A breeding method for dual-purpose (wool and meat) semi-fine wool sheep suitable for cold environments.

Abstract

This invention relates to the field of livestock genetics and breeding, and discloses a method for breeding a dual-purpose (wool and meat) semi-fine wool sheep suitable for high-altitude and cold environments. The method involves using local Tibetan sheep breeds from the river valleys of the Shigatse agricultural area as the maternal line, and crossing them with Tsigai sheep, Romni sheep, and Leicester sheep from the border region to obtain Tsigai, Romni, and border Tibetan hybrid sheep. Then, Tsigai is crossed with Romni to obtain Tsigai-Romni hybrid sheep, and Romni is crossed with border Tibetan to obtain border-Romni hybrid sheep. Tsigai-Romni hybrid sheep are then crossed with border-Romni hybrid sheep to obtain border-Tsigai-Romni hybrid sheep with a wool fineness of 46–52 count. Subsequently, using border-Tsigai-Romni hybrid sheep as the maternal line and Xinjiang fine wool sheep as the paternal line, a semi-fine wool sheep F0 generation with a wool fineness of 54–58 count is obtained. After crossbreeding and continuous generation selection from F0 to F5, a dual-purpose (wool and meat) semi-fine wool sheep breed with a wool fineness of 56–58 count and a consistent phenotype is obtained. This invention can preserve the high-altitude adaptability of Tibetan sheep while taking into account wool fineness, body shape, and meat performance.

Description

Technical Field

[0001] This invention relates to the field of livestock genetics and breeding technology, and in particular to a method for breeding a dual-purpose (wool and meat) semi-fine wool sheep suitable for cold environments. Background Technology

[0002] The Tibet Autonomous Region and similar high-altitude agro-pastoral transitional areas are characterized by high altitudes, large diurnal temperature variations, and significant seasonal fluctuations in forage resources. This places high demands on sheep breeds' environmental adaptability, tolerance to roughage, disease resistance, growth rate, and production performance. The valley-type Tibetan sheep of the Shigatse agricultural region are a local breed developed through long-term domestication, possessing a certain degree of high-altitude adaptability and tolerance to roughage, and are able to adapt to the local climate, feeding management, and grassland resources. However, this breed also suffers from relatively small body size, slow growth rate, long fattening period, and limited potential for improvement in meat and wool performance, making it difficult to fully meet the needs of improving the quality and efficiency of animal husbandry and increasing farmers' income in high-altitude agricultural areas.

[0003] Semi-fine wool sheep possess both wool and meat production value. Their wool can be used in textile products such as carpets, curtains, quilts, and felt products, while their meat quality directly impacts breeding profitability. To improve the overall production performance of local sheep breeds, current techniques typically involve introducing exotic sheep breeds for crossbreeding with local sheep to improve offspring physique, growth rate, wool fineness, wool length, and meat quality. For example, breeds such as the Cige sheep, Romney sheep, Border Leicester sheep, and Xinjiang fine wool sheep each possess unique characteristics in terms of physique, growth, and wool or meat traits, and can serve as genetic sources for improving local sheep breeds.

[0004] However, sheep breeding in high-altitude regions cannot simply replicate the crossbreeding improvement models used in low-altitude areas. On the one hand, excessively pursuing individual physique or growth rate may result in offspring with insufficient adaptability to high-altitude, low-oxygen, and extensive feeding conditions. On the other hand, merely retaining the adaptive advantages of local Tibetan sheep makes it difficult to significantly improve wool fineness, shearing yield, and meat performance. Furthermore, some existing crossbreeding improvement methods only involve the introduction of a single sire or simple binary or ternary crossbreeding, lacking a systematic breeding path that combines phased improvements in physique, growth, wool quality, and meat performance. They also lack technical measures to stably maintain target wool fineness and phenotypic consistency across generations. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a breeding method for a dual-purpose (wool and meat) semi-fine wool sheep suitable for high-altitude and cold environments. This method aims to obtain a semi-fine wool sheep breed that is moderately sized, highly adaptable, fast-growing, with stable wool fineness, and possesses both wool and meat value. This method is achieved by multi-breed staged crossbreeding, constructing composite crossbreeding populations, introducing target fineness, crossbreeding fixation, and continuous generational selection. This solves the problems of existing local sheep in high-altitude and cold regions having relatively small body size, slow growth rate, long slaughter cycle, difficulty in achieving both wool fineness and meat performance, and insufficient trait stability in offspring obtained through simple crossbreeding.

