Breeding method of high-propagation fast-growing short-leg slow-feathering Guangxi partridge chickens

Abstract

The invention relates to the technical field of poultry breeding, in particular to a breeding method of high-reproduction fast-growth short-foot slow-feathering Guangxi partridge chickens, which comprises the following steps: constructing a molecular detection system of a chicken sex-associated short-foot gene GHR and a recessive white feather RWC gene; guangxi partridge chicken breeder hens and short-foot recessive white feather breeder cocks are hybridized to obtain a hybridized F1 generation group, and the F1 generation is selfed to generate an F2 generation; aiming at the F2 generation group, phenotypic selection is combined with a molecular detection technology, and short-foot slow-feathering Guangxi partridge chicken individuals are screened out; then, breeding cocks and hens are screened, and a short-foot slow-feathering Guangxi partridge chicken core group is built; a zero-generation family is established, and a new high-propagation and fast-growing short-leg slow-feathering Guangxi partridge chicken strain is bred through subculture breeding. The short-leg slow-feathering Guangxi partridge chicken strain bred by the method inherits the short-leg characteristic of short-leg recessive white-feather chickens, the feed intake in the egg producing period is reduced compared with that of Guangxi partridge chickens, the egg producing number, the hatching egg insemination rate and the hatching egg qualification rate are improved, and the breeding cost is effectively reduced; meanwhile, a gene detection technology is applied, so that the breeding accuracy and efficiency are improved.

Description

Technical Field

[0001] This invention relates to the field of poultry breeding, and more specifically, to a breeding method for a high-breeding, fast-growing, long-legged, slow-feathering Guangxi Ma chicken. Background Technology

[0002] Guangxi Ma chickens are characterized by their "one mackerel, two slender, and three short" features. They are of moderate weight, with tender meat, and are a major slow-growing breed of chicken raised and consumed in Guangxi, with an annual output of over 600 million birds and a promising market prospect. However, in recent years, affected by factors such as avian influenza and a sluggish market economy, many live poultry markets across the country have been closed, and problems such as high breeding costs, slow growth rate, low feed conversion rate, and low meat yield of Guangxi Ma chickens have become increasingly prominent. Therefore, developing a breeding line for Guangxi Ma chickens with high broiler production, fast growth rate, good breast meat quality, good uniformity, and high feed conversion rate has become an urgent need in the industry. This invention provides a method for breeding high-breeding, fast-growing, short-legged, slow-feathering Guangxi Ma chickens, which can quickly cultivate breeding materials for crossbreeding to improve the problems of low meat yield, slow growth rate, low feed conversion rate, poor uniformity, and high breeding costs in Guangxi Ma chickens.

[0003] In yellow-feathered broiler breeding, due to the faster early growth rate and feather growth of fast-feathering strains, purebred lines are often selected towards fast-feathering. In Guangxi Ma chicken production, since purebred lines are often fast-feathering, the sex of newly hatched chicks still requires manual identification. Manual identification is labor-intensive, slow, and causes significant stress and damage to the chicks. This invention develops a slow-feathered, dwarf Ma chicken strain that can be paired with fast-feathered Guangxi Ma chicken purebreds to form a feathering speed self-identification system, simplifying the sexing process and reducing the potential risks of stress, damage, and lateral disease transmission caused by vent examination. Furthermore, it also alleviates the difficulty in recruiting sexing personnel to some extent.

[0004] Due to their low basal metabolic rate, low feed consumption, excellent reproductive performance, strong heat resistance, outstanding stress resistance, and delicious meat, dwarf chickens can effectively increase the stocking density per unit area. Furthermore, the commercial broilers produced by crossbreeding with normal-sized roosters exhibit normal body size and production performance comparable to conventional broilers, resulting in significant economic benefits. Therefore, the introduction of sex-linked dwarf genes has become an important breeding method in the commercial breeding practices of laying hens and broilers both domestically and internationally.

[0005] The traditional method of introducing sex-linked dwarf gene mainly relies on breeding experience, and the offspring are selected by phenotype, which cannot directly identify the genotype of the target gene. This leads to the emergence of heterozygous individuals in the dwarf chicken population, or the production of non-target dwarf individuals due to environmental factors, resulting in low selection accuracy and breeding efficiency. Therefore, it usually needs to go through multiple phenotype selection to gradually purify. Moreover, at least 8 weeks of age, the dwarf chicken can be distinguished according to body weight, tibia length and other indicators to distinguish between homozygotes, heterozygotes and homozygotes of sex-linked dwarf gene. Compared with this, molecular marker-assisted selection technology can effectively overcome the difficulty of trait phenotype identification, realize early accurate selection, and significantly improve the efficiency of backcross breeding.

[0006] As the major gene that regulates body weight, feed efficiency, egg production performance and many other quantitative traits, sex-linked dwarf gene dw(dwarf) is the only recessive mutant gene with positive utilization value among the eight dwarf genes in chicken, which has no adverse effects on the health of the organism. Studies have shown that the variation of chicken growth hormone receptor(GHR) gene is the key factor leading to linked dwarf chicken. Due to the lack of growth hormone receptor in dwarf chickens, the biological function of growth hormone is affected. Currently, four types of GHR gene mutations have been found to cause dwarf chickens: (1) Two bases after position 352 in the coding sequence have a T→C mutation; (2) There is a 1773 bp base deletion between the end of exon 10 and the untranslated region(UTR) 1744-3516; (3) The base at position 679 in the coding region is mutated from G to T; (4) Single base T→C mutation occurs at position 335 in the coding region. In addition, the coexistence of multiple mutations may have additive effects, resulting in large differences in tibia length and poor uniformity in the dwarf chicken population.

