Biological fermentation feed and complete feed for Changrong binary pigs in growth stage

Abstract

The invention belongs to the technical field of animal husbandry feeds, and particularly relates to a biological fermentation feed and a complete feed used in the growth stage of Changrong binary pigs. The biological fermentation feed is prepared from fermented distiller's grains and fermented rapeseed dregs, and the mass ratio of the fermented distiller's grains to the fermented rapeseed dregs is 1: (1.5-5); the feeding object is a hybrid pig (Changbai pig and Rongchang pig) of a Changbai pig and a Rongchang pig. The fermented white spirit vinasse is prepared by fermenting cellulase, pectinase, candida tropicalis, bacillus subtilis and lactobacillus plantarum; the fermented rapeseed meal is prepared by fermenting lactobacillus plantarum, candida tropicalis, acid protease, cellulase, beta-glucanase and xylanase. The complete feed prepared from the biological fermentation feed provided by the invention is used for feeding the Changrong binary pigs in the growth stage, so that the feed cost of the Changrong binary pigs is reduced, the economic benefits of the Changrong binary pigs are improved, and meanwhile, the disease resistance of the Changrong binary pigs is enhanced.

Description

Technical Field

[0001] This invention belongs to the field of livestock feed technology, specifically relating to a bio-fermented feed and complete feed for the growth stage of Changrong crossbred pigs. Background Technology

[0002] Soybean meal is an important protein feed ingredient, high in protein and rich in nutrients, and is widely used in livestock and poultry farming. In recent years, with declining global soybean production and increasing demand for soybean meal in domestic and international markets, soybean meal prices have continued to rise, significantly increasing the cost of livestock and poultry farming. Therefore, developing and applying unconventional protein feed ingredients and promoting low-protein diets to reduce reliance on soybean meal can, to some extent, address the protein shortage problem in my country's livestock industry.

[0003] Currently, unconventional feed ingredients that can replace soybean meal mainly include cottonseed meal, rapeseed meal, peanut meal, distillers' grains (DGD), corn distillers' grains (DDGD) and their solubles. Among these, rapeseed meal and DGD are preferred alternatives to soybean meal due to their high yield, low price, and high nutritional content. However, rapeseed meal and DGD have poor palatability and high levels of crude fiber and anti-nutritional factors, which severely restrict their application in livestock and poultry feed. Studies have confirmed that using bio-fermentation technology can effectively improve the nutritional value of DGD and rapeseed meal and degrade the content of anti-nutritional factors, thereby eliminating the adverse effects of unconventional feed ingredients on the growth performance of livestock and poultry to a certain extent. Bio-fermentation technology often uses single-strain fermentation; however, research has found that during fermentation, multi-strain mixed fermentation results in more thorough degradation of anti-nutritional factors and better fermentation effects compared to single-strain fermentation. For example, Xu Fazhi et al., in their study "Effects of fermented rapeseed meal on growth performance and serum parameters in ducks," found that rapeseed meal fermented with a mixture of *Lactobacillus plantarum* and *Bacillus subtilis* increased the crude protein content from 37.1% to 58.4%. Yongna Hu et al., in their study "Effects of fermented rapeseed meal on antioxidant functions, serum biochemical parameters, and intestinal morphology in broiler," found that rapeseed meal fermented with a mixture of *Bacillus subtilis*, *Candida utilis*, and *Enterococcus faecalis* increased the crude protein content from 42.11% to 44.63%. Wei Lai, in his study "Optimization of Fermentation Process of Baijiu Distillers' Grains and Its Effects on the Growth Performance of Finishing Pigs," found that baijiu distillers' grains fermented with a mixture of *Ichthyophthirius multifiliis*, *Bacillus oryzae*, and *Lactobacillus ferruginea* increased the crude protein content by 23.6% and decreased the fiber content by 43%. These results indicate that mixed-microbial fermentation can significantly reduce anti-nutritional factors in feed, improve feed quality, and thus enhance the production performance of growing pigs.

