A breeding method and feed for enhancing cold stress resistance of chickens

Abstract

The application discloses a breeding method and feed for enhancing cold stress resistance of chickens and belongs to the technical field of chicken breeding. The breeding method comprises an environment adaptation process and a feeding adaptation process. The specific operation is as follows: broiler chickens are fed at an environment of 35 DEG C for 3 days, the temperature is lowered to 33 DEG C for feeding for 4 days, then the temperature is lowered by 3 DEG C, the temperature is lowered at a rate of 1 DEG C per two days for feeding, when the temperature is lowered to 26 DEG C, the temperature is lowered at a rate of 2 DEG C per two days to 16 DEG C, and the temperature is kept constant for 10 days to complete the environment adaptation process of the broiler chickens; the feeding adaptation is simultaneously performed during the environment adaptation process, when the feeding temperature is lowered to 16 DEG C, the ordinary feed is fed while the anti-cold stress feed is added once a day, the feeding is continuously performed until before the temperature is suddenly lowered, the feeding frequency of the anti-cold stress feed is increased to twice a day or three times a day after the temperature is suddenly lowered, and the feeding adaptation is completed after the feeding is continuously performed for at least one week, so that the influence of low temperature on the chicken breeding industry is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chicken breeding, in particular to a breeding method for enhancing the cold stress resistance of chickens and a feed. BACKGROUND

[0002] "Cold stress" generally refers to a series of adverse reactions in physiology and function caused by the destruction of body heat balance when the environmental temperature is lower than the lower limit of the critical temperature of the animal. Cold stress can adversely affect the health and production performance of animals. Experimental studies have found that after 1-day-old broiler chickens are raised in a cold stress environment for 3 weeks and then raised in a normal temperature environment, it is found that cold stress significantly reduces the body weight and body weight gain of broiler chickens; 14-day-old Ross 308 broiler chickens are raised in a cold environment of 13-15℃ until they are 42 days old, and it is found that cold stress reduces the weight gain of broiler chickens, increases the feed conversion ratio, and causes broiler chickens to develop ascites syndrome. In addition to affecting the immunity of chickens, causing high morbidity and mortality of chickens, cold stress also significantly affects the production performance of chickens, such as slow growth of chicken flocks, reduced feed conversion, and significantly decreased egg production rate and eggshell quality. Therefore, the problem of cold stress in chicken breeding needs to be solved urgently.

[0003] At present, the methods for relieving cold stress of chickens mainly include increasing feeding amount, adding a large amount of vitamins, amino acids, trace elements and other substances in feed to improve immunity, but the above operations have little effect on sudden temperature drop or cold regions. If the chicken coop is insulated, the cost is too high, so there is an urgent need to find a new method to resist cold stress to alleviate the impact of low temperature on the chicken breeding industry. SUMMARY

[0004] In view of this, the purpose of the present application is to provide a breeding method for enhancing the cold stress resistance of chickens and a feed thereof, and to reduce the impact of low temperature on the chicken breeding industry.

[0005] The present application solves the above technical problems through the following technical means:

[0006] A breeding method for enhancing the cold stress resistance of chickens, the breeding method comprises an environmental adaptation and a feeding adaptation process, and the specific operation is as follows:

[0007] The broiler chickens are raised at 35℃ for 3 days, then the temperature is reduced to 33℃ for 4 days, then the temperature is reduced by 3℃, and the broiler chickens are raised at a rate of 1℃ per two days, when the temperature is reduced to 26℃, the temperature is reduced to 16℃ at a rate of 2℃ per two days, and the temperature is kept constant for 10 days to complete the environmental adaptation process of the broiler chickens;

[0008] During the environmental adaptation process, feeding adaptation is carried out at the same time, when the feeding temperature is reduced to 16 DEG C, ordinary feed is fed while anti-cold stress feed is added once a day, and the feeding is continuously carried out until before the temperature drops, after the temperature drops, the feeding frequency of the anti-cold stress feed is increased to twice a day or three times a day, and the feeding adaptation is completed after at least one week of continuous feeding.