[0007] Therefore, when using molecular marker-assisted breeding to breed sex-linked dwarf chicken lines, screening homozygous mutant individuals is the key to improving the uniformity of the line and offspring. Studies by Chen Zhongcan et al. have shown that compared with normal chickens, the ino-adipose deposition capacity of the dwarf-type recessive white-feathered chicken caused by the deletion mutation of the GHR gene is significantly enhanced, the muscle fiber diameter is extremely significantly reduced, and the muscle fiber density is extremely significantly increased, indicating that the histological characteristics and fat deposition capacity of the dwarf-type chicken have changed significantly, which is beneficial to improve meat quality.

[0008] As an important breeding material, recessive white feather is widely used in Chinese local high-quality chicken breeding. Because its colored feathers are recessive to Chinese local high-quality chicken breeds, it is of great concern to breeders when using foreign chicken breeds to improve local chickens. The recessive white feather gene type is diverse, and the tyrosinase(TYR) gene is the major gene controlling the expression of recessive white feather, located on chromosome 1, regulating melanin production. When the TYR gene has a reverse transcriptase inserted into both alleles, it will cause the expression of recessive white feather.

[0009] In breeding practice, although there are cases of introducing sex-linked dwarf genes into dwarf yellow-feathered chickens, the offspring of dwarf yellow-feathered chickens and Guangxi Ma chickens have yellow feathers and no speckled features, which cannot meet the specific feather color selection requirements of dwarf slow-feathered Guangxi Ma chickens.

[0010] In the breeding process of introducing desirable traits through hybridization of recessive white-feathered chickens, traditional methods rely on the phenotypic traits of the hybrid offspring for breeding stock, followed by testcross testing, breeding and expansion, etc., resulting in a lengthy breeding cycle. However, molecular marker-assisted identification technology can achieve rapid identification of recessive white-feathered genes.

[0011] Therefore, a breeding method for a high-breeding, fast-growing, short-legged, slow-feathering Guangxi Ma chicken is needed to solve the problems of high breeding cost, slow growth rate, low feed conversion rate, low slaughter rate, and poor uniformity of the existing Guangxi Ma chicken. Summary of the Invention

[0012] In view of this, the present invention addresses the shortcomings of the existing technology by proposing a breeding method for a high-breeding, fast-growing, short-legged, slow-feathering Guangxi Ma chicken, aiming to solve the problems of high breeding cost, slow growth rate, low feed conversion rate, low slaughter rate, and poor uniformity of the existing Guangxi Ma chicken.

[0013] This invention provides a breeding method for the Guangxi Ma Chicken, a high-breeding, fast-growing, long-legged, slow-feathering breed, comprising the following steps:

[0014] Establish molecular detection methods for the sex-linked dwarf gene GHR and the recessive white-feathered RWC gene in chickens;

[0015] Based on body shape and appearance standards, closed-loop breeding was carried out on Guangxi Ma Chicken and Dwarf Recessed White-feathered Chicken to obtain basic populations;

[0016] The dwarf recessive white-feathered roosters and Guangxi Ma chicken hens in the basic population were first screened. The dwarf recessive white-feathered roosters and Guangxi Ma chicken hens selected in the first screening were used as the male and female parents, respectively, and the eggs were collected and incubated to obtain the F1 generation.

[0017] From the F1 generation, select normal-legged, slow-feathered, mottled-feathered roosters that meet the described body shape and appearance standards and contain heterozygotes of the dw gene. Self-cross them with dwarf-legged, slow-feathered, mottled-feathered hens that meet the described body shape and appearance standards. Collect the eggs and incubate them to obtain the F2 generation.

[0018] The F2 generation chicks were raised and then subjected to a second screening. The chicks after the second screening were molecularly tested using the gene molecular detection method. The roosters and hens with mottled feathers that were homozygous for the dw gene and had no recessive white feather gene were selected and raised in individual cages to obtain the basic population of dwarf slow-feathered Guangxi mottled chickens.

[0019] The third screening is performed on the male chickens in the dwarf slow-feather Guangxi chicken basic population to obtain final core group males, and the fourth screening is performed on the male chickens in the dwarf slow-feather Guangxi chicken basic population to obtain final core group females;

[0020] The final core group males and the final core group females are randomly grouped into 0th generation families, and the high-reproduction fast-growing dwarf Guangxi chicken is obtained after subsequent breeding.

[0021] Further, the body appearance standard is specifically: the selection standard of the body appearance of the dwarf recessive white-feather chicken is recessive white feather, slow feather, yellow shank and good breast meat development, and the Guangxi chicken is slow feather, scaly feather and yellow shank.

[0022] Further, the first screening is specifically: screening the dwarf recessive white-feather male chicken with shank length of 95-105% of the average value, body weight of 95%-110% of the average value, semen volume of not less than 105% of the average semen volume, semen density of more than 3.5 billion / mL of sperm cells, and the family egg production performance of the female chicken of the same family is higher than the average family egg production value; screening the Guangxi chicken female chicken with egg number of more than 100 at 43 weeks and egg quality rate of not less than 103% of the average egg quality rate of the population.

[0023] Further, the second screening is specifically: screening the individual with scaly feather and shank length of not more than 6.0 cm when the chicken of F2 generation is raised to 60-70 days old.