[0004] In the prior art, patent CN110024903A discloses a protein feed optimized by solid-state aerobic fermentation with compound bacteria and its preparation method. The raw materials are cottonseed meal, rapeseed meal, fresh distiller's grains, *Aspergillus niger*, *Aspergillus oryzae*, and *Bacillus subtilis*. The preparation method involves first preparing a dedicated feed fermentation bed with uniform temperature, and then using compound bacteria to perform a two-stage solid-state aerobic fermentation of the protein feed, resulting in the optimized protein feed. This invention belongs to the category of compound-bacterial solid-state aerobic fermentation technology that does not require turning the feed, but it is complex to operate and requires sophisticated equipment. Gu Fang et al., in their paper "The Effects of Adding Fermented Rapeseed Meal to Low-Protein Diets on the Growth Performance and Meat Quality of Finishing Pigs," disclosed a two-step, two-stage fermentation method for rapeseed meal. The first step uses *Aspergillus oryzae* for shallow solid-state fermentation, and the second step uses a compound bacteria strain composed of *Bacillus subtilis*, *Candida tropicalis*, and *Lactobacillus casei* for deep solid-state fermentation. This method is complex and requires a high ambient temperature for the fermented feed. Xu Duhan et al. disclosed in their paper "The Effects of Fermented Distillers' Grains Feeding Level on Growth Performance, Blood Biochemical Indicators and Muscle Amino Acid Composition of Western Cross Cattle" that they used probiotic groups such as lactic acid bacteria, yeast, and Bacillus, as well as compound enzyme preparations such as amylase, protease, and cellulase to ferment distillers' grains. However, this method has a long fermentation time, requiring more than 15 days, and is inefficient.

[0005] Therefore, it is necessary to propose a fermentation method that can improve the nutritional value of baijiu lees and rapeseed meal, and is simple to operate, has high fermentation efficiency, and low environmental requirements. Summary of the Invention

[0006] To address the shortcomings of the existing technologies, this invention proposes a fermentation method that can improve the nutritional value of baijiu lees and rapeseed meal, is easy to operate, has high fermentation efficiency, and low environmental requirements, as well as a bio-fermented feed for the growth stage of Changrong crossbred pigs. This bio-fermented feed can be used as a substitute for soybean meal in livestock and poultry feeding.

[0007] One of the objectives of this invention is to provide a bio-fermented feed for the growth stage of Changrong crossbred pigs.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] This is a bio-fermented feed for the growth stage of Changrong crossbred pigs. The bio-fermented feed consists of fermented liquor lees and fermented rapeseed meal, with a mass ratio of fermented liquor lees to fermented rapeseed meal of 1:1.5-5. The feed is for crossbred pigs of Changbai and Rongchang.

[0010] Furthermore, the preferred feeding species is a crossbreed of Landrace pigs and Rongchang pigs in the growth stage, referred to as the Changrong crossbred pig.

[0011] Furthermore, the preferred mass ratio of the fermented liquor lees to the fermented rapeseed meal is 1:2.

[0012] The second objective of this invention is to provide a method for preparing the aforementioned bio-fermented feed.

[0013] To achieve the above objectives, the present invention adopts the following technical solution:

[0014] The preparation method of bio-fermented feed includes the following steps:

[0015] (1) Fermented baijiu lees are prepared by using baijiu lees, wheat bran and water as raw materials and through synergistic fermentation of bacteria and enzymes; the enzymes include cellulase and pectinase; the bacteria include Candida tropicalis, Bacillus subtilis and Lactobacillus plantarum.

[0016] (2) Fermented rapeseed meal is prepared by using rapeseed meal, wheat bran and water as raw materials through synergistic fermentation of bacteria and enzymes; the bacteria include Lactobacillus plantarum and Candida tropicalis; the enzymes include acidic protease, cellulase, β-glucanase and xylanase;

[0017] (3) Mix the fermented liquor lees obtained in step (1) with the fermented rapeseed meal obtained in step (2) to obtain biological fermented feed.

[0018] Furthermore, in step (1), the inoculation amount of Candida tropicalis is 4%-6%, the inoculation amount of Bacillus subtilis is 0.8%-1.2%, and the inoculation amount of Lactobacillus plantarum is 0.8%-1.2%; in step (2), the inoculation amount of Lactobacillus plantarum is 0.8%-1.2%, and the inoculation amount of Candida tropicalis is 1.5%-2.5%.

[0019] Preferably, in step (1), the inoculation amount of Candida tropicalis is 5%, the inoculation amount of Bacillus subtilis is 1%, and the inoculation amount of Lactobacillus plantarum is 1%; in step (2), the inoculation amount of Lactobacillus plantarum is 1%, and the inoculation amount of Candida tropicalis is 2%.

