Breeding method of high-quality pork pigs

Abstract

The invention discloses a breeding method of high-quality pork pigs, and belongs to the technical field of livestock breeding. The breeding method comprises the following steps: by taking Nanjiang pigs and Candian large white pigs as materials, performing selection and retention, cross production and multi-stage selection and retention by establishing selection index rating, and performing cross fixation and generation breeding by adopting a group subculture breeding method, thereby obtaining the Nanjiang pigs and the Candian large white pigs. According to the breeding method disclosed by the invention, interspecific hybridization advantages are fully utilized, the bred high-quality pork pigs not only keep excellent meat quality characteristics of the injiang pigs to the greatest extent, but also greatly improve production performance indexes such as growth speed, feed conversion efficiency and lean meat percentage; high-quality commercial pork pigs with white hair characteristics, high growth speed, high breeding efficiency, excellent meat quality and high meat yield are obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of livestock breeding, and in particular relates to a method for breeding high-quality meat pigs. Background Art

[0002] Local pig germplasm resources play a vital role in revitalizing the seed industry. As one of the major countries in the world for pork consumption and breeding, China needs to rely on local pig germplasm resources to develop its pig seed industry. Faced with the current dependence on foreign core breeding pigs, the use of local pig resources can effectively reduce this dependence and promote the independent breeding of excellent pig breeds. In-depth exploration of the genetic resources of local pigs will help build a complete industrial chain and promote the sustainable development of the industry. Local pigs are known for their resistance to adversity, high-quality meat quality and tolerance to roughage. High-quality commercial pigs can be bred through hybridization technology. The increasing diversification of consumer demand has also prompted the development of local pig resources to meet the market's growing demand for high-quality pork.

[0003] China has a wide variety of local pig breeds, but is facing the impact of foreign pig breeds, resulting in a reduction in population size and size, and a decrease in genetic diversity. As one of the local breed resources that are key protected by the state, Neijiang pigs are famous for their excellent meat quality and unique flavor, and are a high-quality gene pool for raw pork quality. However, Neijiang pigs also have some genetic defects, such as thick skin, slow weight gain, low lean meat rate, low slaughter rate, and fewer litters compared to foreign pigs, which seriously limit the development of their production potential. Summary of the invention

[0004] The problem to be solved by the present invention is to provide a method for breeding high-quality meat pigs to solve the problems of thick skin, slow weight gain, low lean meat rate, low slaughter rate and small litter size of Neijiang pigs, so as to cultivate high-quality meat pigs that meet the needs of the modern market.

[0005] The technical solution adopted to solve the technical problem is to provide a method for breeding high-quality pigs, comprising the following steps: (1) Neijiang pigs were selected as the sire, and the black pig index of the selected individuals was not less than 120. The restrictive selection indicators were: the number of nipples of the individual was ≥6 pairs, the pigs were from a litter with a total number of piglets ≥10, the inbreeding coefficient was ≤3%, and the number of family groups was ≥12. The calculation formula of the black pig index was I1=0.4*60kg corrected age+0.3*60kg back fat thickness+0.3*60kg eye muscle thickness; (2) Select Canadian Large White pigs as the female parent, and the breeding index of the selected individual Large White pigs shall not be less than 120. The restrictive selection indicators are: the number of nipples of the individual is ≥7 pairs, the pigs are from a litter with a total number of piglets ≥15, the inbreeding coefficient is ≤3%, and the number of families in the group is ≥20; the formula for calculating the breeding index of Large White pigs is I2=0.17*total piglets+0.3*live piglets+0.1*weaning litter weight+0.25*100kg corrected age+0.05*feed-to-meat ratio+0.08*100kg eye muscle thickness+0.05*100kg back fat thickness; (3) using the male and female parents selected in steps (1) and (2) to perform hybrid production to obtain a hybrid base population; (4) Multi-stage selection is performed to obtain a core basic group under the premise that the number of blood relations in the group is ≥12; (5) The core basic group obtained in step (4) is used as the F0 generation, and the group succession breeding method is used for cross-crossing fixation and generational breeding. The annual generation renewal rate is 100%, and the number of group bloodlines in each generation is ensured to be ≥12 to obtain high-quality meat pigs.

