Application of Lactobacillus plantarum fermented whole plant corn in improving growth performance, slaughter performance and meat quality of black dorset down sheep

Abstract

The application discloses application of Lactobacillus plantarum fermented whole-plant corn in improving growth performance, slaughtering performance and meat quality of black sheep, and belongs to the field of livestock feeding. The technical problem solved by the application is how to improve the growth performance, slaughtering performance and meat quality of livestock. It is found that after livestock is fed with Lactobacillus plantarum fermented corn prepared by using Lactobacillus plantarum 6H2, the average daily weight gain and daily feed intake are significantly improved, the feed conversion ratio is significantly reduced, the carcass weight is significantly improved, the meat shear force is significantly reduced, the number of white blood cells, the number of lymphocytes and the percentage of lymphocytes are significantly improved, the percentage of neutrophils is significantly reduced, and the content of total protein and albumin in serum is significantly improved. In summary, Lactobacillus plantarum 6H2 and the fermented corn obtained by using the same can improve the growth performance, slaughtering performance and muscle tenderness of livestock, improve the blood physiological and biochemical indexes, and improve the breeding benefit.

Description

Technical Field

[0001] This invention belongs to the field of livestock breeding, specifically relating to the application of Lactobacillus plantarum fermentation of whole corn in improving the growth performance, slaughter performance and meat quality of Black Fur sheep. Background Technology

[0002] In recent years, with changes in people's dietary structure, the demand for meat products has been on the rise, and the requirements for meat quality have become increasingly stringent. The Qinghai-Tibet Plateau region is a major meat-producing area in China. However, due to grassland degradation and the constraints of long winters and low temperatures, the shortage of forage supply in winter and spring is a prominent problem, leading to frequent weight loss in livestock and a gap in meat supply. Corn is a commonly grown crop in high-altitude and cold regions. Its fermented silage has high nutritional value and, when applied in high-altitude areas, can effectively solve the problem of feed shortage in winter and spring, prevent weight loss in cattle and sheep, improve feed conversion rate, and increase breeding profits. However, in actual production, the low-temperature environment in the plateau region inhibits the growth of lactic acid bacteria in silage, reduces fermentation quality, and leads to a decrease in livestock feed intake and reduced effective nutrient intake. Summary of the Invention

[0003] The technical problem to be solved by this invention is how to improve the growth performance, slaughter performance and meat quality of livestock.

[0004] To address the aforementioned technical problems, this invention first provides at least one of the following applications of Lactobacillus plantarum fermentation of corn: X1) Promotes livestock growth; X2) Improves livestock growth performance; X3) Improves livestock slaughter performance; X4) Improves the quality of livestock meat; X5) Improves livestock immunity; X6) Improve livestock health; The fermented corn with Lactobacillus plantarum was obtained by fermenting corn plants with Lactobacillus plantarum 6H2.

[0005] The present invention also provides at least one of the following applications of Lactobacillus plantarum 6H2 or Lactobacillus plantarum 6H2 inoculum: X1) Promotes livestock growth; X2) Improves livestock growth performance; X3) Improves livestock slaughter performance; X4) Improves the quality of livestock meat; X5) Improves livestock immunity; X6) Improves the health of livestock.

[0006] Specifically, the growth performance refers to feed conversion ratio, daily weight gain, and / or daily feed intake.

[0007] Specifically, the slaughter performance refers to carcass weight. Carcass weight (kg) = pre-slaughter live weight - [weight of head, tail, skin, hooves, reproductive organs, and internal organs (excluding kidneys)]. Pre-slaughter live weight refers to the weight after fasting for a certain period of time before slaughter.

[0008] Specifically, the meat quality refers to muscle tenderness. Furthermore, muscle tenderness is reflected in the shear strength of the meat.

[0009] Specifically, the improvement in livestock immunity is reflected in the increase in the number of white blood cells, the number of lymphocytes, the percentage of lymphocytes, and / or the percentage of neutrophils.

[0010] Specifically, the improvement in livestock health is reflected in the increase of total blood protein content, the increase of albumin content, and / or the decrease of urea nitrogen content.

