Application of Hangzhou white chrysanthemum straw in improving meat safety and quality of Hu sheep

Abstract

The invention relates to the technical field of biomass waste reutilization, in particular to application of Hangzhou white chrysanthemum straw to improvement of meat safety and quality of Hu sheep. Peanut vines in daily ration are partially replaced by the Hangzhou white chrysanthemum straw, so that the apparent digestibility of the Hu sheep can be remarkably improved, a rumen microflora is improved, the metabolism capability of the rumen is enhanced, and the production performance of the Hu sheep is improved; active ingredients such as flavonoids and terpenoids in the Hangzhou white chrysanthemum straw can improve the oxidation resistance and the immune function of the Hu sheep, and the overall health level is improved; in addition, the Hangzhou white chrysanthemum straw is fed, so that the fatty acid composition in the mutton can be improved, the content of flavor amino acid in the mutton can be increased, the nutritional value of the mutton is improved, beneficial effects are generated on the health of consumers, and then the meat safety and quality of the Hu sheep are improved.

Description

Technical Field

[0001] The invention relates to the technical field of biomass waste recycling, and in particular to application of chrysanthemum straw in improving the safety and quality of Hu sheep meat. Background Art

[0002] The traditional treatment methods for crop and cash crop straw mainly include incineration, landfill or composting, but these traditional treatment methods not only require a large amount of capital investment, but also cause waste of resources and serious environmental pollution.

[0003] Chrysanthemum is a traditional famous flower and traditional Chinese medicinal material in my country. It has a long history of cultivation. It is not only a popular ornamental flower, but also a plant with both medicinal and edible properties. At present, after the chrysanthemum is picked, its non-medicinal parts, stems and leaves are mostly discarded, causing resource waste and environmental pollution in local areas. However, the stems and leaves of chrysanthemum contain chemical components similar to those of chrysanthemum, including volatile oils, flavonoids, phenolic components, polysaccharides, etc., which have antibacterial and antioxidant activities. Many studies have shown that the non-medicinal parts of chrysanthemum also have broad application prospects. According to statistics, the chrysanthemum cultivation area in my country reached about 75.205 million hm2 in 2017. In recent years, the cultivation area has been on the rise, and a large amount of chrysanthemum straw is produced every year. If it can be effectively utilized, the social and economic benefits generated cannot be underestimated. Tongxiang is known as the hometown of Chinese chrysanthemum, and it has a cultivation history of more than 370 years. Due to the suitable natural environment such as soil and climate, the production of chrysanthemum has been prosperous for a long time, with a planting area of ​​4000 hm2. 2 According to statistics, the average 2 Chrysanthemum produces 2,000 kg of fresh stems and leaves, which means that while producing chrysanthemum, Tongxiang has 120,000 tons of chrysanthemum straw to be processed every year. Chrysanthemum straw is an important biomass resource, with a protein content of about 5%, a cellulose content of about 30%, and a certain amount of minerals such as calcium and phosphorus. Its calorific value is about 50% of standard coal. Chrysanthemum straw is basically left in the field to rot or even be burned, and only a small amount is used as firewood by farmers, resulting in a large amount of waste and low-quality use of resources.

[0004] According to the determination of relevant departments, the chrysanthemum straw contains 13.5% moisture, 18.2% crude protein, 2.80% crude fat, and 19.3% crude fiber, and its nutritional value is equivalent to that of high-quality hay. Therefore, if the chrysanthemum straw can be used as animal feed, it can turn waste into treasure, improve resource utilization, and promote cost-saving and efficiency-enhancing breeding and healthy animal production. Summary of the invention

[0005] The purpose of the invention is to improve the safety and quality of Hu sheep meat through the application of chrysanthemum straw.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] An application of chrysanthemum straw in improving the safety and quality of Hu sheep meat.

[0008] The experiment showed that the pH value of the LS group was significantly lower than that of the CON and HS groups after 24 hours, indicating that the addition of chrysanthemum straw can improve the acidity of the meat and further enhance the tenderness and flavor of the meat. The drip loss rate in the LS group was significantly lower than that in the CON group, indicating that the water retention of the meat was improved, and although there was no significant difference in shear force between the groups, the value of the LS group was lower than that of the CON and HS groups, suggesting that the tenderness of the meat was improved. Therefore, the addition of chrysanthemum straw significantly improved the meat quality of Hu sheep, as shown by increasing the brightness and hue angle of the meat, reducing the final pH value and drip loss rate, which may help to improve the water retention and tenderness of the meat, showing the potential application value of chrysanthemum straw in improving the meat quality of Hu sheep.

[0009] The addition of chrysanthemum straw to the diet significantly affected the fatty acid composition of Hu mutton. Compared with other groups, saturated fatty acids such as capric acid, lauric acid, pentadecanoic acid, stearic acid and arachidic acid in the LS group were significantly reduced, while excessive intake of saturated fatty acids may have adverse effects on health and increase the risk of cardiovascular disease. In addition, Omega-3 fatty acids such as α-linolenic acid were significantly increased in the LS group. Omega-3 fatty acids are beneficial to improving health, and higher intakes are closely related to reducing inflammatory responses and promoting cardiovascular health, indicating that this treatment method may enhance the anti-inflammatory and cardiovascular protective effects of meat. At the same time, the Omega-6 / Omega-3 ratio in the LS group was significantly reduced. A lower Omega-6 / Omega-3 ratio is usually considered a sign of health because an excessively high ratio is associated with inflammation and a variety of chronic diseases. Therefore, the addition of chrysanthemum straw to the diet can significantly change the fatty acid composition of mutton. These changes not only improve the nutritional value of the meat, but may also have a beneficial effect on the health of consumers, thereby improving the safety and quality of Hu mutton.

