High-quality processing type Wenchang chicken variety breeding method and application thereof

Abstract

The invention belongs to the technical field of poultry breeding, and provides a high-quality processing type Wenchang chicken variety breeding method and application thereof, and the method comprises the following steps: (1) D line breeding: (2) Y2 line breeding; (3) M line breeding; (4) breeding a D-line ancestral generation, a Y2-line ancestral generation and an M-line ancestral generation by using the D-line, the Y2-line and the M-line respectively; (5) breeding a D-line parent generation by using the D-line ancestral generation; hybridizing the Y2-line male individuals and the M-line ancestral female individuals to breed Y2M parental generations; and (6) breeding a DY2M commercial generation by using the male individuals of the D-line parent generation and the female individuals of the Y2M parent generation. The commercial strain of the Tanshu No.3 broiler bred by the method is stable in production performance, good in slaughter performance, attractive in carcass, excellent in meat quality, high in reproductive capacity, high in adaptability, high in feed reward, good in market response and remarkable in social and economic benefits.

Description

Technical Field

[0001] This application belongs to the field of poultry breeding technology. Specifically, this application provides a method for breeding a high-quality processing-type Wenchang chicken and its application. Background Technology

[0002] Wenchang chicken, a tropical specialty livestock breed, is a pillar industry of Hainan Province's animal husbandry, providing over 70% of the province's chicken products. It is a crucial source of animal products for the province and a model for the development and utilization of local resources. However, with the shift in demand from e-commerce for chilled yellow-feathered broiler products and processed ready-to-eat meals, existing Wenchang chicken breeding systems suffer from problems such as poor uniformity in free-range farming, low feed conversion efficiency (above 3.6:1), long rearing cycles, and high abdominal fat percentage. These issues fail to meet the demands of industrial transformation, which requires superior production performance, efficient rearing methods, and suitability for slaughtering and processing. Therefore, there is an urgent need to develop new breeding systems to comprehensively improve production efficiency and processing characteristics. Summary of the Invention

[0003] On the one hand, this application provides a method for breeding a high-quality processing-type Wenchang chicken breed, the method comprising:

[0004] (1) D line breeding: The top 10% of the weight of the male chickens and the top 30% of the weight of the female chickens of the K line of the Wenchang chickens were selected from the Wenchang chicken breeding group and matched to form a basic group; individuals with body shape, white skin, small pores and fast growth rate were selected to form the 0th generation for closed family breeding; fast feathering, 5 generations were selected; among them, the G0 to G2 generations were selected based on body shape, comb development and weight at 98 to 100 days of age; the G3 to G5 generations were selected based on feed conversion ratio, abdominal fat percentage and weight uniformity.

[0005] (2) Y2 line breeding: Using recessive white roosters separated from the Wenchang chicken breeding group over multiple generations and hens of the recessive white-feathered chicken breed of the French company Clement, select hens with good uniformity, and then continuously crossbreed for 2-3 generations. Select individuals with the same body shape and appearance as Wenchang chickens to form the basic group; select individuals with the same body shape, skin color and other appearance as Wenchang chickens to form the 0th generation for closed family breeding; slow feathering, breeding for 5 generations; during this period, the main selection criteria are body shape, comb development, initial egg weight and number of eggs;

[0006] (3) M-strain breeding: Select individuals with high egg production performance and slow feathering from the Wenchang chicken breeding population to form a basic group, and on this basis, breed a strain with high egg production;

[0007] (4) Use the D line, Y2 line and M line to breed the D line ancestor, Y2 line ancestor and M line ancestor respectively;

[0008] (5) Use D line grandparents to breed D line parents; use Y2 line males and M line grandparent females to breed Y2M parents;

[0009] (6) Use male individuals from the D lineage parent generation and female individuals from the Y2M parent generation to breed DY2M commercial offspring.

[0010] Furthermore, avian leukosis purification is performed in each generation from step (1) to step (4).

[0011] Furthermore, in each generation from step (1) to step (4), chicken pullorum was purified.

[0012] Furthermore, the avian leukosis eradication involves blood testing and culling of chickens infected with avian leukosis; and / or the fowl pullorum eradication includes blood testing and culling of chickens infected with fowl pullorum.

[0013] Furthermore, the Y2M parent generation 66-week-old hens obtained in step (5) laid 184-191 eggs, 169-173 hatching eggs, with a hatching egg fertilization rate of 92%-95% and a full-life survival rate of 95%-97%.

[0014] Furthermore, the DY2M commercial chickens obtained in step (6) can be sexed by fast or slow feathering. Hens are marketed at 100-105 days of age with a market weight of 1700-1800g, a feed conversion ratio of 3.3:1-3.5:1, and an abdominal fat percentage of 3%-5%. Roosters are marketed at 80-85 days of age with a market weight of 1550-1650g and a feed conversion ratio of 2.8:1-3.0:1.