[0009] Cold stress can cause disorder of balance regulation in the animal body, and gradually damage the antioxidant function of the animal, induce cell apoptosis, and promote autophagy. Severe cold stress directly exposed to a 10 DEG C environment for 24 hours can up-regulate the level of genes involved in necrosis, which is a death pathway leading to cold-induced death. During the feeding process of anti-cold stress, the production performance of a certain stage appears obvious fluctuation, and if the environmental temperature continues to drop, the production performance is significantly reduced, so in the process of enhancing the anti-cold stress breeding of the chicken, the chicken is subjected to cold adaptation first, and by properly adjusting the temperature and the cooling rate, the series of adverse reactions caused by cold stress can be alleviated, and on this basis, the cold adaptation operation is cooperated with the anti-cold stress feed feeding to reduce the disease of the chicken during the cooling process, and the production performance is stabilized and improved.

[0010] Further, the mass ratio of the ordinary feed to the anti-cold stress feed is (5-20):1.

[0011] Further, the temperature drop refers to a cooling amplitude of ≥5 DEG C, or a minimum temperature of ≤10 DEG C.

[0012] The feed added at the initial cooling stage can be once a day, so as to slowly pass through the early cooling process and resist the initial production performance fluctuation, when the air temperature drops, the chicken needs higher anti-cold stress capacity, the feeding frequency of the anti-cold stress feed is increased, so as to ensure that the cooling period and the subsequent cold weather can be smoothly passed through and the production performance is maintained.

[0013] Further, the breeding method of the present application is suitable for broiler breeding in the rearing period, the growth period and the fattening period.

[0014] The breeding method of the present application is mainly suitable for broiler breeding, including small day-old chicks in the rearing period, and mature chickens in the growth period and the fattening period which grow rapidly, and the method is convenient to use in actual chicken farms and is convenient for one-time management.

[0015] Further, the present application also discloses an anti-cold stress feed, which comprises the following components: 1,4-dicaffeoyl quinine, tripterygium glycoside, silicon dioxide powder, xylose, L-methionine, soybean protein.

[0016] Further, the anti-cold stress feed comprises the following mass parts of raw materials:

[0017] 0.1-0.2 parts by mass of 1,4-dicaffeoylquinic acid, 0.5-0.8 parts by mass of tripterygium glycosides, 2-5 parts by mass of silicon dioxide powder, 10-15 parts by mass of xylose, 5-7 parts by mass of L-methionine, and 20-25 parts by mass of soybean protein.

[0018] Further, the preparation method of the anti-cold stress feed is as follows:

[0019] After mixing the xylose and L-methionine, water is added for dissolution, the pH is adjusted to 8-8.5, then the silicon dioxide is added, and the reaction is carried out at a temperature of 100-120 DEG C for 1-2 hours; immediately after the reaction is completed, the soybean protein is added, and after uniform stirring, the temperature is cooled to room temperature; then the 1,4-dicaffeoylquinic acid and tripterygium glycosides are added and stirred uniformly to obtain the anti-cold stress feed.

[0020] In the process of preparing the anti-cold stress feed, the xylose and L-methionine are first subjected to a Maillard reaction under weak alkaline conditions to glycosylate the raw materials, so that after the chickens eat the feed, the protein degradation can be resisted, the protein is accumulated in the cells, and the growth is promoted; then the 1,4-dicaffeoylquinic acid and tripterygium glycosides in the feed synergistically and efficiently activate the PI3K / AKT signaling pathway to reduce the thymus tissue cell apoptosis and programmed necrosis caused by cold stress, protect the thymus tissue from cold stress damage, and maintain faster growth. The added soybean protein not only neutralizes and reduces the concentration of other raw materials, but also serves as a high-quality feed to promote the growth and development of the chicken population.

[0021] Further, in the preparation method, the amount of water added is 1.1-1.2 times the total mass of the xylose and L-methionine.

[0022] The anti-cold stress feed disclosed in the application is used by being directly mixed with ordinary feed.