[0010] The addition of chrysanthemum straw resulted in significant changes in the content of several important amino acids. The contents of isoleucine, leucine, glutamic acid, alanine, and arginine in the LS group were significantly higher than those in the CON group, indicating that the addition of chrysanthemum straw promoted the synthesis and accumulation of these amino acids. In particular, branched-chain amino acids such as isoleucine play an important role in improving meat quality and flavor. In addition, the addition of chrysanthemum straw also significantly increased the content of flavor amino acids such as glutamic acid, which contribute significantly to the umami taste and overall flavor of the meat.

[0011] The addition of chrysanthemum straw significantly changed the fatty acid and amino acid composition of Hu sheep meat, increased the content of key flavor fatty acids, reduced the content of saturated fatty acids, increased the content of key flavor and nutritional amino acids, and improved the flavor and nutritional value of the meat. These changes indicate that chrysanthemum straw has important potential in improving the quality and flavor of Hu sheep meat.

[0012] The invention discloses an application of chrysanthemum straw in improving the production performance and slaughtering performance of Hu sheep. The appropriate amount of chrysanthemum straw can increase the daily weight gain rate and feed intake of Hu sheep, thereby increasing the muscle area of ​​Hu sheep and reducing the fat thickness, which is beneficial to improving the meat quality.

[0013] An application of chrysanthemum straw in promoting rumen growth of Hu sheep.

[0014] The experiment showed that the concentrations of acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid and valeric acid in the LS group were significantly higher than those in the CON group and the HS group, indicating that the appropriate addition of chrysanthemum straw can significantly increase the production of rumen volatile fatty acids, and the total amount also increased significantly in the LS group. Furthermore, the appropriate addition of chrysanthemum straw can significantly improve the rumen fermentation environment of Hu sheep, increase the content of volatile fatty acids, MCP, and NH3-N, and promote the effective utilization of nutrients. The addition of chrysanthemum straw may further affect the rumen function and overall health of Hu sheep by adjusting the structure of rumen microbial communities. Feeding chrysanthemum straw can promote the content of metabolites such as amino acids, fatty acids, and nucleotides in the rumen, which can be absorbed by Hu sheep and transported to the corresponding tissues to exert their effects, thereby promoting the growth and health of Hu sheep.

[0015] The addition of chrysanthemum straw has a positive effect on the antioxidant capacity of Hu sheep. Adding chrysanthemum straw to the diet can significantly improve the blood biochemical indicators of Hu sheep, enhance the antioxidant capacity, and improve the immune function.

[0016] Preferably, the chrysanthemum straw in the above application is added in an amount of 6%-10% by weight in the diet.

[0017] It is further preferred that the mass percentage of the chrysanthemum straw added to the diet in the above application is 7%-8%.

[0018] A chrysanthemum straw feed, comprising the following components in weight percentage: 6%-10% chrysanthemum straw, 35%-40% peanut vine, 12%-15% bean dregs, 3%-5% wheat bran, 20%-25% corn, and 10-14% concentrate mixture. Each raw material is crushed to 2-3 mm and then mixed. The chrysanthemum straw feed is added with a suitable proportion of chrysanthemum straw, which can make full use of waste, turn waste into treasure and reuse it, and at the same time improve the functionality of the feed, improve the production performance of Hu sheep after feeding, improve the overall health level, and effectively improve the meat quality and nutritional value.

[0019] Preferably, the chrysanthemum straw feed comprises the following components in weight percentage: 7%-8% chrysanthemum straw, 37%-38% peanut vine, 13%-14% bean dregs, 4%-5% wheat bran, 23%-24% corn, and 12-13% concentrate mixture.

[0020] Preferably, the formula of the concentrate mixture is: 39.6 kg corn, 28 kg soybean meal, 17.4 kg bran, 10 kg premix, 4 kg baking soda, and 1 kg salt.

[0021] The present invention can significantly improve the apparent digestibility of Hu sheep, improve the rumen microbial flora and enhance the metabolic capacity of the rumen by using chrysanthemum straw to partially replace the peanut vine in the diet, thereby improving the production performance of Hu sheep; the active ingredients such as flavonoids and terpenoids in the chrysanthemum straw can improve the antioxidant capacity and immune function of Hu sheep, and improve the overall health level; in addition, feeding chrysanthemum straw can improve the fatty acid composition of mutton, increase the content of flavor amino acids in mutton, enhance the nutritional value of mutton, have a beneficial effect on the health of consumers, and thereby improve the application of Hu sheep meat safety and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the basic situation of 16s high-throughput sequencing of rumen microorganisms, where A: dilution curve based on Shannon index; B: Venn diagram of rumen microorganisms based on ASV level; CH: α-diversity index of rumen microorganisms;

[0023] Figure 2 Figure 1 is the difference of rumen microbiome in Hu sheep, where A: principal coordinate analysis (PCoA) between LS group and CON group; B: PCoA analysis between HS group and CON group; C: change of ratio between Firmicutes and Bacteroidetes among the three groups; D: composition of rumen microorganisms at phylum level; E: composition of rumen microorganisms at genus level; FH: co-occurrence network analysis between CON group (F), LS group (G) and HS group (H) based on Spearman correlation analysis;

[0024] Figure 3 The rumen metabolism of Hu sheep in the LS group and the CON group, where A: rumen multivariate statistical analysis results; B: rumen differential metabolites; C: rumen KEGG metabolic pathway enrichment analysis;

[0025] Figure 4 The blood metabolism of Hu sheep in the LS group and the CON group, where A: blood multivariate statistical analysis results; B: blood differential metabolites; C: blood KEGG metabolic pathway enrichment analysis;

[0026] Figure 5 It is the correlation analysis between apparent indexes, rumen differential metabolites and blood differential metabolites;

[0027] Figure 6 It is a correlation analysis between flavonoids and terpenoids and their metabolites in rumen and blood and apparent indicators. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described in detail below through specific embodiments. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the protection scope of the present invention.