[0024] Further, the genetic molecular detection method is specifically:

[0025] The blood of the chicken after the second screening is collected, and chicken blood genomic DNA is extracted;

[0026] By primer design, dwarf gene identification primers are obtained, such as SEQ ID No. 1, SEQ ID No. 2 and SEQ ID No. 3, PCR amplification and sequencing of the chicken blood genomic DNA are performed using the dwarf gene identification primers, the dwarf heterozygote and the normal foot homozygote are removed, and the dwarf homozygote individual is retained;

[0027] By primer design, recessive white feather gene identification primers are obtained, such as SEQ ID No. 4, SEQ ID No. 5, SEQ ID No. 6 and SEQ ID No. 7, PCR amplification and sequencing of the chicken blood genomic DNA are performed using the recessive white feather gene identification primers, and the recessive white feather heterozygote is removed.

[0028] Further, when performing PCR amplification, the PCR system reaction conditions are: 94℃ pre-denaturation for 5 min; 94℃ denaturation for 30 s, 53℃ annealing for 30 s, 72℃ extension for 30 s, for 35 cycles; and finally 72℃ extension for 5 min.

[0029] Further, the third screening is specifically: the male chickens of the short-feathered Guangxi chicken in the short-feathered Guangxi chicken basic population are raised to 90 days old, and individuals with a body weight in the range of average value + 25% and excellent secondary sexual characteristics are screened out, then the individuals screened out are detected for semen before laying and before breeding, and the male chickens with a semen ejaculation volume greater than or equal to 103% of the average ejaculation volume, a semen density greater than 3.5 billion / mL of sperm cells, and a milk-white color are screened out.

[0030] Further, the fourth screening is specifically: the female chickens of the short-feathered Guangxi chicken in the short-feathered Guangxi chicken basic population are selected according to the size and characteristics of the crown before laying, the female chickens with excellent secondary sexual characteristics are selected, and the number of eggs laid by the individuals at 43 weeks, the egg weight, and the number of eggs laid at 66 weeks are collected, and the individuals with more than 100 eggs laid at 43 weeks and a body weight greater than the average body weight of the female chicken population are selected.

[0031] Further, when the final core group of male chickens and the final core group of female chickens are randomly grouped into 0-generation pedigrees, the final core group of male chickens and the final core group of female chickens are randomly grouped into 0-generation pedigrees according to a male to female ratio of 1:8.

[0032] Further, in the subsequent selection breeding, the male chickens are mainly selected for growth traits and secondarily for reproductive traits, the female chickens are mainly selected for reproductive traits and secondarily for growth traits, and the slow feather selection breeding is simultaneously carried out for male and female chickens.

[0033] Compared with the prior art, the beneficial effects of the present application are that the short-legged slow-feather Guangxi chicken strain obtained by selection and breeding not only inherits the short-legged characteristics of the short-legged recessive white-feather chicken, but also reduces the feed intake of the laying period by 10%-15% compared with the original Guangxi chicken hens, increases the daily laying number of 66-week-old chickens from 157 to 181, increases the rate of qualified breeder eggs from 93.5% to 95%, and increases the rate of insemination of breeder eggs from 93% to 95%, thereby effectively reducing the breeding cost; in addition, the meat chickens produced in combination retain the excellent characteristics of the Guangxi chicken local breed, such as fresh and tender meat quality and strong disease resistance, and have the advantages of rapid growth, strong disease resistance, high feed conversion rate, good uniformity, good meat quality, and breeding theft prevention, and the marketable generation is 5 days earlier than the original Guangxi chicken hens. In addition, because the short-legged mutation type is single, the uniformity of the marketable meat chickens produced in combination is better. In addition, the gene detection technology used in the present application significantly improves the accuracy and efficiency of screening in the breeding process of the breeding material, effectively avoids the genotype separation phenomenon of the next generation, and compared with the traditional phenotype breeding method, the breeding material breeding cycle is shortened by at least 2-3 generations, greatly accelerating the breeding process. In addition, the new strain of the high-reproduction fast-growth short-legged slow-feather Guangxi chicken can be combined with the fast-feather Guangxi chicken pure line to realize the identification of fast and slow feathered males and females, simplify the male and female identification process, reduce the potential hidden dangers of stress response and damage and disease horizontal transmission caused by rectal examination identification, and also alleviate the problem of labor shortage in artificial identification to a certain extent.

[0034] The foregoing general description and the following detailed description are merely exemplary and explanatory, rather than limiting the present disclosure.

[0035] Other features and aspects of the present disclosure will become more apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0037] Figure 1 The breeding technical roadmap of the high-reproduction fast-growth short-legged slow-feather Guangxi chicken provided in the embodiments of the present application;

[0038] Figure 2 The agarose gel electrophoresis detection result graph of the short-legged gene in the embodiments of the present application;

[0039] Figure 3 The agarose gel electrophoresis detection result graph of the negative white-feather gene in the embodiments of the present application. DETAILED DESCRIPTION

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0041] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0042] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0043] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0044] See Figure 1 As shown, a breeding method for a high-breeding, fast-growing, long-legged, slow-feathering Guangxi Ma Chicken according to an embodiment of this application includes the following steps:

[0045] Establish molecular detection methods for the sex-linked dwarf gene GHR and the recessive white-feathered RWC gene in chickens;

[0046] Based on body shape and appearance standards, closed-loop breeding was carried out on Guangxi Ma Chicken and Dwarf Recessed White-feathered Chicken to obtain basic populations;

[0047] The first screening is performed on the dwarf recessive white-feathered male chickens and Guangxi chicken hens in the basic population, the dwarf recessive white-feathered male chickens and Guangxi chicken hens after the first screening are used as the father and mother, crossbreeding is performed, eggs are collected for hatching, and F1 generation is obtained;