[0006] Preferably, the multi-stage selection in step (4) includes the following steps: S1. Newborn selection: weigh all piglets individually, and select individuals from litters with a total number of piglets ≥ 10. The selected individuals are healthy piglets with ≥ 6 pairs of nipples and an individual weight ≥ 0.8 kg. The selection rate of sows in each litter is ≤ 50%, and the selection rate of boars is ≤ 30%. If there are deformities in the same litter, all litters will be eliminated; S2. Selection at weaning age: weigh all the piglets in the group, and the selected ones must be healthy ones with a body weight of ≥4kg; S3, Selection of piglets for nursery-to-mature age: Weigh all piglets individually and remove the bottom 10% of the individuals by weight; S4. Weigh the whole group of piglets when they are 100-110 days old; S5, whole group performance test is conducted when piglets are 150-160 days old; S6. Draw a growth curve based on the individual body weights collected in S1-S5, and formulate a correction formula based on the growth curve and the performance of the entire group. The growth traits are selected using a comprehensive selection index, and the reproductive traits are selected using a restriction index; S7. Select excellent breeding pig groups according to S1~S6 and meet the requirement of group bloodline number ≥12 to obtain the core basic group.

[0007] More preferably, the herd performance in S5 includes individual body weight, individual backfat thickness and individual eye muscle thickness.

[0008] More preferably, the selection of growth traits using a comprehensive selection index in S6 includes the following steps: sorting and selecting according to the growth selection index of high-quality pigs, with the growth selection index of reserve boars not less than 120, and the growth selection index of reserve sows not less than 100; the calculation formula for the growth selection index of high-quality pigs is: I3=0.4*85kg corrected age+0.3*85kg back fat thickness+0.3*85kg eye muscle thickness; the restrictive indicators are that the number of nipples of an individual pig is ≥6 pairs, and the pig is from a litter with a total number of piglets ≥12, and 1 boar of the same bloodline is selected according to the growth selection index of high-quality pigs, and 1~2 sows from the same litter are selected according to the growth selection index of high-quality pigs.

[0009] Preferably, the generation breeding in step (5) comprises the following steps: S1. Newborn selection: Weigh all piglets individually. The selected individuals come from litters with a total number of piglets ≥ 10. The selected individuals are healthy piglets with ≥ 6 pairs of nipples and an individual weight ≥ 0.8 kg. No more than 4 sows and no more than 2 boars are selected from each litter. The selected individuals are white in color. All deformed piglets in the same litter will be eliminated. S2. Selection at weaning age: weigh all the piglets in the group, and the selected ones must be healthy ones with a body weight of ≥4kg; S3, Selection of piglets for nursery-to-mature age: Weigh all piglets individually and remove the bottom 10% of the individuals by weight; S4. Weigh the whole group of piglets when they are 100-110 days old; S5, whole group performance test is conducted when piglets are 150-160 days old; S6. Draw a growth curve based on the individual body weights collected in S1-S5, and formulate a correction formula based on the growth curve and the performance of the entire group. The growth traits are genetically evaluated using the ABLUP model, and the reproductive traits are selected using restrictive indicators; S7. The principle of selection is homogeneous selection and optimal matching. The inbreeding coefficient is ≤3%. The mating combination is based on the comprehensive selection index. The sow group is selected after 2 litters on average, and the excellent litters are selected for 3~4 litters. S8. After 2 generations, select outstanding individuals for generation overlapping.

[0010] More preferably, the herd performance in S5 includes individual body weight, individual backfat thickness and individual eye muscle thickness.

[0011] More preferably, the genetic evaluation of growth traits in S6 using the ABLUP model includes the following steps: using the individual phenotypic information and pedigree information obtained from S1 to S5, using the ABLUP method to estimate the breeding values ​​of the main selected traits; when selecting, constructing a comprehensive selection index for high-quality pigs based on the breeding values ​​of each main selected trait.

