Method for producing snowflake beef through yak seasonal barn feeding and short-term fattening

Abstract

The invention discloses a method for producing snowflake beef through yak seasonal barn feeding and short-term fattening. Belongs to the field of animal husbandry, and achieves efficient output of yak snowflake beef through short-period seasonal fattening by selecting fattening yaks, selecting fattening seasons and time and cooperating with daily ration in the fattening early stage and the fattening later stage. In the late fattening period, soybean-meal-free low-protein daily ration is adopted to synergistically promote fat deposition in yak muscles, so that efficient output of the yak snowflake beef is achieved, and the method for producing the snowflake beef by using the yaks has important significance for improving the economic benefits of yak breeding in plateau pasturing areas and meeting the requirements of the market in China for high-quality beef.

Description

Technical Field

[0001] The invention relates to the field of animal husbandry, and in particular to a method for producing marbled beef by seasonal short-term fattening of yaks. Background Art

[0002] With rising national incomes and shifting dietary patterns, beef consumption has steadily increased. Marbled beef, a premium cut of beef with fat deposited between muscle fibers, creates a red and white pattern, giving it a snowflake-like appearance. Marbled beef is not only low in cholesterol and high in unsaturated fatty acids, but also tender, juicy, and delicious, making it a favorite among consumers.

[0003] Yaks are a vital source of beef in my country. However, due to the unique climate of the plateau and underdeveloped breeding and production technology, yaks lack the necessary nutritional requirements and adequate feeding standards. This results in a long yak-to-market cycle, coarse muscle fibers, tough meat, and a shortage of high-quality yak beef. Yak beef has long been sold as cheap, frozen, or air-dried meat, resulting in low added value. The economic value of yak beef in the plateau region has yet to be fully realized. Developing new technologies to produce marbled beef from yaks is crucial for improving the economic efficiency of yak farming in plateau pastoral areas and meeting the demand for high-quality beef in the Chinese market.

[0004] However, producing marbled beef from yaks presents the following technical difficulties: First, from a breed perspective, existing marbled beef production technology primarily utilizes Wagyu, Angus, local yellow cattle, and their hybrids. These breeds have a high ability to deposit intramuscular fat, allowing them to easily develop marbling. However, yaks have coarse muscle fibers and low intramuscular fat deposition, making the production of marbled beef from yaks challenging. Second, from a production perspective, yaks primarily inhabit plateau regions, where the warm season is short (May-September) and the cold season is long (October-April). Yaks produce high levels of metabolic heat to withstand the cold, making the production of marbled beef unfavorable. Third, from a nutritional regulation perspective, nutrient requirements vary significantly across seasons, and the nutritional requirements for fattening yaks for marbled beef differ significantly from existing technical parameters. Furthermore, there is a lack of seasonally specific nutritional requirements and feeding standards for yaks. Fourth, from a farming perspective, current marbled beef fattening production for breeds like Wagyu and Angus primarily involves a programmed rearing process, including the calving phase, the growing phase, the early fattening phase, and the late fattening phase, with yaks generally marketed around 25-30 months of age. However, due to the unique natural environment and backward husbandry practices of the plateau, yak farming in pastoral areas differs from beef cattle farming in agricultural areas. Yaks generally begin fattening at 3-4 years old, making it impossible to fatten them throughout the entire process to produce marbled beef. Therefore, existing farming techniques are not suitable for producing marbled beef from yaks. The production of marbled beef from yaks requires the integration of precise nutritional regulation and scientific husbandry management techniques, achieving efficient output through short-term seasonal fattening cycles. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a method for producing marbled beef by seasonal short-term fattening of yaks; belonging to the field of animal husbandry, the present invention realizes efficient output of yak marbled beef through short-term seasonal fattening by selecting fattening yaks, selecting fattening season and time, and coordinating diets in the early and late fattening stages. The core of the present invention is to adopt a high-energy, low-fiber diet in the early fattening stage, and to adopt a soybean meal-free, low-protein diet in the late fattening stage to synergistically promote the deposition of intramuscular fat in the yak, thereby realizing efficient output of yak marbled beef. The production of marbled beef using yaks is of great significance for improving the economic benefits of yak farming in plateau pastoral areas and meeting the demand for high-quality beef in the Chinese market.