[0006] The present invention solves the above-mentioned technical problems through the following technical means: This invention provides a method for breeding dual-purpose (wool and meat) semi-fine wool sheep suitable for cold environments, comprising the following steps: S1. Using the local Tibetan sheep breed of the river valley type in the Shigatse agricultural area as the maternal line, and using Tsigai sheep, Romni sheep and border area Leicester sheep as the paternal line respectively, crossbreeding was carried out to obtain Tsigai-Tibetan hybrid sheep, Romni-Tibetan hybrid sheep and border-Tibetan hybrid sheep; S2. Crossbreed the Cizang hybrid sheep with the Luozang hybrid sheep to obtain the Ciluozang hybrid sheep; crossbreed the Luozang hybrid sheep with the Bianzang hybrid sheep to obtain the Bianluozang hybrid sheep; S3. Crossbreed the Tsilozang crossbred sheep with the Bianluozang crossbred sheep to obtain the Biantsilozang crossbred sheep with a wool fineness of 46-52 count; S4. Crossbreeding with Bianciluozang crossbred sheep as the female parent and Xinjiang fine wool sheep as the male parent to obtain the F0 generation of semi-fine wool sheep with a wool fineness of 54-58 count; S5. The semi-fine wool sheep F0 generation is cross-fixed and continuously selected for generations up to the F5 generation to obtain semi-fine wool sheep with a wool fineness of 56-58 count; S6. Continue to breed semi-fine wool sheep with wool fineness of 56-58 count to obtain a dual-purpose semi-fine wool sheep breed with consistent phenotype.

[0007] Preferably, the ewes among the Tszang-Tibetan hybrid sheep, Lozang-Tibetan hybrid sheep, and Border-Tibetan hybrid sheep obtained in step S1 meet the following conditions: Birth weight is over 2.2kg, weaning weight at three months of age is over 5.25kg, and adult ewe weight is 32-35kg; The head is white or has some brownish-yellow hair, the coat is white, the back and loin are straight, the body is medium-sized, there are no horns, the head is narrow and long, the neck is slender and long, the body is narrow and long, and the limbs are thin and long.

[0008] Preferably, in step S2, the crossbreeding of Cizang hybrid sheep and Luozang hybrid sheep includes crossbreeding Cizang hybrid sheep rams with Luozang hybrid sheep ewes, and / or crossbreeding Cizang hybrid sheep ewes with Luozang hybrid sheep rams.

[0009] Preferably, in step S2, the crossbreeding of Luozang hybrid sheep and Bianzang hybrid sheep includes crossbreeding of Luozang hybrid sheep rams and Bianzang hybrid sheep ewes, and / or crossbreeding of Luozang hybrid sheep ewes and Bianzang hybrid sheep rams.

[0010] Preferably, in step S3, the crossbreeding of Tsering crossbred sheep and Bianluozang crossbred sheep includes crossbreeding a Tsering crossbred ram with a Bianluozang crossbred ewe, and / or crossbreeding a Tsering crossbred ewe with a Bianluozang crossbred ram.

[0011] Preferably, in step S4, before using the Bianciluozang hybrid sheep as the maternal parent, the horn type genotype of the Bianciluozang hybrid sheep maternal parent is tested, and individuals with the horn type genotype pp are selected as the maternal parent and crossbred with the Xinjiang fine wool sheep paternal parent.

[0012] Preferably, in step S5, during the cross-fixation process of the semi-fine wool sheep from generation F0 to generation F5, each generation is selected for breeding based on the fineness of the wool, and individuals with a wool fineness of 56-58 counts are selected to enter the next generation for breeding.

[0013] Preferably, during the breeding of this breed in step S6, the growth performance of candidate semi-fine wool sheep individuals is measured, and they are selected for breeding according to the following growth performance indicators: The average birth weight of male lambs was 2.60 kg, and the average birth weight of female lambs was 2.30 kg. The average weaning weight of male lambs was 6.35 kg, and the average weaning weight of female lambs was 5.25 kg. The average weight of rams at six months of age was 15.80 kg, and the average weight of ewes at six months of age was 13.84 kg. The average weight of adult rams is 45.50 kg, and the average weight of adult ewes is 33.80 kg.