[0012] More preferably, the pigs are ranked and selected according to the comprehensive selection index of high-quality pigs, with the comprehensive selection index of selected boars not less than 120, and the comprehensive selection index of selected sows not less than 100; the calculation formula of the comprehensive selection index of high-quality pigs is: I4=0.3*85kg corrected age+0.3*85kg back fat thickness+0.4*total number of pigs; the restrictive indicators are that if the number of nipples of an individual pig is ≥6 pairs and the pig comes from a litter with a total number of pigs ≥12, and one boar of the same bloodline is selected according to the growth selection index of high-quality pigs, and 1 to 2 sows from the same litter are selected according to the growth selection index of high-quality pigs.

[0013] The present invention has the following beneficial effects: (1) The present invention relies on Neijiang pig, a high-quality local breed, and continuously carries out breeding through the breeding method of the present invention to cultivate a new type of high-quality meat pig breed. This breed combines 50% of the bloodlines of Neijiang pig and Canadian Large White pig, making full use of the hybrid advantages, not only maintaining the excellent meat quality characteristics to the maximum extent, but also improving production performance indicators such as growth rate and feed conversion efficiency; in addition, this breed also retains the white hair characteristics, meeting the producers' demand for meat pig performance and consumers' expectations for meat quality, and at the same time is more in line with the needs of the slaughter and chilled meat market.

[0014] (2) The high-quality pig breed bred by the present invention has the following characteristics: white fur, tall and slender body, broad back and flat abdomen; the number of effective nipples of this breed of pigs reaches 6 to 7 pairs or more, the total number of piglets born in the first birth is more than 11, and the total number of piglets born in the second birth is more than 12; in addition, the corrected age of this breed of pigs when reaching the same weight is more than 30 days shorter than that of Neijiang pigs, and the back fat thickness is reduced by more than 15 mm when reaching the same weight; the slaughter rate is not less than 70%, and there is no significant difference in meat quality indicators such as pH value, meat color and intramuscular fat content compared with Neijiang pigs. DETAILED DESCRIPTION

[0015] The principles and features of the present invention are described below in conjunction with the examples, which are only used to explain the present invention and are not intended to limit the scope of the present invention. If no specific conditions are specified in the examples, the conditions are carried out according to conventional conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0016] Example A method for breeding high-quality pigs, the specific steps are as follows: (1) Compatibility test to select the best breeding combination: Neijiang pigs with a black pig index of not less than 120 and Jiaxi Large White pigs with a Large White breeding index of not less than 120 were selected to participate in the positive and negative cross test, and the performance of the offspring of the two combinations was observed: Neijiang pigs × Jiaxi Large White pigs, Jiaxi Large White pigs × Neijiang pigs. Each combination was randomly mated for 30 litters, and 2 piglets were selected from each litter. A total of 120 test pigs were tested for compatibility; the results are shown in Table 1; Table 1 Compatibility test results

