succinic acid monoester compound for standardized fattening production.

[0047] Preparation steps of ferulic acid lauryl ester modified compounds:

[0048] A1. Add 14.0g ferulic acid, 60.0g 1-dodecyl alcohol, 0.8g p-toluenesulfonic acid monohydrate and 170.0g toluene to a reaction vessel equipped with a reflux condenser, a stirring device and a nitrogen introduction device. After purging the air in the reaction vessel with nitrogen, maintain nitrogen protection and start stirring to form a homogeneous reaction system of ferulic acid, 1-dodecyl alcohol, p-toluenesulfonic acid monohydrate and toluene. Then heat to 110°C and reflux for 13h. During the reaction, keep the reaction system under reflux and remove the generated water through a water separator. After the reaction is completed, cool to room temperature and remove toluene by vacuum distillation to obtain crude ferulic acid lauryl ester intermediate.

[0049] A2. Take 8.0 g of crude ferulic acid lauryl ester intermediate, add 100.0 g of ethyl acetate, and stir at 25°C until the crude ferulic acid lauryl ester intermediate is fully dissolved to obtain the ethyl acetate phase. Add 45.0 g of sodium bicarbonate aqueous solution to the ethyl acetate phase for washing, allow to stand and separate into layers, collect the organic phase, wash the organic phase with 45.0 g of saturated brine, allow to stand and separate into layers, collect the organic phase, add 8.0 g of anhydrous sodium sulfate to the organic phase for drying, filter to remove anhydrous sodium sulfate, and obtain the filtrate; add 0.05 g of 2,6-di-tert-butyl-4-methylphenol to the filtrate, remove ethyl acetate by vacuum distillation, purify the residue by silica gel column chromatography, concentrate under reduced pressure, and dry to obtain the ferulic acid lauryl ester modified compound.

[0050] Preparation steps of eugenol succinate monoester compound:

[0051] B1. Add 10.0g eugenol, 7.5g succinic anhydride, 0.3g 4-dimethylaminopyridine, 7.5g triethylamine, and 140.0g anhydrous dichloromethane to a reaction vessel equipped with a stirrer, temperature control device, and nitrogen inlet device. After purging the air in the reaction vessel with nitrogen, maintain nitrogen protection and stir at 0°C for 1 hour to ensure uniform dispersion of eugenol, succinic anhydride, 4-dimethylaminopyridine, and triethylamine in anhydrous dichloromethane. Then raise the temperature to 25°C and stir for 10 hours to obtain... Add 140.0 g of deionized water to the reaction solution for separation. After standing and separating the layers, collect the organic phase. Wash the organic phase successively with 45.0 g of hydrochloric acid, 45.0 g of deionized water and 45.0 g of saturated saline. After each washing, allow the layers to stand and collect the organic phase. Add 8.0 g of anhydrous sodium sulfate to the organic phase and dry it. Filter to remove anhydrous sodium sulfate and remove anhydrous dichloromethane by vacuum distillation. The crude product obtained is purified by silica gel column chromatography and concentrated under reduced pressure to obtain crude eugenol succinate monoester.

[0052] B2. Take 8.0g of crude eugenol succinate monoester and add it to a mixed solvent of 50.0g ethanol and water, consisting of 37.5g ethanol and 12.5g water. Stir at 60°C until the crude eugenol succinate monoester is fully dissolved. Add 0.02g of 2,6-di-tert-butyl-4-methylphenol and continue stirring until homogeneous. Filter while hot to obtain the filtrate. Cool the filtrate to 0°C and recrystallize. Filter and collect the precipitated solid. Purify the obtained solid by silica gel column chromatography, concentrate under reduced pressure, and dry to obtain the eugenol succinate monoester compound.

[0053] Example 3

[0054] The difference between this embodiment and Embodiment 1 is that this embodiment provides a breeding method for a high-quality large-sized piglet breeding line, including the following steps:

[0055] S1. Select 210 sows and 28 boars of the Dawei pig as the Dawei pig maternal base group, select 22 boars and 160 sows of the Landrace pig as the Landrace pig resource group, and select 17 boars and 105 sows of the Duroc pig as the Duroc pig resource group. Crossbreed the Dawei pig sows as the first maternal line and the Landrace boars as the first paternal line to produce the F1 generation of Dawei pig sows. Select 210 sows from the F1 generation of Dawei pig sows as the parent maternal line.