[0029] In the present invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used can be purchased from the market or are commonly used in the art. The methods in the following embodiments are all conventional methods in the art unless otherwise specified.

[0030] The reagents used in the following examples, unless otherwise specified, can be purchased from conventional biochemical reagent stores.

[0031] Formula of concentrate mixture (kg): 39.6kg corn, 28kg soybean meal, 17.4kg bran, 10kg premix, 4kg baking soda, 1kg salt. The concentrate mixture can be replaced by a commercially available product. The premix is ​​a common premix for sheep in the art, mainly containing multiple vitamins and trace mineral elements required by sheep, and is a commercially available product.

[0032] The invention provides a chrysanthemum straw feed, which comprises the following components in weight percentage: 6%-10% chrysanthemum straw, 35%-40% peanut vine, 12%-15% bean dregs, 3%-5% wheat bran, 20%-25% corn, and 10-14% concentrate mixture. The raw materials are crushed to 2-3 mm and then mixed.

[0033] Example:

[0034] 1 Materials and methods

[0035] 1.1 Experimental design

[0036] This study aimed to explore the effects of chrysanthemum straw on the production performance, health and meat quality of Hu sheep. Twenty-seven 6-month-old Hu sheep with similar body weight and good health were randomly divided into three groups, each with three replicates and three Hu sheep in each replicate. Chrysanthemum straw was used to replace peanut vines in the original feed of mutton sheep. The proportion of chrysanthemum straw replacing peanut vines in the three groups on a dry matter basis was 0% (CON group), 7.9% (LS group) and 15.6% (HS group), respectively. The diet composition and nutritional components of each group are shown in Table 1. The pre-trial period was 7 days and the main trial period was 91 days. Feeding was free at 8:00 and 15:00 every day. There should be leftovers and sufficient clean drinking water. The daily feed intake, initial and final body weight were recorded and feed efficiency was calculated. After the experiment, two Hu sheep in each replicate were randomly selected for slaughter and sampling, and a total of 18 Hu sheep were slaughtered.

[0037] Table 1 Diet composition and nutritional content

[0038]

[0039] 1.2 Sample collection, index determination and data analysis

[0040] 1.2.1 Blood samples

[0041] At the end of the experiment, blood was collected from the jugular vein of the experimental sheep 2 hours after morning feeding. 10 ml of blood was collected from each sheep and injected into a vacuum blood collection tube containing sodium heparin. The collected blood samples were immediately centrifuged at 3500r / min for 15 minutes to obtain plasma supernatant, which was divided into several portions and stored in liquid nitrogen for later use. The plasma supernatant samples were used to measure blood biochemical indicators, immune indicators, and antioxidant indicators, and serum metabolomics analysis was performed.

[0042] 1.2.2 Rumen fluid samples

[0043] After the experimental sheep were slaughtered, the rumen was cut open to collect rumen fluid. To ensure a sterile environment, the workbench was disinfected with alcohol before collecting the rumen fluid. The collected rumen fluid was filtered through four layers of gauze, and its pH was immediately measured. The rumen fluid was then divided into several portions and stored in liquid nitrogen for later use. Volatile fatty acids, microbial protein nitrogen, ammonia nitrogen, rumen microbial flora, and rumen metabolomics analysis were determined in the rumen fluid.

[0044] 1.2.3 Diet and feces samples

[0045] From the 49th to the 51st day of the experiment, the feces and diet of each group of Hu sheep were collected at 09:00, 15:00, 21:00 and 03:00, respectively. The feces and diet were mixed at the four time points and dried at 65°C for 72 hours for apparent digestibility analysis. The apparent digestibility was determined by the acid insoluble ash (AIA) method. The calculation formula is: Apparent digestibility (%) = [1-(AIA concentration in diet / AIA concentration in feces) × (nutrient concentration in feces / nutrient concentration in diet)] × 100%.

[0046] 1.2.4 Slaughter performance measurement

[0047] On the day of slaughter, two Hu sheep from each replicate were selected for slaughter by bleeding from the jugular vein. After slaughter, carcass weight, slaughter rate, carcass oblique length, carcass straight length, eye muscle area, GR value, and backfat thickness were measured. The specific measurement methods are as follows:

[0048] Carcass weight: After the sheep are slaughtered, bled and skinned, the abdomen is opened along the midline. Except for the kidneys and the fat around them, all other viscera and visceral fat (including omental fat and mesenteric fat) are removed. Then the head (cut along the posterior edge of the ear root and the mandibular transverse fold, atlanto-occipital joint, and occipital joint) and the part below the knee joint of the forelimb and the toe joint of the hind limb are removed. The whole carcass is rested for 30 minutes and then weighed to obtain the carcass weight.

[0049] Slaughter rate: After slaughter, the head, hooves, skin, and internal organs (excluding kidneys and surrounding fat) are removed, and the carcass, liver, spleen, rumen weight (including rumen contents) are weighed and calculated.

[0050] Carcass oblique length: the length from the front edge of the intersection of the sternum and the first rib to the midpoint of the front edge of the pubic symphysis.

[0051] Carcass straight length: the length from the midpoint of the front edge of the first cervical vertebra to the midpoint of the front edge of the pubic symphysis.

[0052] Loin eye area: After cutting the carcass between the first and second ribs from the bottom, use sulfuric acid paper to draw the outline of the loin eye area at the rear edge of the second rib from the bottom, and calculate it according to the formula (length × width × 0.7).

[0053] GR value: Measure the tissue thickness at 11 cm on the midline of the spine between the 12th and 13th ribs, that is, the fat content of the carcass.

[0054] Back fat thickness: Measure the back fat in the center of the rib eye between the 12th and 13th ribs.

