A method for breeding Qinglian black pigs

Abstract

The present invention discloses a method for breeding Qinglian black pigs, which relates to the field of animal husbandry industry production. The breeding method of the Qinglian black pig is as follows: Jiaxing black pigs are used as sows, and Berkshire pigs and Duroc pigs are used as sires for progressive crossbreeding to obtain a zero-generation basic group. After four generations of group successive breeding, a Qinglian black pig variety containing 12.5% ​​Jiaxing black pig bloodline, 12.5% ​​Berkshire pig bloodline, and 75% Duroc pig bloodline is obtained. It adopts modern genetic breeding methods and has been bred for multiple generations. The Qinglian black pig has a fast growth rate, a high carcass lean meat rate, and excellent meat quality. It can produce high-quality commercial pigs or serve as the terminal sire for black pig production.

Description

Technical Field

[0001] The invention belongs to the field of animal husbandry industry production, and particularly relates to a Qinglian black pig breeding method. Background Art

[0002] The Jiaxing Black Pig is a renowned local breed in my country, a major subgroup of the Taihu Lake pig family. It is renowned for its high fertility, early sexual maturity, tolerance to roughage, delicious meat, and remarkable hybridization. The Jiaxing Black Pig originates from various counties (cities, and districts) in Jiaxing City, Zhejiang Province, primarily in Xiuzhou District, Jiashan County, Pinghu City, and Haiyan County. The production areas boast a long history of pig farming. The high fertility and excellent meat quality of the Jiaxing Black Pig are highly valued traits, offering significant value in improving litter size and meat quality in low-yielding breeds.

[0003] Due to their slow growth rate, low market yield, low slaughter rate, low lean meat percentage, and poor feed conversion rate, my country's indigenous pig breeds are unable to adapt to the industrialization of the pig farming industry and meet the growing market demand for lean pork, resulting in a continuous decline in pig herd size. Large-scale pig farms have overemphasized lean meat percentage, and the long-term development of the "foreign three-way" hybrid breeding system has resulted in a significant decline in meat quality, characterized by coarse muscle fibers, a lack of intramuscular fat, and a lack of the characteristic pork flavor. In contrast, my country's indigenous pig breeds offer delicious, tender, juicy meat. Their fine, small muscle fibers produce pronounced marbling after slaughter, creating a beautiful, dense, and even pattern that is the key to high-quality meat. For many domestic consumers, this has led to a renewed demand for high-quality pork (high intramuscular fat), prompting a shift towards the high intramuscular fat pork produced by indigenous pig breeds.

[0004] Modern pig breeding has therefore shifted its focus to high-quality pigs, with a preference for utilizing local black pig breeds. To meet market demand for higher-quality and more diversified pork, and to better protect and develop the Jiaxing Black Pig, a renowned local pig breed in Zhejiang Province, it is necessary to develop high-quality black pig breeds. Studies have found that Duroc and Berkshire pigs not only exhibit rapid growth and high meat production, but also excellent meat quality, making them commonly used as terminal sires. Berkshire pigs are the oldest cultivated pig breed in the UK, with a history of over 300 years and a pure breeding record of over 200 years. Berkshire pigs hold a significant position in the global pig breeding landscape due to their superior meat quality and high yield of marbling, particularly the prominent marbling of the front shoulder. Furthermore, of the 16 cultivated breeds developed from my country's local pig genetic resources, Duroc pigs are the most frequently used, but Berkshire pigs are not currently used among my country's established local pig breeds. Therefore, the introduced breeds Duroc and Berkshire pigs are the most promising paternal pigs in my country's local pig breeding system, and are involved in the breeding system of Jiaxing black pig breeding breed Qinglian black pig.

[0005] The main purpose of breeding the new breed of Qinglian black pig is to combine the characteristics of Jiaxing black pigs, such as large litter size and excellent meat quality, Berkshire pigs, which have excellent pork quality and high carcass lean meat rate, and Duroc pigs, which have fast growth rate and high carcass lean meat rate. The new breed has the production performance characteristics of fast growth rate and high carcass lean meat rate, as well as relatively high litter size and excellent meat quality, which can meet the market demand for high-quality black pork and has important practical significance and broad prospects for development and utilization. Summary of the Invention

[0006] The purpose of the present invention is to provide a Qinglian black pig breeding method, and the obtained Qinglian black pig new breed has a fast growth rate, a high lean meat rate, good meat quality and high reproductive performance.

[0007] The technical solutions adopted by the present invention to achieve the above-mentioned purpose are:

[0008] A Qinglian black pig breeding method comprising:

[0009] Step 1: Using Jiaxing black sows as the female parent and Berkshire boars as the male parent, conduct the first crossbreeding to establish the first generation of Bajia sows;

[0010] Step 2: Using the hybrid first-generation Bajia sow as the female parent and the imported American Duroc boar as the male parent, a second hybridization is performed to establish the hybrid second-generation Duroc sow;

[0011] Step 3: Using the hybrid second-generation Duroc sows as the female parent and the imported American Duroc boars as the sire, a third hybridization was conducted to establish the zero-generation foundation group of the new Qinglian Black Pig breed;

[0012] Step 4: Implement closed-line breeding, allowing only male and female pigs in the zero-generation base group to mate and reproduce. Use group successive breeding methods and gene-assisted breeding methods to carry out breeding for four consecutive generations to breed the new Qinglian Black Pig variety.

[0013] The meat quality PH1 of the above-mentioned new Qinglian Black Pig breed is greater than 6, the meat color score and marbling score are 2.5-3.5, and the intramuscular fat content is greater than 4.0%.

[0014] Specifically, the above-mentioned Qinglian Black Pig breeding method includes:

[0015] Step 1: Use Jiaxing black sows as the female parent and Berkshire boars as the male parent for the first crossbreeding. After the offspring are produced, the boars are eliminated and the sows with completely black coats are selected to establish the first generation of Bajia hybrid sows.

