A breeding method for precisely increasing the ratio of chicken wing and chicken claw

Abstract

The present application relates to the technical field of poultry breeding, in particular to a breeding method for precisely increasing the proportion of chicken wings and chicken claws. The breeding method provided by the present application is in line with the demand characteristics of the Chinese consumer market, follows the laws of genetics, and realizes the fine breeding of chicken claw and chicken wing traits through fine determination of the phenotypes of related traits, accurate estimation of individual breeding values, and scientific selection and mating methods. Under the premise of ensuring growth rate, slaughter weight and feed conversion rate, the weight and proportion of chicken wings and chicken claws are effectively increased, meeting the consumer demand for chicken wings and chicken claws in the Chinese market.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of poultry breeding, in particular to a breeding method for precisely increasing the proportion of chicken wings and chicken claws. BACKGROUND

[0002] China is one of the largest chicken consumption markets in the world. Chicken is not only a major source of meat in China, but also deeply rooted in a diverse and rich food culture. Unlike consumer preferences in other parts of the world, Chinese consumers have a unique and refined selection of chicken parts.

[0003] Chicken wings, with their tender texture and unique shape, have been given a variety of cooking methods. And chicken claws, with their low heat, low fat, and high collagen characteristics, have become the first choice for healthy snacks. Whether as a snack or a daily snack, chicken claws have won the taste buds of countless consumers with their unique charm. This widespread consumer demand has made chicken wings and chicken claws one of the most valuable poultry products in the market.

[0004] However, despite the importance of chicken claws and chicken wings in the market, the economic value of these two parts has not been fully valued in the global mainstream broiler commercial breeding program. For a long time, traits such as growth rate, body weight, and feed conversion rate have been the most valued and highly selected traits in broiler breeding, while chicken wings and chicken claws have been relatively marginalized. This imbalance in breeding strategies not only limits the diversification of the broiler industry, but also fails to fully meet the actual needs of consumers. SUMMARY

[0005] To solve the above problems, the present application provides a breeding method for increasing the proportion of chicken wings and chicken claws. The breeding method provided by the present application can breed new varieties (complete lines) of broilers with higher proportions of chicken wings and chicken claws, which not only makes the products more competitive, but also promotes the sustainable development of the Chinese broiler industry.

[0006] To achieve the above purpose, the present application provides the following technical solutions:

[0007] The present application provides a breeding method for increasing the proportion of chicken wings and chicken claws, comprising the following steps:

[0008] 1) The chicks of the breeding chicken population after hatching are divided into a test population and a candidate population;

[0009] The chicks of the test population are free to eat and drink, and after reaching the marketable age, the marketable weight of each chicken is measured, and after being slaughtered and plucked, the weight of the single wing and single claw of each chicken is measured, and the single wing rate and single claw rate of each individual are calculated according to Formula I and Formula II;

[0010] Single wing rate = weight of single wing / weight of marketable chicken × 100% Formula I;

[0011] Single claw rate = weight of single claw / weight of marketable chicken × 100% Formula II;

[0012] 2) the chicks in the candidate population are subjected to restricted feeding for selection;

[0013] 3) according to pedigree records and / or genomic information, and the weight of marketable chicken, single wing rate and single claw rate determined in step 1), the genetic parameters of the weight of marketable chicken, single wing rate and single claw rate of the breeding chicken population are estimated by using best linear unbiased prediction (BLUP) or single-step genomic best linear unbiased prediction (ssGBLUP), and the estimated breeding values of each individual in the candidate population for each trait are solved; the traits include the weight of marketable chicken, single wing rate and single claw rate;

[0014] 4) after the estimated breeding values of each individual in the candidate population for each trait are respectively normalized according to Formula III, the comprehensive breeding values of each individual in the candidate population are calculated by using Formula IV;

[0015] Normalized breeding value = estimated breeding value / σ Formula III;

[0016] wherein σ is the genetic standard deviation of each trait;

[0017] Comprehensive breeding value = A × X1 + B × X2 + C × X3 Formula IV;