[0048] Normal-foot slow-feathered male chickens containing dw gene heterozygotes that meet the body appearance standard are selected from the F1 generation, and are self-crossed with slow-feathered hens that meet the body appearance standard, the eggs are collected for hatching, and F2 generation is obtained;

[0049] The chicken seedlings of the F2 generation are raised, and then the second screening is performed, the chicken seedlings after the second screening are detected by the gene molecular detection method, slow-feathered male chickens and hens that are dw gene homozygotes and do not contain recessive white feather genes are selected and raised in single cages, and the dwarf slow-feathered Guangxi chicken basic population is obtained;

[0050] The third screening is performed on the dwarf slow-feathered Guangxi chicken male chickens in the basic population, and the final core group of male chickens is obtained, the fourth screening is performed on the dwarf slow-feathered Guangxi chicken male chickens in the basic population, and the final core group of hens is obtained;

[0051] The final core group of male chickens and the final core group of hens are randomly grouped into 0-generation families, and the high-reproduction fast-growing dwarf Guangxi chicken is obtained after the inbreeding.

[0052] Specifically, when the final core group of male chickens and the final core group of hens are randomly grouped into 0-generation families, the final core group of male chickens and the final core group of hens are randomly grouped into 0-generation families at a male to female ratio of 1:8.

[0053] It can be understood that the present application takes the dwarf recessive white-feather chicken and Guangxi chicken as breeding basic materials to carry out research on new strain breeding of high-reproduction fast-growth type dwarf slow-feather Guangxi chicken, and the high-reproduction fast-growth type dwarf slow-feather Guangxi chicken prepared by the present application not only has the characteristics of the dwarf chicken, but also has a 10%-15% reduction in feed intake during the egg-laying period compared with the original Guangxi hen, and the daily egg production of 66-week-old feeding reaches more than 180, the rate of qualified breeder eggs is increased from 93.5% to 95%, the insemination rate of breeder eggs is increased from 93% to 95%, and the breeding cost is effectively reduced; the complete set of commercial broilers retains the excellent characteristics of the Guangxi chicken local breed, such as fresh and tender meat quality and strong disease resistance, and has the advantages of fast growth, strong disease resistance, high feed conversion rate, good uniformity, good meat quality and breeding theft prevention, etc., and the marketable date is 3 days earlier than that of the original Guangxi hen. In addition, the gene detection technology used in the present application significantly improves the accuracy and efficiency of screening in the breeding process of the breeding material, effectively avoids the genotype separation phenomenon of the next generation, and greatly accelerates the breeding process compared with the traditional phenotype breeding method. The breeding material breeding cycle is shortened by at least 2-3 generations, which greatly accelerates the breeding process. It also plays a role in throwing a brick to attract jade for the application of molecular marker assisted selection of other trait genes in chicken breeding. In addition, the new strain of high-reproduction fast-growth type dwarf slow-feather Guangxi chicken can be matched with the fast-feather Guangxi chicken pure line to realize the identification of fast and slow feather male and female, simplify the male and female identification process, reduce the potential hidden dangers of stress response and damage and disease horizontal transmission caused by rectal examination identification, and also alleviate the problem of difficult recruitment of identification personnel to a certain extent.

[0054] In some embodiments, the body appearance standard is that the body appearance selection standard of the dwarf recessive white-feather chicken is recessive white feather, slow feather, yellow shank and good chest meat development, and the Guangxi chicken is slow feather, scabrous feather and yellow shank.

[0055] In some embodiments, the first screening is to screen the dwarf recessive white-feather rooster with shank length of 95-105% of the average value, body weight of 95%-110% of the average value, ejaculation volume not less than 105% of the average semen volume, semen density greater than 3.5 billion / mL of sperm cells, and the family egg production of the family female chickens of the same family is higher than the average family egg production; and the Guangxi hen with egg production of more than 100 at 43 weeks and breeder egg qualification rate of not less than 103% of the average breeder egg qualification rate of the group.

[0056] Specifically, when the first screening is performed, the screened dwarf recessive white-feather rooster needs to meet the body appearance standard and be robust and muscular, and the Guangxi hen needs to meet the body appearance standard and have good body shape.

[0057] In some embodiments, the second screening is to screen the individual with scabrous feather and shank length of not more than 6.0 cm when the chicken of F2 generation is fed to 60-70 days old.

[0058] In some embodiments, the gene molecule detection method is specifically:

[0059] Collecting blood of the second screened chicken, extracting chicken blood genomic DNA;

[0060] Through primer design, dwarf gene identification primers are obtained, such as SEQ ID No. 1, SEQ ID No. 2 and SEQ ID No. 3, PCR amplification and sequencing of the chicken blood genomic DNA are performed using the dwarf gene identification primers, and dwarf heterozygotes and normal foot homozygotes are removed, and dwarf homozygote individuals are retained;

[0061] Through primer design, recessive white feather gene identification primers are obtained, such as SEQ ID No. 4, SEQ ID No. 5, SEQ ID No. 6 and SEQ ID No. 7, PCR amplification and sequencing of the chicken blood genomic DNA are performed using the recessive white feather gene identification primers, and recessive white feather heterozygotes are removed.