[0020] Further, in step (1), the amount of cellulase added is 0.6%-0.8%, and the amount of pectinase added is 0.2%-0.4%; in step (2), the amount of acidic protease added is 0.4%-0.6%, the amount of cellulase added is 0.2%-0.4%, the amount of β-glucanase added is 0.05%-0.15%, and the amount of xylanase added is 0.05%-0.15%; all are based on the weight of the fermentation raw material, baijiu lees.

[0021] Preferably, in step (1), the amount of cellulase added is 0.7% and the amount of pectinase added is 0.3%; in step (2), the amount of acidic protease added is 0.5%, the amount of cellulase added is 0.3%, the amount of β-glucanase added is 0.1%, and the amount of xylanase added is 0.1%; all are based on the weight of the fermentation raw material, baijiu lees.

[0022] Furthermore, in step (1), the mass ratio of baijiu lees, wheat bran and water is 80-90:10-20:20-28; in step (2), the mass ratio of rapeseed meal, wheat bran and water is 50-60:10-20:30-40.

[0023] Preferably, in step (1), the mass ratio of baijiu lees, wheat bran and water is 85:15:24; in step (2), the mass ratio of rapeseed meal, wheat bran and water is 55:15:35.

[0024] Furthermore, step (1) includes the following steps:

[0025] 1) Ammoniation: Mix baijiu lees, wheat bran and water, then add ammonia water to carry out the ammoniation reaction to obtain ammonified baijiu lees;

[0026] 2) Aerobic fermentation: Add water, Candida tropicalis, Bacillus subtilis, and cellulase to the ammoniated lees from step 1), mix well, and carry out aerobic fermentation to obtain aerobic fermented lees.

[0027] 3) Anaerobic fermentation: Add Lactobacillus plantarum and pectinase to the lees after aerobic fermentation in step 2) and carry out anaerobic fermentation to obtain fermented baijiu lees.

[0028] Furthermore, the amount of ammonia water added is 5%-8%, based on the weight of the fermentation raw material, baijiu lees.

[0029] Preferably, the amount of ammonia added is 6%, based on the weight of the fermentation raw material, baijiu lees.

[0030] Furthermore, in step 1), the ammoniation reaction is carried out at room temperature for 20-30 hours, preferably 24 hours.

[0031] Furthermore, in step 2), the amount of water added is 30%, based on the weight of the fermentation raw material, baijiu lees.

[0032] Furthermore, in step 2), the aerobic fermentation is performed at room temperature for 45-60 hours, preferably 48 hours.

[0033] Furthermore, in step 3), the anaerobic fermentation time is 4-5 days, preferably 4 days.

[0034] Furthermore, in step (2), the fermentation time is 6-8 days, preferably 7 days.

[0035] Furthermore, in step (2), 0.8%-1.2% brown sugar is added to the fermentation enzyme, based on the weight of the fermentation raw material rapeseed meal.

[0036] Preferably, in step (2), 1% brown sugar is added during bacterial enzyme fermentation, based on the weight of the fermentation raw material rapeseed meal.

[0037] The third objective of this invention is to provide a pig feed containing the aforementioned bio-fermented feed.

[0038] To achieve the above objectives, the present invention adopts the following technical solution:

[0039] The pig feed containing the aforementioned bio-fermented feed is fed to Changrong crossbred pigs.

[0040] As a preferred option, the pigs to be fed are Changrong crossbred pigs in their growth stage.

[0041] Furthermore, the pig feed is composed of the following components in parts by weight: 64-72 parts corn, 0.5-15 parts soybean meal, 8-18 parts wheat bran, 10-15 parts fermented biological feed, 0.1-0.9 parts soybean oil, 0.65-0.89 parts limestone powder, 0.46-0.91 parts dicalcium phosphate, 0.3 parts salt, 0.42-0.78 parts lysine, 0.06-0.11 parts methionine, 0.10-0.24 parts threonine, 0.01-0.08 parts tryptophan, 0.06 parts mold inhibitor, 0.03 parts antioxidant, and 0.97-1 parts premix.

[0042] Furthermore, the premix comprises the following components in parts by weight: 25-30 parts ferrous sulfate monohydrate, 20-25 parts zinc sulfate monohydrate, 1.5-2 parts basic copper chloride, 8-11 parts manganese sulfate monohydrate, 5-8 parts sodium selenite, 0.7-1.2 parts 5% calcium iodate, 800-1000 KIU / kg vitamin A, 200-400 KIU / kg vitamin D3, 2-3 KIU / kg vitamin E, 250-350 parts vitamin K3, 250-350 parts vitamin B1, 700-800 parts vitamin B2, and vitamin B6. 300-400 parts, Vitamin B12 2.5-4 parts, Nicotinamide 2500-3500 parts, Pantothenic Acid 1000-2000 parts, Folic Acid 100-140 parts, Biotin 12-18 parts, Antifungal Agent 55-65 parts, Antioxidant 25-35 parts, Maifan Stone 750-850 parts.