[0014] Preferably, during the breeding of this breed in step S6, the wool performance of candidate semi-fine wool sheep individuals is measured, and they are selected for breeding according to the following wool performance indicators: The wool yield of adult rams is 3.0-3.75 kg / year, and the wool yield of adult ewes is 2.45-2.89 kg / year. The wool has a fineness of 56-58 count, a clean wool yield of ≥64.21%, and a pure white wool color rate of ≥92.75%.

[0015] Preferably, the semi-fine wool sheep are raised by grazing during the day and supplementing with feed at night, with the ambient temperature in the pen not lower than 0°C and the humidity at 30%-50% at night; Nighttime supplementary feeding includes supplementary concentrate and supplementary silage. Specifically, supplementary concentrate should be given at a rate of 200-250g per animal two hours after the animals are brought into the pen. The silage comprises the following components in parts by weight: 70-75 parts corn stalks and 25-30 parts alfalfa.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: 1. This invention uses the local Tibetan sheep breed of the river valley type in the Shigatse agricultural area as the basic maternal line, which can preserve the local sheep's adaptability to high-altitude and cold environments, extensive feeding conditions and local forage resources, and avoid the problem of decreased adaptability to high-altitude and cold environments that may occur after simply introducing foreign breeds.

[0017] 2. This invention crossbreeds Tsogai sheep, Romney sheep, and Border Leicester sheep with local Tibetan sheep, and further conducts Tsogai, Border Romney, and Border Tsogai complex crossbreeding to form an intermediate crossbreed population with multiple breed genetic backgrounds, which is beneficial for comprehensive selection among body shape, growth, wool and meat traits.

[0018] 3. This invention uses the Bianciluozang crossbred sheep with a wool fineness of 46-52 count as the maternal parent and introduces Xinjiang fine wool sheep as the paternal parent to obtain the F0 generation of semi-fine wool sheep with a wool fineness of 54-58 count. It can further improve the wool fineness on the basis of a complex genetic background, laying the foundation for obtaining a core population of 56-58 count semi-fine wool sheep.

[0019] 4. This invention stabilizes the target wool fineness and body shape traits through cross-linking fixation from F0 to F5 generations and continuous generational selection, and further carries out the selection and improvement of this breed, ultimately obtaining a semi-fine wool sheep breed with consistent phenotype, stable wool fineness, both wool and meat value, and suitable for raising in high-altitude and cold environments. Attached Figure Description

[0020] Figure 1 This is a breeding roadmap for the breeding method of dual-purpose (wool and meat) semi-fine wool sheep suitable for cold environments according to the present invention. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. It should be understood that the following embodiments are only used to illustrate the present invention and are not intended to limit the scope of protection of the present invention. All equivalent substitutions or conventional adjustments made based on the technical concept disclosed in the present invention should be included within the scope of protection of the present invention.

[0022] Example 1 This embodiment provides a method for breeding dual-purpose (wool and meat) semi-fine wool sheep suitable for cold environments, specifically including the following steps: S1. Select the local Tibetan sheep breed from the valley type in the Shigatse agricultural area as the base maternal population, and crossbreed them with Tsigai sheep, Romni sheep, and Leicester sheep from the border region. Specifically, 20,000 Tibetan sheep ewes from the valley type in the Shigatse agricultural area were crossbred with Tsigai sheep sires to obtain 16,000 Tsigai-Tibetan crossbred sheep; 20,000 Tibetan sheep ewes from the valley type in the Shigatse agricultural area were crossbred with Romni sheep sires to obtain 16,000 Romni-Tibetan crossbred sheep; and 20,000 Tibetan sheep ewes from the valley type in the Shigatse agricultural area were crossbred with Leicester sheep sires from the border region to obtain 16,000 border-Tibetan crossbred sheep.

[0023] S2. Crossbreed the Cizang hybrid sheep with the Luozang hybrid sheep to obtain Cilu-Luozang hybrid sheep. Specifically, 7,000 Cizang hybrid rams are crossbred with 7,000 Luozang hybrid ewes, and / or 7,000 Cizang hybrid ewes are crossbred with 7,000 Luozang hybrid rams, resulting in 12,000 Cilu-Luozang hybrid sheep. Before crossbreeding or during breeding, the horn genotype of the maternal line is tested, and individuals with the horn genotype pp are selected for reproduction.