[0011] Specifically, the Lactobacillus plantarum fermented corn is obtained by ensiling whole corn plants with Lactobacillus plantarum 6H2. The amount of Lactobacillus plantarum 6H2 added can be determined according to the specific fermentation conditions, as long as it does not affect the functions of the obtained Lactobacillus plantarum fermented corn in promoting livestock growth, improving livestock growth performance, improving livestock slaughter performance, improving livestock meat quality, improving livestock immunity, and / or improving livestock health. Further, the amount of Lactobacillus plantarum 6H2 added is (0.1-10) × 10 6 CFU / g fresh weight. In one embodiment of the present invention, the amount of *Lactobacillus plantarum* 6H2 added is 1 × 10⁻⁶. 6 cfu / g fresh weight.

[0012] Specifically, the method further includes a step of crushing the whole corn plant before ensiling. The ensiling is carried out in an anaerobic environment. The ensiling is conducted at 5–15°C. The ensiling time can be determined based on the effectiveness of the ensiling feed. In one embodiment of the invention, the ensiling time is 45 days.

[0013] When using *Lactobacillus plantarum* fermented corn to promote livestock growth, improve livestock growth performance, improve livestock slaughter performance, improve livestock meat quality, improve livestock immunity, and / or improve livestock health, the amount of *Lactobacillus plantarum* fermented corn added to the diet can be determined according to actual conditions, as long as the above functions are achieved. The amount of *Lactobacillus plantarum* fermented corn added to the diet is 5-50%. Further, the amount of *Lactobacillus plantarum* fermented corn added to the diet is 10-45%. Further, the amount of *Lactobacillus plantarum* fermented corn added to the diet is 15-40%.

[0014] In one embodiment of the present invention, the amount of Lactobacillus plantarum-fermented corn added to the diet is 35%.

[0015] The active ingredient of the Lactobacillus plantarum 6H2 inoculant is Lactobacillus plantarum 6H2.

[0016] The microbial agent may further include a carrier. The carrier may be a solid carrier or a liquid carrier. The solid carrier may be a mineral material, plant material, or a polymer compound; the mineral material may be at least one selected from clay, talc, kaolin, montmorillonite, white carbon, zeolite, silica, and diatomaceous earth; the plant material may be at least one selected from corn flour, soybean flour, and starch; the polymer compound may be polyvinyl alcohol and / or polyethylene glycol. The liquid carrier may be an organic solvent, vegetable oil, mineral oil, or water; the organic solvent may be decane and / or dodecane. In the microbial agent, the active ingredient may be present in the form of cultured live cells, fermentation broth of live cells, filtrate of cell culture, or a mixture of cells and filtrate. The dosage form of the composition may be various, such as liquid, emulsion, suspension, powder, granules, wettable powder, or water-dispersible granules.

[0017] Depending on the requirements, surfactants (such as Tween 20, Tween 80, etc.), binders, stabilizers (such as antioxidants), pH adjusters, etc. may also be added to the bacterial agent.

[0018] Specifically, the livestock in question is sheep.

[0019] In one embodiment of the present invention, the sheep is a black fur sheep.

[0020] The livestock in question are livestock from high-altitude and cold regions. These high-altitude and cold regions are defined as cold areas with an altitude of over 2000 m, an average annual temperature of 0–8℃, and a frost-free period of 90–150 days.

[0021] Experiments have shown that feeding livestock with Lactobacillus plantarum-fermented corn prepared using Lactobacillus plantarum 6H2 significantly improved: 1) average daily weight gain and daily feed intake were significantly increased, while feed conversion ratio was significantly decreased; 2) carcass weight was significantly increased; 3) meat shear force was significantly decreased; 4) white blood cell count, lymphocyte count, and lymphocyte percentage were significantly increased, while neutrophil percentage was significantly decreased; and 5) serum total protein and albumin levels were significantly increased. In conclusion, Lactobacillus plantarum 6H2 and the fermented corn obtained using it can improve livestock growth performance, slaughter performance, muscle tenderness, and blood physiological and biochemical indicators, thereby increasing livestock farming efficiency. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0023] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials, reagents, instruments, etc., used in the following examples are commercially available.

[0024] Example 1 1. Experimental Materials and Methods 1.1 Test Location and Time The Minxian Black Fur Sheep Breeding Farm in Gansu Province is located in Zha'na Village, Qinxu Township, Minxian County, Dingxi City, Gansu Province. It lies between 103°41′29″-104°59′23″ east longitude and 34°07′34″-34°45′45″ north latitude, at an altitude of 2040-3754 m. It has a plateau continental climate, characterized by high altitude, cold, and damp conditions, long and cold winters, a frost period of 221 days, and an average annual temperature of 7℃. The experiment will be conducted at the Minxian Black Fur Sheep Breeding Farm from November 2025 to February 2026.