[0043] Preferably, the premix consists of the following components in parts by weight: 26.66 parts ferrous sulfate monohydrate, 23.18 parts zinc sulfate monohydrate, 1.72 parts basic copper chloride, 9.44 parts manganese sulfate monohydrate, 6.66 parts sodium selenite, 0.94 parts 5% calcium iodate, 900 KIU / kg vitamin A, 300 KIU / kg vitamin D3, 2.4 KIU / kg vitamin E, 300 parts vitamin K3, 300 parts vitamin B1, 750 parts vitamin B2, 360 parts vitamin B6, 3.6 parts vitamin B12, 3000 parts nicotinamide, 1500 parts D-pantothenic acid, 150 parts folic acid, 15 parts D-biotin, 60 parts antifungal agent, 30.40 parts antioxidant, and 811 parts maifanite.

[0044] Furthermore, the antifungal agent is composed of propionic acid, sodium propionate and silicon dioxide, wherein the propionic acid content is ≥50% and the sodium propionate content is ≥2%.

[0045] Furthermore, the antioxidant is composed of ethoxyquinoline, silica, and stone powder, wherein the ethoxyquinoline content is ≥30%.

[0046] The fourth objective of this invention is to provide an application of the aforementioned bio-fermented feed and the aforementioned pig feed in improving the antioxidant capacity of pigs.

[0047] Furthermore, the animals being fed are Changrong crossbred pigs in their growth stage.

[0048] The aforementioned growth stage refers to the period when the pig's weight is approximately 30-65 kg. This stage is the period of fastest growth and development for Changrong crossbred pigs and is also a crucial period for pig farmers to obtain economic benefits. Feeding pigs with existing feed results in a high feed conversion ratio, slow growth, and can easily affect the later fattening process. Furthermore, high-protein feed is costly. Therefore, developing a low-protein feed that can improve the nutritional value of distillers' grains and rapeseed meal is of great significance to the development of animal husbandry.

[0049] The beneficial effects of this invention are as follows:

[0050] 1. This invention uses Candida tropicalis to ferment feed, which can significantly increase the crude protein content of rapeseed meal raw material, significantly reduce the phytic acid content in the raw material, and significantly improve the nutritional value of feed raw material.

[0051] 2. This invention uses Bacillus subtilis to ferment rapeseed meal, which can produce a variety of hydrolytic enzymes such as protease, to hydrolyze the biological macromolecules such as fiber and protein in the raw materials, significantly reducing the content of anti-nutritional factors in feed raw materials and significantly increasing the content of amino acids and proteins, thereby improving the nutritional value of feed.

[0052] 3. When Lactobacillus plantarum is used to ferment feed, a large amount of lactic acid is produced, which effectively improves the palatability of the feed. During the fermentation process, large molecular proteins are degraded into many small molecular substances, which minimizes the damage to nutrients. This can improve protein quality, produce growth-promoting factors, and thus improve feed conversion efficiency, animal growth performance, and feed quality.

[0053] 4. The method for preparing bio-fermented feed through synergistic fermentation of bacteria and enzymes provided by this invention employs mixed-culture fermentation, meaning that multiple bacteria are added and fermented simultaneously during the fermentation process. Compared to conventional fermentation methods, this method is simpler to operate, easier to meet environmental requirements, and has higher fermentation efficiency.

[0054] 5. This invention adds a suitable proportion of bio-fermented feed to the feed to partially replace soybean meal, which can meet the nutritional needs of Changrong crossbred pigs during their growth and development stages, enhance their disease resistance, and play an important role in the later fattening stage of Changrong crossbred pigs.

[0055] 6. This invention uses bio-fermented feed to partially replace soybean meal, which greatly reduces feed costs while meeting the growth needs of Changrong crossbred pigs. Detailed Implementation

[0056] The technical solution of the present invention will be described more clearly and completely below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0057] In this embodiment of the invention, cellulase, pectinase, acidic protease, β-glucanase, and xylanase were purchased from Xiasheng Enzyme Biotechnology Co., Ltd.