[0056] S2. Duroc boars were used as terminal sires and mated with Landrace F1 generation sows to obtain commercial fattening pigs. Reproductive and production performance were measured in the Landrace, Duroc, and F1 generation sows. Production performance and meat quality indicators were measured in the commercial fattening pigs. Production performance indicators included birth weight, weaning weight, 30-day weight, age at 100kg, feed conversion ratio, backfat thickness, and eye muscle area. Meat quality indicators included carcass weight, lean meat percentage, intramuscular fat content, meat color, pH value, drip loss, and shear force. Individual selection was performed on the Landrace, Duroc, and F1 generation sows using a comprehensive selection index method, with 12% of boars and 28% of sows selected in each generation.

[0057] S3. From weaning of commercial piglets to the end of fattening, 1.8g of ferulic acid lauryl ester modified compound and 2.5g of eugenol succinic acid monoester compound are added to 1000.0g of basic diet. The closed-group breeding targets are the Daweizi pig maternal base group, Landrace pig resource group, Duroc pig resource group and Landrace F1 generation sows. Closed-group breeding is carried out for 5 consecutive generations, and production performance and meat quality are measured and evaluated to establish a high-quality three-way crossbreeding system of Daweizi pig × Landrace pig × Duroc pig. Then, a three-level breeding system of core group, propagation group and commercial group is established. The commercial group is combined with ferulic acid lauryl ester modified compound and eugenol succinic acid monoester compound for standardized fattening production.

[0058] Preparation steps of ferulic acid lauryl ester modified compounds:

[0059] A1. Add 16.0g ferulic acid, 75.0g 1-dodecyl alcohol, 1.2g p-toluenesulfonic acid monohydrate and 190.0g toluene to a reaction vessel equipped with a reflux condenser, a stirring device and a nitrogen introduction device. After purging the air in the reaction vessel with nitrogen, maintain nitrogen protection and start stirring to form a homogeneous reaction system of ferulic acid, 1-dodecyl alcohol, p-toluenesulfonic acid monohydrate and toluene. Then heat to 112°C and reflux for 15h. During the reaction, keep the reaction system under reflux and remove the generated water through a water separator. After the reaction is completed, cool to room temperature and remove toluene by vacuum distillation to obtain crude ferulic acid lauryl ester intermediate.

[0060] A2. Take 10.0 g of crude ferulic acid lauryl ester intermediate, add 120.0 g of ethyl acetate, stir at 30°C until the crude ferulic acid lauryl ester intermediate is fully dissolved to obtain ethyl acetate phase. Add 55.0 g of sodium bicarbonate aqueous solution to the ethyl acetate phase for washing, allow to stand and separate into layers, collect the organic phase, wash the organic phase with 55.0 g of saturated brine, allow to stand and separate into layers, collect the organic phase, add 12.0 g of anhydrous sodium sulfate to the organic phase for drying, filter to remove anhydrous sodium sulfate, and obtain filtrate; add 0.08 g of 2,6-di-tert-butyl-4-methylphenol to the filtrate, remove ethyl acetate by vacuum distillation, purify the residue by silica gel column chromatography, concentrate under reduced pressure, and dry to obtain the ferulic acid lauryl ester modified compound.

[0061] Preparation steps of eugenol succinate monoester compound:

[0062] B1. Add 12.0g eugenol, 8.5g succinic anhydride, 0.5g 4-dimethylaminopyridine, 9.0g triethylamine, and 160.0g anhydrous dichloromethane to a reaction vessel equipped with a stirrer, temperature control device, and nitrogen inlet device. After purging the air in the reaction vessel with nitrogen, maintain nitrogen protection and stir at 5°C for 2 hours to ensure uniform dispersion of eugenol, succinic anhydride, 4-dimethylaminopyridine, and triethylamine in anhydrous dichloromethane. Then raise the temperature to 30°C and stir for 12 hours to obtain... Add 160.0 g of deionized water to the reaction solution for separation. After standing and separating the layers, collect the organic phase. Wash the organic phase successively with 55.0 g of hydrochloric acid, 55.0 g of deionized water and 55.0 g of saturated saline. After each washing, allow the layers to stand and collect the organic phase. Add 12.0 g of anhydrous sodium sulfate to the organic phase and dry it. Filter to remove anhydrous sodium sulfate and remove anhydrous dichloromethane by vacuum distillation. The crude product obtained is purified by silica gel column chromatography and concentrated under reduced pressure to obtain crude eugenol succinate monoester.