[0024] S3. Crossbreed the Lozang hybrid sheep with the Border-Zang hybrid sheep to obtain Border-Lozang hybrid sheep. Specifically, crossbreed 7,000 Lozang hybrid rams with 7,000 Border-Zang hybrid ewes, and / or crossbreed 7,000 Lozang hybrid ewes with 7,000 Border-Zang hybrid rams to obtain 12,000 Border-Lozang hybrid sheep. Before crossbreeding or when selecting breeding stock, the horn type genotype of the maternal line is tested, and individuals with the horn type genotype pp are selected for breeding.

[0025] S4. Crossbreed Tsering crossbred sheep with Bianluozang crossbred sheep to obtain Bian-Tsering crossbred sheep. Specifically, crossbreed 7,000 Tsering crossbred rams with 7,000 Bianluozang crossbred ewes, and / or crossbreed 7,000 Tsering crossbred ewes with Bianluozang crossbred rams to obtain 12,000 Bian-Tsering crossbred sheep. The wool fineness of the obtained Bian-Tsering crossbred sheep is 46-52 count.

[0026] S5. Crossbreeding was carried out using Bianciluozang crossbred sheep as the maternal parent and Xinjiang fine-wool sheep as the paternal parent. Specifically, 11,000 Bianciluozang crossbred sheep were selected as the maternal parent, and the horn type genotype of the maternal parent was tested. Individuals with the horn type genotype pp were selected as the maternal parent and crossed with Xinjiang fine-wool sheep as the paternal parent to obtain 5,000 semi-fine-wool sheep of generation F0 with a wool fineness of 54-58 count.

[0027] S6. Crossbreed and fix the F0 generation of semi-fine wool sheep and continuously select and breed them up to the F5 generation. During the selection process from the F0 to the F5 generation, the wool fineness of each generation was measured. Individuals with a wool fineness of 56-58 count were selected to enter the next generation for breeding. Combined with body shape, wool, adaptability and production performance, a comprehensive selection was made to obtain a core population of 800 semi-fine wool sheep with wool fineness mainly of 56-58 count.

[0028] S7. Continue to select and improve the breed of semi-fine wool sheep with a wool fineness of 56-58 count, and obtain 20,000 dual-purpose semi-fine wool sheep with consistent phenotype and wool fineness of 56-58 count.

[0029] The resulting semi-fine wool sheep are a dual-purpose breed, tolerant of roughage, highly disease-resistant, fast-growing, with excellent wool quality and good meat performance. They are medium-sized, well-proportioned, with a moderate head, flat forehead, short neck, cylindrical body, rectangular profile, well-sprung ribs, straight back and loin, full hindquarters, long, slender tail, thin limbs, short legs, upright stance, and white or waxy yellow hooves. The face is smooth, with some individuals having brown hair on the face. The ears are small and erect, the bridge of the nose is prominent, and the nose is white. The skin under the neck has no longitudinal wrinkles, and the skin on the body is thin, pink, and elastic. The entire coat is white, with the wool growing from the line connecting the eyes to the line connecting the legs, from the forelimbs to the carpal joint, and from the hind limbs to the hock; the wool tufts have distinct wavy curves. Most rams have large, spiral horns; most ewes are hornless, some have small horns; a few individuals may have a small number of spots on the head and limbs.

[0030] The growth performance of the semi-fine wool sheep was as follows: the average birth weight of male and female lambs was 2.60 kg and 2.30 kg, respectively; the average weaning weight of male and female lambs was 6.35 kg and 5.25 kg, respectively; the average weight of rams and ewes at six months of age was 15.80 kg and 13.84 kg, respectively; the average weight of rams and ewes at 1.5 years of age was 35.00 kg and 31.00 kg, respectively; and the average weight of adult rams and ewes was 45.50 kg and 33.80 kg, respectively.

[0031] The wool properties of the obtained semi-fine wool sheep are as follows: the wool is fine and uniform in length, with consistent crimp, medium or large crimp, medium density, obvious crimp, moderate grease content, and white or milky white color; the wool fineness is 56-58 count; the shearing yield of adult rams is 3.0-3.75 kg / year, the shearing yield of adult ewes is 2.45-2.89 kg / year, the clean wool yield is ≥64.21%, and the pure white wool rate is ≥92.75%.