[0017] According to the results of combining ability test, the hybrid method of Neijiang pig as the sire and Canadian Large White pig as the dam has a faster growth rate, lower feed-to-meat ratio, higher slaughter rate and lean meat rate, while the difference in meat quality between the two hybrid combinations is not obvious. Comprehensively speaking, the hybrid method of Neijiang pig as the sire and Canadian Large White pig as the dam is selected for breeding high-quality meat pigs. (2) Selection of Neijiang pig sires: Select Neijiang pig boars with good body shape, normal growth and development, and no genetic diseases from the healthy Neijiang pig population as sires. The selected individuals are selected from the black pig index from high to low, and the black pig index of the selected individuals is not less than 120; the restrictive selection index is: the number of nipples of the individual is ≥ 6 pairs, and the total number of piglets is ≥ 10; in order to ensure the genetic diversity of the group and the controllable inbreeding coefficient (inbreeding coefficient ≤ 3%), and to avoid performance decline, the number of families in the selected group is ≥ 12; the calculation formula of the black pig index is I1=0.4*60kg corrected age+0.3*60kg back fat thickness+0.3*60kg eye muscle thickness; the number of sires selected is 40; (3) Selection of foreign sows: Select Canadian Large White sows with good body shape, normal growth and development, and no genetic diseases from the healthy Canadian Large White pig population as sows. The selected individuals are selected from the Large White breeding index from high to low, and the Large White breeding index of the selected individuals is not less than 120; the restrictive selection index is: the number of nipples of the individual is ≥7 pairs, and the total number of piglets is ≥15; in order to ensure the genetic diversity of the group and the controllable inbreeding coefficient (inbreeding coefficient ≤3%), and to avoid performance decline, the selected group has ≥20 families; the calculation formula of the Large White breeding index is I2=0.17*total piglets+0.3*live piglets+0.1*weaning litter weight+0.25*100kg corrected age+0.05*feed-to-meat ratio+0.08*100kg eye muscle thickness+0.05*100kg back fat thickness; the number of selected sows is 113; (4) Hybridization: using the male and female parents selected in steps (2) and (3) to perform hybridization production to obtain a hybrid base population; (5) Multi-stage selection in the group creation stage: In order to quickly create a core group with excellent performance and stability, multi-stage selection is carried out on the premise that the number of blood relations in the group is ≥ 12, including the following steps: S1. When selecting piglets at birth, weigh all the piglets individually. The selected individuals come from litters with a total number of piglets ≥10. The selected individuals are healthy piglets with ≥6 pairs of nipples, ≥0.8kg in weight, good vitality, strong limbs, and normal walking. The selection rate of sows in each litter is ≤50%, and the selection rate of boars is ≤30%. The reproductive organs of the selected individuals are normally developed, the boars have two healthy testicles, and the sows have horizontal or downward vulva. If there are deformities in the same litter, all the litters will be eliminated; S2. At 25 days of weaning, weigh all the piglets individually and select those with a weight of ≥4 kg, no obvious thinness, poor mental state, no clinical symptoms of disease, and no visual abnormalities; S3. When the nursery-raised pigs are older than 70 days old, all the individuals in the group are weighed and the bottom 10% of the individuals in terms of weight are removed. S4. Weigh the whole group of piglets when they are 100-110 days old; S5. The whole group performance of piglets is measured at 150-160 days of age. The whole group performance includes individual weight, individual back fat thickness and individual eye muscle thickness. S6. Draw a growth curve based on the individual body weight collected in S1 to S5 above, and formulate the corrected age, corrected backfat thickness and corrected eye muscle thickness formulas based on the growth curve, individual backfat thickness and individual eye muscle thickness data, and calculate the correction value. The growth traits are selected using the comprehensive selection index, and the reproductive traits are selected using the restrictive indicators; among them, the growth traits are selected using the comprehensive selection index, specifically: sorting and selecting according to the growth selection index of high-quality pigs, the growth selection index of reserve boars is not less than 120, and the growth selection index of reserve sows is not less than 100; the calculation formula for the growth selection index of high-quality pigs is: I3=0.4*85kg corrected age+0.3*85 kg back fat thickness + 0.3*85kg eye muscle thickness; the restrictive indicators are that the number of nipples of individual pigs is ≥6 pairs, and the boars from the litter with a total number of piglets ≥12 are ranked according to the high-quality pig growth selection index and the one with the highest high-quality pig growth