[0055] 1.2.5 Longissimus dorsi muscle samples

[0056] After slaughter, the longissimus dorsi muscle (central part of the longissimus dorsi muscle) at the 10-12 thoracic vertebrae was collected and divided into 8 portions and stored in ziplock bags or cryotubes at 4°C or -20°C. The meat color, pH value, drip loss, cooking loss, shear force, muscle fatty acids, muscle amino acids and other indicators were measured and metabolomics analysis was performed. The specific measurement methods are as follows:

[0057] Meat color: Determine the fresh cross section of the longissimus dorsi muscle between the 10th and 11th ribs within 2 hours after slaughter, and take eye muscle samples cooled at 4℃ for 24 hours for determination.

[0058] Muscle pH value: The longissimus dorsi muscle at the junction between the 10th and 11th ribs was punched and measured, including 2 hours after slaughter and 24 hours of refrigeration at -4℃.

[0059] Drip loss: Remove the fat attached to the epimysium of the longissimus dorsi muscle between the 10th and 11th ribs within 2 hours after slaughter, cut it into 2 cm thick slices, trim it into a rectangular block with a length of 5 cm and a width of 3 cm, and weigh it. Then use a wire to hook one end of the meat sample so that the muscle fibers are vertically upward, put it into an inflated plastic film bag, so that the meat sample does not touch the bag wall, tie the bag mouth, hang it in a 4℃ refrigerator, and weigh it after storing for 24 hours. Drip loss (%) = weight before storage - weight after storage / weight after storage

[0060] Cooking loss: Weigh a 2cm thick piece of meat, heat it in an 80℃ water bath until the center temperature of the meat reaches 75℃, keep it for 20 minutes, then place it in a 0-4℃ refrigerator overnight, use filter paper to absorb the juice on the surface of the meat, and weigh it. Cooking loss rate (%) = before cooking - after cooking / before cooking × 100

[0061] Shear force: After the meat sample is steamed, it is placed on a shear force tester for measurement.

[0062] Fatty acid determination and amino acid determination: collect the longissimus dorsi muscle (central part of the longissimus dorsi muscle) at 10-12 thoracic vertebrae, quickly absorb the residual body fluid with dust-free absorbent paper, divide the meat sample of one sheep into four equal parts, cut the meat sample into small pieces with a side length of 0.5 cm, put them into cryopreservation tubes and store them in liquid nitrogen.

[0063] 1.2.6 Data Statistical Analysis

[0064] SAS 9.0 software mixed procedure (Proc Mixed) was used for statistical analysis. The data analysis method was ANOVA one-way analysis of variance. Repeated measurement analysis of variance was used for data involving repeated measurements. When there were significant differences in the data, Duncan's test was used for multiple comparisons. Metabolomics and microbial flora results were analyzed on the Meiji Cloud platform.

[0065] 2 Results

[0066] 2.1 Effects of adding chrysanthemum straw to diet on production performance and slaughter performance of Hu sheep

[0067] As shown in Table 2, the Hu sheep with chrysanthemum straw added to the diet were significantly better than the control group in terms of dry matter intake (DMI), final weight, and average daily gain (ADG). Specifically, the DMI, final weight, and ADG of the Hu sheep in the LS group were significantly higher than those in the CON group, indicating that the addition of chrysanthemum straw increased the daily weight gain rate and feed intake of the Hu sheep. As shown in Table 3, although there were no significant differences in the live weight before slaughter, carcass weight, slaughter rate, carcass straight length, and carcass oblique length of the Hu sheep in each group, the eye muscle area of ​​the LS group was significantly higher than that of the CON group and the HS group, while the GR value of the LS group was significantly lower than that of the CON group, indicating that the appropriate addition of chrysanthemum straw can increase the muscle area of ​​Hu sheep and reduce fat thickness, which is beneficial to improve meat quality. In summary, the addition of chrysanthemum straw can not only significantly improve the meat quality of Hu sheep and improve production performance, but also has no negative impact on organ weight and health, reflecting its potential and value as a feed additive.

[0068] Table 2 Effects of adding chrysanthemum straw to diet on production performance and slaughter performance of Hu sheep

[0069]

[0070] 2.2 Effect of adding chrysanthemum straw to diet on apparent digestibility of Hu sheep

[0071] As shown in Table 3, the addition of chrysanthemum straw to the diet had a significant effect on the apparent digestibility of Hu sheep. Compared with the CON group, the dry matter digestibility, organic matter digestibility, crude protein digestibility, neutral detergent fiber digestibility, and acid detergent fiber digestibility of the LS group were significantly increased by 3.02%, 3.52%, 1.95%, 4.19%, and 5.53%, respectively. However, compared with other groups, all apparent digestibility indicators of the HS group had no significant differences.

[0072] Table 3 Effect of adding chrysanthemum straw to diet on apparent digestibility of Hu sheep

[0073]

[0074] 2.3 Effects of adding chrysanthemum straw to diet on rumen fermentation parameters of Hu sheep

[0075] As shown in Table 4, the addition of chrysanthemum straw to the diet had a significant effect on the rumen fermentation parameters of Hu sheep. The contents of ammonia nitrogen (NH3-N) and microbial protein (MCP) in the LS group were significantly higher than those in the CON group. Although there was no significant difference in the rumen NH3-N content in the HS group, its MCP content was significantly higher than that in the CON group. There was no significant difference in rumen pH among the three groups. The concentrations of acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid and valeric acid in the LS group were significantly higher than those in the CON group and the HS group, indicating that the appropriate addition of chrysanthemum straw can significantly increase the production of rumen volatile fatty acids, and the total amount also increased significantly in the LS group. These volatile fatty acids are important products of rumen fermentation and play a key role in the energy metabolism of Hu sheep. It can be seen that the appropriate addition of chrysanthemum straw can significantly improve the rumen fermentation environment of Hu sheep, increase the contents of volatile fatty acids, MCP and NH3-N, and promote the effective utilization of nutrients.