[0016] The second step: using the hybrid first-generation Bajia sow as the female parent and the imported American Duroc boar as the sire, a second hybridization is carried out. The boars are eliminated from the offspring and the sows with full black coat are selected to establish the hybrid second-generation Duroc sows.

[0017] The third step: using the hybrid second-generation Duroc sow as the female parent and the imported American Duroc boar as the sire, a third crossbreeding is carried out to produce offspring, and boars and sows with completely black coats are selected to form the zero-generation foundation group of the new Qinglian Black Pig breed;

[0018] Step 4: Implement closed-lineage breeding, allowing only male and female pigs within the zero-generation base group to mate and reproduce, and no longer introduce Duroc boar and female pig bloodlines; use group successive breeding methods and gene-assisted breeding methods, one generation per year, for four consecutive generations to breed the new Qinglian Black Pig variety;

[0019] Preferably, the average daily weight gain of the above-mentioned new Qinglian black pig breed during the fattening period is more than 800g; the lean meat rate of the carcass is 55-65%.

[0020] Preferably, in the first step, the ratio of the number of male and female individuals is 1:13-18.

[0021] Preferably, in the above second step, the ratio of the number of male parents to that of female parents is 1:15-20.

[0022] Preferably, in the third step, the ratio of the number of male and female individuals is 1:10-15.

[0023] The new breed cultivated by the present invention concentrates the advantages of three breeds and has the excellent performances of good reproductive performance, excellent meat quality, fast growth rate, high feed utilization rate, high carcass lean meat rate and strong adaptability.

[0024] The new Qinglian black pig variety of the present invention can be used for pure breeding to produce high-end lean commercial pork; it can also be used as the terminal paternal parent of the black pig matching system to ensure the black hair rate of commercial pigs.

[0025] The Jiaxing Black pig, a Jianghai-type pig breed in my country, is medium-sized, with a sparse, short, and soft black coat. It has a large head and broad forehead, a long, slightly concave muzzle, a prominent forehead wrinkle, large, pendulous ears, a long back and loin, a slightly pendulous but tight abdomen, strong and robust bones, and less muscular buttocks. The main production area is located in the counties (cities and districts) of Jiaxing City, Zhejiang Province. Jiaxing Qinglian Black Pig Breeding Farm Co., Ltd. currently maintains 387 Jiaxing Black pig sows. The Jiaxing Black pig is listed on the National List of Protected Local Pig Breeds, providing valuable genetic resources for the development of new breeding pig breeds.

[0026] After studying the genetic characteristics of Jiaxing Black Pig, its characteristics are as follows:

[0027] (1) Reproductive performance: The average litter size of primiparous sows was 12.56±1.73 piglets, and the average number of live piglets born was 11.99±1.50 piglets; the average litter size of multiparous sows was 14.81±1.04 piglets, and the average number of live piglets born was 13.80±1.37 piglets.

[0028] (2) Growth and development: The birth weight of piglets is 1.01 kg, the weaning weight at 28 days is 4.75 kg, and the adult sow weighs 108.28 kg, with a body height of 69.41 cm, a body length of 124.30 cm, and a chest circumference of 111.16 cm.

[0029] (3) Fattening performance: Body weight 25~75kg, under the condition of daily diet containing digestible energy 11.75MJ / kg and crude protein 13.5%, the average daily weight gain is 421g, feed consumption per kg weight gain is 4.06kg, slaughter rate is 66.47%, average back fat thickness is 2.76cm, and carcass lean meat rate is 45.65%.

[0030] Foreign lean meat breed Berkshire pig:

[0031] The Berkshire pig, originating from Buckshire, England, is one of the oldest cultivated breeds in the world. Its coat color is quite distinctive, owing to its striking "Six Whites": white on the muzzle, limbs, and tail tip, with the rest of the body black. They are tall and slender, with a well-arched back, a slightly concave head, strong limbs, and a muscular body.

[0032] (1) Reproductive performance: The average litter size of multiparous sows is 9.18 piglets.

[0033] (2) Fattening performance: The average daily weight gain during the body weight period of 25kg~110kg was 801.91g, the feed utilization rate was 3.13, and the carcass lean meat rate was about 58.13%.

[0034] Foreign lean meat breed Duroc pig:

[0035] The Duroc pig, originating in New Jersey and New York in the eastern United States, is currently the most widely distributed breed in the country and one of the most popular breeds worldwide. It features a reddish-brown coat, a well-proportioned and compact build, sturdy limbs, a deep and broad body, and well-developed muscles. It is a lean, meat-producing breed. Its head is of medium size and relatively delicate, with a slightly concave face and a short, straight muzzle. Its ears are medium-sized, tilted forward with slightly curved tips. Its chest is broad and deep, its back and loins are slightly arched, its abdomen is straight, and its limbs are strong.

[0036] (1) Reproductive performance: The average litter size of multiparous sows is 10.2 piglets.

[0037] (2) Fattening performance: The average daily weight gain during the body weight period of 25kg~110kg is 839.91g, the feed utilization rate is about 2.6, and the carcass lean meat rate is about 65.69%.

[0038] The present invention also discloses a breeding method for the hybrid first-generation Bajia sows, comprising: when the offspring produced by the first hybridization are weaned at the age of 26-30 days, the offspring are selected, and the offspring have a completely black coat, a body weight of ≥5.0 kg, more than 7 pairs of effective nipples, and no genetic diseases among the same litter; when the offspring are fed with feed to the age of 88-92 days, a second selection is carried out to eliminate individuals with poor growth and development, short body and small body weight; then, when the offspring are 178-183 days old, a comprehensive selection index is formulated based on the body weight, live back fat thickness, and appearance score, and selection is carried out based on the index; thus, the hybrid first-generation Bajia sows are obtained.