[0062] In some embodiments, when PCR amplification is performed, the PCR system reaction conditions are: 94°C pre-denaturation for 5 min; 94°C denaturation for 30 s, 53°C annealing for 30 s, 72°C extension for 30 s, 35 cycles; and finally 72°C extension for 5 min;

[0063] Specifically, 0.5 ml of blood sample is collected from chicken wing vein and placed in an EDTA anticoagulant tube, mixed well by inverting, and stored at -20°C for standby, and genomic DNA is extracted according to the blood DNA extraction kit instructions. According to the previous method of PCR amplification and product sequencing for free dwarf recessive white feather chicken detection, it is known that the sex-linked dwarf gene GHR has four mutation sites that can cause chicken dwarf body type, which are: (1) 2 bases after position 352 of the coding sequence occur T→C mutation; (2) 1773 bp base deletion exists at the end of exon 10 and UTR at position 1744-3516; (3) G→T mutation occurs at base 679 of the coding region; (4) single base T→C mutation occurs at position 335 of the coding region; detection confirms that only the second site mutation (1773 bp base deletion) exists in the hybrid male dwarf recessive white feather chicken population, and the existing dwarf recessive white feather chicken only has a 1.7 kb mutation site, according to the DNA sequences of the dwarf gene and the recessive white feather gene, the primer is designed by using Primer premier 5.0 primer design software, and the molecular detection method of the chicken dwarf gene and the recessive white feather gene is established; the PCR identification primer information table is shown in Table 1.

[0064] Table 1 PCR amplification information table of dwarf gene and recessive white feather gene

[0065]

[0066] The chicken blood genomic DNA was amplified by PCR using the dwarf gene identification primers (dw-F1, dw-F2 and dw-R), and the PCR reaction system was as follows: 25 μL, Mix 12.5 μL, 0.5 μL of the upper and lower primers, 1 μL of template DNA, and 10 μL of ddH2O.

[0067] The reaction condition was as follows: pre-denaturation at 94℃ for 5 min, denaturation at 94℃ for 30 s, annealing at 53℃ for 30 s, extension at 72℃ for 30 s, 35 cycles, and finally extension at 72℃ for 5 min.

[0068] The PCR amplification product was detected by 1.5% agarose gel electrophoresis to determine whether it was the target fragment, and the result was shown in Fig. 1, wherein M was Marker 2000; 1 was a negative control; 2 was a dwarf homozygote; 3 was a normal foot homozygote; and 4 was a normal foot heterozygote. Specifically, when the PCR product size was 400 bp, it indicated no deletion mutation; when the product size was 254 bp, it indicated a deletion mutation homozygote; and when two bands appeared, it indicated a deletion mutation heterozygote. Figure 2

[0069] The chicken blood genomic DNA was amplified by PCR using the recessive white feather gene identification primers (F1, R1, F2 and R2), and the PCR reaction system was as follows: 25 μL, Mix 12.5 μL, 0.5 μL of the upper and lower primers, 1 μL of template DNA, and 10 μL of ddH2O.

[0070] The reaction condition was as follows: pre-denaturation at 94℃ for 5 min, denaturation at 94℃ for 30 s, annealing at 53℃ for 30 s, extension at 72℃ for 30 s, 35 cycles, and finally extension at 72℃ for 5 min.

[0071] The PCR amplification product was detected by 1.5% agarose gel electrophoresis to determine whether it was the target fragment, and the result was shown in Fig. 2, wherein M was Marker 2000; 1 was a negative control; 2 was a recessive white homozygote; 3 was a colored feather homozygote; and 4 was a recessive white heterozygote. Specifically, when the PCR product size was 450 bp, it indicated a colored feather homozygote; when the product size was 226 bp, it indicated a recessive white homozygote; and when two bands appeared, it indicated a recessive white heterozygote. Figure 3

[0072] ​​In some embodiments, the third screening is specifically: the male chickens in the dwarf slow-feather Guangxi chickens basic population are raised to 90 days of age, and individuals with a body weight in the range of average value + 25% and excellent secondary sex characteristics are screened out, and then the individuals screened out are detected for semen before laying and before breeding, and the male chickens with a semen volume greater than or equal to 103% of the average semen volume, a semen density greater than 3.5 billion / mL of sperm cells, and a semen color of milky white are screened out.

[0073] Specifically, the third screening also needs to screen the male chickens meeting the body appearance standard.

[0074] In some embodiments, the fourth screening is specifically: the female chickens in the dwarf slow-feather Guangxi chickens basic population are selected according to the size and characteristics of the comb before laying, and the female chickens with excellent secondary sex characteristics are selected, and the number of eggs laid by the individuals at 43 weeks, the egg weight, and the number of eggs laid at 66 weeks are collected, and the individuals with more than 100 eggs laid at 43 weeks and a body weight greater than the average body weight of the female chicken population are selected.

[0075] Specifically, the fourth screening also needs to screen the female chickens meeting the body appearance standard.

[0076] In some embodiments, when the final core group of male chickens and the final core group of female chickens are randomly grouped into 0-generation families, the final core group of male chickens and the final core group of female chickens are randomly grouped into 0-generation families according to a male to female ratio of 1:8.

[0077] In some embodiments, in the subsequent generation selection, the male chickens are mainly selected for growth traits and secondarily selected for reproductive traits, the female chickens are mainly selected for reproductive traits and secondarily selected for growth traits, and slow feather selection is simultaneously carried out for both male and female chickens.

[0078] Specifically, in the subsequent generation selection, the male chickens are mainly selected for body weight and feed conversion ratio at 90-150 days of age, and the reproductive traits such as the number of eggs laid by the female chickens of the same litter and the semen quality are also considered, the female chickens are mainly selected for reproductive traits such as the number of eggs laid, the percentage of qualified breeding eggs, and the insemination rate, and the growth traits such as body weight are also considered, and slow feather selection is simultaneously carried out for both male and female chickens.