[0023] Beneficial effects:

[0024] The breeding method disclosed in the application and the anti-cold stress feed disclosed in the application can alleviate oxidative stress, efficiently activate the PI3K / AKT signaling pathway, and reduce the expression level of cell apoptosis and programmed necrosis-related genes to reduce the thymus tissue cell apoptosis and programmed necrosis caused by cold stress, protect the thymus tissue from cold stress damage, alleviate the thymus tissue oxidative stress caused by acute cold stress, and maintain the normal tissue morphology of the thymus. In addition, through breeding experiments, it has been proved that after being fed by the breeding method and the feed of the application, the mortality rate of broilers under cold stress conditions can be significantly reduced, the weight gain of the broilers under the condition of establishing cold adaptation is better, the feed conversion ratio is low, the physiological indexes are improved, and the breeding cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1: Thymus histomorphology of cold-acclimated and non-acclimated broilers before and after acute cold stress, wherein A and B represent the control and experimental groups at 42 days of age (before acute cold stress), respectively, and C and D represent the control and experimental groups after acute cold stress, respectively. C: cortical region; M: medullary region; black arrow: apoptotic bodies or necrotic cells or nuclei fragmentation and dissolution; black square: pathologic hyperemia, hemolysis or focal necrosis;

[0026] Figure 2 : Process diagram of chicken breeding. DETAILED DESCRIPTION

[0027] The following will be combined with specific examples and Figure 1 The present application will be described in detail:

[0028] Example 1:

[0029] All procedures described in this study were approved by the Animal Care and Use Committee of Northeast Agricultural University. 240 1-day-old female AA commercial broilers were randomly divided into control and cold-acclimated groups (n = 120, i.e., 4 x 30 per replicate) and were raised in two artificial climate chambers, respectively.

[0030] Control group: raised at normal temperature from 1 to 42 days of age, i.e., 35℃ for 1-3 days of age, 33℃ for 4-7 days of age, and thereafter, the temperature was reduced by 1℃ every two days starting at day 8 (32℃), and maintained at 20℃ from 32 days of age until 07:00 on day 42.

[0031] Cold-acclimated group (experimental group): the temperature from 1 to 7 days of age was the same as the control group, and from 07:00 on day 8, the temperature was 3℃ lower than the control group (29℃), and the temperature reached 26℃ at 14 days of age, and then the temperature was reduced at a rate of 2℃ every two days for 10 days, and reduced to 16℃ at 23 days of age, and maintained at this temperature until 07:00 on day 42.

[0032] At 07:00 on day 42, all broilers were subjected to acute cold stress (7℃, 24h), and the specific temperature program is shown in Table 1. During the entire experiment, the chickens were free to eat and drink, and were fed starter feed (CP: 21%, ME: 12.1 MJ / kg, 3 times / day) from 1 to 3 weeks of age, and grower feed (CP: 19%, ME: 12.6 MJ / kg, 4 times / day) from 4 to 6 weeks of age. During the experiment, an artificial light regime was used, i.e., 23h light and 1h darkness per day for 1-3 days of age, and light intensity was 25 lux, and from 4 days of age to the end of the experiment, 16h light and 8h darkness per day, and light intensity was 20 lux. The relative humidity in the artificial climate chamber was maintained at 55-65%.

[0033] At 07:00 on day 43, 8 chickens were randomly selected from each group (i.e., 4×2 chickens / repeat) and euthanized. Thymus tissue was collected immediately after euthanasia. After rinsing with cold physiological saline, a portion of the tissue was fixed in 4% paraformaldehyde solution, and the remaining samples were stored at -80℃ for subsequent analysis.

[0034] Table 1. Temperature scheme used in this experiment.

[0035]

[0036] The chickens in the above experiment underwent histological observation of their thymus, and the specific procedures were as follows:

[0037] Chicken thymus tissue was fixed in 4% paraformaldehyde solution for at least 24 hours. The tissue was dehydrated by soaking in ethanol with gradually increasing concentration, then embedded in paraffin, stained with hematoxylin and eosin (H&E), and sections of about 5-6 μm were prepared for microscopic observation under an optical microscope (Nikon Eclipse E400).