[0025] 1.2 Test Materials Both the corn variety "Jinhuang 828" and the black fur sheep were provided by the Minxian Black Fur Sheep Breeding Farm.

[0026] There are two types of lactic acid bacteria additives, both of which are Lactobacillus plantarum (Lactobacillus plantarum). Lactobacillus plantarum) 1. *Lactobacillus plantarum* 6H2, this strain is recorded in "Xu Shuangpeng et al., Effects of lactic acid bacteria additives on the quality and enzyme activity of mixed oat and arrowroot silage in high-altitude pastoral areas, *Acta Grasslandica Sinica*, 2025, 33(8):2694". In the article "2702", 2. Lactobacillus plantarum CICC21804 is a product of the China Industrial Microbial Culture Collection Center.

[0027] 1.3 Experimental Design The diets fed to different treatment groups are shown in Table 1. The basal diet was configured according to the farm, as shown in Table 2.

[0028] The experiment was conducted from December 2025 to February 2026. Eighteen male black fur sheep aged 4 months and weighing (17.78±1.29) kg were selected and divided into groups of 6, with each group kept in a separate pen. They were fed twice daily at 8:00 and 18:00, and provided with free access to water. The pre-trial period was 10 days, and the formal trial period was 60 days.

[0029] Table 1. Composition of diets for different treatments

[0030] The amount of fermented whole-plant maize added to each diet accounted for 35% of the daily ration weight, meaning the mass ratio of the basal diet to fermented whole-plant maize in the diet composition was 65:35. The preparation methods for each fermented whole-plant maize diet are as follows: Lactobacillus plantarum 6H2 inoculum was obtained by resuspending a single strain in distilled water. Whole-plant corn fermentation with Lactobacillus plantarum 6H2 involved harvesting and crushing the whole corn plant, spraying it with the Lactobacillus plantarum 6H2 inoculum, mixing, wrapping, and ensiling. The inoculum dosage was 1.0 × 10⁻⁶. 6 CFU / g fresh weight. Silage method: After adding the inoculant, mix well, compact and tightly wrap the mixture into silage bags, 80kg per bag, 3 bags per treatment, and ensilage fermentation at 5-15℃ for 45 days.

[0031] Lactobacillus plantarum CICC21804 inoculum was obtained by resuspending a single strain in distilled water. Whole-plant corn fermentation with Lactobacillus plantarum CICC21804: Whole-plant corn is harvested, crushed, sprayed with Lactobacillus plantarum CICC21804 inoculum, mixed, wrapped, and ensiled. The inoculum dosage is 1.0 × 10⁻⁶. 6 CFU / g fresh weight. Silage method: After adding the inoculant, mix well, compact and tightly wrap the mixture into silage bags, 80kg per bag, 3 bags per treatment, and ensilage fermentation at 5-15℃ for 45 days.

[0032] Additive-free fermented whole-plant corn: Harvest and crush the whole corn plant, spray with an equal amount of distilled water, mix and wrap into silage, 80kg per bag, 3 bags per treatment, and ferment at 5-15℃ for 45 days.

[0033] Table 2. Composition and Nutritional Levels of the Basal Diet

[0034] Note: Each kg of premix provides: Vitamin D 1,500,000 IU, Vitamin D3 8,800,000 IU, Vitamin E 320 IU, Copper 1,500 mg, Iron 7,000 mg, Zinc 6,000 mg, Manganese 4,500 mg, Iodine 90 mg, Cobalt 30 mg, and Selenium 5 mg. In the "Nutritional Components" column, metabolizable energy is a calculated value, and the rest are measured values.

[0035] 1.4 Measurement Indicators and Methods 1.4.1 Growth performance During the trial period, record the body weight before morning feeding on days 1, 31, and 61, and calculate the average daily gain (ADG). Record the daily feed amount and the amount of feed remaining in the trough before morning feeding each day, and calculate the average daily drymatter intake (DMI) and feed to gain ratio (F / G).

[0036] Average daily weight gain (g / d) = (final body weight) Initial body weight / number of days of the trial.

[0037] Average daily feed intake (kg / d) = Total feed intake / Number of days in the experiment.

