The present application claims priority under 35 U.S.C. 119(a-d) to CN 202210554651.X, filed May 19, 2022.
The present invention relates to breeding of heat-resistant chickens, and more particularly to a method and device for evaluating heat-resistance chickens.
With the rapid development of China's economy in the past few decades and the improvement of people's living standards, the demand for meat, eggs, milk and other livestock and poultry products has also continued to increase. Among livestock and poultry products, poultry meat and poultry eggs are cheap, nutritious and delicious, and can be widely accepted by groups with different cultural backgrounds and religious beliefs, and poultry breeding industry plays an important role in promoting agricultural and rural economic development in China. Meanwhile, poultry breeding industry of China ranks front row in the world in terms of breeding volume, egg production and consumption, and plays an important leading role in the development of Chinese animal husbandry industry. Therefore, it is of great significance to ensure the healthy and stable development of poultry breeding industry. However, due to the continuous warming of the global climate, among the five major climate types in China, except for the plateau and mountainous climate in the western region, other climate types have the problem of high temperature in summer, and the modern poultry industry is highly intensified and most poultry have experienced various factors such as high-intensity genetic selection lead to heat stress, which is an unavoidable problem in Chinese poultry farming industry in summer. Affected by heat stress, the growth of poultry is inhibited, the production performance is reduced, the immune function is weakened, and the susceptibility to diseases is weakened. In severe cases, it will directly lead to death, causing significant economic losses to the poultry farming industry.
At present, equipment such as wet curtains, mist lines and fans are often used in production to relieve heat stress through physical methods, but there is a large cost of manpower and material resources. There is also a method of adding antipyretic drugs to feed and drinking water, but It will cause certain toxic and side effects to chickens, and these methods cannot completely eliminate the impact of heat stress. Only by improving the heat resistance of the chicken itself and breeding heat-resistant chickens can the heat stress problem be fundamentally solved. However, the heat stress survival time at 40° C. (HSST40), which is recognized as the most accurate indicator for evaluating the heat tolerance of chickens, is a lethal indicator and cannot be directly used in actual production and research. Therefore how to more accurately judge the heat-resistant performance of chicken under “non-lethal” condition is exactly the key point of carrying out heat-resistant chicken breeding.
Based on the above background, the present invention provides a method and device for judging heat resistance of chickens, which can more accurately judge the heat resistance of chickens under “non-lethal” conditions. By treating the chickens with mild heat stress, detecting the blood biochemical index levels of the chickens before and after heat stress, and substituting into the heat resistance judgment model, so as to judge the heat resistance of the chickens.
Technical solutions of the present invention are as follows.
A device for judging heat-resistance chickens, comprises: a heat resistance discrimination module and a display module, wherein a discriminant function is stored in the heat resistance discrimination module: y=−1.20×10−1×x1+7.80×10−1×x2−6.37×10−2×x3+5.86×10−4×x4+9.43×10−3×x5−2.47×10−1×x6−1.50;
wherein the heat resistance discrimination module is configured to discriminate the heat resistance of chickens according to the blood biochemical index and blood gas index data of chickens before and after mild heat stress treatment;
wherein y represents the heat tolerance of the chicken, x1 is a first TCHO concentration of the chicken before mild heat stress, x2 is a second TCHO concentration of the chicken after mild heat stress, x3 is a Hct level of the chicken after mild heat stress, x4 is a concentration of CK after mild heat stress in the chicken, x5 is a difference in the concentration of AST before and after the mild heat stress in the chicken, x6 is a difference in the concentration of ALB before and after the mild heat stress in the chicken, when an output of y is less than 0, the display module shows that the chicken is heat-labile, and when the output of y is greater than or equal to 0, the display module shows that the chicken is heat-resistant;
wherein the mild heat stress treatment is to transfer the non-heat-stressed chickens to an environment at 32±1° C. and a relative humidity of 60% to 70% for 6 hours.
A method for judging heat-resistance chickens, comprises steps of:
The discriminant function of the present invention is obtained through the following steps:
The mild heat stress treatment described is specifically:
Described 40° C. heat shock treatment specifically comprising:
The screened blood biochemical indicators and blood gas indicators are as follows:
First, calculate the mean value of each group according to
wherein i is a different group, and i→1 is The non-heat-resistant group, i→2 is the heat-resistant group, and j is the symbol of the index.
