Method for creating and breeding high-quality pigs

Abstract

The application discloses a high-quality pig creating and breeding method, which comprises the following steps: 1) a certain blood structure of purebred Luchuan pigs is screened through molecular pedigree construction based on genome information, and the screened Luchuan pigs are used as female parents to cross with Duroc boars to generate Duroc-Luchuan crossbred pigs; 2) the Duroc-Luchuan crossbred pigs are used as female parents to cross with Barcshires boars to generate Bar-Duroc-Luchuan crossbred pigs; 3) the Bar-Duroc-Luchuan crossbred pigs are used as female parents to cross with Duroc boars to generate Duroc-Bar-Duroc-Luchuan crossbred pigs; 4) based on the Duroc-Bar-Duroc-Luchuan crossbred pigs, male and female pigs meeting the breeding target are selected according to a selection index to realize horizontal cross fixation, and an excellent horizontal cross offspring is selected to form a breeding core group; and 5) the core group in the step 4) is used as a zero generation group, a group succession breeding method is adopted, whole genome selection and genome prediction and the like are used to estimate a genome breeding value of breeding pigs and predict a phenotype, and precise intelligent breeding selection and matching are realized.

Description

Technical Field

[0001] This invention belongs to the field of biological breeding, specifically, it relates to a method for creating and breeding high-quality pigs. Background Technology

[0002] High-quality breeds are an important material foundation for pig production. Therefore, it is urgent to conduct resource evaluation, protection, and selective breeding of local pig breeds with outstanding meat quality. By creating new breeding materials through crossbreeding based on superior local pig breeds and further selecting new pig breeds, we can preserve the excellent meat quality characteristics, improve production efficiency, and achieve the "improvement of local pig breeds". Summary of the Invention

[0003] In response to the above situation, the purpose of this invention is to provide a new breeding material for high-quality specialty pigs with market differentiation by crossbreeding the excellent local pig breed Luchuan pig as the maternal line and the introduced pig breeds Duroc and Berkshire pig as the first and terminal sires. This method combines "BT+IT" technology, integrates genomic molecular design breeding methods, and utilizes technologies such as high-throughput genotyping, intelligent phenotyping, and artificial intelligence. It also uses whole-genome selection and genome prediction technologies to estimate the genomic breeding value and predict the phenotypic value of breeding pigs, achieving precise and intelligent selection and mating, and further breeding new pig breeds. The aim is to provide producers with a high-quality pig breed with higher production efficiency and consumers with pork of better quality and flavor.

[0004] The purpose of this invention is to provide a method for creating and breeding high-quality, distinctive pig breeding materials. This method yields high-quality, high-efficiency pig breeds that retain the excellent meat quality and disease resistance of local pig breeds while also exhibiting the rapid growth and high feed conversion efficiency of lean-type pigs. The high-quality pigs referred to in this invention are those that retain the excellent meat quality and disease resistance of local pig breeds while also exhibiting the rapid growth and high feed conversion efficiency of lean-type pigs.

[0005] To achieve the above objectives, the present invention provides a method for creating and breeding high-quality pigs, comprising the following steps:

[0006] 1) By constructing molecular pedigrees based on genomic information, purebred Luchuan pigs with certain bloodlines were screened, and the screened Luchuan pigs were used as maternal lines to crossbreed with Duroc boars to produce Duroc-Duroc hybrid pigs;

[0007] 2) Using Duroc-Grandson crossbred pigs as the female parent and Berkshire boars as the female parent, crossbreeding produces Berkshire-Grandson crossbred pigs;

[0008] 3) Use Duroc-Douglas crossbred pigs as the female parent and crossbred them with Duroc boars to produce Duroc-Douglas crossbred pigs;

[0009] 4) In Durham-Landrace crossbred pigs, select boars and sows that meet the breeding objectives based on the selection index, perform crossbreeding fixation, and select excellent crossbreed offspring to form the breeding core group;

[0010] 5) Using the core group in step 4) as the zero-generation group, the population successive selection method is adopted, with one generation per year. During the selection process, the "BT+IT" technology is combined to integrate the genomic molecular design breeding method. Through high-throughput genotyping, intelligent phenotyping and artificial intelligence technologies, the genomic breeding value of breeding pigs is estimated and phenotypic prediction is made using whole-genome selection and genome prediction methods to achieve precise and intelligent selection and mating.