selection index is selected; the sows from the same litter are ranked according to the high-quality pig growth selection index and the 1~2 pigs with the highest high-quality pig growth selection index are selected; the selected pigs are healthy, with a suitable growth rate, a body weight not lower than the average level of the same batch, and the limbs and hooves are normal and strong, without obvious limb and hoof diseases, arched backs and clinical manifestations of diseases, limb injuries or developmental abnormalities, and no tail biting or ear biting that leads to no breeding value; hermaphroditic pigs are not selected; the size and shape of the sow's vulva are normal and not upturned; S7, build a core basic group of high-quality meat pigs: select excellent breeding pigs according to S1~S6 and meet the group blood number ≥12, so as to build a core basic group, adopt the successive breeding method, carry out cross-crossing fixation, further select excellent cross-crossing offspring groups, and carry out generation breeding; (6) Cross-breeding and generational selection: The core basic group obtained in step (5) is used as the F0 generation. The group succession selection method and group closed selection are adopted. Boars and sows with different bloodlines and inbreeding coefficients ≤ 3% are selected for homogeneous mating. Cross-breeding and generational selection are carried out. The annual renewal rate of generations is 100%. The number of bloodlines in each generation is ensured to be ≥ 12, and high-quality meat pigs are obtained. Among them, generational selection starts from the F1 generation, and each generation carries out breeding work according to the following same main contents: S1. Newborn selection: Weigh all piglets individually. The selected individuals come from litters with a total number of piglets ≥ 10. The selected individuals are healthy piglets with ≥ 6 pairs of nipples, ≥ 0.8 kg body weight, strong limbs and normal walking. No more than 4 sows and no more than 2 boars are selected from each litter. The selected individuals are white in color, with normal reproductive organ development, healthy testicles of boars and horizontal or downward vulva of sows. All the deformed ones in the same litter will be eliminated; S2. Selection at weaning age: Weigh all the piglets individually, and the selection requirements are that the individual weight is ≥4kg, the individual has no abnormal health conditions, no clinical symptoms of disease, and no visual abnormalities; S3, select and retain the piglets at the day of nursery-to-breeding, weigh all the piglets individually, and remove the bottom 10% of the individuals by weight; S4. Weigh the whole group of piglets when they are 100-110 days old; S5. The whole group performance of piglets is measured at 150-160 days of age; the whole group performance includes individual weight, individual back fat thickness and individual eye muscle thickness; S6. Draw a growth curve based on the individual body weight collected in S1~S5, and formulate a correction formula based on the growth curve and the performance of the whole group. Use the individual phenotypic information and pedigree information obtained in S1~S5 to estimate the breeding value of the main selected traits using the ABLUP method; construct a comprehensive selection index for high-quality pigs based on the breeding values ​​of each main selected trait during selection, and select and rank the high-quality pigs according to the comprehensive selection index. The comprehensive selection index of selected boars shall not be less than 120, and the comprehensive selection index of selected sows shall not be less than 100; the calculation formula for the comprehensive selection index of high-quality pigs is: I4=0.3*85kg corrected age+0.3*85 kg back fat thickness + 0.4*total piglets; reproductive traits are selected using restrictive indicators, which are that the number of nipples of individual pigs is ≥6 pairs, and the pigs come from litters with a total piglet number of ≥12 piglets. One boar of the same bloodline is selected according to the high-quality pig growth selection index, and 1-2 sows from the same litter are selected according to the high-quality pig growth selection index; the selected pigs are healthy, with a suitable growth rate, a body weight not lower than the average level of the same batch, and the limbs and hooves are normal and strong, without obvious limb and hoof diseases, arched backs and clinical manifestations of diseases, limb injuries or developmental abnormalities, and no tail biting or ear biting that leads to no breeding value; hermaphroditic pigs are not selected; the size and shape of the sow's vulva are normal and not upturned; S7. When selecting, the principle of homogeneous selection and optimal matching is followed, and the inbreeding coefficient is ≤3%. The mating combination is based on the comprehensive selection index. The sow group is selected after an average of 2 litters, and the excellent litters are selected for 3-4 litters; S8. After 2 generations, a few excellent individuals can be appropriately overlapped to increase the frequency of excellent genes in the pig herd and accelerate the fixation of excellent traits.