[0039] The present invention also discloses a breeding method for the above-mentioned hybrid second-generation Durbarga sows, comprising: selecting offspring produced by the second hybridization at the time of weaning at the age of 26-30 days, wherein the offspring have a completely black coat, a body weight of ≥5.5 kg, more than 7 pairs of effective nipples, and no genetic diseases in the same litter; conducting a second selection when the sows are fed with feed to the age of 88-92 days, mainly eliminating individuals with poor growth and development, short body and small body weight; then conducting a third selection at the age of 178-183 days, formulating a comprehensive selection index based on body weight, live backfat thickness, and appearance score, and selecting according to the index; thereby obtaining hybrid second-generation Durbarga sows.

[0040] The present invention also discloses a breeding method for the zero generation of the new Qinglian black pig variety, comprising: a third hybridization to produce offspring, and when weaning at the age of 26-30 days, the selected offspring have completely black fur, weigh ≥6.0 kg, have more than 7 pairs of effective nipples, and have no genetic diseases in the same litter; a second selection is carried out when the pigs are fed with feed to the age of 88-92 days, and mainly eliminate individuals with poor growth and development, short body and small weight; then a third selection is carried out at the age of 178-183 days, and a comprehensive selection index is formulated based on body weight, live back fat thickness, and appearance score, and selection is carried out based on the index; a fourth selection is carried out when the sows are weaned after their first birth, and the sows are selected based on their own litter size, and the boars are selected based on the litter size of their fellow sows, and both are selected according to the comprehensive breeding value of litter size.

[0041] Preferably, during the above four generations of breeding, the sows selected for breeding are 7-8 months old and weigh 110-130 kg; the boars selected for breeding are 8.5-9.5 months old and weigh 125-135 kg.

[0042] The breeding method of the new breed Qinglian black pig of the present invention adopts a combination of modern conventional breeding technology, namely group successive breeding and gene-assisted breeding technology.

[0043] Modern conventional breeding techniques include: selection and hybridization of starting parent pig herds, establishment of breeding zero-generation basic herds, formulation of breeding pig selection programs, breeding pig performance testing and selection, and formulation of mating programs.

[0044] Gene-assisted breeding technology includes: selecting and utilizing specific sites of the MC1R gene that controls the black color of pig hair, continuously selecting dominant homozygous (AA-GG-CC) offspring from the first to the second generation, and quickly fixing the black hair trait.

[0045] The new breed of Qinglian Black Pig provided by the present invention has the following characteristics: a black coat, a medium-sized, delicate head, a medium-length, straight snout, medium-sized, forward-tilted ears, a straight back and waist, a well-connected gluteal joint, a long, deep, and broad body, full muscles, strong limbs, and at least seven pairs of nipples.

[0046] Preferably, the gene-assisted breeding method includes: the starting parents of the new breed, Jiaxing black sows, Berkshire boars, and Duroc boars, are each tested for halothane gene Hal using PCR-RELP method, and the genotype of Hal is eliminated. nn Of the breeding pigs, only the genotype Hal NN The breeding pigs are selected to ensure that the genetic background of the starting parent group is excellent, so that the new breed will not produce PSE and DFD inferior meat.

[0047] In the first generation of group breeding, gene-assisted selection (GAS) was applied to develop new breeds. The MC1R gene, which controls coat color, was selected to select male and female pigs with dominant homozygous AA-GG-CC patterns. This assisted selection method rapidly stabilized the black coat trait after the first and second generations.

[0048] The selection and selection index of breeding pigs at each stage are as follows:

[0049] First stage selection:

[0050] Selection time: When piglets are weaned at 26-30 days of age;

[0051] Selection principles: keep as many boars as possible in the initial selection and preserve the boar bloodline as much as possible;

[0052] Selection method: 1. First, eliminate all litters of piglets with genetic defects and individuals with disqualified appearance (referring to coat color, head shape, and number of teats that do not meet the breed requirements); 2. Mainly select the number of piglets born, based on the composite breeding value of the mother's litter size, combined with the growth and development of the piglets, and mainly select one boar and more than three sows from each litter for growth and development measurement (males and females are raised in separate groups).

[0053] Select from first-parity sows litters with more than 9 piglets;

[0054] The weaning weight should be above the average weight of the whole herd during the same period;

[0055] Appearance: Full black coat, head shape and body shape meet breed requirements, and the number of teats is not less than 14;

[0056] Formula for composite breeding value of litter size: I x=b0+b1p1+b2p2+b3p3;

[0057] Selection intensity: about 15%~20% for boars and about 75% for sows.

[0058] Second stage selection:

[0059] Selection time: 88-92 days old;

[0060] Selection principles: Eliminate some boars and sows with poor growth and development or genetic defects;

[0061] Selection Method: Individual performance selection will be conducted, eliminating those with poor body shape and appearance, daily weight gain below 1.5 standard deviations, genetic defects, and illnesses. Body shape and appearance requirements conform to the lean type: compact neck and shoulders, straight and long back and waist, and plump legs and hips.

[0062] Phase 3 selection:

[0063] Selection time: 178-183 days old;

[0064] Selection principle: This is the key selection stage, using the multi-trait animal model best linear unbiased estimation method (MTBLUP) to estimate individual breeding values. According to the breeding value ranking, strengthen the selection intensity and eliminate more;

[0065] Selection Method: 1. First, appearance assessment and scoring are conducted. Those that fail the assessment will not be included in performance testing and index selection. 2. Index selection: This is composed of two traits: age at reaching 100 kg body weight and backfat thickness at reaching 100 kg body weight. 3. Genetic evaluation is performed using breeding software, and selection is made based on index ranking and body appearance scores.