[0015] Furthermore, in the DY2M product code obtained in step (6):

[0016] Rooster: Larger (rounder) body, broad chest, deep body, flat back, sturdy body, large comb; head and neck feathers are golden yellow, saddle feathers are red, tail feathers are black; beak, shanks, and skin are yellow; single comb is upright, bright red, with 5-7 serrations, bright red wattles, and red earlobes. Hen: Medium body, broad chest, flat back, early maturity; the hen's feathers are mainly yellow-striped, beak, shanks, and skin are yellow, single comb is upright, with 5-7 serrations, bright red, bright red wattles; iris is orange-red; earlobes are red; newly hatched chicks have neat, clean, and glossy down; abdomen is flat and soft; back is mostly covered with light yellow and black striped feathers.

[0017] Furthermore, the breeding process employs individual selection and / or a combination of genomic chip selection and pedigree selection and individual selection.

[0018] On the other hand, this application provides the application of the above method in breeding Wenchang chicken breeds suitable for chilling and deep processing. Attached Figure Description

[0019] Figure 1 A technical roadmap for breeding the "Tanniu No. 3" broiler chicken breeding system.

[0020] Figure 2 Diagram of the supporting system for "Tanniu No. 3" broiler chickens. Detailed Implementation

[0021] Example 1: Cultivation Objectives and Technical Route

[0022] Benchmarking against the production performance and future market demand of excellent domestic yellow-feathered broiler breeds, and based on the existing Tanniu Wenchang chicken breeding system, a new breeding system, "Tanniu No. 3," suitable for chilled and deep processing, has been developed. This system features superior quality and flavor, improved growth rate and feed conversion rate, reduced abdominal fat percentage, and improved carcass uniformity. The breeding objectives are:

[0023] Parent breeder chickens: Hens that are 66 weeks old lay 184-191 eggs, 169-173 hatching eggs, with a hatching egg fertilization rate of 92%-95% and a survival rate of 95%-97% throughout the breeding period.

[0024] Commercial broiler chickens: sex is determined by the speed of feather growth. Hens are marketed at 100-105 days of age, with a market weight of 1700-1800g, a feed conversion ratio of 3.3:1-3.5:1, and abdominal fat percentage of 3%-5%. Roosters are marketed at 80-85 days of age, with a market weight of 1550-1650g and a feed conversion ratio of 2.8:1-3.0:1.

[0025] A three-line breeding program was adopted, primarily using the Wenchang chicken breed as the breeding stock. The terminal sire line prioritized feed conversion ratio, abdominal fat percentage, and uniformity to maintain early maturity and excellent chicken meat quality. The maternal line prioritized egg production performance, combined with egg weight and age at first laying to improve traits. Combining ability testing was continuously conducted to screen for hybrid combinations with significant hybrid vigor. Commercial hens were the main product type, with some roosters used for slaughter and chilled products, and others used for castration to meet market demand, while also appropriately increasing the overall utilization rate of rooster chicks. To maintain rapid and stable breeding progress, each line increased its overall breeding rate by expanding the number of testing groups and shortening generation intervals. The retention rate for terminal sire roosters was 3%–5%, and for hens, it was 25%–35%, with a generation interval of 43–46 weeks. The maternal line employed a two-round selection strategy: first retention followed by selection, and then selection followed by retention, to improve egg production performance. The first-retention-then-selection method allowed for selection of egg production performance in the early stages of growth.

[0026] Different breeding methods are employed based on different genetic traits. Individual selection is used for traits such as body size, plumage color, early growth rate, and development of secondary sexual characteristics. Reproductive performance, feed efficiency, and abdominal fat percentage are assessed using a combination of genomic microarray technology, family selection, and individual selection. The technical approach is detailed below. Figure 1 .

[0027] Example 2: Composition and Characteristics of the Matching System

[0028] Based on the breeding objectives, a three-line system is adopted, with the terminal paternal line being the D line, the first paternal line being the Y2 line, and the first maternal line being the M line; the system configuration is as follows: Figure 2 As shown. Following a three-tiered breeding system, purebred lines and their propagation flocks produce grandparent breeder chickens; grandparent breeder chickens are then used to produce parent breeder chickens; and parent breeder chickens are crossbred to produce commercial chickens. Figure 2 ).

[0029] strain:

[0030] D strain: Single comb, with red comb, wattles, and earlobes; maroon body feathers, a golden-yellow ring of feathers on the neck, golden-yellow cap feathers, maroon primary and secondary wing feathers; bluish-black, glossy, sickle-shaped tail feathers; pale yellow skin, yellow shanks; white skin, yellow shanks. Compared to the Wenchang chicken breeding population, it grows faster and has well-developed breast and leg muscles.

[0031] Table 1. Range of body size traits in adult D-strain chickens

[0032]

[0033] Y2 series: Single upright crown, bright red in color; rhomboid body shape, well-developed tail feathers, white feathers all over the body; white beak, shanks, and skin.