[0079] The chicks are numbered according to families, and weak and residual chicks and green-legged individuals are eliminated;

[0080] Slow feather selection: at 1 day of age, the wings of each chicken are unfolded, the relative lengths of the primary wing feathers and the overlying primary wing feathers on the outer side of the wings are observed, and the chickens with fast feather type (the primary wing feathers are more than 2 mm longer than the overlying primary wing feathers) are eliminated, and at 10 days of age, the slow feather selection is carried out according to the tail feather development, and the individuals with excessively long tail feathers are eliminated.

[0081] The male chickens are eliminated at 42 days of age if the comb develops slowly, and the female chickens are eliminated at 56 days of age if the comb does not develop and the face is yellow instead of being rosy.

[0082] 70 days old, the whole group weight, weight selection before the group of 10% of the individual body weight, record the average, male chicken with average value-5~+10% as the range of breeding, hens with-8~+10% as the range of breeding, improve the uniformity of the group;

[0083] Before the production of egg cage, eliminate the individual appearance of body type does not meet the requirements, while picking the chest leg muscle development of individual;

[0084] 90 days old male chicken, eliminate the individual, not to crown and high crown, green feet, corner, select the individual with bright and close feather, double meat, round body type, medium weight, hens eliminate the individual, not to crown, green feet, corner, select the individual with close feather, fine hair, a small amount of speckle, round body type, medium weight. After the detection of chicken white diarrhea, eliminate positive chicken to the egg production house.

[0085] 90 days old, after the cage to 150 days old, male chicken single cage feeding, record the chicken empty body weight, cycle feed intake and 150 days old body weight, during the period, not to control the material, individual material meat ratio determination, 150 days old, calculate the material meat ratio of each male chicken.

[0086] 150 days old male chicken semen detection, select the individual with more than or equal to the average ejaculate volume of 103%, semen density greater than 35 billion / mL sperm cells and color is milk white; Male and female chicken avian leukosis detection, eliminate positive chicken;

[0087] Before the onset of production, chicken white diarrhea and avian leukosis detection, eliminate positive and suspicious individual;

[0088] Before the onset of production, the whole group weight, eliminate the individual with the weight deviating from the average value too much;

[0089] 43 weeks old, reproductive performance selection:

[0090] Hens selection: the method of combining family selection and individual selection, reference the last generation of 66 weeks of egg production, combined with the 43 weeks of family egg production of this generation, from the last generation of 66 weeks of egg production higher than the average egg production of the family, the 43 weeks of family egg production of this generation higher than the average egg production of the family, select the individual with more than the average egg production and the egg quality rate greater than or equal to the average egg quality rate of 105%.

[0091] Male selection: according to the performance of the same generation, select the male chicken of the same generation of the most egg production from the 43 weeks of family egg production of this generation higher than the average egg production of the family, and the male chicken with more than the average body weight of 110%, the ejaculate volume greater than or equal to the average ejaculate volume of 105%, the semen density greater than 35 billion / mL sperm cells, and the 90 days old to 150 days old material meat ratio determination low as the breeding male chicken;

[0092] The selected roosters and hens are inbred to form a family, pedigree checking is performed to avoid full-sib and half-sib mating, and the next generation is propagated by rooster to hen ratio of 1:12.

[0093] After 3-4 generations of propagation, a new Guangxi chicken line with high reproduction rate, fast growth, short legs and slow feathering is finally obtained.

[0094] Example 1

[0095] S1, 0.5 ml of blood sample is collected from chicken wing vein and placed in EDTA anticoagulant tube, inverted and mixed, stored at -20℃ for standby, genomic DNA is extracted according to the instruction of blood DNA extraction kit, primer is designed according to the DNA sequence of dwarf gene and recessive white feather gene by Primer premier 5.0 primer design software, and the molecular detection method of chicken dwarf gene and recessive white feather gene is established;

[0096] S2, according to the standard of body shape, Guangxi chicken and dwarf recessive white feather chicken are closed breeding respectively, and the basic population is obtained, wherein the standard of body shape of Guangxi chicken is recessive white feather, slow feather, yellow shank and well-developed breast meat, and the standard of body shape of dwarf recessive white feather chicken is slow feather, scaly feather and yellow shank;

[0097] S3, the dwarf recessive white feather rooster with shank length of 95-105% of the average value, body weight of 95%-110% of the average value, ejaculation volume not less than 105% of the average semen volume, semen density greater than 3.5 billion / mL sperm cells, and the family performance of the family sister hens higher than the average family egg production is selected as the father; the Guangxi chicken hen with egg production number of 43 weeks higher than 100, and the egg quality rate not less than 103% of the average egg quality rate of the population is selected as the mother, the father and the mother are crossbred, the eggs are collected and hatched, and F1 generation is obtained.

[0098] S4, the normal foot slow feather scaly feather rooster with the standard of body shape and containing dw gene heterozygote is selected from F1 generation, and the dwarf slow feather scaly feather hen with the standard of body shape is self-crossed, the fertile eggs are collected and hatched, and F2 generation is obtained.

[0099] S5, the chicken of F2 generation is raised, and the individual with scaly feather and shank length ≤6.0 cm is selected at the age of 60-70 days, the selected chicken is detected by the molecular detection method, the scaly feather rooster and hen with dw gene homozygote and no recessive white feather gene are selected and single-caged, and the dwarf slow feather Guangxi chicken basic population is obtained.