[0006] In order to achieve the above technical effects, the following technical solutions are adopted: A method for producing marbled beef by seasonal short-term fattening of yaks, comprising the following steps: Step S1: Selection of fattening yaks Select 2-2.5 year old castrated male yaks or 3-4 year old culled female yaks with rectangular body shape, deep chest, broad hindquarters, big and bright eyes, solid hooves and short and thick neck; Step S2: Fattening season and time selection In the plateau region, yaks are fattened in sheds from May to July during the warm season and are marketed from November to December during the cold season. The fattening period is 5-6 months. Step S3: Fattening procedures and diet composition 1. Early stage of fattening: The mass proportions of the raw materials in the high-energy, low-fiber diet are as follows: corn 30.0-40.0%, wheat bran 7.0-9.0%, soybean meal 4.0-4.5%, rapeseed meal 4.0-6.0%, salt 0.2-0.4%, baking soda 0.6-1.0%, calcium carbonate 0.2-0.4%, Angel active yeast 0.05-0.10%, soybean oil 0.5-0.8%, fattening cattle premix 2.0-3.0%, oat hay 30.0-50.0%; the nutritional level of the high-energy, low-fiber diet is: net energy for weight gain 4.0-5.0 MJ / kg, crude protein 11.0-12.0%, neutral detergent fiber 30.0-40.0%, acid detergent fiber 15.0-20.00%, calcium 0.40-0.60%, phosphorus 0.40-0.60%; 2. Late fattening period: The mass proportions of the raw materials in the soybean meal-free low-protein diet are: corn 42.0-45.0%, wheat bran 10.0-14.0%, rapeseed meal 4.0-5.0%, calcium bicarbonate 0.10-0.15%, soybean oil 0.60-0.90%, oat hay 32-37%, and fattening cattle premix 3.0-3.5%; the nutritional level of the soybean meal-free low-protein diet is: crude protein 9.0-11.0%, net energy for weight gain 4.8-5.0 MJ / kg, neutral detergent fiber 29.0-33.0%, acid detergent fiber 16.0-18.0%, calcium 0.4-0.7%, and phosphorus 0.3-0.5%; Step S4: Feeding and management First, the yaks selected in step S1 are isolated for 10-15 days and their health status is observed. At the same time, they are quarantined for diseases such as brucellosis and tuberculosis. Sick yaks are eliminated. Second, the fattening yaks are dewormed with trichlorfon. Three days after deworming, they are gavage-administered with Jianwei Powder, 500g / each time, once a day for three consecutive days. Before fattening, after a 10-14 day adaptation period, the feed was gradually changed. During the fattening feeding period, the yaks were fed at 08:00 and 16:00 every day. Before feeding, the corresponding fattening diet was mixed evenly according to the formula ratio to make a complete mixed diet, and then fed. The yaks had free access to food and water, and ensured that 3-8% of the feed was left over after eating. The forage was cut short and picked clean, and foreign objects such as nails and plastic were strictly prohibited. The yaks were ensured to have sufficient and clean water sources. The cattle beds, cattle troughs, and water troughs were cleaned and manure was removed every day. When the yak's feed intake decreases, its back becomes wide and flat, its bone tubercles are not obvious, its ribs are fat, and its body is barrel-shaped, it can be slaughtered.

[0007] Furthermore, the weight of the fattened yaks in step S1 is between 180 and 220 kg.

[0008] Furthermore, the dosage of trichlorfon for fattening cattle in step S4 is: 1 g / 100 kg body weight.

[0009] Furthermore, the mass ratio of each raw material in the high-energy, low-fiber diet in the early fattening stage in step S3 is: Corn 37.80%, wheat bran 8.40%, soybean meal 4.14%, rapeseed meal 4.80%, salt 0.30%, baking soda 0.60%, calcium carbonate 0.30%, Angel active yeast 0.06%, soybean oil 0.6%, fattening cattle premix 3.0%, oat hay 40%; the nutritional level of the high-energy, low-fiber diet in the early fattening stage in step S3 is: net energy for weight gain 4.4 MJ / kg, crude protein content 11.87%, neutral detergent fiber content 37.30%, acid detergent fiber content 18.95%, calcium 0.56%, and phosphorus 0.49%.

[0010] Furthermore, in step S3, the mass ratio of each raw material in the soybean meal-free low-protein diet in the late fattening period is: 43.55% corn, 12.87% wheat bran, 4.55% rapeseed meal, 0.13% calcium bicarbonate, 35.00% oat hay, 0.65% soybean oil, and 3.25% premix; the nutritional level of the soybean meal-free low-protein diet in the late fattening period in step S3 is: crude protein 10.04%, net energy for weight gain 4.92 MJ / kg, neutral detergent fiber 30.38%, acid detergent fiber 17.08%, calcium 0.64%, and phosphorus 0.40%.