[0058] In this embodiment of the invention, *Lactiplantibacillus plantarum* CQWF4 was deposited by the Chongqing Academy of Animal Sciences at the Guangdong Provincial Center for Microbial Culture Collection on October 17, 2023, with the culture collection number GDMCCNO:63895; *Candida tropicalis* and *Bacillus subtilis* were purchased from the China General Microbiological Culture Collection Center, with the culture collection number of *Candida tropicalis* being CGMCC2.1013 and that of *Bacillus subtilis* being CGMCC1.14985.

[0059] In this embodiment of the invention, a feed specifically for the growth stage of Changrong crossbred pigs is provided, comprising the following components by weight: 64-72 parts corn, 0.5-15 parts soybean meal, 8-18 parts wheat bran, 10-15 parts fermented biological feed, 0.1-0.9 parts soybean oil, 0.65-0.89 parts limestone powder, 0.46-0.91 parts dicalcium phosphate, 0.3 parts salt, 0.42-0.78 parts lysine, 0.06-0.11 parts methionine, 0.10-0.24 parts threonine, 0.01-0.08 parts tryptophan, 0.06 parts mold inhibitor, 0.03 parts antioxidant, and 0.97-1 parts premix.

[0060] In this embodiment of the invention, each kilogram of premix contains: 26.66g ferrous sulfate monohydrate, 23.18g zinc sulfate monohydrate, 1.72g basic copper chloride, 9.44g manganese sulfate monohydrate, 6.66g sodium selenite, 0.94g 5% calcium iodate, 900KIU vitamin A, 300KIU vitamin D3, 2.4KIU vitamin E, 300mg vitamin K3, 300mg vitamin B1, 750mg vitamin B2, 360mg vitamin B6, 3.6mg vitamin B12, 3000mg nicotinamide, 1500mg D-pantothenic acid, 150mg folic acid, 15mg D-biotin, 60g antifungal agent, 30.40g antioxidant, and 811g maifanite.

[0061] In this embodiment of the invention, the antifungal agent is composed of propionic acid, sodium propionate and silicon dioxide (carrier), wherein the propionic acid content is ≥50% and the sodium propionate content is ≥2%.

[0062] In this embodiment of the invention, the antioxidant is composed of ethoxyquinoline, silica (carrier), and stone powder (carrier), wherein the content of ethoxyquinoline is ≥30%.

[0063] Example 1. Preparation method of bio-fermented feed

[0064] 1. Preparation of fermented baijiu lees

[0065] (1) Ammoniation: Mix the baijiu lees, wheat bran and water in a mass ratio of 85:15:24, add 6% ammonia water, and ammonify at room temperature for 24 hours;

[0066] (2) Aerobic fermentation: After ammoniation, add 30% water, 5% Candida tropicalis, 1% Bacillus subtilis, and 0.7% cellulase. After mixing, ferment aerobically at room temperature for 48 hours.

[0067] (3) Anaerobic fermentation: After aerobic fermentation, add 1% Lactobacillus plantarum and 0.3% pectinase, mix well, pack into bags and anaerobic ferment for 4 days to obtain fermented baijiu lees.

[0068] 2. Preparation of Fermented Rapeseed Meal

[0069] Rapeseed meal, wheat bran, and water were mixed evenly in a mass ratio of 55:15:35. Then, bacteria, enzymes, and brown sugar were added and mixed thoroughly. The mixture was then anaerobic fermented at room temperature for 7 days to obtain fermented rapeseed meal. The bacteria included *Lactobacillus plantarum* and *Candida tropicalis*, with an inoculum amount of 1% for *Lactobacillus plantarum* and 2% for *Candida tropicalis*. The enzymes included 0.5% acidic protease, 0.3% cellulase, 0.1% β-glucanase, and 0.1% xylanase. The amount of brown sugar used was 1%. The rapeseed meal used was type 95 rapeseed meal.

[0070] 3. Bio-fermented feed

[0071] The bio-fermented feed consists of fermented liquor lees and fermented rapeseed meal, with a mass ratio of fermented liquor lees to fermented rapeseed meal of 1:2.

[0072] Example 2

[0073] By weight, the feed comprises the following components: 65.13 parts corn, 4.1 parts soybean meal, 11.23 parts wheat bran, 15 parts fermented biological feed, 0.9 parts soybean oil, 0.65 parts lysine (78%), 0.07 parts methionine, 0.16 parts threonine, 0.05 parts tryptophan, 0.86 parts limestone powder, 0.46 parts dicalcium phosphate, 0.06 parts mold inhibitor, 0.03 parts antioxidant, 0.3 parts salt, and 1 part premix.