[0018] wherein A is the normalized breeding value of the weight of marketable chicken, B is the normalized breeding value of single wing rate, and C is the normalized breeding value of single claw rate; X1 = 50-60%, X2 = 20-25%, and X3 = 20-25%;

[0019] 5) the first selection is performed in the candidate population, and the individuals with larger comprehensive breeding values are selected to continue restricted feeding;

[0020] 6) the individuals selected after the first selection are fed to the egg-laying period, the second selection is performed to select the individuals with larger comprehensive breeding values, the hens with less than 6 eggs in the last month are removed, and one-third of the lineages of the cocks are ensured to be selected, and the cocks and hens selected in the second selection are subjected to lineage formation;

[0021] 7) after the lineage formation, the next generation is bred, and steps 1) to 6) are repeated until the ratio of chicken wing and chicken claw is improved.

[0022] Preferably, the cock selection rate in the first selection in step 5) is 15% to 25%, and the hen selection rate is 45% to 55%.

[0023] Preferably, the cock selection rate in the second selection in step 6) is 15% to 25%, and the hen selection rate is 45% to 55%.

[0024] Preferably, when the family is established in step 6), the coefficient of common parentage of the cocks and hens to be combined is less than 6.25%.

[0025] Preferably, after each batch of chicks is hatched, weak chicks and individuals with body appearance not meeting the characteristics of the breed selection are eliminated.

[0026] Preferably, the elimination criteria of the weak chicks include eliminating individuals with poor yolk resorption, listlessness, and difficulty standing.

[0027] Beneficial effects:

[0028] First, the present application improves the ratio of chicken wings and claws by including the traits of chicken wings and claws in the selection index, which is more in line with the needs of the Chinese consumer market. This selection method can cultivate new varieties (complete lines) of broilers that are more in line with Chinese consumer habits, not only making the product more competitive, but also promoting the sustainable development of the Chinese broiler industry.

[0029] Second, there is a high positive correlation between wing weight and claw weight and body weight. The present application selects ratio traits (single wing rate and single claw rate) to effectively avoid the influence of body weight. In addition, the present application improves the ratio of chicken wings and claws while also including market weight in the selection target, which can optimize economic benefits.

[0030] Third, the present application produces a sibling test population before the next generation of pure breeding, which is raised according to the production management mode of commercial broilers to measure phenotypic data such as market weight, wing weight, and claw weight under free-feeding. Then, the same family composition is used to produce the next generation of breeding core population, which uses a restricted feeding management mode. Based on the phenotypic data of the sibling test population, the breeding core population under restricted feeding is selected, which not only improves the accuracy of early performance selection, but also ensures the reproductive performance of the breeding core population. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows.

[0032] Figure 1 The technical roadmap of the present application;

[0033] Figure 2 The phenotypic value change results of the single wing rate and single claw rate of the cocks and hens in the three generations in the embodiments. DETAILED DESCRIPTION

[0034] The present application provides a selection method for precisely improving the ratio of chicken wings and claws, comprising the following steps:

[0035] 1) The hatched chicks of the breeding chicken population are divided into a test population and a candidate population;

[0036] The chicks of the test population are allowed to freely eat and drink, and after reaching the market age, the market weight of each chicken is determined, and the weight of the single wing and single claw of each chicken is determined after being slaughtered and plucked, and the single wing rate and single claw rate of each individual are calculated according to Formula I and Formula II;

[0037] Single wing rate = weight of single wing ÷ market weight × 100% Formula I;

[0038] Single claw rate = weight of single claw ÷ market weight × 100% Formula II;

[0039] 2) The chicks of the candidate population are subjected to restricted feeding for selection;

[0040] 3) According to the pedigree record and / or genomic information, and the market weight, single wing rate and single claw rate determined in step 1), the genetic parameters of the market weight, single wing rate and single claw rate of the breeding chicken population are estimated using Best Linear Unbiased Prediction (BLUP) or Single Step Genomic Best Linear Unbiased Prediction (ssGBLUP), and the estimated breeding value of each individual for each trait in the candidate population is solved; the traits include market weight, single wing rate and single claw rate;