[0011] Furthermore, the early fattening period in step S3 is 3 months.

[0012] Furthermore, the late fattening period in step S3 is 2-3 months.

[0013] Furthermore, the formula of the premix for fattening cattle in the early stage is: Each 100kg premix contains VA: 12000000-20000000IU, VE: 75000IU, VK3: 1000mg, VB1: 1000mg, VB2: 2800mg, VB 12 : 10000μg, VD3: 3000000-5000000IU, niacin: 20g, pantothenic acid: 5g, selenium: 200-1000mg, iron: 80-400g, copper: 10-60g, sodium chloride: 5-40kg, biotin: 200mg, folic acid: 400mg, iodine: 500-2800mg, zinc: 50-240g, manganese: 70-300g, magnesium: 400-3000g, VB6: 1g, cobalt: 100-700mg, phosphorus: 200-4500g, calcium: 1-25kg, lysine: 1kg, and the rest are water and a carrier, and the carrier is bran powder or zeolite powder.

[0014] Furthermore, the formula of the late fattening cattle premix is: Every 100kg of premix contains 0.513kg of ferrous sulfate, 0.098kg of copper sulfate, 0.194kg of manganese sulfate, 0.268kg of zinc sulfate, 0.068kg of sodium selenite, 0.048kg of calcium iodate, 0.038kg of cobalt chloride, 1.000kg of multivitamins, 28.000kg of baking soda, 4.500kg of calcium hydrogen phosphate, 29.000kg of table salt, 2.000kg of Angel ruminant yeast, and 34.273kg of CaCO3 carrier.

[0015] The beneficial effects of the present invention are: The present invention discloses a method for producing marbled beef through seasonal short-term fattening of yaks; the method belongs to the field of animal husbandry. The present invention realizes efficient output of yak marbled beef through short-term seasonal fattening by selecting fattening yaks, selecting fattening season and time, and coordinating diets in the early and late fattening stages. The core of the present invention is to adopt a high-energy, low-fiber diet in the early fattening stage, and to adopt a soybean meal-free, low-protein diet in the late fattening stage to synergistically promote yak intramuscular fat deposition, thereby realizing efficient output of yak marbled beef. The production of marbled beef by yaks is of great significance for improving the economic benefits of yak breeding in plateau pastoral areas and meeting the demand for high-quality beef in the Chinese market. The fattening method of the present invention does not reduce the meat production performance of the yak, but also increases the intramuscular fat content and essential fatty acid content of yak beef, thereby improving the nutritional value of the beef. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. The drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0017] Figure 1 This is a cross-sectional view of the marble pattern on the yak upper brain in Example 1 of the present invention; Figure 2 This is a cross-sectional view of the marble pattern on the yak upper brain in Comparative Example 1 of the present invention; Figure 3 This is a cross-sectional view of the marble pattern on the yak upper brain in Comparative Example 2 of the present invention; Figure 4 This is a cross-sectional view of the marble pattern on the yak upper brain in Comparative Example 3 of the present invention; Figure 5 This is a cross-sectional view of the marbled pattern on the yak upper brain in Comparative Example 4 of the present invention; Figure 6 This is a cross-sectional view of the marble pattern on the yak upper brain in Comparative Example 5 of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0020] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations and / or combinations thereof.

[0021] Example 1: (Early fattening period: high energy and low fiber diet, late fattening period: low protein diet without soybean meal) The method for producing marbled beef by seasonal short-term fattening of yaks comprises the following steps: Step 1: Selection of fattening yaks We selected 3-4 year old eliminated female yaks with a rectangular body shape, deep chest, broad hindquarters, big and bright eyes, solid hooves and short and thick necks, weighing 200 kg, a total of 15 heads.

[0022] Step 2: Fattening season and time selection In the plateau area, yaks are fattened in sheds starting in June during the warm season and are slaughtered around December during the cold season. The fattening period is 6 months.

[0023] Step 3: Fattening program and diet composition Fattening began in May. For the first three months, yaks were fed a TMR diet and had free access to water. The TMR diet in the early fattening period consisted of: 37.80% corn, 8.40% wheat bran, 4.14% soybean meal, 4.80% rapeseed meal, 0.30% salt, 0.60% baking soda, 0.30% calcium carbonate, 0.06% Angel active yeast, 0.6% soybean oil, 3.0% feeder premix, and 40% oat hay. The nutritional profile of the TMR diet in the early fattening period was: 4.4 MJ / kg net energy for weight gain, 11.87% crude protein, 37.30% neutral detergent fiber, 18.95% acid detergent fiber, 0.56% calcium, and 0.49% phosphorus.