[0076] Table 4 Effects of adding chrysanthemum straw to diet on rumen fermentation parameters of Hu sheep

[0077]

[0078]

[0079] 2.4 Effect of adding chrysanthemum straw to diet on rumen microbial flora of Hu sheep

[0080] The basic information of 16s sequencing of rumen microorganisms of Hu sheep is as follows Figure 1 As shown, A: Dilution curve based on Shannon index; B: Venn diagram of rumen microorganisms based on ASV level; CH: α-diversity index of rumen microorganisms. The dilution curve based on Shannon index for sequencing quality control shows that when the number of valid sequences obtained reaches 20,000, the dilution curve reaches a plateau and the data volume is reasonable ( Figure 1 A), the coverage rate of each library group was above 99%, indicating that the sequencing results were reasonable and reliable ( Figure 1 H). There were 5945 rumen ASVs unique to the LS group, 6567 rumen ASVs unique to the HS group, 5866 rumen ASVs unique to the CON group, and 952 rumen ASVs shared by the three groups ( Figure 1 B). Effect of adding chrysanthemum straw to the diet on ACE index ( Figure 1 C) Chao Index ( Figure 1 D) Sobs index ( Figure 1 E) Shannon Index ( Figure 1 F) and Simpson index ( Figure 1 These results indicate that, although there were no significant differences in the α-diversity index among the groups, there were significant differences in the composition of the rumen microbial community among the different groups.

[0081] The differences in the rumen microbiome of Hu sheep are shown in Figure 2 , where A: principal coordinate analysis (PCoA) between LS and CON groups; B: PCoA analysis between HS and CON groups; C: changes in the ratio of Firmicutes to Bacteroidetes among the three groups; D: rumen microbial composition at the phylum level; E: rumen microbial composition at the genus level; FH: co-occurrence network analysis between CON group (F), LS group (G) and HS group (H) based on Spearman correlation analysis. Figure 2 It can be seen that the PCoA analysis of the WeightedUnifrac distance algorithm at the ASV level showed that the bacterial communities of the LS group and the CON group were significantly separated (P = 0.047) ( Figure 2 A), while the bacterial communities of the HS group and the CON group were not significantly separated (P = 0.877) ( Figure 2 B). At the phylum level, the main phyla are Bacteroidota and Firmicutes ( Figure 2 C). Compared with the other groups, the relative abundance of Bacteroidota in the LS group was significantly increased, but the relative abundance of Firmicutes was significantly decreased (Table 5). In addition, the ratio of Firmicutes:Bacteroidota in the LS group was significantly lower than that in the other two groups ( Figure 2 C). The dominant genera at the genus level were Prevotella, Rikenellaceae_RC9_gut_group, norank_f__F082, Succiniclasticum, Christensenellaceae_R-7_group ( Figure 2 F), among which the differential bacterial genera were Prevotella, Rikenellaceae_RC9_gut_group and unclassified_f__Prevotellaceae. The relative abundance of Prevotella was significantly increased in the LS group; the relative abundance of Rikenellaceae_RC9_gut_group was significantly increased in the HS group, but the relative abundance of unclassified_f__Prevotellaceae was significantly decreased (Table 5). According to Spearman co-occurrence network analysis, it was observed that the LS group ( Figure 2 G) and other groups ( Figure 2 F. Figure 2Compared with the control group, the network was denser and had more nodes, indicating that the interactions between microbial communities in the LS group may be more complex. In summary, the appropriate addition of chrysanthemum straw had a significant effect on the structure of rumen microbial communities, especially in the abundance of Prevotella. The addition of chrysanthemum straw may further affect the rumen function and overall health of Hu sheep by adjusting the structure of rumen microbial communities.

[0082] Table 5 Effects of adding chrysanthemum straw to diet on rumen microbial flora of Hu sheep

[0083]

[0084] Note: The table only presents the top 10 species in relative ranking at the phylum and genus levels.

[0085] 2.5 Effects of adding chrysanthemum straw to diet on rumen metabolomics of Hu sheep

[0086] Rumen metabolism of Hu sheep in LS and CON groups Figure 3 As shown, A: rumen multivariate statistical analysis results; B: rumen differential metabolites; C: rumen KEGG metabolic pathway enrichment analysis. A total of 1969 metabolites were detected between the LS group and the CON group. According to the results of multivariate statistical analysis (OPLS-DA), it can be seen that there are significant differences in rumen metabolites between the two groups (R2Y=0.998, Q2(cum)=0.434)( Figure 3 A). Rumen differential metabolites were screened according to the threshold conditions of P < 0.05, VIP ≥ 1 and FC ≥ 1 and FC ≤ 0.5. A total of 354 rumen differential metabolites were detected, of which 302 were up-regulated metabolites and 51 were down-regulated metabolites ( Figure 3 B). KEGG topological analysis based on significantly different rumen metabolites revealed six metabolic pathways: "pyrimidine metabolism", "nucleotide metabolism", "biosynthesis of phenylalanine, tyrosine and tryptophan", "biosynthesis of valine, leucine and isoleucine", "degradation of valine, leucine and isoleucine", and "biosynthesis of aminoacyl-tRNA" ( Figure 3 C).