[0018] At present, the high-quality pig has entered the second generation of breeding, and the specific breeding results are as follows: Table 2 Sample size and growth performance results

[0019] From the results in Table 2, we can see that after one generation of breeding, the corrected age was shortened by 3.23 days, the live corrected back fat was reduced by 3.09 mm, and the feed-to-meat ratio was reduced by 0.04. Generation breeding will continue.

[0020] Table 3 Sample size and reproductive performance results

[0021] From the results in Table 3, it can be seen that the hybrid advantage of the F2 generation has weakened, but the average litter size is still above 12, and generational breeding will continue.

[0022] The performance of the high-quality meat pig F2 bred by the present invention was compared with that of Neijiang pigs, and the specific results and analysis are as follows.

[0023] Table 4 Performance comparison between high-quality meat pig F2 and Neijiang pig

[0024] As shown in Table 4, compared with Neijiang pigs, the corrected age of the latest generation of high-quality meat pigs with the same weight was shortened by 39.39 days, the back fat thickness was reduced by 25.92 mm, the feed-to-meat ratio was reduced by 0.75, the total number of piglets per litter increased by 4.06 in the first litter, increased by 3.48 in the multiparity, the slaughter rate and lean meat rate increased by about 3.5%, and the eye muscle area increased by 12.43 cm 2 , while the difference in meat quality indexes was not significant. This shows that the high-quality pork of the present invention not only maintains the quality characteristics of Neijiang pork, but also greatly improves the growth and reproduction efficiency.

[0025] The present invention has been described according to the above embodiments. It should be understood that the above embodiments do not limit the present invention in any form. Any technical solutions obtained by equivalent replacement or equivalent transformation shall fall within the scope of the present invention.

Claims

1. A method for breeding high-quality pigs, characterized in that: The following steps are involved: (1) Neijiang pigs are selected as the sire, the selected individual black pig index is not less than 120, and the restrictive selection index is: the number of individual nipples is ≥ 6 pairs, the total number of piglets is ≥ 10, the inbreeding coefficient is ≤ 3%, and the number of group families is ≥ 12; the calculation formula of the black pig index is I1=0.4*60kg corrected age+0.3*60kg back fat thickness+0.3*60kg eye muscle thickness; (2) Select Canadian Large White pigs as the female parent, and the breeding index of the selected individual Large White pigs shall not be less than 120. The restrictive selection indicators are: the number of individual nipples is ≥ 7 pairs, the pigs are from a litter with a total number of piglets ≥ 15, the inbreeding coefficient is ≤ 3%, and the number of family groups is ≥ 20; the calculation formula of the Large White breeding index is I2=0.17*total piglets+0.3*live piglets+0.1*weaning litter weight+0.25*100kg corrected age+0.05*feed-to-meat ratio+0.08*100kg eye muscle thickness+0.05*100kg back fat thickness; (3) using the male and female parents selected in steps (1) and (2) to perform hybrid production to obtain a hybrid base population; (4) Multi-stage selection is performed to obtain a core basic group under the premise that the number of blood relations in the group is ≥12; (5) The core basic group obtained in step (4) is used as the F0 generation, and the group succession breeding method is used for cross-crossing fixation and generational breeding. The annual generation renewal rate is 100%, and the number of group bloodlines in each generation is ensured to be ≥12 to obtain high-quality meat pigs.

2. The method for breeding high-quality pigs according to claim 1, characterized in that: The multi-stage selection in step (4) includes the following steps: S1. Newborn selection: weigh all piglets individually, and select individuals from litters with a total number of piglets ≥ 10. The selected individuals are healthy piglets with ≥ 6 pairs of nipples and an individual weight ≥ 0.8 kg. The selection rate of sows in each litter is ≤ 50%, and the selection rate of boars is ≤ 30%. If there are deformities in the same litter, all litters will be eliminated; S2. Selection at weaning age: weigh all the piglets in the group, and the selected ones must be healthy ones with a body weight of ≥4kg; S3, Selection of nursery-to-mature piglets: Weigh all the piglets and remove the bottom 10% of the piglets by weight; S4. Weigh the whole group of piglets when they are 100-110 days old; S5, whole group performance test is conducted when piglets are 150-160 days old; S6. Draw a growth curve based on the individual body weights collected in S1-S5, and formulate a correction formula based on the growth curve and the performance of the entire group. The growth traits are selected using a comprehensive selection index, and the reproductive traits are selected using a restriction index; S7. Select excellent breeding pig groups according to S1~S6 and meet the requirement of group bloodline number ≥12 to obtain the core basic group.