[0038] The results obtained are as follows Figure 1 As shown in the analysis results, the following can be concluded:

[0039] The effects of acute cold stress on the morphology of thymus tissue in broilers with and without cold adaptation are shown in [reference needed]. Figure 1 In both the control and experimental groups, the thymus of the broilers exhibited normal morphology, with a large number of well-differentiated or developing T lymphocytes. Only the experimental group showed a few apoptotic cells. After acute cold stress, the thymus tissue in the control group showed significant damage, with a large number of apoptotic or necrotic cells, widespread nuclear fragmentation and dissolution, and localized focal necrosis, along with localized hemorrhage. In the experimental group, a small number of apoptotic bodies and necrotic cells were still observed, but the tissue congestion and hemolysis caused by acute cold stress were significantly improved, and the tissue morphology remained intact. These results indicate that acute cold stress can damage the normal morphology of thymus tissue, while cold acclimatization can alleviate thymus tissue damage caused by cold stress.

[0040] Example 2: Preparation of Cold Stress-Resistant Feed

[0041] 0.1g 1,4-dicaffeoylquinic acid, 0.5g Tripterygium wilfordii glycosides, 2g silica powder (50-100 microns), 10g xylose, 5g L-methionine, 20g soy protein;

[0042] Xylose and L-methionine were mixed and dissolved in 16.5g of water. The pH was adjusted to 8, and then silicon dioxide was added. The mixture was reacted at 100℃ for 2 hours. After the reaction was completed, soybean protein was added immediately, stirred evenly, and cooled to room temperature. Then 1,4-dicaffeoylquinic acid and Tripterygium wilfordii polyglycosides were added and stirred evenly to obtain cold stress resistant feed.

[0043] Example 3:

[0044] Anti-cold stress feed preparation

[0045] 0.15g 1,4-dicaffeoylquinic acid, 0.6g tripterygium glycosides, 4g silicon dioxide powder (50-100 microns), 12g xylose, 6g L-methionine, 22g soybean protein;

[0046] After mixing xylose and L-methionine, dissolve with 21.6g water, adjust pH=8.5, then add silicon dioxide, react at a temperature of 110°C for 1.5 hours, immediately after the reaction is completed, add soybean protein, stir uniformly after cooling to room temperature, then add 1,4-dicaffeoylquinic acid, tripterygium glycosides and stir uniformly to obtain anti-cold stress feed.

[0047] Example 4:

[0048] Anti-cold stress feed preparation

[0049] 0.2g 1,4-dicaffeoylquinic acid, 0.8g tripterygium glycosides, 5g silicon dioxide powder (50-100 microns), 15g xylose, 7g L-methionine, 25g soybean protein;

[0050] After mixing xylose and L-methionine, dissolve with 24.5g water, adjust pH=8, then add silicon dioxide, react at a temperature of 120°C for 1 hour, immediately after the reaction is completed, add soybean protein, stir uniformly after cooling to room temperature, then add 1,4-dicaffeoylquinic acid, tripterygium glycosides and stir uniformly to obtain anti-cold stress feed.

[0051] Example 5:

[0052] Environmental adaptation process: chickens are raised in an environment of 35°C for 3 days, the temperature is lowered to 33°C for 4 days, then lowered by 3°C (33°C-3°C=30°C), then lowered at a rate of 1°C per two days (1°C decrease on the first day of lowering, then maintained for one day, 1°C decrease on the third day, and so on), when the temperature is lowered to 26°C, continue to feed at a rate of 2°C per two days until the temperature is 16°C, continue to feed at a constant temperature for 10 days to complete the environmental adaptation process of broilers;

[0053] Feed adaptation process: feed adaptation is carried out at the same time as the environmental adaptation process, ordinary feed feeding: 1-3 weeks old feeding starter feed CP: 21%, ME: 12.1 MJ / kg, 4-6 weeks old feeding grower feed CP: 19%, ME: 12.6 MJ / kg, 7 weeks old feeding grower feed CP: 18%, ME: 13.17 MJ / kg, free feeding.

[0054] When the temperature of the feeding is reduced to 16℃, the common feed is fed once a day, and the anti-cold stress feed is mixed with one of the common feeds to be evenly fed, and the feeding is continuously performed until the temperature is suddenly reduced (the temperature is suddenly reduced, which means that the temperature reduction range is greater than or equal to 5℃, or the minimum temperature is less than or equal to 10℃), and the feeding frequency of the anti-cold stress feed is increased to twice a day or three times a day after the temperature is suddenly reduced, and the feeding is continuously performed until the 42nd day, and the feeding adaptation is completed.