[0063] B2. Take 10.0g of crude eugenol succinate monoester and add it to a mixed solvent of 70.0g ethanol and water, consisting of 52.5g ethanol and 17.5g water. Stir at 70°C until the crude eugenol succinate monoester is fully dissolved. Add 0.04g of 2,6-di-tert-butyl-4-methylphenol and continue stirring until homogeneous. Filter while hot to obtain the filtrate. Cool the filtrate to 5°C and recrystallize. Filter and collect the precipitated solid. Purify the obtained solid by silica gel column chromatography, concentrate under reduced pressure, and dry to obtain the eugenol succinate monoester compound.

[0064] Comparative Example 1

[0065] The difference between this comparative example and Example 1 is that, in S3, from the time the commercial piglets are weaned until the end of fattening, neither ferulic acid lauryl ester modified compound nor eugenol succinic acid monoester compound is added to the 1000.0g basal diet. Otherwise, it is the same as Example 1.

[0066] Comparative Example 2

[0067] The difference between this comparative example and Example 1 is that in S3, from the time the commercial piglets are weaned until the end of fattening, only 1.3g of ferulic acid lauryl ester modified compound is added to the 1000.0g basal diet, and no eugenol succinic acid monoester compound is added. The rest is the same as in Example 1.

[0068] Comparative Example 3

[0069] The difference between this comparative example and Example 1 is that in S3, from the time the commercial piglets are weaned until the end of fattening, only 1.75g ​​of eugenol succinic acid monoester compound is added to the 1000.0g basal diet, and no ferulic acid lauryl ester modified compound is added. The rest is the same as in Example 1.

[0070] A series of standardized tests were conducted on the breeding methods of the high-quality large-sized pig breeding lines described in Examples 1-3 and Comparative Examples 1-3.

[0071] The commercial fattening pigs obtained from Examples 1, 2, 3, 1, 2, and 3 were used as test subjects. For each group, 60 commercial fattening pigs with consistent health status, sex ratio, weaning age, and initial weight difference not exceeding ±5% were selected. Each group had 3 replicates with 20 pigs in each replicate. The experimental pigs were raised in the same pig house under the same drinking water method, the same immunization program, the same stocking density, and the same basal diet management method. The experiment started after the commercial piglets were weaned and ended when the average weight reached about 100 kg.

[0072] When determining the average daily weight gain, the weight of each commercial fattening pig was measured on an empty stomach at 08:00 on the first and last days of the experiment. The initial weight, final weight, and number of fattening days were recorded. The average daily weight gain was calculated by subtracting the initial weight from the final weight and dividing by the number of fattening days. The result is expressed in g / d.

[0073] When determining the feed conversion ratio, the amount of feed fed and the amount of feed left over are recorded daily in replicates. The actual feed intake for each replicate is calculated, and the feed conversion ratio is obtained by dividing the actual feed intake during the fattening period by the total weight gain of commercial fattening pigs in the same period.

[0074] When determining the age at which the pigs reach 100kg weight, the experimental pigs were weighed regularly, and the age at which each commercial fattening pig reached 100kg weight was recorded. For individuals that did not reach exactly 100kg weight, the age at which they reached 100kg weight was calculated by linear interpolation based on the data from two consecutive weighings. The result is represented by d.

[0075] When determining carcass weight, 12 commercial fattening pigs close to the average weight of the group were selected from each group after the fattening period. After fasting for no less than 12 hours, they were slaughtered. After slaughter, the head, hooves, internal organs and blood were removed according to a uniform trimming method, and the weight of the hot carcass was measured. The result is expressed in kg.

[0076] To determine the intramuscular fat content, the longest back muscle sample was taken after slaughter. Visible fascia and exogenous fat were removed, and the sample was minced and mixed thoroughly. A representative sample was then taken, dried until the mass was constant, and then Soxhlet extraction was performed with petroleum ether. After extraction, the solvent was recovered and the fat residue was dried. The intramuscular fat content was calculated based on the proportion of fat mass to the mass of the dried meat sample, and the result was expressed as a percentage (%).

[0077] For the determination of drip loss, the longest muscle sample was taken after slaughter, cut into pieces of uniform thickness and with consistent muscle fiber direction, and the surface free water was absorbed. The initial mass was then weighed. The meat sample was placed in a suspended state without contacting the container wall and stored at 4°C for 24 hours. After being taken out, the surface moisture was absorbed and the sample was weighed again. The drip loss was calculated based on the ratio of the difference between the initial mass and the mass after storage to the initial mass. The result was expressed as a percentage. For each test item, the average value of all valid data in each group was taken as the final result.