[0034] Table 2. Range of body size traits in adult chickens of the Y2 series

[0035]

[0036] M series: Rooster: Majestic build, single upright comb, bright red in color, with 5-7 serrations; feathers close-fitting and glossy; body feathers maroon, with a golden-yellow ring of feathers around the neck, and golden-yellow plumes; primary and secondary wing feathers maroon, tail feathers bluish-black, glossy, sickle-shaped; beak and shanks yellow, skin white. Hen: Medium-sized, feathers close-fitting and glossy, mostly yellowish-brown, some individuals with light mottled backs, some with a ring of black spots on the neck feathers, beak and skin pale yellow, shanks yellow; single upright comb, bright red in color, with 5-7 serrations.

[0037] Table 3. Range of body size traits in adult M-strain chickens

[0038]

[0039] Parental generation:

[0040] Rooster: Same as D-series rooster.

[0041] Hens: Characterized by yellow or red feathers, with good egg production performance in the parent stock, high qualification rate of hatching eggs, medium to large body size, yellow beak, shanks and skin, single upright comb, bright red color, 5-7 comb teeth; bright red wattles; red earlobes.

[0042] Product Agent:

[0043] Rooster: Larger (rounder) body, broad chest, deep body, flat back, sturdy body, large comb; golden yellow feathers on the head and neck, red saddle feathers, black tail feathers; yellow beak, shanks, and skin; single upright comb, bright red in color, large comb with 5-7 serrations, bright red wattles, and red earlobes.

[0044] Hens: medium-sized, with a broad chest and flat back, and early maturity; the hens are mainly covered with yellow and hemp feathers, with yellow beaks, shanks and skin, a single upright comb with 5-7 bright red serrations, bright red wattles; orange-red irises; and red earlobes.

[0045] Newly hatched chicks have neat, clean, and glossy down feathers; their abdomens are flat and soft; and their backs are mostly covered with light-colored feathers that are yellow and black.

[0046] Example 3: Terminal paternal line selection

[0047] D lineage: The base group is derived from the Wenchang chicken conservation group and the Tanniu chicken K line (a fast-feathering and fast-growing line bred by combining Guangxi Sanhuang chicken and Wenchang chicken). In generation 0, the top 10% of male chickens by weight and the top 30% of female chickens by weight from the Wenchang chicken conservation group are selected and paired to form the base group.

[0048] Individuals with good body shape, white skin, small pores, and fast growth rate were selected to form Generation 0 for closed-family breeding. Fast Feathering has been achieved, with 5 generations already bred. Each generation underwent strict purification against avian leukosis and pullorum disease.

[0049] Generations G0-G2: The primary selection traits were body size, comb development, and weight at 98-100 days of age. Weight was primarily determined by individual selection, combined with family mean and evenness. Each generation had 98 male rooster families, with a male-to-female ratio of 1:9.

[0050] Generations G3-G5: The main selection traits are feed conversion ratio, abdominal fat percentage, and body weight uniformity. Individual feed intake is measured, and abdominal fat percentage and meat yield are measured at slaughter. Genomic selection technology based on 55KSNP chips is used for comprehensive improvement.

[0051] Breeding procedures:

[0052] Day 1 selection: Select qualified and healthy individuals. Measure birth weight (sample 100 birds), cull individuals with poor development, leg color, feather color, or other obvious deviations from the strain characteristics, and statistically analyze fertilization rate, hatchability of fertilized eggs, and other indicators for each family. Check feathering speed for each chicken and select those with fast feathering. Use meconium to test for avian leukosis, cull full-sib families containing positive individuals, and assign individual wing tags to healthy individuals according to their family lineage.

[0053] Selection of chickens aged 70-84 days: Body shape, appearance (feather color), shank length, and development of secondary sexual characteristics are the main selection traits. Select individuals whose body shape and appearance conform to the breed characteristics, focusing on culling white and black-feathered chickens, those with drooping combs, small combs, excessively upturned tails, longer body shapes, and those with poor growth and development. Sort by weight from highest to lowest, retaining the top 30%-40% of roosters and the top 60%-70% of hens.

[0054] Selection at 100-105 days of age: Focus on feed conversion ratio, body weight, and abdominal fat percentage. Measure feed intake at 70-100 / 110 days of age, slaughter a portion of individuals, and calculate feed conversion ratio (FCR), residual feed intake (RFI), breast muscle percentage, leg muscle percentage, and abdominal fat percentage. Use the one-step method (SSGBLUP) to estimate the genome-wide breeding value (GEBV) for selection.

[0055] Selection at 21-22 weeks of age: Eliminate individuals with no sperm or defects, check the semen quality of each individual, and eliminate individuals with poor semen quality; select individuals with large, thick, and high crowns (large crown area), red faces, large spurs, long back feathers, large and symmetrical wattles, full body shape (pectoral muscles), longer and redder neck and saddle feathers, and larger tail feathers.

[0056] Selection of breeding stock at 38-40 weeks of age: For G0-G2 generation roosters, selection is primarily based on individual weight and body size; for G3-G5 generation roosters and hens, selection is based on a comprehensive index including RFI, abdominal fat percentage, and GEBV. Before breeding, the first three eggs from each hen are collected and tested for avian leukosis; positive individuals are culled. Family mating is conducted while avoiding inbreeding across three generations.