[0055] The mass ratio of the common feed to the anti-cold stress feed is (5-20):1, wherein the anti-cold stress feeding is started from the brooding period, and the mass ratio of the common feed to the anti-cold stress feed is preferably (5-10):1, and more preferably 5:1. The anti-cold stress feeding is started from the growth period and the fattening period, and the mass ratio of the common feed to the anti-cold stress feed is (10-20):1, and the mass ratio of the common feed to the anti-cold stress feed is preferably 10:1 in the growth period, and preferably 15:1 in the fattening period.

[0056] Comparative Example 1:

[0057] The present application is compared with Example 4, and the difference lies in that xylose and L-methionine do not need to be subjected to a Maillard reaction, but are directly mixed with other raw materials, and the other raw materials and the mass are the same as those in Example 1, and the specific operation is as follows:

[0058] After the xylose, L-methionine, silicon dioxide and soybean protein are uniformly mixed, 1,4-dicaffeoyl quinic acid and tripterygium glycosides are added and stirred to obtain the anti-cold stress feed.

[0059] Comparative Example 2:

[0060] The present application is compared with Example 4, and the difference lies in that the pH is not adjusted during the Maillard reaction, and the other raw materials and the mass are the same as those in Example 1. The xylose and L-methionine are dissolved in water and then directly added to the silicon dioxide. After being uniformly stirred, the soybean protein is added after being reacted at 120℃ for 1 hour. After being cooled, 1,4-dicaffeoyl quinic acid and tripterygium glycosides are continuously added.

[0061] Comparative Example 3:

[0062] The present application is compared with Example 4, and the difference lies in that 1,4-dicaffeoyl quinic acid is not added, and the other raw materials, the mass and the process are the same.

[0063] Comparative Example 4:

[0064] The present application is compared with Example 4, and the difference lies in that tripterygium glycosides are not added, and the other raw materials, the mass and the process are the same.

[0065] Comparative Example 5:

[0066] The present application is compared with Example 4, which is different in that 1,4-dicaffeoylquinic acid and tripterygium glycosides are not added, and the rest of the raw materials, quality, and process are the same.

[0067] Example 6:

[0068] Production performance experiment on broiler chickens during the rearing period.

[0069] 1. The rearing period of the chicks in the house, as shown in Table 2:

[0070] Table 2

[0071]

[0072]

[0073] During the rearing period experiment, the age of the chickens entering the house was 1-day-old chickens, the temperature when entering the house was 35℃, the breeding humidity was 60-65%, the feeding frequency was 3-4 times / day, and the chickens were free to eat and drink water;

[0074] Daily ration: the energy of the ration for 1-3 week-old chickens was 12.1 MJ / kg, and the crude protein was 21%; the energy of the ration for 4-6 week-old chickens was 12.6 MJ / kg, and the crude protein was 19%, and the chickens were free to eat. The rest was referred to Experiment 1.

[0075] 2. Experimental conditions

[0076] Experimental group: anti-cold stress feed prepared in Example 2 + rearing method in Example 5;

[0077] Control group 1: anti-cold stress feed prepared in Comparative Example 1 + rearing method in Example 5;

[0078] Control group 2: anti-cold stress feed prepared in Comparative Example 2 + rearing method in Example 5;

[0079] Control group 3: anti-cold stress feed prepared in Comparative Example 3 + rearing method in Example 5;

[0080] Control group 4: anti-cold stress feed prepared in Comparative Example 4 + rearing method in Example 5;

[0081] Control group 5: anti-cold stress feed prepared in Comparative Example 5 + rearing method in Example 5;

[0082] Control group 6: only the environmental adaptation process in Example 5 is implemented, and no anti-cold stress feed is fed;

[0083] Control group 7: the rearing adaptation process in Example 5 is implemented, the anti-cold stress feed is prepared in Example 2; uniform speed cooling environmental adaptation;

[0084] Blank control group: No environmental or feeding adaptation process was carried out; conventional feeding and constant temperature feeding methods were used.