[0078] The performance test data above are shown in Table 1.

[0079] Table 1 Performance Test Results

[0080] As can be seen from the above, Examples 1-3 showed significant improvements over Comparative Examples 1-3 in terms of growth performance, feed utilization efficiency, slaughter efficiency, carcass performance, and meat quality stability.

[0081] Compared with Comparative Example 1, which did not contain the modified compound of ferulic acid lauryl ester and the compound of eugenol succinic acid monoester, the average daily weight gain in Examples 1-3 increased from 748 g / d to 815-858 g / d, an increase of 67-110 g / d; the feed conversion ratio decreased from 2.91 to 2.53-2.66, indicating a reduction in feed consumption required for the same weight gain; the age at which the pigs reached 100 kg body weight decreased from 177 days to 161-168 days, a reduction of 9-16 days, indicating an increased rate of market exit for commercial fattening pigs; the carcass weight increased from 71.4 kg to 75.2-77.6 kg, an increase of 3.8-6.2 kg, indicating an increase in carcass production after fattening; the intramuscular fat content increased from 3.36% to 4.08-4.41%, indicating improved meat deposition; and the drip loss decreased from 3.42% to 1.75-2.05%, indicating improved water retention of the meat.

[0082] Compared with Comparative Example 2, which only added ferulic acid lauryl ester modified compound, Examples 1-3 showed an average daily weight gain of 26-69 g / d, a feed conversion ratio of 0.10-0.23, a 3-10 day reduction in the age to reach 100 kg body weight, a 1.3-3.7 kg increase in carcass weight, a 0.36-0.69 percentage point increase in intramuscular fat content, and a 0.69-0.99 percentage point reduction in drip loss.

[0083] Compared with Comparative Example 3, which only added eugenol succinate monoester, Examples 1-3 showed an average daily weight gain increase of 37-80 g / d, a feed conversion ratio decrease of 0.15-0.28, a 5-12 day reduction in the age to reach 100 kg body weight, a 2.1-4.5 kg increase in carcass weight, a 0.27-0.60 percentage point increase in intramuscular fat content, and a 0.56-0.86 percentage point reduction in drip loss.

[0084] The above results indicate that the combined effect of ferulic acid lauryl ester modified compound and eugenol succinic acid monoester compound is better than that of adding ferulic acid lauryl ester modified compound or eugenol succinic acid monoester compound alone. This can solve the problems of insufficient growth rate, low feed utilization rate, long slaughter cycle, insufficient carcass output, unstable intramuscular fat deposition, and poor water retention of meat in existing high-quality large-scale pig breeding systems for commercial fattening pigs.

[0085] Meanwhile, Examples 1-3 combine the continuous closed-loop breeding of large-scale breeding sows, Landrace pig resource groups, Duroc pig resource groups, and Landrace F1 generation sows with standardized feeding of commercial fattening pigs, so that the genetic selection, commercial verification, and nutritional regulation of the three-way crossbred system are in a corresponding relationship, thereby improving the production performance and meat quality stability of commercial fattening pigs while maintaining the basic quality of local pork.

Claims

1. A breeding method for a high-quality large-sized pig breeding system, characterized by the following steps: include: S1. Select large-bred sows and large-bred boars as the basic maternal line of large-bred pigs; Landrace boars and Landrace sows were selected as the Landrace pig resource group, and Duroc boars and Duroc sows were selected as the Duroc pig resource group; Large White sows were used as the first maternal line and Landrace boars were used as the first paternal line to crossbreed and produce Large White F1 generation sows; Sows were selected from the F1 generation of Large White pigs to serve as parent sows; S2. Duroc boars were used as terminal sires and mated with Landrace F1 generation sows to obtain commercial fattening pigs. The reproductive and production performance of the Landrace, Duroc, and F1 generation sows were measured, and the production performance and meat quality of the commercial fattening pigs were measured. Individual selection was carried out on the Landrace, Duroc, and F1 generation sows using the comprehensive selection index method, and boars and sows were selected in each generation. S3. From the time commercial piglets are weaned until the end of fattening, ferulic acid lauryl ester modified compound and eugenol succinic acid monoester compound are added to the basal diet; closed-group selection is carried out. Production performance testing and meat quality assessment were conducted to establish a high-quality three-way crossbreeding system of Landrace pigs × Duroc pigs. A three-tiered breeding system of core group, propagation group, and commercial group was then established. The commercial group was fed with a standardized fattening production using a modified compound of ferulic acid lauryl ester and a compound of eugenol succinic acid monoester.