[0066] The calculation formula of paternal index and maternal index is:

[0067] Paternity Index:

[0068]

[0069] If the paternity index is standardized, that is, the mean is 100 and the standard deviation is 25, it becomes:

[0070]

[0071] Among them: EBV day : To correct the estimated breeding value at 100 kg age;

[0072] EBV bf : Estimated breeding value corrected for backfat thickness up to 100 kg;

[0073] σ day : Standard deviation of the estimated breeding value corrected for 100 kg age;

[0074] σ bf : Standard deviation of the estimated breeding values ​​corrected for backfat thickness up to 100 kg;

[0075] σ I : is the standard deviation of I before standardization;

[0076] Ī: the average value of I before standardization;

[0077] Maternal Index:

[0078]

[0079] If the maternal index is standardized, that is, the mean is 100 and the standard deviation is 25, it becomes:

[0080]

[0081] Among them: EBV day : To correct the estimated breeding value at 100 kg age;

[0082] EBV bf : Estimated breeding value corrected for backfat thickness up to 100 kg;

[0083] EBV tnb : Estimated breeding value of total litter size;

[0084] σ day : Standard deviation of the estimated breeding value corrected for 100 kg age;

[0085] σ bf : Standard deviation of the estimated breeding values ​​corrected for backfat thickness up to 100 kg;

[0086] σ tnb : standard deviation of the estimated breeding value for total litter size;

[0087] σ I : is the standard deviation of I before standardization;

[0088] Ī: the average value of I before standardization;

[0089] Selection intensity: boar selection is about 10% to 20% of the number of sows selected at the weaning stage, and sow selection is about 30% of the number of sows selected at the weaning stage.

[0090] Preferably, the feed comprises: fish meal, montmorillonite powder, eggshell powder, starch derivatives, rapeseed cake, salt, wheat, corn, bone meal and styrax oil.

[0091] The present invention also discloses a method for preparing the feed, comprising:

[0092] Fish meal, montmorillonite powder, eggshell powder, starch derivative, rapeseed cake, salt, wheat, corn, bone meal and styrax oil are mixed uniformly and then ground to obtain feed.

[0093] Preferably, in the above feed, by weight, the amount of fish meal is 2-5 parts, the amount of montmorillonite powder is 1-2 parts, the amount of eggshell powder is 5-10 parts, the amount of starch derivative is 3-5 parts, the amount of rapeseed cake is 5-10 parts, the amount of salt is 2-5 parts, the amount of wheat is 20-30 parts, the amount of corn is 20-40 parts, the amount of bone meal is 1-2 parts, and the amount of storax oil is 2-5 parts.

[0094] The invention also discloses the use of the styrax oil in preparing pig feed.

[0095] According to the invention, styrax oil is added in the process of preparing the feed, and then the feed is used for feeding pigs, so that the pigs have good reproductive performance and feed utilization rate.

[0096] The present invention also discloses a method for preparing a starch derivative, which comprises: carrying out a grafting reaction between S-allyl-L-cysteine ​​and allyl cinnamate and starch to prepare the starch derivative.

[0097] The present invention provides a method for preparing starch derivatives. S-allyl-L-cysteine ​​and allyl cinnamate are used as modifiers to graft-modify starch. The obtained starch derivatives are used for preparing feed, and then used for feeding pigs, so that the pigs have good reproductive performance, carcass lean meat rate and feed utilization rate.

[0098] Specifically, the preparation method of the starch derivative comprises the following steps:

[0099] Under the condition of 0-5°C, deionized water is added to starch, and after stirring and mixing evenly, S-allyl-L-cysteine ​​and allyl cinnamate are added, and after stirring and mixing for 10-15 minutes, sodium persulfate and anhydrous sodium sulfite are added, and then Span-80 is added. Under a nitrogen atmosphere, the mixture is stirred at 8-15°C for 25-40 minutes, and then the temperature is raised to 45-55°C, and the reaction is stirred for 2.5-4 hours. The mixture is washed alternately with anhydrous ethanol and acetone for 3-5 times, filtered, and dried to obtain a starch derivative.

[0100] Preferably, the mass volume ratio of the above-mentioned starch to deionized water is: 1 g: 20-30 mL; the molar ratio of S-allyl-L-cysteine ​​to allyl cinnamate is: 1:0.5-1.5; the mass ratio of starch to S-allyl-L-cysteine ​​is: 1:3-5; the mass ratio of starch to sodium persulfate is: 1:0.05-0.08; the mass ratio of starch to anhydrous sodium sulfite is: 1:0.025-0.04; and the mass ratio of starch to Span-80 is: 1:1-2.5.

[0101] The invention also discloses the use of the starch derivative prepared by the preparation method in the breeding of Qinglian black pigs.

[0102] The beneficial effects of the present invention include:

[0103] The present invention provides a breeding method for Qinglian Black pigs. This method involves progressively crossbreeding Jiaxing Black pigs with Berkshire and Duroc sires to obtain a zero-generation base group. After four generations of successive breeding, the resulting Qinglian Black pig breed contains 12.5% ​​Jiaxing Black pig ancestry, 12.5% ​​Berkshire pig ancestry, and 75% Duroc pig ancestry. This method utilizes modern genetic breeding methods and has been continuously bred over multiple generations. Qinglian Black pigs exhibit rapid growth, a high carcass lean meat percentage, and excellent meat quality, making them suitable for producing high-quality commercial pigs or serving as terminal sires for black pig production.