[0024] During the last three months of fattening, yaks were fed a TMR diet with free access to water. The TMR diet consisted of 43.55% corn, 12.87% wheat bran, 4.55% rapeseed meal, 0.13% calcium bicarbonate, 35.00% oat hay, 0.65% soybean oil, and 3.25% premix. The nutritional levels of the TMR diet were 10.04% crude protein, 4.92 MJ / kg net energy per kg gain, 30.38% neutral detergent fiber, 17.08% acid detergent fiber, 0.64% calcium, and 0.40% phosphorus.

[0025] Step 4: Feeding and Management First, the selected cattle were quarantined for 10 to 15 days and their health was observed. They were also quarantined for diseases such as brucellosis and tuberculosis; sick cattle were culled. Next, the fattening cattle were dewormed with trichlorfon (1g / 100kg body weight). Three days after deworming, they were given Jianwei San (500g) orally once daily for three consecutive days.

[0026] Before fattening, after a 14-day acclimatization period, the feed was gradually changed. During the fattening period, feeding was conducted at 8:00 AM and 4:00 PM daily. Before feeding, the corresponding fattening ration was mixed evenly according to the formula ratio to make a total mixed ration (TMR). The yaks were given free access to food and water, ensuring that approximately 5% of the feed was leftover after each feeding. Forage was cut short and cleaned, and foreign objects such as nails and plastic were strictly prohibited. The yaks were ensured to have sufficient and clean water. Daily cleaning of the cattle's beds, troughs, and water troughs was performed, and manure was removed.

[0027] When the yak's feed intake decreases, its back becomes wide and flat, its bone tubercles are not obvious, its ribs are fat, and its body is barrel-shaped, it can be slaughtered.

[0028] Step 5: Slaughter test After the two fattening stages, 7 yaks were selected from the yaks obtained in Example 1 for slaughter. The live yaks were fasted for 12 hours before slaughter and had free access to water until 3 hours before slaughter. The slaughter method was in accordance with the "GB / T19477-2018 Cattle Slaughtering Operating Procedures". The slaughter performance was determined in accordance with the "NY / T 2660-2014 Technical Specifications for the Determination of Beef Cattle Production Performance": Live weight before slaughter: The live weight before slaughter is measured using an electronic floor scale.

[0029] Carcass weight: The cattle are slaughtered and bled, and then weighed after the skin, head, hooves, tail, internal organs and genitals are removed.

[0030] Dressing rate: Dressing rate = carcass weight / pre-slaughter weight × 100% Net meat weight: the total meat weight after the carcass is deboned.

[0031] Net meat rate: Net meat rate = net meat weight / weight before slaughter × 100% Bone weight: After the carcass is deboned, weigh all the bones. The amount of meat on the bones should not exceed 2kg-3kg.

[0032] Meat-to-bone ratio: Meat-to-bone ratio = net meat weight / bone weight Backfat thickness: Use a backfat meter and press the probe vertically 5 cm below the spine between the 12th and 13th ribs to measure.

[0033] Step 6: Muscle sensory index measurement Flesh color, pH 24hThe muscle sensory level of the cattle is comprehensively assessed based on the indexes such as tenderness, shear force (tenderness), and water holding capacity.

[0034] (1) Meat color: Use a meat sample with a thickness of about 1 cm to select three evenly distributed measurement points on the diagonal on both sides, and use a colorimeter to measure the color of each measurement point. L *(brightness), a *(redness), b * (yellowness) value, then read the data directly, repeat the measurement 3 times for each test point, and take the average value after measurement as the final value of the sample L *(brightness), a *(redness), b *(Yellowness) value.

[0035] (2) pH 24h pH value: Refer to NY / T 1333-2007 "Determination of Meat Quality of Livestock and Poultry". Make an incision along the muscle fiber direction in the cross-sectional area of ​​the muscle. Insert the pH meter electrode into the incision so that the meat sample completely covers the probe. Read the value after it stabilizes. Take three measurement points for each sample and take the average.

[0036] (3) Water retention: Refer to the method of NY / T 1333-2007 "Determination of Meat Quality of Livestock and Poultry", take a 3 cm × 3 cm × 1 cm piece of meat, weigh it (W1), place 10 layers of absorbent filter paper on the top and bottom of the meat sample, apply 35 kg of pressure on the pressure platform of the pressure instrument, keep it for 5 minutes, then remove it, and then weigh the weight of the meat sample after compression (W2). A represents the water content in the original muscle.