2. The breeding method for the high-quality large-sized piglet breeding system according to claim 1, characterized in that, In step S1, select 190-210 large-breasted sows and 22-28 large-breasted boars; select 18-22 Landrace boars and 140-160 Landrace sows; select 13-17 Duroc boars and 95-105 Duroc sows; and select 190-210 sows from the F1 generation of large-breasted sows.

3. The breeding method for the high-quality large-sized piglet breeding system according to claim 1, characterized in that, In step S2, the production performance indicators include: birth weight, weaning weight, body weight at 30 days of age, age at 100kg body weight, feed conversion ratio, backfat thickness, and eye muscle area; the meat quality indicators include: carcass weight, lean meat percentage, intramuscular fat content, meat color, pH value, drip loss, and shear force; the proportion of boars selected per generation is 8-12%, and the proportion of sows is 22-28%.

4. The breeding method for the high-quality large-sized piglet breeding system according to claim 1, characterized in that, In step S3, the closed-group breeding targets are large-bred sows, Landrace pigs, Duroc pigs, and Landrace F1 generation sows. The proportion of ferulic acid lauryl ester modified compound added to the basal diet was 0.08-0.18%, and the proportion of eugenol succinic acid monoester compound was 0.10-0.25%; closed group selection was carried out for 4-5 generations.

5. The breeding method for the high-quality large-sized piglet breeding system according to claim 1, characterized in that, The preparation method of the ferulic acid lauryl ester modified compound includes: A1. By weight, 14.0-16.0 parts of ferulic acid, 60.0-75.0 parts of 1-dodecyl alcohol, 0.8-1.2 parts of p-toluenesulfonic acid monohydrate and 170-190 parts of toluene are mixed and reacted under nitrogen protection at 110-112℃. The generated water is removed by a water separator, cooled to room temperature, and distilled under reduced pressure to obtain crude ferulic acid lauryl ester intermediate. A2. Mix 8.0-10.0 parts of crude crude ferulic acid lauryl ester intermediate with 100-120 parts of ethyl acetate, stir, wash successively with sodium bicarbonate aqueous solution and saturated brine, dry with anhydrous sodium sulfate, filter to obtain filtrate, add 0.05-0.08 parts of 2,6-di-tert-butyl-4-methylphenol to filtrate, distill under reduced pressure, purify by silica gel column chromatography, concentrate under reduced pressure, and dry.

6. The breeding method for the high-quality large-sized piglet breeding system according to claim 5, characterized in that, In step A1, the reflux reaction at 110-112℃ takes 13-15 hours.

7. The breeding method for the high-quality large-sized piglet breeding system according to claim 5, characterized in that, In step A2, the stirring temperature is 25-30℃.

8. The breeding method for the high-quality large-sized piglet breeding system according to claim 1, characterized in that, The preparation method of the eugenol succinic acid monoester compound includes: B1. By weight, 10.0-12.0 parts of eugenol, 7.5-8.5 parts of succinic anhydride, 0.3-0.5 parts of 4-dimethylaminopyridine, 7.5-9.0 parts of triethylamine, and 140-160 parts of anhydrous dichloromethane are mixed and stirred at 0-5°C under nitrogen protection; then the temperature is raised to 25-30°C and the mixture is stirred to obtain a reaction solution; 140-160 parts of deionized water are added to the reaction solution for separation, and the organic phase is collected. The organic phase is washed successively with hydrochloric acid, deionized water, and saturated brine, dried over anhydrous sodium sulfate, purified by vacuum distillation, purified by silica gel column chromatography, and concentrated under vacuum to obtain crude eugenol succinic acid monoester. B2. Add 8.0-10.0 parts of crude eugenol succinate monoester to a mixed solvent of 50.0-70.0 parts of ethanol and water, stir at 60-70℃, add 0.02-0.04 parts of 2,6-di-tert-butyl-4-methylphenol, stir, filter, and obtain filtrate; cool the filtrate, recrystallize, filter, purify by silica gel column chromatography, concentrate under reduced pressure, and dry.

9. The breeding method for the high-quality large-sized piglet breeding system according to claim 8, characterized in that, In step B1, the stirring time at 0-5℃ is 1-2 hours; the stirring reaction time at 25-30℃ is 10-12 hours.

10. The breeding method for the high-quality large-sized piglet breeding system according to claim 8, characterized in that, In step B2, the filtrate is cooled to 0-5°C.

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