[0087] Table 6 Details of differential metabolites in the rumen enrichment pathways of Hu sheep after adding chrysanthemum straw to the diet

[0088]

[0089] The details of the differential metabolites in the enriched pathways of the rumen of Hu sheep after adding chrysanthemum straw to the diet are shown in Table 6. As can be seen from Table 6, according to the "HMDB Class" classification, a total of 14 differential metabolites were identified in the enriched KEGG metabolic pathways. The main categories include pyrimidine nucleotides (deoxycytidine monophosphate, thymine, deoxyuridine), purine nucleotides (2'-deoxyadenosine-5'-phosphate, xanthine nucleoside, deoxyinosine), keto acids and their derivatives (acetoacetic acid, prebenzoic acid), carboxylic acids and their derivatives (L-isoleucine, L-valine), as well as L-tryptophan, 2-isopropylmalonic acid, orotic acid and 4-hydroxyphenylpyruvic acid, which belong to the categories of indole and its derivatives, fatty acids, diazonium salts and benzene and its substituted derivatives, respectively. In addition, among the 354 different metabolites, we also found flavonoids and terpenoids (Table 7). These compounds had AUC>0.8 in the ROC analysis, so they can be used as biomarkers for feeding chrysanthemum straw. Therefore, feeding chrysanthemum straw can promote the content of metabolites such as amino acids, fatty acids, and nucleotides in the rumen. These metabolites can be absorbed by the Hu sheep and transported to the corresponding tissues to exert their effects, thereby promoting the growth and health of the Hu sheep.

[0090] Table 7 Details of the effects of adding chrysanthemum straw to diet on the metabolites of flavonoids and terpenes in the rumen of Hu sheep

[0091]

[0092] 2.6 Effects of adding chrysanthemum straw to diet on blood biochemical, antioxidant and immune indicators of Hu sheep

[0093] As shown in Table 8, the superoxide dismutase (SOD) in the blood of the LS group was significantly lower than that of the CON group and the HS group, but the total antioxidant capacity (T-AOC) in the blood was significantly higher than that of the other two groups, indicating that the addition of chrysanthemum straw had a positive effect on the antioxidant capacity of Hu sheep. In terms of immune indicators, immunoglobulin A (IgA) and immunoglobulin M (IgM) in the LS group were significantly higher than those in the CON group and the HS group, while tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in the LS group were significantly lower than those in the CON group and the HS group, indicating that the addition of chrysanthemum straw helped to enhance the immune function of Hu sheep and reduce inflammatory response. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the LS group were significantly higher than those in the CON group. Although the liver function indicators of LS Hu sheep were significantly increased, the numerical ranges of AST and ALT still met the reference range of sheep liver function defined by the German Laboklin laboratory, so feeding chrysanthemum straw would not have a negative impact on the liver health of Hu sheep. In summary, adding chrysanthemum straw to the diet can significantly improve the blood biochemical indicators of Hu sheep, enhance antioxidant capacity, and improve immune function.

[0094] Table 8 Effects of adding chrysanthemum straw to diet on blood biochemical, antioxidant and immune indicators of Hu sheep

[0095]

[0096] Note: TP is total protein; ALB is albumin; TG is triglyceride; TC is total cholesterol; NEFA is free fatty acid; Glu is glucose; BUN is urea nitrogen; ALP is alkaline phosphatase; ALT is alanine aminotransferase; AST is aspartate aminotransferase; SOD is superoxide dismutase; MDA is malondialdehyde; GSH-PX is glutathione peroxidase; T-AOC is total antioxidant capacity; IgA is immunoglobulin A; IgG is immunoglobulin G; IgM is immunoglobulin M; IL-6 is interleukin 6; TNF-α is tumor necrosis factor-α; IFN-γ is interferon-γ.

[0097] 2.7 Effects of adding chrysanthemum straw to diet on blood metabolomics of Hu sheep

[0098] Blood metabolism of Hu sheep in LS group and CON group is shown in Figure 4 , A: blood multivariate statistical analysis results; B: blood differential metabolites; C: blood KEGG metabolic pathway enrichment analysis. A total of 1523 metabolites were detected between the LS group and the CON group. According to the results of multivariate statistical analysis (OPLS-DA), it can be seen that there are significant differences in rumen metabolites between the two groups (R2Y=0.996, Q2(cum)=0.638)( Figure 4 A). Rumen differential metabolites were screened according to the threshold conditions of P < 0.05, VIP ≥ 1 and FC ≥ 1 and FC ≤ 0.5. A total of 96 rumen differential metabolites were detected, of which 70 were up-regulated metabolites and 26 were down-regulated metabolites ( Figure 4 B). These differential metabolites were enriched in six KEGG metabolic pathways ( Figure 4 C), namely, “arachidonic acid metabolism”, “glycine, serine and threonine metabolism”, “glycerophospholipid metabolism”, “tryptophan metabolism”, “valine, leucine and isoleucine biosynthesis”, and “aminoacyl-tRNA biosynthesis”.

[0099] Table 9 Details of differential metabolites in the enrichment pathways of Hu sheep blood after adding chrysanthemum straw to the diet

[0100]