[0041] 4) After the estimated breeding value of each individual for each trait in the candidate population is standardized according to Formula III respectively, the comprehensive breeding value of each individual in the candidate population is calculated using Formula IV;

[0042] Standardized breeding value = estimated breeding value / σ Formula III;

[0043] Wherein σ is the genetic standard deviation of each trait;

[0044] Comprehensive breeding value = A × X1 + B × X2 + C × X3 Formula IV;

[0045] Wherein A is the standardized market weight breeding value, B is the standardized single wing rate breeding value, and C is the standardized single claw rate breeding value; X1 = 50-60%, X2 = 20-25%, and X3 = 20-25%;

[0046] 5) First selection is performed in the candidate population, and individuals with higher comprehensive breeding values are selected and continue to be subjected to restricted feeding;

[0047] 6) The individuals selected after the first selection are raised to the laying period, second selection is performed to select individuals with higher comprehensive breeding values, hens with less than 6 eggs laid in the last month are removed, and one-third of the lineages of roosters are ensured to be selected, and the roosters and hens selected in the second selection are subjected to lineage formation;

[0048] 7) After the family is established, the next generation is bred, and steps 1) to 6) are repeated until the ratio of chicken wings and chicken claws is improved.

[0049] The breeding chicken population is preferably hatched in at least two batches per year according to the present application, the first batch of chicks is free-feeding and free-drinking, and after reaching the market age, the market weight of each chicken is determined, and the weight of the single wing and the single claw of each chicken is determined after being slaughtered and plucked, and the single-wing rate and the single-claw rate of each individual are calculated according to Formula I and Formula II. The market weight according to the present application is preferably the weight before being slaughtered after reaching the market age. In the present application, after each batch of hatching, the weak chicks are preferably culled, and the individuals with body appearance not meeting the characteristics of the breed selection are also culled; the culling standard of the weak chicks preferably includes the individuals with poor yolk resorption, listlessness, and difficulty standing. According to the different batches of hatching, when the number of batches of hatching per year of the breeding chicken population is 2, the second batch of chicks is selected for restricted feeding for selection, which is recorded as the candidate population, and the first batch of chicks is recorded as the determination population; when the number of batches of hatching per year of the breeding chicken population is > 2, the present application preferably selects the chicks after the first batch according to the population size to select part of the batches or individuals in the batches, and the above-mentioned method is used for feeding and determining the market weight of each chicken, the weight of the single wing and the single claw, and recording the first batch of chicks together as the determination population, and the remaining batches or individuals are restricted for feeding for selection, which is recorded as the candidate population. The present application does not have special requirements for the method of restricted feeding, and the method known to those skilled in the art can be used.

[0050] After obtaining the market weight, the single-wing rate and the single-claw rate of the determination population, the genetic parameters of the market weight, the single-wing rate and the single-claw rate of the breeding population are estimated according to the pedigree record and / or genomic information of the breeding line, and the estimated breeding value of each individual in the candidate population for each trait is solved by using BLUP or ssGBLUP; the traits include the market weight, the single-wing rate and the single-claw rate.

[0051] The present application does not have special requirements for the evaluation method and tool of BLUP or ssGBLUP, and the evaluation method and tool known to those skilled in the art can be used. The evaluation method and tool recorded in the literature

Genomic prediction in a nuclear population of layers using single-step models. Yan et al., 2017

[0052] After obtaining the estimated breeding value of each trait of each individual in the candidate population, the estimated breeding value of each individual in the candidate population is normalized according to Formula III, and the comprehensive breeding value of each individual in the candidate population is calculated according to Formula IV. In the present application, the X1:X2:X3 is 2:1:1 to 3:1:1, preferably 2:1:1.

[0053] After obtaining the comprehensive breeding value of each individual for selection, the present application performs the first selection in the candidate population, and the individuals with larger comprehensive breeding values are selected to continue to be fed. In the present application, the cock selection rate of the first selection is preferably 15% to 25%, more preferably 20%; the hen selection rate is preferably 45% to 55%, more preferably 50%.