[0011] In step 1), the Luchuan sows are a purebred Luchuan sow group with a certain bloodline structure; the Duroc boars are selected from purebred Duroc boars from more than 8 families; the ratio of boars to sows is approximately 1:6.

[0012] In step 2), the Duroc-Landrace hybrid pig has 50% of both Luchuan and Duroc bloodlines; the Berkshire boar comprises more than 10 families; and the ratio of boar to sow is approximately 1:6.

[0013] In step 3), the Berkshire-Duloc hybrid pig has 25% Luchuan pig bloodline, 25% Duroc pig bloodline, and 50% Berkshire pig bloodline; the Duroc boar comes from more than 16 families.

[0014] In step 4), the Duroc-Dubar-Duroc hybrid pig has 12.5% ​​of the bloodline of a Luchuan sow, 62.5% of the bloodline of a Duroc pig, and 25% of the bloodline of a Berkshire pig.

[0015] Among them, the generational selection in step 5) includes genotyping, performance testing, genetic evaluation, and selection and mating for each generation.

[0016] The genotyping process includes ear tissue collection and genomic DNA extraction, and obtaining individual genomic SNP information through gene chips or low-depth sequencing. The performance testing includes performance testing of growth and fattening, carcass and meat quality, and reproduction for each generation. The genetic assessment utilizes the obtained individual gene information, phenotypic information, and pedigree information, and employs methods such as ssGBLUP to estimate the genomic breeding value (EBV / GEBV) of the primary selected traits. The selection and mating process refers to constructing a comprehensive selection index I based on the EBV / GEBV of each primary selected trait (total litter size & age at 100kg body weight & intramuscular fat content & live backfat thickness), combining body shape, pedigree distribution, and other factors to select subsequent generations of breeding pigs, and conducting precise mating based on genomic information to carry out generational breeding.

[0017] During the breeding process, the principle for selecting breeding pigs is to retain them for their first litter in order to shorten the generation interval. After the pig herd has been bred to the fourth generation, a few outstanding individuals can be allowed to overlap generations appropriately to increase the frequency of superior genes in the pig herd and accelerate the fixation of superior traits.

[0018] The beneficial effects of this invention are as follows:

[0019] (1) The high-quality pig breed selected and bred by this invention is characterized by: black hair (with a few white hooves allowed), tall and long body, wide back and flat abdomen, 6 to 7 pairs or more of effective teats, total litter size of 9 or more primiparous pigs and 10 or more multiparous pigs, average daily weight gain of 800g or more and feed conversion ratio of no more than 2.6:1 during the fattening stage of 30 to 100kg; age at which pigs reach 100kg weight not exceeding 165 days; backfat thickness of live pigs at 100kg weight not exceeding 20mm, lean meat percentage not less than 60%, and intramuscular fat content of 3.5% or more.

[0020] (2) This invention is based on the excellent local breed Luchuan pig material. Through multiple crossbreeding and continuous breeding, a new breeding material was created. The final product contains 12.5% ​​Luchuan pig bloodline, 25% Berkshire pig bloodline and 62.5% Duroc pig bloodline. The new breed has a rich basic bloodline source, which can effectively utilize the hybrid vigor between groups. It maintains good meat quality and improves production efficiency traits such as growth rate and feed utilization rate. It also retains the black hair trait, which is more in line with the market demand of producers and consumers.

[0021] (3) During the breeding process, the "BT+IT" technology is combined to integrate the genomic molecular design breeding method. Through high-throughput genotyping, intelligent phenotyping and artificial intelligence technologies, efficient and accurate phenotyping and selection are carried out, which greatly improves the breeding efficiency compared with conventional breeding methods. Attached Figure Description

[0022] Figure 1 A schematic diagram of the technical route for creating hybridization for breeding new materials. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0024] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0025] The Luchuan sows in the following examples were from the Guangxi Animal Husbandry Research Institute; the Duroc boars were from Guangxi Yibiantian Breeding Pig Co., Ltd.; and the Berkshire boars were from Anhui Haoxiang Animal Husbandry Co., Ltd.