[0057] Table 4 shows the results of feed conversion ratio, slaughter performance, and number of individuals measured in chips for the three generations from G4 to G6.

[0058] To increase the selection of key traits such as feed conversion ratio, the number of chicks hatched and selected in the D strain has been gradually increasing in recent generations. Eight batches of the G4 generation were tested. Since this generation serves as a reference group for genomic selection, one batch was tested using commercial broiler feed, resulting in 1535 chickens slaughtered; the remaining batches were tested using breeder feed. Four batches of the G5 generation were tested, all using breeder feed; eight batches of the G6 generation were tested, all using breeder feed. The G7 generation (2024) is currently being tested, with six batches tested, all using breeder feed.

[0059] Different feeds were used for testing between batches. To ensure the breeding performance of the core flock of roosters, they were mostly raised using a breeder's feed model, fed with breeder's feed and individual feed intake was measured. To accurately reflect the performance differences between individuals under commercial broiler feeding conditions, commercial broiler feed was used for 1-2 batches during the generational selection process, especially to highlight individual differences in abdominal fat percentage. When evaluating breeding values, batch effects were corrected, and genomic breeding values ​​were used uniformly for estimation. Families with high feed conversion rates across multiple batches were given priority for breeding.

[0060] Table 4. Number of representative typologies and genotypes determined in the last three generations of the D lineage.

[0061]

[0062] Progress in selective breeding across generations:

[0063] Table 5 shows the retention rate of D-line chickens across generations. The average retention rate of roosters over the past five generations was 5.1%, and the average retention rate of hens was 27.0%, with a rooster-to-hen ratio of 1:9 to 1:10.

[0064] Table 5. Seed retention rate of D-line successive breeding.

[0065]

[0066] Note: The rate of male (female) chickens retained for breeding = number of male (female) chickens retained for breeding / (number of chicks hatched / 2).

[0067] Table 6 shows the breeding progress of growth traits and feed efficiency of each generation of the D line.

[0068] After six generations of selection, the growth performance of roosters continued to improve, while the feed conversion ratio (FCR) gradually decreased. Compared with the third generation, the average weight of D-strain roosters at 12 weeks of age increased from 1693g in the third generation to 1742g in the sixth generation, with a coefficient of variation of less than 10%; the weight at 14 weeks of age increased from 2057g in the third generation to 2151g in the sixth generation, with a coefficient of variation of less than 10%, and the coefficient of variation of shank length was within 4%; the remaining feed intake continued to decrease, and compared with the fourth generation, the FCR decreased from 5.69 to 5.40. The results of selective breeding of the main traits in hens showed the same trend as those in roosters.

[0069] Table 6. Progress in the selection of body weight and shank length in D-strain roosters and hens

[0070]

[0071] Note: X: mean; S: standard deviation; CV: coefficient of variation.

[0072] Table 7 shows the results of slaughter performance selection for the D strain over the past five generations. Using genomic selection to assess GEBV, the breeding values ​​of meat yield indicators such as breast muscle weight, breast muscle percentage, leg muscle weight, and leg muscle percentage have consistently improved. From generation G4 to generation G6, the breast muscle percentage in roosters increased from 11.9% to 15.2%, and the leg muscle percentage increased from 23.4% to 24.5%. The breeding values ​​and phenotypic changes in hens showed the same trend after selection: breast muscle percentage increased from 14.4% to 14.9%, and leg muscle percentage increased from 19.8% to 23.7%. Table 7 also shows the progress of slaughter performance selection for the D strain at 100 days of age. After three generations of selection, the slaughter performance of both male and female D strain hens has significantly improved.

[0073] Table 7. Breeding results of slaughter performance of D strain across generations

[0074]

[0075] Note: X: mean; S: standard deviation; CV: coefficient of variation; the calculation of the rate uses live weight as the denominator, such as leg muscle rate: the percentage of the weight of the muscles of both legs to the total clean body (excluding leg bones, skin and subcutaneous fat).

[0076] Table 8 shows the breeding performance results of the D strain over the past five generations. Family selection was performed on egg production in the first four generations, and the age at first egg production remained between 115 and 118 days in these five generations. Egg production rate, fertilization rate, and hatchability were only observed indicators and were not selected.

[0077] Table 8. Breeding performance of D lineage across generations

[0078]

[0080] Example 3 First Paternal Line Selection

[0081] Y2 strain: Derived from a recessive white strain separated from the Wenchang chicken conservation population and a recessive white-feathered chicken from the French company Cremo, achieving a Wenchang chicken bloodline ratio of 87.5%. In generation 0, recessive white roosters separated from the Wenchang chicken conservation population over multiple generations were crossbred with hens from the French company Cremo's recessive white-feathered chicken breed. Hens with good uniformity were selected, and then crossbred continuously for 2-3 generations, selecting those with the same body shape and appearance as the Wenchang chicken to form the foundation group.