3. The method for breeding high-quality pigs according to claim 2, characterized in that: The overall performance of the S5 group includes individual body weight, individual back fat thickness and individual eye muscle thickness.

4. The method for breeding high-quality pigs according to claim 2, characterized in that: The selection of growth traits using a comprehensive selection index in S6 includes the following steps: sorting and selecting according to the growth selection index of high-quality pigs, with the growth selection index of reserve boars not less than 120, and the growth selection index of reserve sows not less than 100; the calculation formula for the growth selection index of high-quality pigs is: I3=0.4*85kg corrected age+0.3*85kg back fat thickness+0.3*85kg eye muscle thickness; the restrictive index is that the number of nipples of an individual pig is ≥6 pairs, and the pig comes from a litter with a total number of piglets ≥12, and one boar of the same bloodline is selected according to the growth selection index of high-quality pigs, and 1 to 2 sows from the same litter are selected according to the growth selection index of high-quality pigs.

5. The method for breeding high-quality pigs according to claim 1, characterized in that: The generation breeding in step (5) comprises the following steps: S1. Newborn selection: Weigh all piglets individually. The selected individuals come from litters with a total number of piglets ≥ 10. The selected individuals are healthy piglets with ≥ 6 pairs of nipples and an individual weight ≥ 0.8 kg. No more than 4 sows and no more than 2 boars are selected from each litter. The selected individuals are white in color. All deformed piglets in the same litter will be eliminated. S2. Selection at weaning age: weigh all the piglets in the group, and the selected ones must be healthy ones with a body weight of ≥4kg; S3, Selection of piglets for nursery-to-mature age: Weigh all piglets individually and remove the bottom 10% of the individuals by weight; S4. Weigh the whole group of piglets when they are 100-110 days old; S5, whole group performance test is conducted when piglets are 150-160 days old; S6. Draw a growth curve based on the individual body weights collected in S1-S5, and formulate a correction formula based on the growth curve and the performance of the entire group. The growth traits are genetically evaluated using the ABLUP model, and the reproductive traits are selected using restrictive indicators; S7. The principle of selection is homogeneous selection and optimal matching. The inbreeding coefficient is ≤3%. The mating combination is based on the comprehensive selection index. The sow group is selected after 2 litters on average, and the excellent litters are selected for 3~4 litters. S8. After 2 generations, select outstanding individuals for generation overlapping.

6. The method for breeding high-quality pigs according to claim 5, characterized in that: The overall performance of the S5 group includes individual body weight, individual back fat thickness and individual eye muscle thickness.

7. The method for breeding high-quality pigs according to claim 5, characterized in that: The genetic evaluation of the growth traits in S6 using the ABLUP model includes the following steps: using the individual phenotypic information and pedigree information obtained in S1 to S5, using the ABLUP method to estimate the breeding values ​​of the main selected traits; when selecting, based on the breeding values ​​of each main selected trait, constructing a comprehensive selection index for high-quality pigs.

8. The method for breeding high-quality pigs according to claim 7, characterized in that: The pigs are sorted and selected according to the comprehensive selection index of high-quality pigs, the comprehensive selection index of selected boars is not less than 120, and the comprehensive selection index of selected sows is not less than 100; the calculation formula of the comprehensive selection index of high-quality pigs is: I4=0.3*85kg corrected age+0.3*85kg back fat thickness+0.4*total number of piglets; the restrictive indicators are that the number of nipples of an individual pig is ≥6 pairs, and the pig comes from a litter with a total number of piglets ≥12, and 1 boar of the same bloodline is selected according to the high-quality pig growth selection index, and 1~2 sows from the same litter are selected according to the high-quality pig growth selection index.

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