[0037] Water holding capacity (%) Step 7: Determination of longissimus dorsi muscle nutrient composition index (1) Determination of moisture The Petri dish was weighed (W1), and about 60 g of meat sample was cut and weighed (m). The rest was returned to the original ziplock bag and stored at -20°C. The meat sample was minced and placed in a Petri dish, which was placed in a freeze dryer (FDU2110, EYELA, Japan) for 48 h. After thawing at room temperature for 24 h, it was weighed (W2) and stored in a ziplock bag for routine sample fraction determination.

[0038] Moisture (%) =

[0039] (2) Determination of crude protein Protein was determined using the Kjeldahl method as described in GB 5009.5—2016, "Determination of Protein in Foods." A 0.3 g sample of freeze-dried meat was weighed to the nearest 0.001 g and placed in a digestion tube. 0.4 g of copper sulfate, 6 g of potassium sulfate, and 20 mL of sulfuric acid were added and digested in a digestion oven. After cooling, the sample was analyzed using an automatic Kjeldahl nitrogen analyzer (KJELTEC 8420, FOSS, Denmark). Protein content was calculated based on acid consumption.

[0040] Protein content (%) =

[0041] Where: V 1 : The volume of sulfuric acid standard titrant consumed by the sample, in milliliters (mL); V 2 : Blank, unit is milliliter (mL); c : The concentration of sulfuric acid standard titrant, in moles per liter (mol / L); m : Sample weight, in grams (g); (3) Determination of muscle fat Determine muscle fat using the Soxhlet extraction method described in GB 5009.6-2016, "Determination of Fat in Foods." Weigh 0.5 g of freeze-dried sample (m) into a filter paper bag to the nearest 0.001 g. Place the sample in a constant-temperature drying oven and weigh it to a constant weight (W1). Extract the sample using the Soxhlet extraction method until the weight is constant (W2). Perform three replicates for each sample.

[0042] Fat content (%) =

[0043] Step 8: Determination of muscle nutritional fatty acid composition A 0.2 g longissimus dorsi muscle sample was weighed and homogenized using a cryogenic tissue grinder. Lipids were extracted with 3 mL of a chloroform-methanol-water (8:4:3, volume ratio) mixture, centrifuged at 1500 rpm for 5 min at 4°C, and dried in a vacuum oven to obtain a fatty acid glyceride mixture. Then, 2 mL of KOH-CH3OH (c = 0.5 mol / L) was added and the mixture was reacted in a 50°C water bath for 10 min to complete saponification and obtain a free fatty acid mixture. After cooling for 3 min, 2 mL of BF3-CH3OH solution (w = 14%) was added and the mixture was heated under reflux at 80°C for 2 min to complete methyl esterification. After cooling to room temperature, 1 mL of n-hexane (0.05 g / L BHT in n-hexane) and 2 mL of saturated sodium chloride solution were added and centrifuged at 1000 rpm for 5 min at room temperature. The upper n-hexane layer (at least 600 μL) was aspirated into a sample vial and analyzed for muscle fatty acid content using a gas chromatograph (GC-2010plus).

[0044] Comparative Example 1: (Early fattening period: low-energy, high-fiber diet; late fattening period: soybean meal, high-protein diet) Taking Example 1 as a benchmark, only the diets in the early fattening stage and the late fattening stage are different from those in Example 1, and the other steps are completely consistent with those in Example 1.

[0045] Difference: Fattening process and diet composition For the first three months of the fattening period, yaks were fed a TMR diet and had free access to water. The TMR diet in the early fattening period consisted of: 21.60% corn, 7.6% wheat bran, 3.8% soybean meal, 3.8% rapeseed meal, 0.40% salt, 0.32% baking soda, 0.24% calcium carbonate, 0.12% calcium hydrogen phosphate, 0.04% Angel active yeast, 0.08% soybean oil, 2.0% feeder premix, and 60% oat hay. The nutritional profile of the TMR diet in the early fattening period was: 3.4 MJ / kg net energy per kilogram, 11.83% crude protein, 50.53% neutral detergent fiber, 28.65% acid detergent fiber, 0.50% calcium, and 0.48% phosphorus.