[0082] Individuals with body shape, skin color, and other physical characteristics identical to Wenchang chickens were selected to form Generation 0 for closed-line breeding. Slow-feathering has been achieved, and five generations have been bred. Each generation undergoes strict eradication against avian leukosis and pullorum disease. Selection is primarily based on body shape, comb development, initial egg weight, and egg production count. Initial egg weight is mainly determined by individual hens, while egg production count is primarily determined by family lineage selection.

[0083] Breeding process:

[0084] 1-day-old selection: Same as D series, select slow-feathering.

[0085] Selection of breeding stock at 70-84 days of age: Focus on culling mixed-feather chickens, chickens with drooping combs, chickens with small combs, and chickens with poor growth and development. Based on the average egg production of roosters from the previous generation at 43-56 weeks of age and the individual weight of this generation, select the best individuals, with the top 40%-50% of roosters being selected.

[0086] Selection of breeding stock aged 100-105 days: Focus on uniformity, weight, and body type.

[0087] Selection of breeding stock at 38-44 weeks of age: Roosters are selected based on a comprehensive evaluation of family egg production, individual weight, and body size; hens are selected based on the number of qualified hatching eggs per hen. Before selection, the first three eggs laid by each hen are collected and tested for avian leukosis; positive individuals are culled. Family mating is conducted while avoiding inbreeding over three generations. The family coefficient for each generation of the Y2 strain is 60, and the retention rates for roosters and hens at 38 weeks of age are 3.0%–4.3% and 28.0%–33.1%, respectively. The family coefficient and retention rates for each generation of the Y2 strain are shown in Table 9.

[0088] Table 9. Coefficients and Seed Retention Rates of Y2 Series

[0089]

[0090] Breeding progress:

[0091] Table 10 shows the body weights of the Y2 strain at different ages. Body weight at 12-14 weeks of age was not considered a primary trait in generational selection; it was maintained at a constant level or increased slightly, and adult body weight remained within the normal range. Progress in reproductive performance selection is shown in Table 11. The age at first egg lay remained around 120 days; the first egg weight increased from 27.6g in generation 1 to 29.6g in generation 5. Egg production has been affected by diseases such as mycoplasma in the last two generations, resulting in limited progress in selection; further expansion of the population is needed to improve progress.

[0092] Table 10. Weight of Y2 lineage at different ages

[0093]

[0094] Table 11. Breeding progress of reproductive performance of Y2 line generations

[0095]

[0097] Example 4: First Maternal Line Selection

[0098] The M strain originates from the maternal line of the "Tanniu Chicken" breeding line and has been continuously bred for 19 generations. The base population of this strain comes from individuals with high egg production performance and slow feathering in the Wenchang Chicken conservation population, and it has been bred as a specialized strain with high egg production. Each generation undergoes strict eradication against avian leukosis and pullorum disease. In the last three generations, genomic selection based on egg production has been added using the "Jingxin No. 1" chip for measurement.

[0099] Breeding procedures:

[0100] Selection of 1-day-old individuals: Strictly screen for slow-feathering individuals, select healthy and qualified individuals, determine the average weight of the family, and assign wing numbers to individuals according to the family. Inspect appearance, test for avian leukosis, and cull positive individuals.

[0101] Selection of breeding stock at 70-84 days of age: Early selection based on the average number of eggs laid by roosters in the previous generation at 43-56 weeks of age, selecting the best individuals, with the top 40%-50% of roosters selected.

[0102] Selection of breeding stock aged 100-105 days: Focus on uniformity, weight and body type.

[0103] Selection of breeding stock at 38-44 weeks of age: Roosters are selected based on a comprehensive evaluation of family egg production, individual weight, and body size; hens are selected based on the number of qualified hatching eggs per hen. Before selection for breeding, the first three eggs laid by each hen are collected and tested for avian leukosis; positive individuals are culled. Family mating is conducted while avoiding inbreeding over three generations. Egg production records and the number of individuals measured using microchips from the last three generations (G17-G19) are shown in Table 12.

[0104] Table 12. Number of representative typologies and genotypes determined in the last three generations of the M lineage.

[0105]

[0106] The family coefficient of the M lineage ranges from 98 to 120, with a male-to-female ratio of 1:9. The breeding rates of male and female chickens at 38 weeks are 5.5%–7.3% and 27.5%–33.9%, respectively. The family coefficient and breeding rate of the M lineage are shown in Table 13.

[0107] Table 13. Breeding Retention Rate of M Lineage in Each Generation

[0108]

[0109] Note: The rate of male (female) chickens retained for breeding = number of male (female) chickens retained for breeding / (number of chicks hatched / 2).

[0110] Breeding progress:

[0111] The breeding progress of growth traits in each generation of the M strain is shown in Table 14. The weight of 12-week-old roosters increased from 1482g in the 15th generation to 1758g in the 19th generation; the weight of 14-week-old hens increased from 1260g in the 15th generation to 1551g in the 19th generation; the coefficient of variation of weight for both roosters and hens remained below 10. Adult weight remained stable.