[0074] Example 3

[0075] By weight, the feed comprises the following components: 71.64 parts corn, 0.5 parts soybean meal, 8.8 parts wheat bran, 15 parts fermented biological feed, 0.1 parts soybean oil, 0.78 parts lysine (78%), 0.1 parts methionine, 0.23 parts threonine, 0.08 parts tryptophan, 0.89 parts limestone powder, 0.49 parts dicalcium phosphate, 0.06 parts mold inhibitor, 0.03 parts antioxidant, 0.3 parts salt, and 1 part premix.

[0076] Comparative Example 1

[0077] By weight, the feed comprises the following components: 69.31 parts corn, 12.18 parts soybean meal, 14.53 parts wheat bran, 0.2 parts soybean oil, 0.54 parts lysine (78%), 0.08 parts methionine, 0.16 parts threonine, 0.04 parts tryptophan, 0.69 parts limestone, 0.91 parts dicalcium phosphate, 0.06 parts mold inhibitor, 0.03 parts antioxidant, 0.3 parts salt, and 0.97 parts premix.

[0078] Example 4. Determination of nutrient composition in fermented feed

[0079] This embodiment further measures the changes in nutritional components and amino acid content of rapeseed meal and liquor lees before and after fermentation.

[0080] As shown in Table 1, the contents of crude protein, acid-soluble protein, crude fat, calcium, and phosphorus in fermented rapeseed meal increased by 5.00%, 72.34%, 61.19%, 6.49%, and 8.11%, respectively, while the contents of acid detergent fiber and neutral detergent fiber decreased by 1.03% and 7.42%, respectively. The contents of essential amino acids, non-essential amino acids, and total amino acids increased by 8.94%, 10.07%, and 9.65%, respectively, with all 17 amino acids showing varying degrees of increase.

[0081] As shown in Table 2, after fermentation, the crude protein, acid-soluble protein, crude fat, calcium, and phosphorus content of the baijiu lees increased by 6.87%, 17.31%, 5.14%, 6.25%, and 8.33%, respectively, while the crude fiber content decreased by 10.11%. The contents of essential amino acids, non-essential amino acids, and total amino acids increased by 17.29%, 16.54%, and 16.80%, respectively. All 16 amino acids showed varying degrees of increase, with methionine, threonine, valine, leucine, isoleucine, and proline increasing by 5.00%, 24.32%, 18.97%, 17.07%, 13.83%, and 32.95%, respectively.

[0082] Table 1. Nutrient content of rapeseed meal before and after fermentation (dry matter basis, %)

[0083]

[0084]

[0085] Table 2. Nutrient content of baijiu lees before and after fermentation (dry matter basis, %)

[0086] project Baijiu lees Fermented Baijiu lees pH 5.39 4.54 crude protein 18.04 19.28 acid-soluble proteins 8.03 9.42 Crude fat 3.31 3.48 calcium 0.16 0.17 phosphorus 0.36 0.39 crude fiber 27.80 24.99 Acid detergent fibers 46.63 45.60 Neutral detergent fiber 54.00 53.43 essential amino acids Lysine 0.30 0.30 Methionine 0.14 0.21 Valine 0.58 0.69 Isoleucine 0.41 0.48 Leucine 0.94 1.07 Phenylalanine 0.50 0.59 Histidine 0.23 0.27 threonine 0.37 0.46 Non-essential amino acids Alanine 0.77 0.83 Aspartic acid 0.75 0.90 glutamate 2.48 2.81 Arginine 0.45 0.46 glycine 0.51 0.64 Serine 0.47 0.54 Tyrosine 0.29 0.34 Proline 0.88 1.17 Cysteine 0.11 0.13 Total essential amino acids 3.47 4.07 Total non-essential amino acids 6.71 7.82 Total amino acids 10.18 11.89

[0087] Example 5. Animal Experiment

[0088] 1. Experimental Design

[0089] Forty-eight healthy Changrong crossbred pigs (half male and half female) with similar weights (31.21±0.07kg) were selected and divided into two groups, with six replicates in each group and four pigs in each replicate: the control group was fed the complete feed of Example 1, and the experimental group was fed the complete feed of Example 2. All pigs had free access to feed and water during the experiment.