[0038] Feed conversion ratio (%) = Average daily feed intake / Average daily weight gain × 100%.

[0039] 1.4.2 Slaughter Performance After the experiment, four sheep from each treatment were selected, fasted for 24 hours and deprived of water for 2 hours, and then weighed alive (i.e., pre-slaughter live weight) before slaughter.

[0040] Carcass weight (kg) = pre-slaughter live weight - [weight of head, tail, skin, hooves, reproductive organs, and internal organs (excluding kidneys)].

[0041] Slaughter rate (%) = Carcass weight / Live weight before slaughter × 100%.

[0042] 1.4.3 Measurement of blood physiological and biochemical indicators: On the morning before feeding on the last day of the experiment, blood was collected from each group of experimental sheep via the jugular vein using disposable vacuum blood collection tubes. 5 mL was collected from each sheep, and each treatment was performed in quadruplicate for both physiological and biochemical parameters. Complete blood count indicators were measured using the Mindray BC-5000vet fully automated veterinary blood cell analyzer, and serum biochemical indicators were measured using the Chemray 240 fully automated biochemical analyzer.

[0043] 1.4.4 Meat quality The water loss rate, cooked meat rate, tenderness, meat color, and pH of the longissimus dorsi muscle of mutton in different treatment groups were determined. 45min and pH 24h .

[0044] Determination of water loss rate: Cut a thick strip of meat, weigh it, suspend the meat sample with wire, and place it in a resealable bag. Seal the bag, leaving enough space for moisture evaporation, and ensure that the meat sample has no contact with the resealable bag; it must be completely suspended. Then, place the sealed meat sample in a 4℃ environment for 24 hours. After that, remove the plastic bag, absorb the surface moisture with filter paper, and weigh it again. Water loss rate (%) = (weight of meat sample before hanging - weight of meat sample after hanging) / weight of meat sample before hanging × 100%.

[0045] Determination of cooked meat percentage: Take approximately 30g of meat sample, remove the fat attached to the perimysium, weigh it using an electronic balance, place the sample in a constant temperature water bath, cover, and heat continuously until the center temperature of the meat sample reaches 70℃. Remove the meat sample and cool for 30 minutes, then weigh it again. Cooked meat percentage (%) = (weight of meat sample before cooking - weight of meat sample after cooking) / weight of mutton before cooking × 100%; Tenderness: Shear force is measured using a tenderness meter to evaluate the tenderness of the meat.

[0046] Flesh color: Measured using a flesh colorimeter.

[0047] longissimus dorsi pH 45min (i.e., pH value of the longissimus dorsi muscle 45 minutes after slaughter): measured using a piercing handheld pH meter.

[0048] longissimus dorsi pH 24h (i.e., pH value of the longissimus dorsi muscle 24 hours after slaughter): measured using a piercing handheld pH meter.

[0049] 1.5 Data Statistics and Analysis Data was organized using Excel 2026 and analyzed using SPSS 31. All data are expressed as mean ± standard deviation (Mean ± SD). P <0.05 indicates a significant difference. P < 0.01 indicates a highly significant difference.

[0050] 2. Results and Analysis 2.1 Effects of Lactobacillus plantarum 6H2 on the growth performance of black fur sheep Table 3 shows that there were no significant differences in body weight between the 6H2, CI, and CK treatment groups before and after feeding. P >0.05); After 60 days of feeding, the average daily weight gain in the 6H2 treatment group was significantly higher than that in the CK treatment group ( P <0.05), with no significant difference from the CI treatment group ( P >0.05); the average daily feed intake in the CK treatment group was significantly lower than that in the 6H2 treatment group and the CI treatment group ( P <0.05), but there was no significant difference between the 6H2 treatment group and the CI treatment group ( P >0.05); the material weight ratio of the 6H2 treatment group was significantly lower than that of the CI and CK treatment groups ( P <0.05).

[0051] Table 3. Effects of Lactobacillus plantarum 6H2 on the growth performance of black fur sheep

[0052] In Table 3, the differences between data with different lowercase letters in the same row are significant. P <0.05), the differences between data with no letter or the same letter were not significant ( P >0.05).

[0053] 2.2 Effects of Lactobacillus plantarum 6H2 on the slaughter performance of black fur sheep As shown in Table 4, after 60 days of feeding, there were no significant differences in backfat thickness, eye muscle area, dressing percentage, and pre-slaughter live weight among the 6H2, CI, and CK treatment groups. P>0.05); Carcass weight in the 6H2 treatment group was significantly higher than that in the CI treatment group and the CK treatment group ( P <0.001).