[0101] According to the “HMDB Class” classification, a total of 20 differential metabolites were identified on the enriched KEGG metabolic pathways ( Table 9 ), and the main categories included glycerophospholipids (PC (15: 0 / 0:0), PC (22: 5 / 0:0), PC (16: 0 / 18: 1 (11Z)), LysoPC (22: 5 (7Z, 10Z, 13Z, 16Z, 19Z) / 0:0), LysoPC (22: 5 (4Z, 7Z, 10Z, 13Z, 16Z) / 0:0), LysoPC (18: 3 (6Z, 9Z, 12Z) / 0:0), LysoPC (22: 6 (4Z, 7Z, 10Z, 13Z, 16Z) / 0:0). ,19Z) / 0:0), LysoPC(15:0 / 0:0), LysoPC(17:0 / 0:0), PE(15:0 / 22:1(13Z)GPCho(18:1 / 16:1)), carboxylic acids and their derivatives (L-isoleucine, L-threonine, L-2,4-diaminobutyric acid, exopurine), indole and its derivatives (N-ε-acetyl-L-lysine, 5-hydroxyindoleacetic acid), as well as arachidonic acid, CDP-ethanolamine and PE-NMe2(15.0 / 18:1(11Z)):0 / 18:1(11Z)), which belong to fatty acids, pyrimidine nucleotides and unclassified, respectively. The addition of chrysanthemum straw resulted in a significant upregulation of ethanolamine and arachidonic acid, indicating an increase in phospholipid synthesis activity, which may contribute to the maintenance of cell membrane structure and function, while regulating inflammation and immune responses. The upregulation of lysophosphatidylcholine (LysoPC) series metabolites indicated that phospholipid metabolism activity was enhanced, promoting cell membrane repair and function maintenance. The upregulation of 5-hydroxyindoleacetic acid and L-2,4-diaminobutyric acid indicated that chrysanthemum straw may affect nerve function and protein metabolism. The upregulation of L-threonine and L-isoleucine indicated that chrysanthemum straw may promote protein synthesis and muscle growth. The downregulation of glycerophosphatidylcholine (GPCho) may reflect the dynamic changes of cell membrane components, while the upregulation of N-ε-acetyl-L-lysine indicated that chrysanthemum straw may affect protein function through protein acetylation modification. No large number of flavonoid and terpenoid metabolites were found in the blood metabolites, but the products of flavonoid and terpenoid metabolism in the liver, such as "organic sulfuric acid and its derivatives", "cinnamaldehyde", and "cinnamic acid and its derivatives", were detected in 96 differential metabolites (Table 10).

[0102] Table 10 Effect of adding chrysanthemum straw to diet on flavonoid and terpenoid metabolites in Hu sheep blood

[0103]

[0104] 2.8 Effect of adding chrysanthemum straw to diet on the meat quality of Hu sheep

[0105] As shown in Table 11, adding chrysanthemum straw promoted 1h The meat has improved in brightness. 1h and b 1h There was no significant difference between the groups. The pH value of the LS group after 24 hours was significantly lower than that of the CON and HS groups, indicating that the addition of chrysanthemum straw can improve the acidity of the meat and may improve the tenderness and flavor of the meat. In addition, the drip loss rate in the LS group was significantly lower than that in the CON group, indicating that the water retention of the meat was improved, and although there was no significant difference in shear force between the groups, the value of the LS group was lower than that of the CON and HS groups, suggesting that the tenderness of the meat was improved. In summary, the addition of chrysanthemum straw significantly improved the meat quality of Hu sheep, which was manifested in the improvement of the brightness and hue angle of the meat, the reduction of the final pH value and drip loss rate, which may help to improve the water retention and tenderness of the meat, showing the potential application value of chrysanthemum straw in improving the meat quality of Hu sheep.

[0106] Table 11 Effect of adding chrysanthemum straw to the diet on the meat quality of Hu sheep

[0107]

[0108] Note: L 1h a is the brightness of the longissimus dorsi muscle 1 hour after slaughter; 1h b is the redness of the longissimus dorsi muscle 1 hour after slaughter; 1h C is the yellowness of the longissimus dorsi muscle 1 hour after slaughter; 1h H is the maximum color of the back 1 hour after slaughter; 1h It is the hue angle of the longissimus dorsi muscle 1 hour after slaughter.

[0109] 2.9 Effect of adding chrysanthemum straw to diet on flavor substances of Hu sheep meat

[0110] As shown in Table 12, the addition of chrysanthemum straw to the diet significantly affected the fatty acid composition of Hu mutton. Compared with other groups, the LS group had significantly lower saturated fatty acids such as capric acid, lauric acid, pentadecanoic acid, stearic acid and arachidic acid. Excessive intake of saturated fatty acids may have adverse effects on health and increase the risk of cardiovascular disease. In addition, the LS group had significantly higher levels of Omega-3 fatty acids such as α-linolenic acid. Omega-3 fatty acids are beneficial to improving health. Higher intake is closely related to reducing inflammatory response and promoting cardiovascular health, indicating that this treatment method may enhance the anti-inflammatory and cardiovascular protective effects of meat. At the same time, the Omega-6 / Omega-3 ratio in the LS group was significantly reduced. A lower Omega-6 / Omega-3 ratio is usually considered a sign of health because a high ratio is associated with inflammation and a variety of chronic diseases. In summary, the addition of chrysanthemum straw to the diet can significantly change the fatty acid composition of mutton. These changes not only improve the nutritional value of the meat, but may also have a beneficial effect on the health of consumers.

[0111] Table 12 Effect of adding chrysanthemum straw to the diet on fatty acids in Hu sheep meat

[0112]

[0113] Note: C10:0 is capric acid; C12:0 is lauric acid; C14:0 is myristic acid; C15:0 is pentadecanoic acid; C16:0 is palmitic acid; C17:0 is pearly acid; C18:0 is stearic acid; C20:0 is arachidic acid; C21:0 is heneicosanoic acid; C22:0 is behenic acid; C24:0 is linalool acid; C14:1n5 is myristic acid; C16:1 is palmitic acid; C17:1 is cis-10-heptadecanedenoic acid; C18:1n9t is elaidic acid; C18:1n9c is oleic acid; C18:2n6c is linoleic acid; C20:1 is cis-11-eicosaenoic acid; C18:3n3 is α-linolenic acid; C20:3n6 is dihomo-γ-linolenic acid; C20:4n6 is arachidonic acid; EPA (C20:5n3) is eicosapentaenoic acid; DHA (C22:6n3) is docosahexaenoic acid; SFA is a saturated fatty acid; MUFA is a monounsaturated fatty acid; PUFA is a polyunsaturated fatty acid.

