A method for screening laying fowl based on eggshell strength and its application

Abstract

The present invention relates to a method for screening laying birds based on eggshell strength, comprising the following steps: S1 constructing a candidate population; S2 collecting multiple eggs from each individual in the candidate population, measuring the horizontal eggshell strength a and the vertical eggshell strength b of the eggs; S3 calculating a selection index I under different weights: I=a×A+b×B, where A and B represent the weighted weights of a and b, respectively; S4 sorting the candidate population according to the selection index I under different weights, proportionally screening the top-ranked individuals to form a selected population, calculating the average selection difference between the selected population and the candidate population in eggshell strength, and the weighted ratio corresponding to the largest average selection difference is the optimal weighted ratio; S5 selecting the selection index I corresponding to the optimal weighted ratio, sorting all individuals in the candidate population according to I, and performing last-place elimination to obtain a dominant population. Compared with the prior art selection method of directly using the vertical eggshell strength measurement to perform last-place elimination, the present invention screens laying birds with higher egg strength.

Description

Technical Field

[0001] The present invention relates to the technical field of poultry and livestock breeding, and in particular to a method for screening laying fowls based on eggshell strength and an application thereof. Background Art

[0002] Eggshell quality is a crucial trait in poultry breeding, directly impacting egg shelf life, breakage rate during distribution, and hatchability. Eggshell strength is one of the most important indicators for evaluating eggshell quality. Traditionally, eggshell strength is measured by placing an egg lengthwise on an eggshell strength tester and applying increasing pressure at both ends. The maximum value at which the eggshell breaks is considered the eggshell strength. Traditional egg-laying chicken production relies on manual egg collection and egg trays. Eggs in egg trays are most susceptible to impact at their ends, so eggshell strength is typically measured along the longitudinal axis. With the rapid expansion of large-scale caged laying hens in my country since the 1990s, egg collection methods have undergone significant changes. Egg-laying chicken operations are equipped with automated farming equipment that enables mechanical feeding, mechanical egg collection, and intelligent environmental control. Eggs roll laterally during transportation from cages and egg collection equipment. Consequently, this shift in egg collection methods has led to new requirements for eggshell quality: the need to improve both the transverse and longitudinal shell strength. In addition, the determination of eggshell strength is destructive, and only one eggshell strength index can be measured on the same egg, which creates certain difficulties in collecting phenotypic data on eggshell strength.

[0003] Therefore, the selection and improvement of poultry eggshell strength requires a method for measuring eggshell strength at different positions, as well as a selection method for comprehensively improving eggshell strength along both the horizontal and vertical axes. Summary of the Invention

[0004] In order to solve the problems existing in the above technology, the present invention provides a method for screening laying fowls based on eggshell strength for pure breeding of laying fowls, comprising the following steps:

[0005] S1 builds a candidate population;

[0006] S2 collects data on the candidate population: collects multiple eggs from each individual in the candidate population, and measures the horizontal eggshell strength a and the vertical eggshell strength b of the eggs;

[0007] S3 calculates the selection index I under different weights: I = a × A + b × B, where A and B represent the weighted weights of a and b respectively;

[0008] S4 determines the optimal weighted ratio: the candidate groups are ranked according to the selection index I under different weights, the individuals with the highest ranking are selected proportionally to form a selected group, the average selection difference between the eggshell strength of the selected group and the candidate group is calculated, and the weighted ratio corresponding to the largest average selection difference is the optimal weighted ratio;

[0009] S5 Candidate group screening: Select the selection index I corresponding to the optimal weighted ratio, sort all individuals in the candidate group by I, and eliminate the last-placed individuals to obtain the dominant group.

[0010] Preferably, the method for collecting poultry eggs and measuring the eggshell strength in step S2 is as follows: collect poultry eggs produced by the test laying birds for 7 consecutive days, measure the eggshell strength vertically along the longitudinal axis of the eggs collected on the 1st, 3rd and 5th days, measure the eggshell strength horizontally along the transverse axis of the eggs collected on the 2nd, 4th and 6th days, and randomly perform longitudinal or transverse measurements on the 7th day.

[0011] In any of the above solutions, preferably, in step S3, the horizontally measured eggshell strength a and the vertically measured eggshell strength b are normalized.

[0012] The present invention has the beneficial effect of measuring eggshell strength using the method provided herein, which allows for the collection of eggshell strength phenotypes for both horizontal and vertical dimensions at the same age. By selecting using a weighted index of eggshell strength, compared to traditional methods that only measure eggshell strength vertically, more selection differences for both horizontal and vertical eggshell strength can be obtained, thereby accelerating the genetic advancement of eggshell strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Schematic diagram of weighted analysis of the present invention;

[0014] Figure 2 The eggshell strength of different weighted combinations of the embodiments of the present invention is selected to be poor. DETAILED DESCRIPTION

[0015] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0016] The present invention provides a method for screening laying birds based on eggshell strength, which can be used in the field of egg breeding, comprising the following steps:

[0017] S1 builds a candidate population;

[0018] S2 collects data on the candidate population: collects multiple eggs from each individual in the candidate population, and measures the horizontal eggshell strength a and the vertical eggshell strength b of the eggs;

[0019] S3 calculates the selection index I under different weights: I = a × A + b × B, where A and B represent the weighted weights of a and b respectively;

[0020] S4 determines the optimal weighted ratio: the candidate groups are ranked according to the selection index I under different weights, the individuals with the highest ranking are selected proportionally to form a selected group, the average selection difference between the eggshell strength of the selected group and the candidate group is calculated, and the weighted ratio corresponding to the largest average selection difference is the optimal weighted ratio;

[0021] S5 Candidate group screening: Select the selection index I corresponding to the optimal weighted ratio, sort all individuals in the candidate group with I, and eliminate the last-ranked individuals to obtain the dominant group.