[0104] Therefore, the present invention provides a Qinglian black pig breeding method, and the obtained Qinglian black pig new breed has a fast growth rate, a high lean meat rate, good meat quality and high reproductive performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0105] Figure 1 This is the technical roadmap for the breeding method of the new variety Qinglian Black Pig in Example 1;

[0106] Figure 2 The peak diagram of the three mutation sites of the MC1R gene in Example 1;

[0107] Figure 3 These are the infrared spectrum test results of the starch derivative and starch prepared in Example 1. DETAILED DESCRIPTION

[0108] In order to make the purpose, technical solutions and advantages of the present invention more clear, the technical solutions of the present invention are further described in detail below in conjunction with specific embodiments:

[0109] Example 1:

[0110] A Qinglian black pig breeding method comprising:

[0111] Step 1: Perform PCR-RFLP testing on each American Berkshire pig to eliminate those containing Hal nnBerkshire boars were crossbred with 10 imported American Berkshire boars and 150 Jiaxing Black sows, a local breed in Zhejiang Province, to produce the first-generation hybrid Bajia pigs. The boars were eliminated and sows with all-black coats were selected. The Bajia sows contain 50% Berkshire pig ancestry and 50% Jiaxing Black pig ancestry. The average litter size for first-time Bajia sows is 12.21 piglets, the average live piglet number per litter is 11.55 piglets, and the weaning survival rate at 28 days of age is 96.13%. The average litter size for multiparous sows is 13.28 piglets, the average live piglet number per litter is 12.02 piglets, and the weaning survival rate at 28 days of age is 96.55%. The average daily weight gain of finishing pigs is 645g, and the lean meat percentage of carcasses is 51.42%, which is 5 percentage points higher than that of Jiaxing Black pigs.

[0112] Selection of hybrid first generation Bajia pigs:

[0113] The selection of hybrid first-generation Bajia pigs is carried out at the time of weaning at the age of 28 days. The main selection requirements are sows with completely black coat, no genetic diseases, strong physique, symmetrical body shape, weaning weight of more than 5.0kg, and a high total number of piglets in the same litter. From weaning to the 80kg weight stage, the weight and feed consumption of each pig are measured, and the daily weight gain and feed-to-meat ratio are calculated. The second selection is at the age of 90 days, and the main focus is on eliminating individuals with poor growth and development, short body and small weight. The third selection is at the age of 180 days. First, an appearance assessment is carried out, and those with unqualified appearance are eliminated. The selection index is used to select sows with a large body weight at 6 months of age and thin back fat. At this stage, 200 hybrid first-generation Bajia sows are selected;

[0114] Step 2: Perform PCR-RFLP on each American Duroc pig to eliminate the pigs containing Hal nn Duroc boars were crossbred with 12 Duroc sires and 200 first-generation Baja pigs as dams to produce the second-generation Duroc hybrid pigs. Boars were eliminated, and only high-quality sows with a completely black coat were selected. Duroc sows contain 50% Duroc, 25% Berkshire, and 25% Jiaxing Black pig ancestry. The average litter size for primiparous sows is 11.14 piglets, while the average litter size for multiparous sows is 12.43 piglets. Piglets weigh 1.34 kg at birth, 6.4 kg at 28 days of age, and average daily weight gain for finishing pigs is 736 g. Carcass lean meat percentage is 57.16%, 5.7 percentage points higher than Baja sows.

[0115] Selection of the second generation hybrid Dubajia pigs:

[0116] The selection of hybrid second-generation Dubaga pigs is carried out at the time of weaning at the age of 28 days. The main selection requirements are sows with all-black coat, no genetic diseases, strong physique, symmetrical body shape, weaning weight of more than 5.5kg, and the total number of piglets born in the same litter. The weight and feed consumption of each pig are measured from weaning to the 80kg weight stage, and the daily weight gain and feed-to-meat ratio are calculated. The second selection is at the age of 90 days, and the main focus is on eliminating individuals with poor growth and development, short body and small weight. The third selection is at the age of 180 days. First, an appearance assessment is carried out to eliminate those with unqualified appearance. The selection index is used to select sows with a large body weight at 6 months of age and thin back fat. At this stage, 250 hybrid second-generation Dubaga sows are selected for the next step of hybridization;

[0117] Step 3: Perform PCR-RFLP test on each American Duroc pig to eliminate the pigs containing Hal nn Duroc boars, with Duroc (20 heads) as sire and second-generation Duroc (250 heads) as dam, were crossed to produce a zero-generation base group containing 75% Duroc, 12.5% ​​Berkshire and 12.5% ​​Jiaxing Black pigs;

[0118] The first selection is carried out at 28 days of age. The number of piglets to be selected is not less than 10. The piglets should be completely black in coat, grow well, weigh more than 6.0 kg, have more than 7 pairs of effective nipples, and have no genetic diseases in the same litter.

[0119] The second selection is carried out at 90 days of age, mainly to eliminate piglets with poor growth and development, short body and small weight;

[0120] At 180 days of age, a comprehensive selection index is formulated based on body weight, live backfat thickness, and appearance scores, and a third round of selection is conducted based on the index. Finally, 30 boars (10 bloodlines) and 300 sows are selected to form the zero-generation breeding herd;

[0121] Step 4: Implement herd closure, allowing only male and female pigs in the zero-generation base group to mate and reproduce, and no longer introduce Duroc boar bloodlines or sow bloodlines;

[0122] (1) Carry out group succession breeding starting from the zero generation: that is, each generation consists of 10 boar bloodlines (30 heads) and 300 excellent sows to form a breeding group, without introducing new foreign genes for breeding, and avoiding inbreeding of full siblings and half siblings in the zero generation, with the aim of fixing the excellent performance of the new breed;

[0123] (2) Generation interval: A hybrid pig herd containing 75% Duroc pig pedigree, 12.5% ​​Berkshire pig pedigree, and 12.5% ​​Jiaxing black pig pedigree is used as the zero generation. After three selections, it enters the breeding stage. 8-month-old boars weighing 130 kg and 7-month-old sows weighing about 120 kg are selected for breeding in March. Full siblings and half siblings are avoided during breeding. The offspring are born in July, and the fully black offspring enter the next generation. The first-born are retained for one generation per year and the cycle is repeated for 1 to 4 generations.