[0054] After the first selection, the individuals selected by the first selection are fed to the egg laying period, the second selection selects individuals with larger comprehensive breeding values, removes hens with less than 6 eggs in the last month, and ensures that one-third of the cock family line is selected, and the cocks and hens selected by the second selection are used for family line construction. In the present application, the cock selection rate of the second selection is preferably 15% to 25%, more preferably 20%; the hen selection rate is preferably 45% to 55%, more preferably 50%; when the family line is constructed, the common coefficient of the cocks and hens to be matched is preferably <6.25% to avoid inbreeding depression.

[0055] After the family line is constructed, the next generation is bred, and the above technical solutions are repeated until the ratio of chicken wings and chicken claws is improved.

[0056] The breeding method provided by the present application is based on the demand characteristics of the Chinese consumer market, follows the laws of genetics, accurately estimates the breeding value of the related traits by fine determination of the phenotypes, and realizes the breeding of chicken claw and chicken wing traits by reasonable selection and matching methods. Under the premise of ensuring the growth rate, slaughter weight and feed conversion rate, the weight ratio of chicken wings and chicken claws is effectively improved, which meets the consumer demand for chicken wings and chicken claws in the Chinese market.

[0057] In order to further illustrate the present application, a precise breeding method for improving the ratio of chicken wings and chicken claws is described in detail below in combination with the drawings and examples, but they should not be understood as limiting the scope of protection of the present application.

[0058] Example 1

[0059] In this embodiment, the pure line population used is the Cornish breed, which is used as the paternal line of white-feathered broiler chickens, and the feeding method is three-dimensional cage feeding. The present application provides a precise breeding method for improving the ratio of chicken wings and chicken claws, which specifically comprises the following steps (technical route as shown in Figure 1 ​

[0060] (1) The breeding core group of chickens is hatched in two batches per year. The chickens in the first batch can freely eat and drink water, and are slaughtered at 42 days of age for determination of the weight of the single wing and foot claw. The second batch is restricted in feeding for breeding;

[0061] (2) At the time of hatching, weak chicks such as those with poor yolk absorption, listlessness, and difficulty standing, as well as individuals with small body size and mixed feathers that do not meet the characteristics of the breed are eliminated. The healthy chicks that meet the selection requirements are gender identified and raised in the same environment with wing numbers;

[0062] (3) At 42 days of age, the body weight of the chickens in the first batch is determined, and the weight of the single wing and single foot claw is determined by slaughtering and feathering. All chickens are measured on the right side;

[0063] (4) The single wing rate (single wing weight ÷ body weight × 100%) and single claw rate (single foot claw weight ÷ body weight × 100%) of the individuals in the first batch are calculated;

[0064] (5) Based on the pedigree records and genomic information of all individuals, as well as the determined phenotypes of each trait, the genetic parameters and breeding values (EBV) of the slaughter weight, single wing rate, and single claw rate of all individuals are estimated using ssGBLUP. The genetic variance σ 2 and the EBV of the individuals in the second batch are extracted for each trait;

[0065] (6) After standardizing the EBV of the three traits (EBV / σ), the comprehensive breeding value of all male and female chickens in the second batch is calculated according to the weight of the slaughter weight: single wing rate: single claw rate = 2:1:1;

[0066] (7) The individuals in the second batch are selected according to the comprehensive breeding value, and the male and female chickens with larger comprehensive breeding values are selected for continued restricted feeding. The breeding rate of male chickens is 15%, and the breeding rate of female chickens is 45%;

[0067] (8) After being raised to the laying period, the male chickens 120 (breeding rate 20%) and the female chickens 1200 (breeding rate 50%) are selected for family establishment by considering the comprehensive breeding value of the selected individuals (individuals with larger comprehensive breeding values are selected), the reproductive performance of the parents (female chickens with less than 6 eggs in the last month are not selected), and the family content (to ensure that one-third of the male chicken families have individuals selected). In the family establishment, the coefficient of common kinship of each male and female combination is controlled to be below 6.25%;

[0068] (9) After the family establishment, the next generation is bred, and the above steps are repeated. After three generations of determination, selection, and pure breeding, the proportion of chicken wings and chicken claws is improved Figure 2 ).