[0046] During the last three months of fattening, yaks were fed a TMR diet with free access to water. The TMR diet consisted of 38.03% corn, 7.80% wheat bran, 8.45% soybean meal, 6.83% rapeseed meal, 0.65% soybean oil, 35.00% oat hay, and 3.25% premix. The nutritional levels of the TMR diet were 13.50% crude protein, 4.92 MJ / kg net energy per weight gain, 29.47% neutral detergent fiber, 17.25% acid detergent fiber, 0.65% calcium, and 0.40% phosphorus.

[0047] Comparative Example 2: (Early fattening period: low-energy, high-fiber diet; late fattening period: low-protein diet without soybean meal) Taking Example 1 as a benchmark, only the diet in the early fattening stage was different from that in Example 1, and other steps such as the diet in the late fattening stage were completely consistent with those in Example 1.

[0048] Difference: Fattening process and diet composition For the first three months of the fattening period, yaks were fed a TMR diet and had free access to water. The TMR diet in the early fattening period consisted of: 21.60% corn, 7.6% wheat bran, 3.8% soybean meal, 3.8% rapeseed meal, 0.40% salt, 0.32% baking soda, 0.24% calcium carbonate, 0.12% calcium hydrogen phosphate, 0.04% Angel active yeast, 0.08% soybean oil, 2.0% feeder premix, and 60% oat hay. The nutritional profile of the TMR diet in the early fattening period was: 3.4 MJ / kg net energy per kilogram, 11.83% crude protein, 50.53% neutral detergent fiber, 28.65% acid detergent fiber, 0.50% calcium, and 0.48% phosphorus.

[0049] Comparative Example 3: (Early fattening period: high energy and low fiber diet, late fattening period: soybean meal and high protein diet) Taking Example 1 as a benchmark, only the diet in the late fattening period was different from that in Example 1, and other steps such as the diet in the early fattening period were completely consistent with those in Example 1.

[0050] Difference: Fattening process and diet composition During the last three months of fattening, yaks were fed a TMR diet with free access to water. The TMR diet consisted of 38.03% corn, 7.80% wheat bran, 8.45% soybean meal, 6.83% rapeseed meal, 0.65% soybean oil, 35.00% oat hay, and 3.25% premix. The nutritional levels of the TMR diet were 13.50% crude protein, 4.92 MJ / kg net energy per weight gain, 29.47% neutral detergent fiber, 17.25% acid detergent fiber, 0.65% calcium, and 0.40% phosphorus.

[0051] Comparative Example 4: (different fattening periods) Taking Example 1 as a benchmark, only the fattening season selection is different from Example 1, and the other steps are completely consistent with Example 1.

[0052] Difference: Fattening season and time selection: In the plateau area, yaks are fattened in sheds starting in December during the cold season and are slaughtered around June during the warm season. The fattening period is 6 months.

[0053] Comparative Example 5: (Different fattening procedures) Taking Example 1 as a benchmark, only the time selection of the early fattening stage and the late fattening stage is different from that of Example 1, and the other steps are completely consistent with those of Example 1.

[0054] Difference: Fattening procedure: Fattening starts in May, the first 4.5 months of fattening period, and the last 1.5 months of fattening period.

[0055] The yak parameters in Example 1 and Comparative Examples 1-5 were evaluated: Table 1 shows the average slaughter performance of 7 yaks in Comparative Examples 1-5 and Example 1. The results of Example 1 show that the live weight, carcass weight, slaughter rate and backfat thickness of the beef cattle obtained by the method of the present invention did not change significantly compared with the comparative example.

[0056] Table 1 Average slaughter performance of 7 yaks

[0057] Table 2 shows the nutritional components of the longissimus dorsi muscles of 7 yaks in Comparative Examples 1-5 and Example 1. The fat content of the longissimus dorsi muscles of the beef cattle in the examples of the method of the present invention was significantly increased, by 471.89%, 323.20%, 139.37%, 624.66% and 226.54% respectively compared with the comparative examples.

[0058] Table 2 Average nutritional composition of the longissimus dorsi muscle of 7 yaks (dry matter basis)

[0059] Table 3 shows the average fatty acid composition of the longissimus dorsi muscles of seven yaks from Comparative Examples 1-5 and the Example. The Example treatment reduced the saturated fatty acid (SFA) content in the longissimus dorsi muscles of yaks by 4.51%, 3.32%, 3.10%, 3.80%, and 3.18% compared to Comparative Examples 1-5, while increasing the monounsaturated fatty acid (MUFA) content by 11.57%, 10.54%, 10.32%, 10.43%, and 10.37%, respectively. Furthermore, the content of essential polyunsaturated fatty acids (PUFAs), such as α-linolenic acid (C18:3n3), EPA (C20:5n3), DHA (C22:6n3), linoleic acid (C18:2n6), and arachidonic acid (C20:4n6), was also increased. This demonstrates that the Example treatment significantly improved the fatty acid composition of the longissimus dorsi muscles of beef cattle by adjusting the nutritional strategy.