[0054] Table 4. Effects of Lactobacillus plantarum 6H2 on the slaughter performance of black fur sheep

[0055] In Table 4, the differences between data with different lowercase letters in the same row are significant. P <0.05), the differences between data with no letter or the same letter were not significant ( P >0.05).

[0056] 2.3 Effects of Lactobacillus plantarum 6H2 on the quality of black fur mutton As shown in Table 5, the pH 45 min and pH 24 h of the 6H2, CI, and CK treatment groups after slaughter were all within the normal range, and there were no significant differences among the treatment groups. P >0.05); the shear force in group 6H2 was significantly lower than that in group CK ( P <0.05), there was no significant difference between the CK and CI treatment groups ( P >0.05), and there were no significant differences in meat quality among the 6H2, CI, and CK treatment groups. P >0.05).

[0057] Table 5. Effects of Lactobacillus plantarum 6H2 on the slaughter performance of black fur sheep

[0058] In Table 5, the differences between data with different lowercase letters in the same row are significant. P <0.05), the differences between data with no letter or the same letter were not significant ( P >0.05).

[0059] 2.4 Effects of Lactobacillus plantarum 6H2 on routine blood parameters of black fur sheep As shown in Table 6, the number of white blood cells, the number of lymphocytes, and the percentage of lymphocytes in the 6H2 treatment group were all significantly higher than those in the CK treatment group. P <0.05); the percentage of neutrophils in the CK treatment group was significantly higher than that in the 6H2 treatment group and the CI treatment group ( P <0.05); other serum physiological indicators showed no significant differences in 6H2, CI, and CK treatment groups after 60 days of feeding. P >0.05).

[0060] Table 6. Effects of Lactobacillus plantarum 6H2 on the slaughter performance of black fur sheep

[0061] In Table 6, the differences between data with different lowercase letters in the same row are significant. P <0.05), the differences between data with no letter or the same letter were not significant ( P >0.05).

[0062] 2.5 Effects of Lactobacillus plantarum 6H2 on serum biochemical parameters of black fur sheep As shown in Table 7, the levels of total protein and albumin in sheep serum in the 6H2 treatment group were significantly higher than those in the CK and CI treatment groups. P <0.05), the urea nitrogen content in the 6H2 treatment group was significantly lower than that in the CK and CI treatment groups; there were no significant differences in other biochemical indicators among the 6H2, CI, and CK treatments. P >0.05).

[0063] Table 7. Effects of Lactobacillus plantarum 6H2 on the slaughter performance of black fur sheep

[0064] In Table 7, the differences between data with different lowercase letters in the same row are significant. P <0.05), the differences between data with no letter or the same letter were not significant ( P >0.05).

[0065] 3. Discussion 3.1 Effects of Lactobacillus plantarum 6H2 on the growth performance of black fur sheep Feed intake and daily weight gain are important indicators for measuring growth performance. They not only reflect the palatability and digestibility of feed, but also, in conjunction with the feed conversion ratio, comprehensively evaluate the breeding benefits of experimental feeds. This invention found that adding *Lactobacillus plantarum* 6H2 and CICC21804 to whole-plant corn silage significantly increased the average daily feed intake of Black Fur sheep, indicating that *Lactobacillus plantarum* can lower the pH of the feed through anaerobic fermentation, improve the quality of silage fermentation, and thus promote the daily feed intake of Black Fur sheep. This invention also found that the average daily weight gain of Black Fur sheep in the *Lactobacillus plantarum* 6H2 treatment group was significantly higher than that in the control group (CK). The results of this invention indicate that whole-plant corn silage fermented with *Lactobacillus plantarum* 6H2 can significantly improve the feed conversion ratio of Black Fur sheep, with a better weight gain effect than the CI treatment group.

[0066] 3.2 Effects of Lactobacillus plantarum 6H2 on the slaughter performance of black fur sheep Slaughterability reflects the production performance and efficiency of ruminants, primarily measured by carcass weight. This invention found that, compared to the CI and CK treatment groups, the addition of *Lactobacillus plantarum* 6H2 increased the carcass weight of black fur sheep.