[0026] The technical solution adopted in this invention mainly includes three stages: selection of parental materials, hybridization innovation, and generational selection based on genomic information. The specific steps are as follows:

[0027] (1) Step 1: Parental selection and hybridization innovation stage:

[0028] 1) By constructing molecular pedigrees based on genomic information, purebred Luchuan pigs with a certain bloodline structure are crossbred with purebred Duroc boars from more than 8 families to produce Duroc-Luchuan (Duroc ♂ × Luchuan pig ♀) hybrid pigs;

[0029] 2) Using black-coated Duroc-Luchuan (Duroc ♂ × Luchuan ♀) crossbred pigs as the female parent and purebred Berkshire boars from more than 10 families to produce Berkshire-Duchuan (Barkshire ♂ × (Duroc ♂ × Luchuan ♀) ♀) crossbred pigs;

[0030] 3) Crossbreeding black-coated Berkshire (Duroc♂×(Duroc♂×LuchuanPig♀)♀) with purebred Berkshire boars from more than 16 families produces Duroc-Duroc (Duroc♂×(Duroc♂×(Duroc♂×LuchuanPig♀)♀)♀) hybrid pigs;

[0031] 4) Based on coat color, bloodline structure, breed characteristics, etc., select boars and sows that meet the breeding objectives from Duroc♂×(Barkshire♂×(Duroc♂×LuchuanPig♀)♀)♀ and fix them by crossbreeding. Then, select the best crossbreed offspring to form the breeding core group (generation zero) according to the selection index.

[0032] In the above steps, the bloodline structure refers to the family lineage. Fewer families or narrower bloodlines make inbreeding more likely, which can lead to performance decline. This invention is not based on the individual level, but on the group level. The genetic background of pig herds is diverse and consists of multiple families (a family is defined as having no common ancestor within three generations).

[0033] (2) Step Two: Generational Selection and Breeding Stage

[0034] 1) Based on the aforementioned core group of Generation Zero, a group-based generational selection method will be adopted, with one generation per year;

[0035] 2) By combining "BT+IT" technologies, integrating genomic molecular design breeding methods, and using technologies such as high-throughput genotyping, intelligent phenotyping and artificial intelligence, and utilizing technologies such as whole-genome selection and genome prediction, we can estimate the genomic breeding value and predict the phenotypic value of breeding pigs, thereby achieving precise and intelligent selection and mating;

[0036] 3) Generational breeding mainly includes key steps such as genotyping and performance testing, genetic evaluation, and selection and mating. Performance testing of important economic traits such as growth and fattening, carcass and meat quality, and reproduction is conducted for each generation. Ear tissue is collected and genomic DNA is extracted from all replacement breeding pigs that have completed testing and entered the core group. Genomic SNP information is obtained through gene chips or genome resequencing. Based on genetic, phenotypic, and pedigree information, methods such as ssGBLUP are used (to estimate the EBV / GEBV of the primary selected trait and construct a comprehensive selection index I (total litter size & age at 100kg body weight & intramuscular fat content & live backfat thickness). Combined with body shape, family distribution, and other factors, individual breeding pigs are selected for the next generation. Precise mating is then conducted based on genomic information to carry out generational breeding.

[0037] 4) During the breeding process, the principle of selecting and retaining breeding pigs is to retain them in their first litter in order to shorten the generation interval. After the pig herd has been bred to the fourth generation, a few outstanding individuals can be appropriately overlapped in generations to increase the frequency of superior genes in the pig herd and accelerate the fixation of superior traits.

[0038] Example 1

[0039] This embodiment provides a method for creating and breeding high-quality pigs, the steps of which include:

[0040] 1. Using 70 Luchuan sows with a certain bloodline as maternal lines and 8 Duroc boars (or semen) from 8 families as paternal lines, crossbreeding was conducted to produce Duroc-Luchuan (Duroc ♂ × Luchuan ♀) hybrid pigs. The boar-to-sow ratio was approximately 1:6, and random mating was implemented. Based on the selection index combined with bloodline structure and physical characteristics, 100 Duroc-Luchuan sows from the 8 families were selected for the next crossbreeding stage.

[0041] 2. Using 100 Duroc sows as the female line and 10 Berkshire boars (or semen) from 10 families as the male line, crossbreed to produce Berkshire-Duroc (Barkshire♂ × (Duroc♂ × Luchuan Pig♀)♀) hybrid pigs. The boar-to-sow ratio is approximately 1:6, and random mating is implemented. Based on the selection index combined with bloodline structure and physical characteristics, 100 Berkshire sows from the 10 families are selected for the next crossbreeding stage.