According to average means of each group, calculating an overall mean;
After obtaining the overall mean, calculate the covariance matrix Si of each group and the covariance matrix Sp within the joint group, the SSCP matrix W within the group and the SSCP matrix B between the groups, wherein X(j)i is the jth sample of the i-th group:
The “T” symbol is to take the transposed matrix. After obtaining W and B to calculate the characteristic root k of the discriminant function, the number of roots t is min (p, g−1), which is the number of discriminant functions, and p is related to heat resistance The number of indicators with strong sex, p=6, g=2. Then calculate the characteristic root according to (W″−1 ″B−λ I) E=0, I and E are unit matrix; finally get k and calculate the coefficient a“t” of each index in the discriminant function:
According to (W−1 B−λt I)at=0, (atT Sp at)=1, and ct=−atT
wherein y represents the heat tolerance of the chicken, x1 is the TCHO concentration of the chicken before mild heat stress, x2 is the TCHO concentration of the chicken after mild heat stress, x3 is the Hct level of the chicken after mild heat stress, x4 is the concentration of CK in chickens after mild heat stress, x5 is the difference in AST concentration in chickens before and after mild heat stress, and x6 is the difference in ALB concentration in chickens before and after mild heat stress. When the y output is less than 0, it is judged that the chicken is heat-labile (HSST40<120 min), when the y Output is greater than or equal to 0, it is judged that the chicken is heat-resistant (HSST40 120 min).
The beneficial effects that the present invention has are as follows.
The invention can be used to judge the heat resistance of different breeds of laying hens;
The invention can more accurately judge the heat resistance of chickens under the “non-lethal” condition.
These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.
Preferred embodiment of the present invention are described below in conjunction with the accompanying drawings:
The overall structure of the temperature control cabin of the present invention is symmetrical, as shown in
Use the remaining samples of preTCHO, postTCHO, postHct, postCK, difAST and difALB after screening and regrouping, and set the sample data of chickens with HSST40<120 min after heat stress treatment at 32±1° C. as intolerant For the heat group, set the sample data of chickens with HSST40≥120 min after heat stress at 32±1° C. as the heat-resistant group, and establish the Fisher discriminant function. The sample size of each group is ni, and the total sample size is n.
First, calculate the mean value of each group according to
wherein i is a different group, and i→1 is The non-heat-resistant group, i→2 is the heat-resistant group, and j is a symbol of the index.
Then calculate the overall mean based on the mean of each group:
After obtaining the overall mean, calculate the covariance matrix Si of each group and the covariance matrix Sp within the joint group, the SSCP matrix W within the group and the SSCP matrix B between the groups, wherein X(j)i is the jth sample of the ith group:
The “T” symbol is to take the transposed matrix. After obtaining W and B to calculate the characteristic root λ of the discriminant function, the number of roots t is min (p, g−1), which is the number of discriminant functions, and p is related to heat resistance The number of indicators with strong sex, p=6, g=2. Then calculate the characteristic root according to (W·1B−λ I) E=, I and E are unit matrix: finally get λ and calculate the coefficient at of each index in the discriminant function: according to (W−1 B−λt I)at=0, (atT Sp at)=1 and ct=−atT
y=−1.20×10−1×x1+7.80×10−1×x2−6.37×10−2×x3+5.86×10−4×x4+9.43×10−3×x5−2.47×10−1×x6−1.50;
wherein y represents the heat tolerance of the chicken, x1 is the TCHO concentration of the chicken before mild heat stress, x2 is the TCHO concentration of the chicken after mild heat stress, x3 is the Hct level of the chicken after mild heat stress, x4 is the CK concentration of the chicken after mild heat stress, x5 is the AST of the chicken before and after mild heat stress difference in concentration change, x6 is difference in ALB concentration before and after mild heat stress in chickens. When y<0, it is judged that the chicken is heat-labile, and when y≥0, it is judged that the chicken is heat-resistant.
One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting.
It will thus be seen that the objects of the present invention have been fully and effectively accomplished. Its embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.
Number | Date | Country | Kind |
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202210554651.X | May 2022 | CN | national |