[0067] 3.3 Effects of Lactobacillus plantarum 6H2 on the quality of black fur mutton Meat quality is a comprehensive indicator for judging the quality of meat and a major factor influencing meat prices in the sheep farming industry. It mainly includes indicators such as pH, meat color, marbling, cooked meat yield, cooking loss, and shear force. Cooked meat yield, cooking loss, and water loss are closely related to muscle water-holding capacity; the stronger the water-holding capacity, the better the water retention of the meat, and the higher the meat yield. This invention found that adding *Lactobacillus plantarum* 6H2 to whole-plant corn silage improved the cooked meat yield, cooking loss, and water loss of Black Fur sheep muscle, increasing muscle water-holding capacity, but there was no significant difference compared to the CI and CK treatment groups. Shear force is an important indicator of meat tenderness; the lower the shear force, the more tender the meat. The results of this invention show that the shear force value of the 6H2-treated sheep muscle was lower than that of the CI treatment group and significantly lower than that of the CK treatment group, indicating more tender muscle. Meat color directly reflects the freshness and quality of the meat and is affected by factors such as feed type, slaughtering method, and feeding management. This invention found that, compared with the CI and CK treatment groups, the a* value of the longissimus dorsi muscle of black fur sheep in the group treated with *Lactobacillus plantarum* 6H2 was increased, while the L* and b* values ​​were decreased. pH reflects the rate and intensity of post-slaughter muscle glycolysis and is closely related to indicators such as meat color and tenderness, thus affecting meat quality. The results of this invention show that there were no significant differences in pH 45 min and pH 24 h between the 6H2, CI, and CK treatment groups of black fur sheep.

[0068] 3. Effects of Lactobacillus plantarum 6H2 on blood physiological parameters of black fur sheep Blood is the medium for substance transport between various organs of the body, the foundation of metabolism, and responsible for removing metabolic waste to ensure normal bodily function. The levels of white blood cells (WBC), red blood cells (RBC), and petroleum thrombi (PLT) in the blood are used to determine whether an animal is in a normal physiological state. WBC is a direct indicator of the body's defense mechanisms and physiological state; a decrease in WBC levels indicates a decline in the body's disease resistance. This invention found that the WBC count in the *Lactobacillus plantarum*-treated group of black fur sheep was significantly higher than that in the blank control group. Lym count is generally used as an indicator of the host's immune status; within the normal range, a higher Lym count indicates a more complete host immune function. This invention found that compared to the CK treatment group, the 6H2 and CI treatment groups of black fur sheep showed a significant increase in Lym count, effectively improving the body's immunity. RBC is responsible for the blood's transport function; RBC, high blood glucose (HGB), and high blood lipid (HCT) directly affect the blood's transport and buffering functions, reflecting the body's ability to transport oxygen (O2) and carbon dioxide (CO2). The results of this invention indicate that adding *Lactobacillus plantarum* during whole-plant corn silage production had no significant effect on RBC, HGB, and HCT levels in Black Fur sheep, and did not negatively impact the body's transport function. MCV and MCH levels reflect the size, content, and pigment saturation of hemoglobin in erythrocytes, and also reduce levels that predict iron deficiency anemia in livestock. This invention found that fermenting whole-plant corn with *Lactobacillus plantarum* had no significant effect on MCV and MCH levels in Black Fur sheep, and did not inhibit erythropoietin release. PLT and MPV mainly play a role in maintaining normal blood circulation. PLT plays an important role in pathological processes such as hemostasis, wound healing, inflammatory responses, and thrombosis; MPV mainly reflects platelet enzyme activity, function, and inflammation in the body. This invention found that adding *Lactobacillus plantarum* during silage production had no significant effect on PLT and MPV in Black Fur sheep, indicating that no inflammation or other diseases occurred during the experiment, and the added strain did not have any adverse effects on Black Fur sheep.

[0069] 3. Effects of *Lactobacillus plantarum* 6H2 on serum biochemical parameters of black fur sheep Blood biochemical indicators are important indicators for assessing the physiological and health status of sheep in livestock farms. Serum total protein and albumin can reflect the body's liver synthesis and protein utilization status. This invention found that in the experiment of feeding black fur sheep supplemented with Lactobacillus plantarum 6H2, TP and ALB were significantly higher than those supplemented with Lactobacillus plantarum CICC21804 and the blank control group, and BUN was significantly reduced, indicating that Lactobacillus plantarum 6H2 can significantly improve the protein digestibility and utilization rate of black fur sheep.