[0085] The specifics are as follows:

[0086] (1) Temperature:

[0087] During the experiment, experimental group 1 and control groups 1-6 were fed at 35℃ for 3 days, then fed at 33℃ for 4 days, then fed at 3℃, and then fed at a rate of 1℃ / two days. When the temperature dropped to 26℃, they were fed at a rate of 2℃ / two days until the temperature reached 16℃. They were fed at 16℃ for 10 days to complete the broiler's environmental adaptation process. Then the temperature in the chicken house was lowered to 10℃ and they were fed until they were 42 days old.

[0088] Control group 7: The temperature was lowered from 35°C to 10°C at a rate of 1°C / day, and then the animals were fed at a constant temperature of 10°C until 42 days of age;

[0089] Blank control group: 1-5 days old were fed at a constant temperature of 35℃, 6-8 days old were fed at 33℃, and 9 days old and thereafter were fed at a constant temperature of 22℃ after being cooled at a rate of 1℃ / two days.

[0090] (2) Cold stress-resistant feed supplementation:

[0091] Add the feed at a ratio of 5:1 (common feed to cold stress-resistant feed).

[0092] Frequency of addition: When the temperature is ≤16℃, feed regular feed 3 times a day (1-3 weeks old) or 4 times a day (over 3 weeks old) + 1 time of cold stress-resistant feed. The cold stress-resistant feed is randomly added to any regular feed meal on the same day. When the temperature is ≤10℃, feed regular feed 3 times a day (1-3 weeks old) or 4 times a day (over 3 weeks old) + 2 times of cold stress-resistant feed. The cold stress-resistant feed is randomly added to any two regular feed meals on the same day.

[0093] The specific feeding and cooling process is shown in Table 3:

[0094] Table 3 Detailed feeding and cooling process

[0095]

[0096]

[0097] 3. Each group consisted of 120 chickens (n ​​= 120, i.e., 4 × 30 chickens / repeat). The chicks weighed approximately 40g each. They were raised for a total of 42 days. The weight of the chickens (fasting) and the cumulative mortality rate (i.e., the cumulative mortality rate from day 1 to days 7, 21, 28, and 42) were recorded on days 7, 21, 28, and 42. The data are shown in Table 4.

[0098] Table 4

[0099]

[0100]

[0101] The results of Table 4 can be analyzed as follows:

[0102] 1. The blank control is a conventional means for coping with cold winter breeding in the chicken house, to prevent the chickens from having a serious stress reaction and causing death under low temperature conditions. The experimental group uses the environmental adaptation process and the feeding adaptation process combined anti-cold stress breeding method. The chickens in this experiment are 1-day-old chicks. When the temperature drops to 16℃, the chicks reach 23 days of age. According to the feeding rules, the chicks above 3 weeks of age are fed 4 times a day with the addition of 1 time of anti-cold stress feed. At 33 days of age, the temperature is directly reduced to 10℃, and the ordinary feeding is changed to 4 times a day with the addition of 2 times of anti-cold stress feed. Compared with the blank control, the cumulative mortality rate of the experimental group on the 42nd day is lower than that of the blank control, and the weight of the chickens is slightly higher than that of the control group, indicating that the mortality rate of the ordinary feeding of the blank control group is higher than that of the anti-cold stress feeding. The breeding method of the present application can enhance the anti-cold stress of the chickens and improve the production performance. In the breeding process, not only can the constant temperature of the chicken house be reduced to achieve the purpose of energy saving and efficiency improvement, but also the adaptation of the chickens to the sudden temperature drop during transportation in cold weather can be improved, and the mortality rate can be reduced.