[0069] Table 1 shows the estimated genetic parameters of the slaughter weight, single wing rate and single claw rate; Figure 2 The phenotypic values of the single wing rate and single claw rate of the three generations of male and female chickens in the examples are changed.

[0070] Table 1 shows the estimated genetic parameters of the slaughter weight, single wing rate and single claw rate

[0071]

[0072]

[0073] Note: The diagonal values are the heritability, and the upper and lower triangular values are the genetic correlation and the phenotypic correlation, respectively.

[0074] In addition, the breeding method defined in the present application is used to breed multiple strains of breeding populations in the manner of Example 1, and similar results to Example 1 can be obtained. After multiple generations of determination, selection and pure breeding, the wing rate and claw rate of the base population are successfully improved.

[0075] Although the above examples have made a detailed description of the present application, it is only a part of the examples of the present application, but not all the examples, and other examples can be obtained according to the present examples without creativity, which all belong to the protection scope of the present application.

Claims

1. A breeding method for increasing the ratio of wing to leg in chickens, characterized by, The method comprises the following steps: 1) the hatched chicks of the breeding chicken population are divided into a test population and a candidate population; The chicks of the test population are allowed to freely eat and drink, and after reaching the marketable age, the marketable weight of each chicken is determined, and the weight of the single wing and single claw of each chicken is determined after being slaughtered and plucked, and the single-wing rate and single-claw rate of each individual are calculated according to Formula I and Formula II; Formula I: single-wing rate = weight of single wing ÷ marketable weight × 100%; Formula II: single-claw rate = weight of single claw ÷ marketable weight × 100%; 2) the chicks of the candidate population are subjected to restricted feeding for selection; 3) according to the pedigree record and / or genomic information, and the marketable weight, single-wing rate and single-claw rate determined in step 1), the genetic parameters of the marketable weight, single-wing rate and single-claw rate of the breeding chicken population are estimated by using the best linear unbiased prediction or one-step genomic best linear unbiased prediction, and the estimated breeding value of each individual for each trait in the candidate population is solved; the traits include the marketable weight, single-wing rate and single-claw rate; 4) after the estimated breeding value of each individual for each trait in the candidate population is standardized according to Formula III respectively, the comprehensive breeding value of each individual in the candidate population is calculated by using Formula IV; Formula III: standardized breeding value = estimated breeding value / σ; wherein σ is the genetic standard deviation of each trait; Formula IV: comprehensive breeding value = A × X1 + B × X2 + C × X3; wherein A is the standardized marketable weight breeding value, B is the standardized single-wing rate breeding value, and C is the standardized single-claw rate breeding value; X1 = 50-60%, X2 = 20-25%, and X3 = 20-25%; 5) the first selection is performed in the candidate population, and individuals with a larger comprehensive breeding value are selected and retained for restricted feeding; the cock selection rate of the first selection is 15%-25%, and the hen selection rate is 45%-55%; 6) the individuals selected and retained after the first selection are raised to the egg-laying period, the second selection is performed to select and retain individuals with a larger comprehensive breeding value, hens with less than 6 eggs laid in the last month are removed, and one-third of the cock lineages are ensured to be selected, and the cocks and hens selected and retained in the second selection are subjected to lineage formation; when the lineages are formed, the inbreeding coefficient of the cocks and hens to be matched is less than 6.25%; the cock selection rate of the second selection is 15%-25%, and the hen selection rate is 45%-55%; 7) after the lineages are formed, the next generation is bred, and steps 1)-6) are repeated until the proportion of chicken wings and chicken claws is improved.

2. The breeding method according to claim 1, characterized by, After each batch of chicks is hatched, weak chicks and individuals with a body appearance not conforming to the characteristics of the breed selection are eliminated.

3. The selection method according to claim 2, wherein The elimination criteria of the weak chicks include eliminating individuals with poor yolk resorption, listlessness and standing difficulty.

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