[0114] As shown in Table 13, the addition of chrysanthemum straw resulted in significant changes in the content of multiple important amino acids. The contents of isoleucine, leucine, glutamic acid, alanine, and arginine in the LS group were significantly higher than those in the CON group, indicating that the addition of chrysanthemum straw promoted the synthesis and accumulation of these amino acids. In particular, branched-chain amino acids such as isoleucine play an important role in improving meat quality and flavor. In addition, the addition of chrysanthemum straw also significantly increased the content of flavor amino acids such as glutamic acid, which contribute significantly to the umami taste and overall flavor of the meat.

[0115] The addition of chrysanthemum straw significantly changed the fatty acid and amino acid composition of Hu sheep meat, increased the content of key flavor fatty acids, reduced the content of saturated fatty acids, increased the content of key flavor and nutritional amino acids, and improved the flavor and nutritional value of the meat. These changes indicate that chrysanthemum straw has important potential in improving the quality and flavor of Hu sheep meat.

[0116] Table 13 Effect of adding chrysanthemum straw to the diet on amino acids in Hu sheep meat

[0117]

[0118]

[0119] Note: TAA is total amino acid; LAA is limiting amino acid; BCAA is branched-chain amino acid; FAA is flavor amino acid; SAA is sweet amino acid; EAA is essential amino acid; NEAA is non-essential amino acid.

[0120] 2.10 Correlation Analysis

[0121] Correlation analysis between apparent indexes, rumen differential metabolites and blood differential metabolites is shown in Figure 5 The correlation analysis between flavonoids and terpenoids and their metabolites in rumen and blood and the apparent indices is shown in Figure 6 .Depend on Figure 5 , Figure 6 It can be seen that Prevotella was significantly positively correlated with ADG and DMI in growth performance, all apparent digestibility indices, acetic acid and isobutyric acid in rumen fermentation index, and ALP, AST, and IgM in blood biochemical indices. In addition, Prevotella was significantly negatively correlated with TNF-α. These correlations highlight the role of Prevotella in promoting growth, digestion, rumen fermentation, liver function, and immune response. The correlation analysis between rumen differential metabolites and phenotypic indices showed that there was a strong correlation between DMI, liver function indices, antioxidant indices, and immune indices of Hu sheep and various different metabolites in the rumen. In addition, there was a significant correlation between apparent digestibility and rumen fermentation indices and 2-isopropylmalonic acid in the rumen, as well as flavonoid differential metabolites and terpenoid differential metabolites. The correlation between blood differential metabolites and phenotypic indices showed that there was a close connection between apparent digestibility, liver function, antioxidant and immune indices and various plasma differential metabolites. Significant correlations were observed between DMI and metabolites of Hu sheep, excluding glycerophospholipids. Rumen fermentation indices were significantly correlated with arachidonic acid, CDP-ethanolamine, and organic sulfuric acid and its derivatives. The correlation between Prevotella and rumen and plasma metabolomes showed that Prevotella was significantly correlated with 2-isopropylmalonic acid, flavonoids, and terpenoids in the rumen. Prevotella was significantly correlated with L-isoleucine, L-2,4-diaminobutyric acid, 5-hydroxyindoleacetic acid, N-ε-acetyl-L-lysine, 2-hydroxycinnamic acid, p-coumaraldehyde, arachidonic acid, CDP-ethanolamine, and glycerophospholipids in the blood.

[0122] 3 Conclusion

[0123] The results of this study showed that using chrysanthemum straw to partially replace peanut vines in the diet can significantly improve the apparent digestibility of Hu sheep, improve the rumen microbial flora, and enhance the metabolic capacity of the rumen, thereby improving the production performance of Hu sheep; the active ingredients such as flavonoids and terpenes in chrysanthemum straw can improve the antioxidant capacity and immune function of Hu sheep, and improve the overall health level; in addition, feeding chrysanthemum straw can improve the fatty acid composition of mutton, increase the content of flavor amino acids in mutton, enhance the nutritional value of mutton, and have a beneficial effect on the health of consumers.

[0124] Through this study, the application of chrysanthemum straw in Hu sheep feed not only effectively utilizes agricultural waste, turns waste into treasure, reduces resource waste and environmental pollution, and promotes the efficient utilization of agricultural by-products. In the context of rising feed prices today, replacing peanut vines with chrysanthemum straw is an effective means of "reducing costs and increasing efficiency". In addition, the use of chrysanthemum straw reduces straw burning, reduces environmental pollution, improves the ecological environment, and promotes the sustainable development of agriculture.

Claims

1. An application of chrysanthemum straw in improving the safety and quality of Hu sheep meat.

2. An application of chrysanthemum straw in improving the production performance and slaughtering performance of Hu sheep.

3. An application of chrysanthemum straw in promoting rumen growth of Hu sheep.

4. The use according to claim 1, 2 or 3, characterized in that: The mass percentage of the chrysanthemum straw added in the diet is 6%-10%.

5. The use according to claim 1, 2 or 3, characterized in that: The mass percentage of the chrysanthemum straw added in the diet is 7%-8%.

6. A chrysanthemum straw feed, characterized in that The chrysanthemum straw feed includes the following components by weight percentage: Chrysanthemum straw 6%-10%, Peanut vine 35%-40%, Okara 12%-15%, Wheat bran 3%-5%, Corn 20%-25%, Concentrate mix 10-14%.

7. The chrysanthemum straw feed according to claim 6, characterized in that The chrysanthemum straw feed includes the following components by weight percentage: Chrysanthemum straw 7%-8%, Peanut vine 37%-38%, Okara 13%-14%, Wheat bran 4%-5%, Corn 23%-24%, Concentrate mix 12-13%.

8. The chrysanthemum straw feed according to claim 6 or 7, characterized in that The formula of the concentrate mixture is: 39.6kg corn, 28kg soybean meal, 17.4kg bran, 10kg premix, 4kg baking soda, and 1kg salt.

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