[0124] (3) Seed selection method:

[0125] First selection: Ear tissue samples were collected from newborn black piglets and sent to a third-party laboratory for sequencing of the three detection sites using the Sanger sequencing method;

[0126] Sanger sequencing method: The collected ear tissue samples are first extracted for DNA (deoxyribonucleic acid) in the laboratory, and then the MC1R gene is amplified by polymerase chain reaction (PCR). The amplified product is then sequenced for the first generation. The offspring contain heterozygotes AG-GA-CT, dominant homozygotes AA-GG-CC, and recessive homozygotes GG-AA-TT. The peak diagram of the relevant sites is shown in the figure below. Figure 2 As shown;

[0127] Dominant homozygous individuals with the MC1R genotype of AA-GG-CC were selected;

[0128] The first selection is carried out at 28 days of age. The number of piglets to be selected is not less than 10. The piglets should be completely black in coat, grow well, weigh more than 6.0 kg, have more than 7 pairs of effective nipples, and have no genetic diseases in the same litter.

[0129] The second selection is carried out at 90 days of age, mainly to eliminate pigs with poor growth and development, short body and weight below 25kg;

[0130] Selection of reserve pigs at 180 days of age: For the first generation of pigs, a combination of gene-assisted breeding methods and conventional selection indexes is used to select reserve breeding pigs;

[0131] The specific operation is to eliminate a small number of pigs that do not meet the requirements of body shape and appearance, and then determine the boars and sows to be kept for breeding based on the comprehensive selection index composed of weight at 180 days of age, live back fat and body shape and appearance scores, combined with the MC1R genotype detected at birth. 30 boars (10 bloodlines) and 300 sows are selected to form a new generation breeding group. This cycle is repeated for 4 generations to breed the new Qinglian Black Pig variety. The technical route is as follows: Figure 1 shown.

[0132] A method for preparing a feed, comprising:

[0133] Fish meal, montmorillonite powder, eggshell powder, a starch derivative, rapeseed cake, salt, wheat, corn, bone meal, and storax oil are uniformly mixed and then ground to obtain a feed. The feed comprises, by weight, 2 parts fish meal, 1 part montmorillonite powder, 5 parts eggshell powder, 5 parts starch derivative, 10 parts rapeseed cake, 2 parts salt, 20 parts wheat, 20 parts corn, 1 part bone meal, and 2 parts storax oil.

[0134] A method for preparing a starch derivative comprises the following steps:

[0135] At 0°C, deionized water was added to starch and stirred until uniformly mixed. S-allyl-L-cysteine ​​and allyl cinnamate were then added. After stirring for 10 minutes, sodium persulfate and anhydrous sodium sulfite were added, followed by Span-80. The mixture was stirred at 8°C for 40 minutes under a nitrogen atmosphere, then heated to 45°C and stirred for 4 hours. The mixture was washed alternately with anhydrous ethanol and acetone three times, filtered, and dried to obtain a starch derivative. The mass-to-volume ratio of starch to deionized water was 1 g:20 mL; the molar ratio of S-allyl-L-cysteine ​​to allyl cinnamate was 1:1; the mass ratio of starch to S-allyl-L-cysteine ​​was 1:3; the mass ratio of starch to sodium persulfate was 1:0.05; the mass ratio of starch to anhydrous sodium sulfite was 1:0.025; and the mass ratio of starch to Span-80 was 1:1.

[0136] Example 2:

[0137] The difference between a Qinglian black pig breeding method and Example 1 is that the feed is different.

[0138] The difference between the method for preparing a feed and Example 1 is that starch is used instead of starch derivatives.

[0139] Example 3:

[0140] The difference between a Qinglian black pig breeding method and Example 1 is that the feed is different.

[0141] The difference between the preparation method of a feed and Example 1 is that no styrax oil is added.

[0142] The preparation method of starch derivatives is the same as that in Example 1.

[0143] Example 4:

[0144] The difference between a Qinglian black pig breeding method and Example 2 is that the feed is different.

[0145] The difference between the preparation method of a feed and Example 2 is that no styrax oil is added.

[0146] Comparative Example 1:

[0147] The difference between a Qinglian black pig breeding method and Example 1 is that the feed is different.

[0148] The difference between the method for preparing a feed and Example 1 is that acrylic acid is used instead of S-allyl-L-cysteine ​​and allyl cinnamate.

[0149] Comparative Example 2:

[0150] A Qinglian black pig breeding method differs from Example 1 in that Meishan black sows are used instead of Jiaxing black sows.

[0151] Test example:

[0152] 1. Infrared spectrum test

[0153] The samples were analyzed and tested using Fourier transform infrared spectrometer.

[0154] The above test was performed on the starch derivative and starch prepared in Example 1, and the results are shown in Figure 3. Figure 3 It can be seen that compared with the infrared spectrum of starch, the infrared spectrum of starch derivatives is at 1709cm -1 There is an infrared characteristic absorption peak of the C=O bond in S-allyl-L-cysteine ​​at 1117 cm -1 There is an infrared characteristic absorption peak of CS bond at 1400-1600cm -1 There is an infrared characteristic absorption peak of the benzene ring in allyl cinnamate at the position, indicating that S-allyl-L-cysteine ​​and allyl cinnamate are involved in the formation reaction of starch derivatives.

[0155] 2. Reproduction performance test

[0156] Ten boars of the new Qinglian black pig breed selected and bred using different feeds according to Examples 1 to 4 and Comparative Examples 1 and 2 were mated with 100 sows, and the total number of piglets born by the sows was recorded.