[0042] 3. Using 100 Duroc sows as the female line and 16 Duroc boars (or semen) from 16 families as the male line, a Duroc-Duroc-Duroc (Duroc♂×(Barkshire♂×(Duroc♂×Luchuan Pig♀)♀)♀) crossbreed was produced. The boar-to-sow ratio was approximately 1:6, and random mating was implemented.

[0043] 4. Based on the selection index, bloodline structure, and physical characteristics, 25 and 150 Durbar and Duroc replacement boars and sows from 16 families were selected for crossbreeding and fixation. The crossbred offspring were then selected to form a breeding core group (generation zero) and enter the group successive breeding stage.

[0044] 5. Performance testing of generational breeding: The performance of pigs in each generation was tested according to the following methods.

[0045] 1) Growth performance assessment: After the piglets have completed their nursery period at 70 days of age, a growth performance assessment group (at least 1 male and 2 female piglets per litter) is selected based on their body shape, appearance, and growth status. The assessment continues until the piglets reach 90-110 kg. Individual weights at 70 days of age, 8 months of age, and traits such as backfat thickness and eye muscle area are measured.

[0046] 2) Fattening performance testing: For each generation, more than 120 piglets of normal growth and development, similar age and weight (covering all families) were selected for fattening performance testing. Fattening began when the piglet reached a weight of about 25-30 kg and ended when the piglet reached a weight of about 90-110 kg. The following traits were measured: age at which the target weight was reached, average daily weight gain during the testing period, feed conversion ratio, backfat thickness at the target weight, and eye muscle area.

[0047] 3) Carcass and meat quality testing: At the end of each generation of fattening performance testing, no fewer than 30 pigs were selected for slaughter (confirmatory performance testing). The carcass traits and muscle quality of each individual were measured in accordance with industry standards NY / T 825-2019 and NY / T 821-2019. Carcass traits include live weight before slaughter, carcass length and oblique length, dressing percentage, average backfat thickness, eye muscle area, and lean meat percentage. Muscle quality indicators include meat color score, marbling score, pH1 and pH24, water loss rate, cooked meat rate, drip loss, and intramuscular fat content.

[0048] 4) Reproductive performance testing: The reproductive performance of the core group sows was tested in each generation. The tested traits included total number of piglets born, number of live piglets born, number of healthy piglets, farrowing interval, birth weight and litter weight, litter weight at 21 days of age, number of live piglets and litter weight at 28 days of age (weaning), and sow weaning interval.

[0049] 6. Genetic evaluation of generational selection: After the growth and development performance of each generation of replacement breeding pigs reaches a weight of 90-110kg and is tested, ear samples are collected for genotyping. The breeding values ​​(EBV / GEBV) of each major selected trait (total number of piglets & age at 100kg weight & feed conversion ratio & live backfat thickness) in the selection index are calculated. Based on this, the individual selection index is calculated and ranked, which serves as an important basis for selecting breeding pigs.

[0050] 7. Selection of breeding stock for each generation: In principle, the first litter of breeding pigs in the core group should be retained for breeding. Each generation of breeding pigs is selected at four (five) stages: at birth, at the end of weaning and nursery, at the end of testing when they reach 90-110kg, and before the first mating.

[0051] General requirements: ① Physical appearance: Boars and sows have black hair (a few white hooves are allowed), normal growth and development, no obvious physical defects, long body, full hindquarters, and no less than 6 to 7 pairs of effective teats, which are evenly and neatly arranged;

[0052] ② Bloodline Structure: A certain number of boars and sows are selected from each family. Generally, two boars are selected from the offspring of each boar, with one to two more selected from exceptionally outstanding individuals. One sow is selected from each litter, with one to two more selected from exceptionally outstanding individuals. 1) Birth Selection: After birth, piglets are initially selected based on coat color differentiation, and breeding pigs are tagged with ear tags. 2) Weaning and Nursery Selection: At the end of the nursery period at 70 days of age, piglets are further selected based on body shape, individual growth and development, and parental reproductive performance. Individuals with substandard body shape or slow growth are prioritized for culling. At least one boar and two sows are selected from each litter for growth and development testing, with more selected from exceptionally outstanding individuals. 3) Final Selection: When replacement breeding pigs reach 90-110kg and growth and development testing is completed, the selection of breeding pigs is based primarily on the individual comprehensive selection index, while also considering family distribution. In principle, at least 2 boars should be selected from each family line, and at least 1 sow should be selected from the offspring of each sow. More outstanding individuals should be selected. 4) Final selection: When the breeding pigs reach about 115kg at 8 months of age and are first mated, individuals with poor estrus or mating results will be culled based on estrus and other conditions. The breeding pigs that are selected to enter the basic core group will be selected in the end.