[0090] 2. Detection indicators

[0091] At the start and end of the experiment, the initial and final body weights of each pig were measured. Feed intake was recorded during the experiment, and the average daily weight gain, average daily feed intake, and feed conversion ratio (FCR) of the growing pigs were calculated. On the last day of the experiment, venous blood samples were collected, and serum samples were analyzed. Serum biochemical indicators such as total protein, albumin, and globulins, as well as immunoglobulins IgA, IgG, IgM, superoxide dismutase, glutathione, malondialdehyde, and total antioxidant capacity were measured.

[0092] 3. Data Analysis

[0093] After preprocessing the experimental data in Excel 2019, independent t-tests were performed on the obtained data using SPSS 26.0 statistical software. The experimental results were expressed as P<0.05 as statistically significant and P<0.01 as highly statistically significant.

[0094] 4. Test Results

[0095] As shown in Table 3, there were no significant differences in average daily weight gain, average daily feed intake, and feed conversion ratio between the two groups (P>0.05). Compared with the control group, the experimental group had a feed cost reduction of 0.26 yuan / kg and a weight gain cost reduction of 0.25 yuan / kg, respectively, resulting in an increase in production efficiency of 0.25 yuan / kg. Serum marker levels are shown in Tables 4-6. The experimental group showed a highly significant increase in glutathione content (P<0.01) and a significant increase in total antioxidant capacity (P<0.05). There were no significant changes in immune markers between the two groups.

[0096] Table 3. Effects of different feeds on the growth performance and economic benefits of Changrong pigs.

[0097] project control group experimental group P-value Initial weight (kg) 31.29±0.08 31.17±0.18 0.368 Final weight (kg) 62.34±1.25 62.00±1.23 0.545 Average daily weight gain (kg) 0.76±0.03 0.75±0.03 0.553 Average daily feed intake (kg) 2.03±0.04 2.15±0.07 0.436 Material weight ratio 2.71±0.11 2.86±0.06 0.237 Feed price (yuan / kg) 3.28 3.02 - Cost of weight gain (RMB / kg) 8.89 8.64 - Production revenue (RMB / kg) 8.43 8.68 -

[0098] Note: Calculated based on the following prices: Changrong live pig price 17.32 yuan / kg, feed ingredient prices: corn 3.05 yuan / kg, soybean meal 4.50 yuan / kg, wheat bran 2.35 yuan / kg, fermented baijiu lees 1.30 yuan / kg, fermented rapeseed meal 2.35 yuan / kg, soybean oil 9.00 yuan / kg, L-lysine 11 yuan / kg, DL-methionine 20.60 yuan / kg, L-threonine 12.60 yuan / kg, L-tryptophan 73.0 yuan / kg, limestone powder 0.30 yuan / kg, dicalcium phosphate 2.25 yuan / kg, salt 0.60 yuan / kg, premix 10.00 yuan / kg, mold inhibitor 8.00 yuan / kg, and antioxidant 19.00 yuan / kg.

[0099] Table 4. Effects of different feeds on serum biochemical parameters of Changrong pigs

[0100] project control group experimental group P-value Total protein (g / L) 62.90±1.72 68.05±2.09 0.086 Albumin (g / L) 36.86±0.33 36.68±0.45 0.736 Globulin (g / L) 26.57±1.71 31.37±2.01 0.099 White ball ratio 1.40±0.10 1.18±0.07 0.079 Blood urea nitrogen (nmol / L) 2.03±0.34 1.97±0.15 0.876 Total cholesterol (mmol / L) 2.67±0.11 2.61±0.10 0.690 Triglycerides (mmol / L) 0.28±0.03 0.37±0.04 0.110 High-density lipoprotein (mmol / L) 1.20±0.08 1.16±0.08 0.754 Low-density lipoprotein (mmol / L) 1.09±0.07 1.01±0.12 0.599

[0101] Table 5. Effects of different feeds on serum antioxidant indices in Changrong pigs

[0102] project control group experimental group P-value Superoxide dismutase (U / g) 22.62±3.09 16.31±3.31 0.139 Glutathione (Ug / g) 65.34±5.43 111.72±2.23 <0.010 Malondialdehyde (nmol / g) 2.26±0.12 3.01±0.65 0.351 Total antioxidant capacity (μmol / g) 0.14±0.01 0.23±0.03 0.041

[0103] Table 6. Effects of different feeds on serum immune indicators in Changrong pigs

[0104] project control group experimental group P-value Immunoglobulin A (mg / mL) 2.20±0.20 2.40±0.28 0.778 Immunoglobulin G (mg / mL) 57.20±4.88 48.53±4.44 0.226 Immunoglobulin M (mg / mL) 6.30±0.20 6.94±1.04 0.589

[0105] The above results indicate that the use of fermented rapeseed meal and fermented distillers' grains in the diet of Changrong crossbred pigs during their growth period reduced the amount of soybean meal in the diet, lowered feeding costs, significantly improved antioxidant function, and improved the health of the pigs, laying the foundation for the growth of Changrong crossbred pigs during their fattening period.