[0157] Table 1 Reproduction performance test results

[0158]

[0159] The above test was conducted on the new Qinglian black pig breeds bred by feeding different feeds of Example 1 to Example 4 and Comparative Example 1 to Comparative Example 2, and the results are shown in Table 1. As can be seen from Table 1, compared with Example 2 as well as Example 3 and Example 4, the average number of piglets born by primiparous sows and the average number of piglets born by multiparous sows were both increased, indicating that the starch derivatives prepared by using S-allyl-L-cysteine ​​and allyl cinnamate were used for the preparation of feed, and the feed was used for the breeding of the new Qinglian black pig breed, so that the new Qinglian black pig breed had good reproductive performance; compared with Example 3 as well as Example 2 and Example 4, the average number of piglets born by primiparous sows and the average number of piglets born by multiparous sows were both increased, indicating that the use of storax oil in the preparation of feed and the use of feed in the breeding of Qinglian black pig breed had good reproductive performance. The breeding of new pig breeds also makes the new Qinglian black pig breed have good reproductive performance; compared with Example 1, the average number of piglets born by primiparous sows and the average number of piglets born by multiparous sows in Example 1 are also improved, indicating that the starch derivatives prepared by S-allyl-L-cysteine ​​and allyl cinnamate are more beneficial to the reproductive performance of the new Qinglian black pig breed than the starch derivatives prepared by the prior art; compared with Example 1, the average number of piglets born by primiparous sows and the average number of piglets born by multiparous sows are both increased, indicating that using Jiaxing black sows as the maternal parent can make the new Qinglian black pig breed have better reproductive performance.

[0160] 3. Carcass lean meat percentage test

[0161] The new Qinglian Black pig breed was raised to 100 kg, and then the carcasses were separated into bones, meat, and fat. Hot carcass weight refers to the weight of the fresh hot carcass after removing the tail, viscera, head, skin, lard, hooves, and trimmings. Cold carcass weight refers to the weight of the hot carcass after cooling at 0°C for 24 hours. The lean meat percentage was calculated using the following formula:

[0162] S / %=(K / M)×100%

[0163] Among them, S is the lean meat percentage; K is the lean meat weight; M is the cold carcass weight.

[0164] Lean meat amount = front leg meat + tenderloin + shoulder meat + sirloin + hind leg meat + trough head × 0.2 + coccyx × 0.28 + diaphragm angle × 0.4 + front cervical ridge × 0.41 + sternum × 0.5 + cun bone × 0.78.

[0165] Table 2 Carcass lean meat percentage test results

[0166]

[0167] The above test was performed on the new Qinglian black pig breeds bred by feeding different feeds in Examples 1 to 4 and Comparative Examples 1 and 2, and the results are shown in Table 2. As can be seen from Table 2, compared with Example 1 and Example 2, and Example 3 and Example 4, the lean meat rate is improved, indicating that the starch derivative prepared by S-allyl-L-cysteine ​​and allyl cinnamate is used for the preparation of feed, and the feed is used for the breeding of the new Qinglian black pig variety, so that the new Qinglian black pig variety has a good lean meat rate; compared with Example 1 and Example 3, and Example 2 and Example 4, the lean meat rate is not much different, indicating that the use of storax oil for the preparation of feed and the use of feed for the breeding of the new Qinglian black pig variety has no negative effect on the lean meat rate of the new Qinglian black pig variety; compared with Comparative Example 1, the lean meat rate of Example 1 is also improved, indicating that the starch derivative prepared by S-allyl-L-cysteine ​​and allyl cinnamate is more beneficial to the improvement of the lean meat rate of the new Qinglian black pig variety than the starch derivative prepared by the prior art; compared with Comparative Example 1, the lean meat rate of Example 1 is increased, indicating that the use of Jiaxing black sows as the sow can make the new Qinglian black pig variety have a better lean meat rate.

[0168] 4. Feed utilization test

[0169] The new Qinglian black pig breed was divided into 6 groups, with 10 pigs in each group, including 5 boars and 5 sows. From weaning to the stage of 80 kg body weight, they were fed once at 8 am and 5 pm, with each feeding amount of feed being 1.5wt% of the pig's body weight. They were fed ad libitum and provided with clean and sufficient drinking water. The fasting weight of the new Qinglian black pig breed was weighed and recorded on the morning of the first day of the experiment and the morning of the second day. The feed-to-meat ratio was calculated as follows:

[0170] Feed-to-meat ratio = average daily feed intake / average daily weight gain.

[0171] Table 3 Feed utilization test results

[0172]

[0173] The above test was performed on the new Qinglian black pig breeds bred by feeding different feeds in Examples 1 to 4 and Comparative Examples 1 and 2, and the results are shown in Table 3. As can be seen from Table 3, compared with Example 2, and Example 3 and Example 4, the feed-to-meat ratio of Example 1 is reduced, indicating that the starch derivative prepared by S-allyl-L-cysteine ​​and allyl cinnamate is used for the preparation of feed, and the feed is used for the breeding of the new Qinglian black pig variety, so that the new Qinglian black pig variety has a good feed utilization rate; compared with Example 1 and Example 3, and Example 2 and Example 4, the feed-to-meat ratio is reduced, indicating that storax oil is used for the preparation of feed, and the feed is used for the breeding of the new Qinglian black pig variety, which also makes the new Qinglian black pig variety have a good feed utilization rate; compared with Comparative Example 1, the feed-to-meat ratio of Example 1 is also reduced, indicating that the starch derivative prepared by S-allyl-L-cysteine ​​and allyl cinnamate is more beneficial to the improvement of the feed utilization rate of the new Qinglian black pig variety than the starch derivative prepared by the prior art; compared with Comparative Example 1, the feed-to-meat ratio of Example 1 is also reduced, indicating that using Jiaxing black sows as the sows can make the new Qinglian black pig variety have a better feed utilization rate.

[0174] The conventional techniques in the above embodiments are prior arts known to those skilled in the art, and thus will not be described in detail here.