[0112] Table 14. Weight of different generations of the M series at different ages

[0113]

[0114] Table 15 shows the progress of breeding performance selection for the M line over the past five generations. After selection, the age at first laying has been maintained at 118-121 days; the weight of the first egg has increased from 29.8g in the 15th generation to 30.3g in the 19th generation; the number of eggs laid at 56 weeks of age has increased from 153.1 in the 15th generation to 156.5 in the 19th generation; the hatchability of eggs has increased from 87.6% in the 15th generation to 88.4% in the 19th generation; and the survival rate has also improved.

[0115] Table 15. Breeding progress of reproductive performance of M lineage across generations

[0116]

[0118] Example 5 Disease Purification

[0119] Purification of chicken diarrhea:

[0120] The core group of breeder chickens underwent two full-group purification processes for each generation. The first purification was conducted after selection at 14 weeks of age, and the second was conducted before propagation. The whole blood plate agglutination reaction was used for on-site testing, and positive chickens were culled.

[0121] Standardized training is regularly provided to testing personnel, and fixed operators and result interpreters are assigned to implement streamlined testing operations, significantly improving testing speed, making on-site testing more convenient, and avoiding errors in result interpretation by different personnel. A strict regular disinfection system is implemented, and feces are cleaned up promptly to prevent the spread of pullorum disease among chickens. Disposable lancets are used, with a new needle used for each chicken to avoid cross-infection during blood collection. Pullorum disease test results are shown in Table 16-1. The positive rates of pullorum disease in the three chicken strains decreased to 0.35%, 0.27%, and 0.19%; the effect is significant, effectively preventing the impact of the disease on production and breeding.

[0122] Table 16-1. Eradication status of pullorum disease in different generations of D, M, and Y2 strain chickens

[0123]

[0124] Purification of avian leukosis:

[0125] Two flock-wide purification tests were conducted on each generation of breeding chickens in the core flock. The first test (after selection at 14 weeks) and the second test (before propagation) were performed on the entire flock to detect fowl leukosis. Positive chickens were culled. The test results are shown in Table 16-2 below.

[0126] Since 2019, a total of 59,231 birds have been eradicated of avian leukosis. Leukosis first appeared in 2021, and eradication control measures were implemented for each generation. The leukosis positivity rate of the M strain decreased from 2.0% in the 17th generation to 1.4% in the 18th generation; the leukosis positivity rate of the D strain decreased from 1% in the 3rd generation to 0.8% in the 5th generation; and the leukosis positivity rate of the Y2 strain decreased from 1% in the 3rd generation to 0.4% in the 5th generation. After 2-3 generations of eradication, the avian leukosis positivity rate of each strain has significantly decreased and has been effectively controlled.

[0127] Table 16-2. Purification status of avian leukosis in different generations of D, M, and Y2 strains

[0128]

[0130] Example 6: Determination of Coordination Strength

[0131] To select a suitable breeding combination with excellent production performance and low economic cost, multiple combining ability tests were conducted during the breeding process. The parent lines (primary hybrids) were primarily compared for reproductive performance, while terminal hybrids were primarily compared for growth performance and slaughtering characteristics. Five strains—K, M, D, Y1, and Y2—were tested with different hybridization combinations. The reproductive performance, body shape, plumage color, precocity, and slaughtering performance of the breeder chickens and commercial broilers from each combination were comprehensively evaluated to select the best combinations as the optimal breeding model.

[0132] Selection of maternal parents:

[0133] Four hybrid combinations were compared and measured against their maternal parents. The egg production of hens entering the henhouse at 66 weeks of age for the four combinations was 182, 188, 184, and 180, respectively. Combination two (Y2♂×M♀) had the highest egg production and superior performance in terms of fertilization and hatchability. Based on physical characteristics such as feather growth speed, body shape, and plumage color, combination two was determined as the hybridization form for the parental line.

[0134] Table 17. Comparison of reproductive performance of maternal parents

[0135]

[0136] Filtering of terminal combination formats:

[0137] During the peak egg production period of chicken flocks, comparative tests were conducted on terminal hybrids using a uniform paternal line, the D line. Considering the growth rate, feed conversion ratio, disease resistance, and meat yield of the terminal hybrids, as well as the reproductive performance of the parent maternal lines, the optimal hybrid hybrid was determined to be D line as the terminal paternal line and Y2♂×M♀ as the hybrid maternal line, i.e., hybrid hybrid D♂×(Y2♂×M♀).

[0138] Table 18. Results of slaughter performance testing at 100 days of age for different feed combinations

[0139]

[0141] Example 7: Performance Comparison Test with Similar Products in the Market

[0142] To evaluate the differences between the "Tanniu No. 3" broiler breeding system and other breeds, a comparison was made with the Tanniu chicken breeding system and commercial broilers from other companies in the province. Besides meeting local market demands in terms of body size, feather color, and meat flavor, the "Tanniu No. 3" broiler breeding system, compared to local breeds, exhibits faster growth, earlier maturity and easier fattening, reaching marketable age in 100-105 days, better feed conversion ratio, and higher meat yield, making it highly favored by farmers.