[0060] Table 3 Average fatty acid composition of longissimus dorsi muscle of 7 yaks (%)

[0061] It can be seen that the fattening method of the present invention does not reduce the meat production performance of yaks, but also increases the intramuscular fat content and essential fatty acid content of yak beef, thereby improving the nutritional value of beef.

[0062] like Figures 1-6As shown, the marbled cross-sections of the yak upper brain in Example 1 and Comparative Examples 1-5 show that the fat content of the marbled beef in Example 1 is significantly increased, which is significantly different from that of the comparative examples.

[0063] It also verifies that the core of the present invention is to use a high-energy, low-fiber diet in the early fattening stage, combined with a soybean meal-free, low-protein diet in the late fattening stage to synergistically promote the deposition of intramuscular fat in yaks, thereby achieving efficient production of marbled beef.

[0064] In summary, the present invention discloses a method for producing marbled beef by seasonal short-term fattening of yaks; it belongs to the field of animal husbandry. The present invention realizes efficient output of yak marbled beef through short-term seasonal fattening by selecting fattening yaks, selecting fattening season and time, and coordinating diets in the early and late fattening stages. The core of the present invention is to adopt a high-energy, low-fiber diet in the early fattening stage, and to adopt a soybean meal-free, low-protein diet in the late fattening stage to synergistically promote the deposition of intramuscular fat in the yak, thereby realizing efficient output of yak marbled beef. The production of marbled beef by yaks is of great significance for improving the economic benefits of yak farming in plateau pastoral areas and meeting the demand for high-quality beef in the Chinese market.

[0065] At this point, those skilled in the art will recognize that, although the embodiments of the present invention have been shown and described in detail herein, many other variations or modifications consistent with the principles of the present invention may be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims

1. A method for producing marbled beef by seasonal short-term fattening of yaks, characterized in that: The method comprises the following steps: Step S1: Selection of fattening yaks Select 2-2.5 year old castrated male yaks or 3-4 year old culled female yaks with rectangular body, deep chest, broad hindquarters, large and bright eyes, solid hooves and short and thick neck; Step S2: Fattening season and time selection In the plateau region, yaks are fattened in sheds from May to July during the warm season and are marketed from November to December during the cold season. The fattening period is 5-6 months. Step S3: Fattening procedure and diet composition 1. Early stage of fattening: The mass proportions of the raw materials in the high-energy, low-fiber diet are as follows: corn 30.0-40.0%, wheat bran 7.0-9.0%, soybean meal 4.0-4.5%, rapeseed meal 4.0-6.0%, salt 0.2-0.4%, baking soda 0.6-1.0%, calcium carbonate 0.2-0.4%, Angel active yeast 0.05-0.10%, soybean oil 0.5-0.8%, fattening cattle premix 2.0-3.0%, oat hay 30.0-50.0%; the nutritional level of the high-energy, low-fiber diet is: net energy for weight gain 4.0-5.0 MJ / kg, crude protein 11.0-12.0%, neutral detergent fiber 30.0-40.0%, acid detergent fiber 15.0-20.00%, calcium 0.40-0.60%, phosphorus 0.40-0.60%; 2. Late fattening period: The mass proportions of the raw materials in the soybean meal-free low-protein diet are: corn 42.0-45.0%, wheat bran 10.0-14.0%, rapeseed meal 4.0-5.0%, calcium bicarbonate 0.10-0.15%, soybean oil 0.60-0.90%, oat hay 32-37%, and fattening cattle premix 3.0-3.5%; the nutritional level of the soybean meal-free low-protein diet is: crude protein 9.0-11.0%, net energy for weight gain 4.8-5.0 MJ / kg, neutral detergent fiber 29.0-33.0%, acid detergent fiber 16.0-18.0%, calcium 0.4-0.7%, and phosphorus 0.3-0.5%; Step S4: Feeding and management First, the yaks selected in step S1 are isolated for 10-15 days and their health status is observed. At the same time, they are quarantined for diseases such as brucellosis and tuberculosis. Sick yaks are eliminated. Second, the fattening yaks are dewormed with trichlorfon. Three days after deworming, they are gavage-administered with Jianwei Powder, 500g / each time, once a day for three consecutive days. Before fattening, after a 10-14 day adaptation period, the feed was gradually changed. During the fattening feeding period, the yaks were fed at 08:00 and 16:00 every day. Before feeding, the corresponding fattening diet was mixed evenly according to the formula ratio to make a complete mixed diet, and then fed. The yaks had free access to food and water, and ensured that 3-8% of the feed was left over after eating. The forage was cut short and picked clean, and foreign objects such as nails and plastic were strictly prohibited. The yaks were ensured to have sufficient and clean water sources. The cattle beds, cattle troughs, and water troughs were cleaned and manure was removed every day. When the yak's feed intake decreases, its back becomes wide and flat, its bone tubercles are not obvious, its ribs are fat, and its body is barrel-shaped, it can be slaughtered.