[0175] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A Qinglian Black Pig breeding method comprising: Step 1: Using Jiaxing black sows as the female parent and Berkshire boars as the male parent, conduct the first crossbreeding to establish the first generation of Bajia sows; Step 2: Using the hybrid first-generation Bajia sow as the female parent and the imported American Duroc boar as the male parent, a second hybridization is performed to establish the hybrid second-generation Duroc sow; Step 3: Using the hybrid second-generation Duroc sows as the female parent and the imported American Duroc boars as the sire, a third hybridization was conducted to establish the zero-generation foundation group of the new Qinglian Black Pig breed; Step 4: Implement closed-line breeding, allowing only male and female pigs in the zero-generation base group to mate and reproduce. Use group successive breeding methods and gene-assisted breeding methods to carry out breeding for four consecutive generations to breed the new Qinglian Black Pig variety. Jiaxing black sows, Berkshire boars, and Duroc boars were all tested for halothane gene Hal using PCR-RELP method, and the genotype Hal was eliminated. nn Of the breeding pigs, only the genotype Hal NN of breeding pigs; Gene-assisted breeding technology includes: utilizing a specific locus of the MC1R gene that controls the black color of pig coat, continuously selecting dominant homozygous AA-GG-CC offspring from the first to the second generation; in the first generation of group breeding, retaining dominant homozygous AA-GG-CC male and female pigs; In the selection of sires and dams at each step, a comprehensive selection index is formulated based on body weight, live back fat thickness, and appearance scores, and selection is made based on the index; The comprehensive selection index includes the paternal index and the maternal index; Paternity Index: If the paternity index is standardized, that is, the mean is 100 and the standard deviation is 25, it becomes: Among them: EBV day : To correct the estimated breeding value at 100 kg age; EBV bf : Estimated breeding value corrected for backfat thickness up to 100 kg; σ day : Standard deviation of the estimated breeding value corrected for 100 kg age; σ bf : Standard deviation of the estimated breeding values ​​corrected for backfat thickness up to 100 kg; σ I : is the standard deviation of I before standardization; Ī: the average value of I before standardization; Maternal Index: If the maternal index is standardized, that is, the mean is 100 and the standard deviation is 25, it becomes: Among them: EBV day : To correct the estimated breeding value at 100 kg age; EBV bf : Estimated breeding value corrected for backfat thickness up to 100 kg; EBV tnb : Estimated breeding value of total litter size; σ day : Standard deviation of the estimated breeding value corrected for 100 kg age; σ bf : Standard deviation of the estimated breeding values ​​corrected for backfat thickness up to 100 kg; σ tnb : standard deviation of the estimated breeding value for total litter size; σ I : is the standard deviation of I before standardization; Ī: the average value of I before standardization; The meat quality PH1 of the new Qinglian black pig breed is greater than 6, and the intramuscular fat content is greater than 4.0%.

2. The Qinglian Black Pig breeding method according to claim 1, characterized in that: The carcass lean meat rate of the new Qinglian black pig breed is 55-65%.

3. The Qinglian Black Pig breeding method according to claim 1, characterized in that: The breeding method of the hybrid first-generation Bajia sows comprises: when the offspring produced by the first hybridization are weaned at the age of 26-30 days, the offspring selected have a completely black coat, a body weight of ≥5.0 kg, more than 7 pairs of effective nipples, and no genetic diseases in the same litter; when the offspring are fed with feed to the age of 88-92 days, a second selection is carried out to eliminate individuals with poor growth and development, short body and small body weight; then, when the offspring are 178-183 days old, a comprehensive selection index is formulated based on body weight, live back fat thickness, and appearance score, and selection is carried out based on the index; thus, the hybrid first-generation Bajia sows are obtained;.

4. The Qinglian Black Pig breeding method according to claim 3, characterized in that: The feed comprises fish meal, montmorillonite powder, eggshell powder, starch derivatives, rapeseed cake, salt, wheat, corn, bone meal and styrax oil; the starch derivatives are obtained by grafting S-allyl-L-cysteine, allyl cinnamate and starch.

5. The Qinglian Black Pig breeding method according to claim 1, characterized in that: The breeding method for the hybrid second-generation Dubaga sows comprises: selecting offspring produced by the second hybridization at the time of weaning at the age of 26-30 days, wherein the offspring have a completely black coat, a body weight of ≥5.5 kg, more than 7 pairs of effective nipples, and no genetic diseases in the same litter; conducting a second selection when the sows are fed with feed to the age of 88-92 days, mainly eliminating individuals with poor growth and development, short body and small body weight; then conducting a third selection at the age of 178-183 days, formulating a comprehensive selection index based on body weight, live backfat thickness, and appearance score, and selecting according to the index; thereby obtaining the hybrid second-generation Dubaga sows.

6. The Qinglian Black Pig breeding method according to claim 1, characterized in that: The breeding method for the zero-generation of the new Qinglian black pig variety includes: the third hybridization produces offspring, and when weaning at the age of 26-30 days, the selected offspring have completely black fur, weigh ≥6.0 kg, have more than 7 pairs of effective nipples, and have no genetic diseases in the same litter; the second selection is carried out when the pigs are fed with feed to the age of 88-92 days, and mainly eliminate individuals with poor growth and development, short body and small weight; then the third selection is carried out at the age of 178-183 days, and a comprehensive selection index is formulated based on body weight, live back fat thickness, and appearance score, and selection is based on the index; the fourth selection is carried out when the sows are weaned after their first birth, sows are selected based on their own litter size, and boars are selected based on the litter size of their fellow sows, and both are selected according to the comprehensive breeding value of litter size.

7. The Qinglian Black Pig breeding method according to claim 1, characterized in that: During the four-generation breeding process, the sows selected for breeding are 7-8 months old and weigh 110-130k.

8. The Qinglian Black Pig breeding method according to claim 1, characterized in that: During the four-generation breeding process, the boars selected for breeding are 8.5-9.5 months old and weigh 125-135 kg.

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