[0143] Table 19. Performance Comparison of "Tanniu No. 3" Broiler Breeding Line with Other Chicken Breeds

[0144]

[0146] Example 8: Production Performance of the Matching System

[0147] Based on the above combining ability tests and pilot-scale comparisons, the production performance of the parent generation of the "Tanniu No. 3" broiler breeding line is shown in Table 20, and the main production and slaughter performance of the commercial generation is shown in Table 21, including data from the Poultry Quality Supervision and Testing Center and the company's big data self-testing data.

[0148] Table 20. Production performance of the parent generation of “Tanniu No. 3” broiler breeding line

[0149]

[0150] Note: The age for the laying period is 22-66 weeks, and the age for hatching eggs is 25-66 weeks.

[0151] Table 21. Commercial Production Performance of the "Tanniu No. 3" Broiler Chicken Breeding System

[0152]

[0154] Example 9: Pilot-scale application and economic effect analysis

[0155] Production performance of pilot-scale application:

[0156] Since 2022, large-scale pilot-scale rearing of "Tanniu No. 3" commercial broiler chickens has been conducted. Under cage-rearing conditions, the slaughter time is 103-105 days, the average weight of hens is 1640-1840g, the feed conversion ratio is 3.38-3.77, and the survival rate is over 97%. This is 5-10 days earlier than the original breeding lines, demonstrating excellent prospects for widespread application. Feed conversion ratio optimization has been carried out on the new breed, and the feed conversion ratio of the "Tanniu No. 3" broiler breeding lines has been decreasing year by year. The pilot-scale results and production performance of the commercial breeding lines are shown in Table 22.

[0157] Table 22. Pilot production status and production performance of supporting products (2022)

[0158]

[0159] The new breeds have increased the selection of body weight uniformity, improving the yield of the slaughter line. Table 23 shows that the slaughter uniformity of the new breeding lines gradually improved in 2023: the proportion below 1.0 gradually decreased, and the proportion above 1.3 gradually increased, resulting in an additional profit increase of more than 5% for the company.

[0160] Table 23. Slaughter uniformity of the "Tanniu No. 3" broiler breeding system

[0161]

[0162] Table 24. The feed conversion ratio of commercial broiler chickens in the "Tanniu No. 3" broiler breeding system has decreased year by year.

[0163]

[0164] Economic effect analysis of pilot-scale application:

[0165] To promote the application of the "Tanniu No. 3" broiler breeding system in production and quickly transform it into real productivity, the company formulated breed standards and various feeding standards. Through the integration and assembly of supporting technologies, demonstration breeding was conducted in major Wenchang chicken producing areas such as Haikou, Wenchang, Qionghai, and Ding'an in Hainan Province. Through these demonstrations, users understood the production performance of the breeding system, and the scale of breeding was expanded by the demonstration households. This has continuously improved the product's market awareness and influence, resulting in strong sales momentum. Commercial broiler chicks are mainly sold throughout Hainan Island. Their uniformity, survival rate, feed conversion ratio, disease resistance, and chicken meat quality have been widely recognized.

[0166] Genetic parameter estimation:

[0167] To accurately analyze the genetic characteristics of key economic traits, genetic parameter estimation was conducted. During the breeding process, gene chip sequencing was performed on the strains, and genomic information was used to assist in genetic parameter estimation. Genetic parameter estimation was performed using the Genomic Best Linear Unbiased Prediction (GBLUP) model based on additive effects. The traits studied included meat-producing traits such as body weight at 110 days of market age (BW110), kill weight (DW), dressing percentage (DP), breast muscle weight (BM), and breast muscle percentage (BMP). The results in Tables 25 and 26 show that the average weight of Wenchang chicken at market age was 1897.60g. The heritability of body weight, carcass weight, semi-eviscerated weight, and fully eviscerated weight were 0.41, 0.40, 0.41, and 0.38, respectively, which were at a moderately high level. The heritability of other traits was at a low level. Among the genetic correlations, body weight was highly correlated with carcass weight and breast muscle weight (1.00 and 0.81), but less correlated with breast muscle percentage and dressing percentage (0.21 and 0.25).

[0168] Table 25. Estimation results of the heritability of growth traits in the “Tanniu No. 3” broiler breeding line.

[0169]

[0170] The formula for calculating heritability is: h2 = σa 2 / (σa 2 +σe 2 )

[0171] Table 26. Estimation of genetic correlations of major growth traits using the G matrix

[0172]

[0173] The creativity, advancement, and significance of the breeding achievements:

[0174] To proactively address the demands of slaughtering chilled chickens and prepared dishes, we focused on selective breeding for traits such as abdominal fat weight and carcass uniformity, based on a comprehensive evaluation of carcass appearance, including color and skin thickness. In conjunction with the development of our company's "Coconut Wenchang Chicken" and other end-processed products, we established breeding techniques for high-quality slaughter-ready broiler chickens with processing-oriented traits.