[0100] S6. Select the male chickens in the dwarf slow-feather Guangxi chicken basic population at 90 days of age, and select the individuals with the body weight in the range of the average value+25% and excellent secondary sex characteristics, then detect the semen of the selected individuals before laying and before breeding, and select the male chickens with the semen volume greater than or equal to 103% of the average semen volume, the semen density greater than 3.5 billion / mL of sperm cells and the color of milk white as the final core group of male chickens;

[0101] S7. Before the female chickens in the dwarf slow-feather Guangxi chicken basic population lay eggs, select the female chickens with excellent secondary sex characteristics according to the size and characteristics of the crown, and collect the number of eggs laid by the 43-week-old individuals, the egg weight, and the number of eggs laid by the 66-week-old individuals, select the individuals with more than 100 eggs laid at 43 weeks of age and the body weight greater than the average body weight of the female chicken population as the final core group of female chickens.

[0102] S8. Randomly establish the 0th generation family line according to the ratio of 1:8 of the male to female ratio of the final core group of male chickens and the final core group of female chickens.

[0103] S9. Select and breed the 0th generation family line by succession.

[0104] S9.1. Wear wing numbers according to family line when the chicks are hatched, and eliminate weak and disabled chicks and green-footed individuals.

[0105] S9.2. Slow-feather selection: at 1 day of age, spread the wings of each chicken one by one, observe the relative length of the primary wing feather and the overlying primary wing feather on the outside of the wing, and eliminate the fast-feather type (the primary wing feather is more than 2 mm longer than the overlying primary wing feather) chickens, and at 10 days of age, select and eliminate the individuals with excessively long tail feathers according to the tail feather development.

[0106] S9.3. At 42 days of age, eliminate the individuals with slow-developing combs for male chickens, and at 56 days of age, eliminate the individuals without developed combs and with yellowish rather than rosy faces for female chickens.

[0107] S9.4. At 70 days of age, weigh the whole group, select the individuals with the body weight of 10% of the heavy group before the selection, record the average value, and take the average value-5~+10% as the breeding range for male chickens and-8~+10% as the breeding range for female chickens to improve the uniformity of the group.

[0108] S9.5. Before transferring to the egg laying cage, eliminate the individuals with the body type and appearance not meeting the requirements, and at the same time, pick the individuals with well-developed breast and leg muscles.

[0109] S9.6. At 90 days of age, eliminate the individuals with inverted combs, no combs, extra-high combs, green feet, and crooked feet for male chickens, and select the individuals with bright and close-fitting feathers, double meat, round body shape, and medium to high body weight, and eliminate the individuals with dwarf combs, no combs, inverted combs, green feet, and crooked feet for female chickens, and select the individuals with close-fitting feathers, fine and slightly mottled feathers, round body shape, and medium body weight. After detecting and eliminating the positive chickens of chicken white diarrhea, transfer them to the egg laying house.

[0110] S9.7, from 90 days of age to 150 days of age, the male chickens are individually caged, the empty body weight, the periodic feed intake and the body weight at 150 days of age are recorded, no feed is controlled during the period, the individual feed-meat ratio is determined, and the feed-meat ratio of each male chicken is calculated after 150 days of age.

[0111] S9.8, the semen of the male chickens at 150 days of age is detected, and the male chickens with the ejaculatory volume greater than or equal to 103% of the average ejaculatory volume, the semen density greater than 3.5 billion sperm cells per mL and the color being milky white are selected and reserved; the avian leukosis of the male and female chickens is detected, and the positive chickens are eliminated;

[0112] S9.9, the chicken white diarrhea and avian leukosis are detected before the onset of production, and the positive and suspicious individuals are eliminated;

[0113] S9.10, the whole population is weighed before the onset of production, and the individuals with the body weight deviating from the average value too much are eliminated;

[0114] S9.11, the reproductive performance selection is performed at 43 weeks of age:

[0115] S9.12, the female chicken selection: the method combining family selection and individual selection is adopted, the egg production number at 66 weeks of age of the last generation is referred to, the egg production number at 43 weeks of age of the current generation is combined, the individuals with the egg production number greater than the average egg production number and the egg quality rate greater than or equal to 105% of the average egg quality rate are selected from the offspring of the family with the egg production number at 66 weeks of age of the last generation higher than the average egg production number and the family with the egg production number at 43 weeks of age of the current generation higher than the average egg production number.

[0116] S9.13, the male chicken selection: the siblings are evaluated according to the performance, the male chicken with the largest egg production number is selected from the siblings of the female chicken in the family with the egg production number at 43 weeks of age of the current generation higher than the average egg production number, and the male chicken with the body weight greater than or equal to 110% of the average body weight of the male chickens, the ejaculatory volume greater than or equal to 105% of the average ejaculatory volume, the semen density greater than 3.5 billion sperm cells per mL and the feed-meat ratio lower than the determination from 90 days of age to 150 days of age is selected as the breeding male chicken;

[0117] S9.14, the selected male and female chickens are selected and mated in the same way to form a family, pedigree checking is simultaneously performed to avoid full-sibling and half-sibling mating, and the families can be randomly formed after 3 generations.

[0118] S10, after 3-4 generations of breeding, the new line of Guangxi Black-Belly Chicken with high reproduction and fast growth and short legs and slow feathering is finally obtained.

[0119] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and the equivalent technologies thereof, the present application also intends to include these modifications and variations.