2. The method for producing marbled beef by seasonal short-term fattening of yaks as claimed in claim 1, characterized in that: The fattening yaks in step S1 weigh 180-220 kg.

3. The method for producing marbled beef by seasonal short-term fattening of yaks as claimed in claim 1, characterized in that: The dosage of trichlorfon for fattening cattle in step S4 is: 1 g / 100 kg body weight.

4. The method for producing marbled beef by seasonal short-term fattening of yaks as claimed in claim 1, characterized in that: The mass ratio of each raw material in the high-energy, low-fiber diet in the early fattening stage in step S3 is: Corn 37.80%, wheat bran 8.40%, soybean meal 4.14%, rapeseed meal 4.80%, salt 0.30%, baking soda 0.60%, calcium carbonate 0.30%, Angel active yeast 0.06%, soybean oil 0.6%, fattening cattle premix 3.0%, oat hay 40%; the nutritional level of the high-energy, low-fiber diet in the early fattening stage in step S3 is: net energy for weight gain 4.4 MJ / kg, crude protein content 11.87%, neutral detergent fiber content 37.30%, acid detergent fiber content 18.95%, calcium 0.56%, and phosphorus 0.49%.

5. The method for producing marbled beef by seasonal short-term fattening of yaks as claimed in claim 1, characterized in that: In step S3, the mass ratio of each raw material in the low-protein diet without soybean meal in the late fattening period is: 43.55% corn, 12.87% wheat bran, 4.55% rapeseed meal, 0.13% calcium bicarbonate, 35.00% oat hay, 0.65% soybean oil, and 3.25% premix; the nutritional level of the soybean meal-free low-protein diet in the late fattening period in step S3 is: crude protein 10.04%, net energy for weight gain 4.92 MJ / kg, neutral detergent fiber 30.38%, acid detergent fiber 17.08%, calcium 0.64%, and phosphorus 0.40%.

6. The method for producing marbled beef by seasonal short-term fattening of yaks as claimed in claim 1, characterized in that: The early fattening period in step S3 is 3 months.

7. The method for producing marbled beef by seasonal short-term fattening of yaks as claimed in claim 1, characterized in that: The late fattening period in step S3 is 2-3 months.

8. The method for producing marbled beef by seasonal short-term fattening of yaks as claimed in claim 1, characterized in that: The formula of the fattening early stage cattle premix is: Each 100kg premix contains VA: 12000000-20000000IU, VE: 75000IU, VK3: 1000mg, VB1: 1000mg, VB2: 2800mg, VB 12 : 10000μg, VD3: 3000000-5000000IU, niacin: 20g, pantothenic acid: 5g, selenium: 200-1000mg, iron: 80-400g, copper: 10-60g, sodium chloride: 5-40kg, biotin: 200mg, folic acid: 400mg, iodine: 500-2800mg, zinc: 50-240g, manganese: 70-300g, magnesium: 400-3000g, VB6: 1g, cobalt: 100-700mg, phosphorus: 200-4500g, calcium: 1-25kg, lysine: 1kg, and the rest are water and a carrier, and the carrier is bran powder or zeolite powder.

9. The method for producing marbled beef by seasonal short-term fattening of yaks as claimed in claim 1, characterized in that: The formula of the fattening late stage cattle premix is: Every 100kg of premix contains 0.513kg of ferrous sulfate, 0.098kg of copper sulfate, 0.194kg of manganese sulfate, 0.268kg of zinc sulfate, 0.068kg of sodium selenite, 0.048kg of calcium iodate, 0.038kg of cobalt chloride, 1.000kg of multivitamins, 28.000kg of baking soda, 4.500kg of calcium hydrogen phosphate, 29.000kg of table salt, 2.000kg of Angel ruminant yeast, and 34.273kg of CaCO3 carrier.

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