Claims

1. A bio-fermented feed for the growth stage of Changrong crossbred pigs, characterized in that, The bio-fermented feed consists of fermented liquor lees and fermented rapeseed meal, with a mass ratio of fermented liquor lees to fermented rapeseed meal of 1:1.5-5; the feed is for crossbred pigs of Landrace and Rongchang.

2. The method for preparing bio-fermented feed according to claim 1, characterized in that, The steps include: (1) Fermented baijiu lees are prepared by using baijiu lees, wheat bran and water as raw materials and through synergistic fermentation of bacteria and enzymes; the enzymes include cellulase and pectinase; the bacteria include Candida tropicalis, Bacillus subtilis and Lactobacillus plantarum. (2) Fermented rapeseed meal is prepared by using rapeseed meal, wheat bran and water as raw materials through synergistic fermentation of bacteria and enzymes; the bacteria include Lactobacillus plantarum and Candida tropicalis; the enzymes include acidic protease, cellulase, β-glucanase and xylanase; (3) Mix the fermented liquor lees obtained in step (1) with the fermented rapeseed meal obtained in step (2) to obtain biological fermented feed.

3. The method according to claim 2, characterized in that, In step (1), the inoculum size of *Candida tropicalis* is 4%-6%. The inoculation amount of Bacillus subtilis is 0.8%-1.2%, and the inoculation amount of Lactobacillus plantarum is 0.8%-1.2%; in step (2), the inoculation amount of Lactobacillus plantarum is 0.8%-1.2%, and the inoculation amount of Candida tropicalis is 1.5%-2.5%.

4. The method according to claim 2, characterized in that, In step (1), the amount of cellulase added is 0.7% and the amount of pectinase added is 0.3%; in step (2), the amount of acidic protease added is 0.5%, the amount of cellulase added is 0.3%, the amount of β-glucanase added is 0.1%, and the amount of xylanase added is 0.1%; all are based on the weight of the fermentation raw material, baijiu lees.

5. The method according to claim 2, characterized in that, In step (3), the mass ratio of the fermented liquor lees to the fermented rapeseed meal is 1:1.5-5.

6. The method according to claim 2, characterized in that, Step (1) includes the following steps: 1) Ammoniation: Mix baijiu lees, wheat bran and water, then add ammonia water to carry out the ammoniation reaction to obtain ammonified baijiu lees; 2) Aerobic fermentation: Add water, Candida tropicalis, Bacillus subtilis, and cellulase to the ammoniated lees from step 1), mix well, and carry out aerobic fermentation to obtain aerobic fermented lees. 3) Anaerobic fermentation: Add Lactobacillus plantarum and pectinase to the lees after aerobic fermentation in step 2) and carry out anaerobic fermentation to obtain fermented baijiu lees.

7. The method according to claim 6, characterized in that, In step 1), the ammoniation reaction is carried out at room temperature for 20-30 hours; in step 2), the aerobic fermentation is carried out at room temperature for 45-60 hours; in step 3), the anaerobic fermentation time is 4-5 days.

8. The method according to claim 2, characterized in that, In step (2), the fermentation time is 6-8 days.

9. Pig feed containing the bio-fermented feed of claim 1.

10. The pig feed according to claim 9, characterized in that, The pig feed is composed of the following components in parts by weight: 64-72 parts corn, 0.5-15 parts soybean meal, 8-18 parts wheat bran, 10-15 parts fermented biological feed, 0.1-0.9 parts soybean oil, 0.65-0.89 parts limestone powder, 0.46-0.91 parts dicalcium phosphate, 0.3 parts salt, 0.42-0.78 parts lysine, 0.06-0.11 parts methionine, 0.10-0.24 parts threonine, 0.01-0.08 parts tryptophan, 0.06 parts mold inhibitor, 0.03 parts antioxidant, and 0.97-1 parts premix.

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