[0175] Actively adopt omics and genomics breeding technologies to conduct genetic analysis of quality and flavor traits, genetic analysis of production efficiency traits, and construction of a quality-efficiency balanced breeding system. Develop new supporting lines that meet current needs, change the low efficiency caused by the traditional consumption pattern of Hainan Wenchang chicken in terms of quality requirements, lead the transformation of the local chicken industry, and fully demonstrate the application effect of advanced technologies.

[0176] Scope, conditions, and prospects for promotion and application:

[0177] From the overall pilot-scale application, the "Tanniu No. 3" broiler breeding system demonstrates stable production performance, good slaughtering performance, aesthetically pleasing carcasses, excellent meat quality, high reproductive capacity, strong adaptability, high feed conversion ratio, and positive market response, resulting in significant socio-economic benefits and widespread popularity among farms and farmers. Not only has the efficiency of free-range hens been gradually improved locally, but the "cage-raised roosters" product has also been promoted and sold in major supermarkets and e-commerce platforms, becoming a significant symbol of transformation and efficiency improvement in the Hainan Wenchang chicken industry. The new breed is expected to be promoted annually with approximately 300,000 sets of parent stock and around 10 million commercial broilers, showing broad prospects for widespread adoption.

Claims

1. A method for breeding a high-quality processing-oriented Wenchang chicken breed, characterized in that, The method includes: (1) D line breeding: The top 10% of the weight of the male chickens and the top 30% of the weight of the female chickens of the K line of the Wenchang chickens were selected from the Wenchang chicken breeding group and matched to form a basic group; individuals with body shape, white skin, small pores and fast growth rate were selected to form the 0th generation for closed family breeding; fast feathering, 5 generations were selected; among them, the G0 to G2 generations were selected based on body shape, comb development and weight at 98 to 100 days of age; the G3 to G5 generations were selected based on feed conversion ratio, abdominal fat percentage and weight uniformity. (2) Y2 line breeding: Using recessive white roosters separated from the Wenchang chicken breeding group over multiple generations and hens of the recessive white-feathered chicken breed of the French company Clement, select hens with good uniformity, and then continuously crossbreed for 2-3 generations. Select individuals with the same body shape and appearance as Wenchang chickens to form the basic group; select individuals with the same body shape, skin color and other appearance as Wenchang chickens to form the 0th generation for closed family breeding; slow feathering, breeding for 5 generations; during this period, the main selection criteria are body shape, comb development, initial egg weight and number of eggs; (3) M-strain breeding: Select individuals with high egg production performance and slow feathering from the Wenchang chicken breeding population to form a basic group, and on this basis, breed a strain with high egg production; (4) Use the D line, Y2 line and M line to breed the D line ancestor, Y2 line ancestor and M line ancestor respectively; (5) Use D line grandparents to breed D line parents; use Y2 line males and M line grandparent females to breed Y2M parents; (6) Use male individuals from the D lineage parent generation and female individuals from the Y2M parent generation to breed DY2M commercial offspring.

2. According to the method of claim 1, avian leukosis is eradicated in each generation in steps (1) to (4).

3. According to the method of claim 2, each generation in steps (1) to (4) is purified for pullorum disease.

4. The method according to claim 3, wherein the avian leukosis purification is achieved by blood sampling and culling chickens infected with avian leukosis; and the fowl pullorum purification includes blood sampling and culling chickens infected with fowl pullorum.

5. The Y2M parent generation of 66-week-old hens obtained by step (5) of the method according to claim 1 has an egg production of 184-191 eggs, 169-173 hatching eggs, a hatching egg fertilization rate of 92%-95%, and a survival rate of 95%-97% throughout the period.

6. According to the method described in claim 1, the DY2M commercial chickens obtained in step (6) can be sexed by distinguishing between fast and slow feathering. Hens are marketed at 100-105 days of age with a market weight of 1700-1800g, a feed conversion ratio of 3.3:1-3.5:1, and an abdominal fat percentage of 3%-5%. Roosters are marketed at 80-85 days of age with a market weight of 1550-1650g and a feed conversion ratio of 2.8:1-3.0:

1.

7. According to the method of claim 1, in the DY2M commodity obtained in step (6): Rooster: Larger (rounder) body, broad chest, deep body, flat back, sturdy body, large comb; head and neck feathers are golden yellow, saddle feathers are red, tail feathers are black; beak, shanks, and skin are yellow; single comb is upright, bright red, with 5-7 serrations, bright red wattles, and red earlobes. Hen: Medium body, broad chest, flat back, early maturity; the hen's feathers are mainly yellow-striped, beak, shanks, and skin are yellow, single comb is upright, with 5-7 serrations, bright red, bright red wattles; iris is orange-red; earlobes are red; newly hatched chicks have neat, clean, and glossy down; abdomen is flat and soft; back is mostly covered with light yellow and black striped feathers.

8. The method according to claim 1, wherein the breeding process uses individual selection and / or a combination of genomic chip selection and family selection and individual selection.

9. The application of the method according to claim 1 in breeding a Wenchang chicken breed suitable for chilling and deep processing.

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