[0022] Example

[0023] 1. Constructing a candidate population: In this embodiment, 1934 hens were selected as breeding screening objects, 1084 hens were planned to be eliminated, and 850 excellent individuals were left for successive pure breeding.

[0024] 2. Data collection for the candidate population: Eggs laid by the candidate population hens were collected for seven consecutive days. The eggshell strength (a) was measured vertically along the longitudinal axis of the eggs collected on days 1, 3, and 5. The eggshell strength (b) was measured horizontally along the transverse axis of the eggs collected on days 2, 4, and 6. On day 7, either the longitudinal (a) or transverse (b) measurements were randomly performed.

[0025] In the present invention, the eggshell strength measured along the horizontal axis is referred to as the horizontal eggshell strength a, and the eggshell strength measured along the vertical axis is referred to as the vertical eggshell strength b.

[0026] 3. Calculate the selection index I under different weights: I = a × A + b × B, where A and B represent the weighted weights of a and b respectively.

[0027] In this embodiment, the weights set for A and B are 10%-90%, resulting in a total of 9 weighted combinations, as shown in Table 1.

[0028] Table 1 Weighted weights of eggshell strength in different determination methods in the present invention

[0029]

[0030] The horizontal eggshell strength a and the vertical eggshell strength b are normalized respectively. The normalization method is Min-MaxNormalization:

[0031] 4. Determine the optimal weighting ratio: weight the normalized data of the weighted combination in Table 1. The weighting method is as follows: Figure 1 As shown, Figure 1 The medium weight gradient is 10% (A and B). For example, for a hen numbered M1, the normalized horizontal eggshell strength a and vertical eggshell strength b are 0.129 and 0.299 respectively. Then the selection index I of this hen is: 0.129*0.1+0.299*0.9=0.282.

[0032] The candidate groups were ranked according to the selection index I under different weights, and the individuals in the candidate groups with higher rankings were screened proportionally to form a selected group. That is, the top 850 individuals in the candidate group with the highest I ranking were selected as the selected group from the candidate group of 1934 individuals. The average selection difference in eggshell strength between the selected group and the candidate group was calculated, and the weighted ratio corresponding to the largest average selection difference was the optimal weighted ratio.

[0033] The average selection difference of each weighted group is calculated as follows: the average horizontal eggshell strength of the 850 selected individuals minus the average horizontal eggshell strength of the 1934 individuals in the candidate group is taken as C1, and the average vertical eggshell strength of the 850 selected individuals minus the average vertical eggshell strength of the 1934 individuals in the candidate group is taken as C2. The average selection difference of the weighted group is: (C1+C2) / 2.

[0034] As shown in Table 2 and Figure 2 As shown in the figure, with the change of weighted weights, the selection effect of each combination shows a trend of first increasing and then decreasing. The weighted combination 4 has the largest average selection difference in eggshell strength, that is, when the weighted ratio A:B of the horizontal eggshell strength a and the vertical eggshell strength b is 4:6, the selection difference is the largest.

[0035] Table 2 Different weighted combinations of eggshell strength selection differences

[0036]

[0037] 5. Candidate screening: Select the selection index I corresponding to the optimal weighted ratio, sort all individuals in the candidate group with I, and eliminate the last-ranked individuals to obtain 850 hens as the dominant group for succession and pure breeding.

[0038] Comparative Example

[0039] In this comparative example, the above 1934 hens were eliminated according to the traditional vertical eggshell strength test to obtain a selected group as the control group;

[0040] The data of the control group and the 850 hens selected in the embodiment were compared and the results are shown in Table 3.

[0041] Table 3 Comparison of selection differences between the two selection methods

[0042]

[0043] Note: Data in the same column with different lowercase letters indicate significant differences (P<0.05), and data with the same lowercase letters indicate no significant differences (P>0.05).

[0044] It can be seen that the elimination selection method according to this method makes the average selection difference of eggshell strength increase by 0.07kg / cm compared with the traditional selection method.2 , and the horizontal eggshell strength of the experimental group was significantly higher than that of the control group, indicating that the effect of this method is significantly better than the traditional eggshell strength breeding method.

[0045] Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

Claims

1. A method for screening laying fowl based on eggshell strength, characterized in that: The process includes the following steps: S1 builds a candidate population; S2: Collect data on the candidate population: collect multiple eggs from each individual in the candidate population, and measure the horizontal eggshell strength a and the vertical eggshell strength b of the eggs; S3 calculates the selection index I under different weights: I=a×A+b×B, where A and B represent the weighted weights of a and b respectively; S4 determines the optimal weighted ratio: the candidate groups are ranked according to the selection index I under different weights, the individuals with the highest ranking are selected proportionally to form a selected group, the average selection difference between the eggshell strength of the selected group and the candidate group is calculated, and the weighted ratio corresponding to the largest average selection difference is the optimal weighted ratio; S5 Candidate group screening: select the selection index I corresponding to the optimal weighted ratio, sort all individuals in the candidate group by I, and eliminate the last-place individuals to obtain the dominant group; The egg collection method and eggshell strength measurement method in step S2 are as follows: eggs laid by the test laying birds are collected for 7 consecutive days, the eggshell strength of the eggs collected on the 1st, 3rd, and 5th days are measured vertically along the longitudinal axis of the egg, the eggshell strength of the eggs collected on the 2nd, 4th, and 6th days are measured horizontally along the transverse axis of the egg, and the longitudinal or transverse measurement is randomly performed on the 7th day; The horizontal eggshell strength a and the vertical eggshell strength b measured in step S2 are the normalized eggshell strengths.

2. An application of the method for screening laying birds based on eggshell strength as claimed in claim 1 in the field of laying bird breeding.

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