[0070] ALT and AST are important indicators for assessing liver function and liver damage in animals; elevated serum levels indicate potential liver impairment. In this invention, the serum ALT and AST levels of black fur sheep in the group treated with *Lactobacillus plantarum* showed no significant difference compared to the control group, indicating no negative impact on liver function. T-CHO, HDL, and LDL levels are important indicators for measuring lipid metabolism and utilization. Lower HDL levels indicate higher fat utilization, and decreased T-CHO is generally associated with better lipid metabolism and cardiovascular health. HDL and LDL are cholesterol transport carriers, responsible for cholesterol transport within and outside the liver, maintaining stable lipid metabolism. In this invention, the addition of *Lactobacillus plantarum* to silage corn had no significant effect on serum HDL and LDL in black fur sheep. CRE levels are closely related to kidney function. The results of this study show no significant difference in serum CRE levels among the 6H2, CI, and CK treatment groups, indicating that the addition of *Lactobacillus plantarum* during silage treatment had no negative impact on kidney function in black fur sheep. Changes in GLU levels reflect the dynamic balance of glucose absorption, transport, and metabolism in the body. This invention found that adding Lactobacillus plantarum during silage has no significant effect on the serum GLU content of black fur sheep and does not have any adverse effect on the body's sugar metabolism.

[0071] 4. Conclusion This invention demonstrates that fermenting whole-plant corn with *Lactobacillus plantarum* 6H2 can increase the daily feed intake and reduce the feed conversion ratio of Minxian Black Fur Sheep, thereby promoting flock growth, improving slaughter performance, enhancing blood physiological and biochemical indicators, and strengthening immunity, thus improving breeding efficiency. This invention provides a theoretical basis for the application of *Lactobacillus plantarum* 6H2 in livestock farming in high-altitude and cold regions and has certain application value. In practical applications, further optimization and screening of its concentration are needed to fully realize the application potential of *Lactobacillus plantarum* 6H2.

[0072] The present invention has been described in detail above. For those skilled in the art, the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. Although specific embodiments have been given, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein. Some of the essential features can be applied within the scope of the following appended claims.

Claims

1. At least one of the following applications of Lactobacillus plantarum fermentation of corn: X1) Promotes livestock growth; X2) Improves livestock growth performance; X3) Improves livestock slaughter performance; X4) Improves the quality of livestock meat; X5) Improves livestock immunity; X6) Improve livestock health; The fermented corn was obtained by fermenting corn plants with Lactobacillus plantarum 6H2.

2. The application according to claim 1, characterized in that: The growth performance refers to feed conversion ratio, daily weight gain, and / or daily feed intake.

3. The application according to claim 1, characterized in that: The slaughter performance refers to carcass weight.

4. The application according to claim 1, characterized in that: The meat quality refers to the tenderness of the muscle.

5. The application according to claim 1, characterized in that: The improvement in livestock immunity is reflected in the increase in the number of white blood cells, the number of lymphocytes, the percentage of lymphocytes, and / or the percentage of neutrophils.

6. The application according to claim 1, characterized in that: The improvement in livestock health is reflected in the increase of total blood protein content, the increase of albumin content, and / or the decrease of urea nitrogen content.

7. The application according to any one of claims 1-6, characterized in that: The Lactobacillus plantarum fermented corn is obtained by ensiling whole corn plants with Lactobacillus plantarum 6H2.

8. The application according to any one of claims 1-7, characterized in that: The livestock in question is a sheep.

9. At least one of the following applications of *Lactobacillus plantarum* 6H2 or *Lactobacillus plantarum* 6H2 inoculum: X1) Promotes livestock growth; X2) Improves livestock growth performance; X3) Improves livestock slaughter performance; X4) Improves the quality of livestock meat; X5) Improves livestock immunity; X6) Improves the health of livestock.

10. The application according to claim 9, characterized in that: The growth performance refers to feed conversion ratio, daily weight gain and / or daily feed intake; The slaughter performance refers to carcass weight; The meat quality refers to muscle tenderness; The improvement in livestock immunity is reflected in the increase in the number of white blood cells, the number of lymphocytes, the percentage of lymphocytes, and / or the percentage of neutrophils. The improvement in livestock health is reflected in the increase of total blood protein content, the increase of albumin content, and / or the decrease of urea nitrogen content.

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