[0103] 2. The difference between the control group 6, the control group 7 and the experimental group is the use of different environmental adaptation processes or feeding adaptation processes. For the 1-3 week stage with higher temperature in the early stage, there is no obvious difference in cumulative mortality rate or weight, but from the 4th week, the temperature drops significantly and the air temperature is low, and the data shows a significant difference. The mortality rate of the control group 7 increases significantly, indicating that relying on environmental adaptation or feeding adaptation alone is difficult to resist the damage caused by cold stress. In addition, the temperature adaptation of the control group 7 is a slow cooling method combined with anti-cold stress feed feeding, and the mortality rate and production performance are still poor. Although the feed is fed, the overall cooling rate is too fast, and the sudden rapid increase in mortality rate in the later stage is caused by the lack of temperature buffering. The stepwise buffering environmental adaptation method of the present application can significantly improve the survival rate and reduce the mortality rate caused by the decrease in air temperature. The mortality rate of the control group 6 is consistent with the results of experiment 1. Pure anti-cold stress environmental feeding can reduce the mortality rate, but the production performance is still low.

[0104] 3. The only difference between control groups 1-5 and the experimental groups was the ratio or preparation method of the cold stress-resistant feed. The fact that the raw materials in control group 1 did not undergo Maillard reaction and the pH of control group 2 was not adjusted significantly affected the experimental results. This indicates that directly adding raw materials such as xylose and L-methionine cannot improve the production performance or reduce the mortality rate in the cold stress-resistant breeding process. After Maillard reaction under specific conditions, glycosylated xylose and L-methionine have a significant impact on the feeding process under cold environment conditions. The comparison of control groups 3-5 also suggests that 1,4-dicaffeoylquinic acid and Tripterygium wilfordii polyglycosides have a promoting effect on alleviating cold stress and can significantly improve production performance and enhance the cold stress resistance effect.

[0105] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention. Technical aspects, shapes, and structures not described in detail in this invention are all well-known technologies.

Claims

1. A method for raising chickens to enhance their resistance to cold stress, characterized in that, The breeding method includes environmental adaptation and feeding adaptation processes, and the specific operations are as follows: The broilers were fed at 35℃ for 3 days, then cooled to 33℃ for 4 days. After that, the temperature was lowered by 3℃ and fed at a rate of 1℃ every two days. When the temperature dropped to 26℃, it was lowered to 16℃ at a rate of 2℃ every two days. The broilers were kept at a constant temperature for 10 days to complete the environmental adaptation process. During the environmental adaptation process, feeding adaptation should be carried out simultaneously. When the feeding temperature drops to 16℃, cold stress-resistant feed should be added once a day while feeding ordinary feed. Continue feeding until the temperature drops sharply. After the temperature drops sharply, the feeding frequency of cold stress-resistant feed should be increased to two or three times a day. Feeding adaptation should be completed after at least one week of continuous feeding. The cold stress-resistant feed comprises the following raw materials in parts by weight: 0.1-0.2 parts by weight of 1,4-dicaffeoylquinic acid, 0.5-0.8 parts by weight of Tripterygium wilfordii polyglycosides, 2-5 parts by weight of silica powder, 10-15 parts by weight of xylose, 5-7 parts by weight of L-methionine, and 20-25 parts by weight of soybean protein; The method for preparing the cold stress-resistant feed is as follows: Xylose and L-methionine are mixed and dissolved in water. The pH is adjusted to 8-8.5, and then silicon dioxide is added. The mixture is reacted at 100-120℃ for 1-2 hours. After the reaction is complete, soybean protein is added immediately, stirred evenly, and cooled to room temperature. Then 1,4-dicaffeoylquinic acid and Tripterygium wilfordii polyglycosides are added and stirred evenly to obtain cold stress resistant feed. In the preparation method, the amount of water added is 1.1-1.2 times the total mass of xylose and L-methionine.

2. The method for enhancing chickens' resistance to cold stress according to claim 1, characterized in that, The mass ratio of the ordinary feed to the cold stress-resistant feed is (5-20):

1.

3. A method for raising chickens to enhance their resistance to cold stress according to claim 2, characterized in that, The sudden drop in temperature refers to a temperature drop of ≥5℃, or a minimum temperature of ≤10℃.

4. A method for raising chickens to enhance their resistance to cold stress according to claim 3, characterized in that, The breeding method described is applicable to broiler chicken farming during the brooding, growth, and fattening periods.

5. A method for preparing a cold stress-resistant feed for chickens according to claim 4, characterized in that, The cold stress-resistant feed is used by mixing it directly with ordinary feed.

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