[0053] 8. Selection and Mating in Generational Breeding: The selection of boars and sows should combine kinship-based and quality-based selection. To prevent a rapid increase in the inbreeding coefficient, mating between boars and sows with a common ancestor within three generations should be avoided as much as possible (inbreeding coefficient < 0.0625; kinship coefficient < 0.125). Based on the selection index, performance, and genomic information of boars and sows, mating should be conducted according to the principle of pairing excellent boars with excellent sows and excellent boars with average sows. The boar-to-sow mating ratio is approximately 1:5, and the mating rate of a few excellent bloodline boars can be increased to 130-150% of the herd average. According to the herd's production rhythm, synchronous mating should be implemented as much as possible to allow for simultaneous performance testing and reduce the impact of non-genetic factors on the herd.

[0054] The present invention has been described in detail above. For those skilled in the art, the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. Although specific embodiments have been given, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein. Some of the essential features can be applied within the scope of the following appended claims.

Claims

1. A method for creating and breeding high quality pigs, characterized by, It comprises the following steps: 1) screening the pure-bred Luchuan pigs with certain blood structure by constructing molecular pedigree based on genomic information, crossing the screened Luchuan pigs with Duroc boars to produce Duro-Landrace crossbred pigs; the Luchuan sows are a population of pure-bred Luchuan sows with certain blood structure; the Duroc boars are selected from pure-bred Duroc boars of more than 8 lineages; the ratio of boars to sows is about 1:6; 2) crossing the Duro-Landrace crossbred pigs with Barwick boars to produce Bar-Duro-Landrace crossbred pigs; the Duro-Landrace crossbred pigs have 50% of Luchuan pig and Duroc pig blood; the Barwick boars include more than 10 lineages; the ratio of boars to sows is about 1:6; 3) crossing the Bar-Duro-Landrace crossbred pigs with Duroc boars to produce Duro-Bar-Duro-Landrace crossbred pigs; the Bar-Duro-Landrace crossbred pigs have 25% of Luchuan pig blood, 25% of Duroc pig blood and 50% of Barwick pig blood; the Duroc boars are derived from more than 16 lineages; 4) selecting the boars and sows that meet the breeding goal according to the selection index in the Duro-Bar-Duro-Landrace crossbred pigs to carry out crossbreeding and fixation, and selecting the excellent crossbred offspring to form a breeding core population; the Duro-Bar-Duro-Landrace crossbred pigs have 12.5% of the blood structure of Luchuan sows, 62.5% of Duroc pig blood and 25% of Barwick pig blood structure; 5) taking the core population in step 4) as the zero generation population, adopting population generation selection method, one generation per year, combining "BT+IT" technology in the selection process, integrating genomic molecular design breeding method, using high-throughput genotyping, intelligent phenotype determination and artificial intelligence technology, using whole genome selection and genomic prediction methods to estimate genomic breeding value and phenotype of breeding pigs, and realizing precise intelligent selection and mating; the generation selection in step 5) includes genotyping, performance determination, genetic evaluation and selection of each generation: the genotyping includes ear tissue collection, genomic DNA extraction, obtaining individual genomic SNP information by gene chip or low-depth sequencing method; the performance determination includes performance determination of growth and fattening, carcass and meat quality, and reproduction for each generation; the genetic evaluation is to estimate the genomic breeding value (EBV / GEBV) of the main selection traits by using the obtained individual genetic information, phenotype information and pedigree information, and using ssGBLUP method; the selection refers to constructing a comprehensive selection index I based on the EBV / GEBV of each main selection trait (total litter size & age at 100 kg body weight & intramuscular fat content & live backfat thickness), combining body shape, family distribution and other conditions to select and reserve the generation breeding pigs, and carrying out precise mating based on genomic information to carry out generation selection; In the selection process, the breeding pigs are selected and reserved in principle to shorten the generation interval, and after the pig population is selected and bred to the fourth generation, a small number of excellent individuals can be appropriately overlapped to increase the frequency of excellent genes in the pig population and speed up the fixation of excellent traits.

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