Claims

1. A breeding method for a high-breeding, fast-growing, long-legged, slow-feathering Guangxi Ma Chicken, characterized in that, The method comprises the following steps: A molecular detection method for chicken sex-linked dwarf gene GHR and recessive white feather RWC is established; According to the body appearance standard, the Guangxi chicken and the dwarf recessive white feather chicken are closed breeding respectively to obtain a basic population; The first screening is performed on the dwarf recessive white feather cock and the Guangxi chicken hen in the basic population, the dwarf recessive white feather cock and the Guangxi chicken hen after the first screening are used as the father and the mother, cross breeding is performed, the eggs are collected and hatched to obtain F1 generation; The normal foot slow feather and slow feather cock with dw gene heterozygote which meets the body appearance standard is selected from F1 generation, the cock is self-crossed with the dwarf slow feather and slow feather hen which meets the body appearance standard, the eggs are collected and hatched to obtain F2 generation; The chicken of F2 generation is raised, then the second screening is performed, the chicken after the second screening is detected by the molecular detection method, the slow feather cock and the slow feather hen with dw gene homozygote and without recessive white feather gene are selected and raised in a single cage to obtain a dwarf slow feather Guangxi chicken basic population; The third screening is performed on the dwarf slow feather Guangxi chicken cock in the basic population to obtain the final core group cock, the fourth screening is performed on the dwarf slow feather Guangxi chicken cock in the basic population to obtain the final core group hen; The final core group cock and the final core group hen are randomly grouped into 0th generation family, and the high-breeding fast-growing dwarf Guangxi chicken is obtained after the breeding.

2. The breeding method of the high-breeding fast-growing dwarf slow feather Guangxi chicken according to claim 1, wherein the body appearance standard is that the body appearance selection standard of the dwarf recessive white feather chicken is recessive white feather, slow feather, yellow shank and good chest meat development, and the Guangxi chicken is slow feather, slow feather, yellow shank. The first screening is specifically: screening the dwarf recessive white feather cock with shank length of 95-105% of the average value, body weight of 95%-110% of the average value, ejaculation volume of not less than 105% of the average semen volume, semen density of more than 3.5 billion / mL sperm cells, and the family egg production performance of the family sister hen is higher than the average family egg production value; screening the Guangxi chicken hen with egg number of more than 100 at 43 weeks and egg quality rate of not less than 103% of the average egg quality rate of the population.

3. The breeding method for the high-breeding, fast-growing, long-legged, slow-feathering Guangxi Ma Chicken according to claim 2, characterized in that, 4. The breeding method of the high-breeding fast-growing dwarf slow feather Guangxi chicken according to claim 3, wherein the second screening is specifically: screening the slow feather and shank length≤6.0cm individuals when the F2 generation chicken is raised to 60-70 days old. The molecular detection method is specifically: Blood of the chicken after the second screening is collected, and chicken blood genomic DNA is extracted; 5. The breeding method for the high-breeding, fast-growing, long-legged, slow-feathering Guangxi Ma Chicken according to claim 4, characterized in that, The dwarf gene identification primer is obtained by primer design, as shown in SEQ ID No. 1, SEQ ID No. 2 and SEQ ID No. 3, the chicken blood genomic DNA is amplified and sequenced by PCR using the dwarf gene identification primer, the dwarf heterozygote and normal homozygote are removed, and the dwarf homozygote individual is retained. ​ ​ The recessive white feather gene identification primers are obtained by primer design, as shown in SEQ ID No. 4, SEQ ID No. 5, SEQ ID No. 6 and SEQ ID No. 7, and the chicken blood genomic DNA is subjected to PCR amplification and sequencing by using the recessive white feather gene identification primers, and the recessive white feather heterozygote is eliminated.

6. The breeding method of the high-reproduction fast-growth type short-shank slow-feather Guangxi fowl chicken according to claim 5, characterized in that, When the PCR amplification is performed, the PCR system reaction conditions are as follows: 94℃ pre-denaturation for 5 min; 94℃ denaturation for 30 s, 53℃ annealing for 30 s, 72℃ extension for 30 s, 35 cycles; and finally 72℃ extension for 5 min.

7. The breeding method of the high-reproduction fast-growth type short-shank slow-feather Guangxi fowl chicken according to claim 6, characterized in that, The third screening is specifically as follows: the short-shank slow-feather Guangxi fowl chicken roosters in the short-shank slow-feather Guangxi fowl chicken basic population are raised to 90 days old, and the individuals with the body weight in the range of average value + 25% and excellent second trait development are screened out, and then the individuals screened out are subjected to semen detection before laying and before breeding, and the roosters with the ejaculate volume greater than or equal to 103% of the average ejaculate volume, the semen consistency greater than 3.5 billion / mL of sperm cells, and the color being milky white are screened out.

8. The breeding method for the high-breeding, fast-growing, long-legged, slow-feathering Guangxi Ma Chicken according to claim 7, characterized in that, The fourth screening is specifically as follows: the short-shank slow-feather Guangxi fowl chicken hens in the short-shank slow-feather Guangxi fowl chicken basic population are selected before laying according to the size and trait of the crown, and the hens with excellent second sex traits are selected, and the 43-week individual egg production number, egg weight, and 66-week egg production number are collected, and the individuals with the 43-week individual egg production number greater than 100 and the body weight greater than the average body weight of the hen population are selected.

9. The breeding method of the high-reproduction fast-growth type short-shank slow-feather Guangxi fowl chicken according to claim 8, characterized in that, When the 0-generation family line is randomly established, the final core group roosters and hens are randomly established in a ratio of 1:

8.

10. The breeding method of the high-reproduction fast-growth type short-shank slow-feather Guangxi fowl chicken according to claim 9, characterized in that, In the subsequent breeding, the roosters are mainly selected for growth traits, and the breeding traits are selected as auxiliary traits, the hens are mainly selected for breeding traits, and the growth traits are selected as auxiliary traits, and the slow-feather breeding is simultaneously carried out for the roosters and the hens.

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