[0032] In this embodiment, the semi-fine wool sheep are raised using a daytime grazing and nighttime supplementary feeding method. The ambient temperature in the pen at night is not lower than 0℃, and the humidity is 30%-50%. Nighttime supplementary feeding includes supplementary concentrate and supplementary silage. Specifically, two hours after grazing and entering the pen, 200-250g of concentrate is given per sheep. The concentrate comprises the following components in parts by weight: 50 parts corn, 13 parts soybean meal, 12 parts wheat bran, 1.8 parts dicalcium phosphate, 1.1 parts edible salt, and 4.0 parts sheep compound premix. The silage comprises the following components in parts by weight: 70-75 parts corn stalks and 25-30 parts alfalfa.

[0033] The compound premix for sheep comprises the following components in parts by weight: 72 parts calcium carbonate, 12 parts dicalcium phosphate, 7.5 parts ferrous sulfate, 0.8 parts copper sulfate, 1.0 part zinc oxide, 5.0 parts manganese sulfate, 0.032 parts sodium selenite carrier premix, 0.12 parts potassium iodide, and 0.20 parts cobalt chloride.

[0034] Example 2 This embodiment provides a method for breeding intermediate semi-fine wool sheep breeds without introducing Xinjiang fine wool sheep sires, specifically including the following steps: S1. Select 20,000 Tibetan sheep ewes of the valley type in the Shigatse agricultural area, which are hornless or have small horns and large body size, and crossbreed them with Tsigai sheep as the sire to obtain 16,000 Tsigai-Tibetan crossbred sheep; select 20,000 Tibetan sheep ewes of the valley type in the Shigatse agricultural area, which are hornless or have small horns and large body size, and crossbreed them with Romni sheep as the sire to obtain 16,000 Romni-Tibetan crossbred sheep; select 20,000 Tibetan sheep ewes of the valley type in the Shigatse agricultural area, which are hornless or have small horns and large body size, and crossbreed them with Leicester sheep from the border area as the sire to obtain 16,000 Border-Tibetan crossbred sheep.

[0035] S2. Crossbreed 7,000 Cizang hybrid rams with Luozang hybrid ewes, and / or crossbreed 7,000 Cizang hybrid ewes with Luozang hybrid rams, and perform horn genotyping on the maternal line, select individuals with the horn genotype pp to participate in breeding, and obtain 12,000 Cizang-Luozang hybrid sheep.

[0036] 7,000 rams of the Luozang hybrid sheep were crossed with ewes of the Bianzang hybrid sheep, and / or 7,000 ewes of the Luozang hybrid sheep were crossed with rams of the Bianzang hybrid sheep. The horn genotype of the maternal line was tested, and individuals with the horn genotype pp were selected to participate in breeding, resulting in 12,000 Bianzang hybrid sheep.

[0037] S3. Crossbreed 7,000 Tsering crossbred rams with Bianluozang crossbred ewes, and / or crossbreed 7,000 Tsering crossbred ewes with Bianluozang crossbred rams, and perform horn genotyping on the maternal line, select individuals with the horn genotype pp to participate in breeding, and obtain 12,000 Bian Tsering crossbred sheep.

[0038] S4. Using the aforementioned Bianciluozang hybrid sheep as the starting population for crossbreeding fixation, without introducing Xinjiang fine-wool sheep as the sire, direct continuous generations of crossbreeding fixation and selection are carried out.

[0039] S5. The Bianciluozang hybrid sheep were continuously selected and bred to the F5 generation. During the selection process of each generation, the horn genotype of the maternal line was tested. Individuals with the horn genotype pp were selected to participate in breeding, and a core population of 800 semi-fine wool sheep with wool fineness of 47-50 count was obtained.

[0040] S6. Continue to select and improve the breed of semi-fine wool sheep with a wool fineness of 47-50 count, and obtain 20,000 semi-fine wool sheep with consistent phenotype and wool fineness of 47-50 count.

[0041] The semi-fine wool sheep obtained in this embodiment belongs to the intermediate strain of semi-fine wool sheep that is suitable for both wool and meat production. It is tolerant of roughage, has strong disease resistance, grows and develops relatively quickly, and has excellent wool quality and good meat performance. It is of medium size, well-proportioned structure, moderate head shape, flat forehead, short neck, cylindrical body, rectangular side profile, well-spread ribs, straight back and loin, full hindquarters, slender tail, thin limbs, short legs, upright stance, and white or waxy yellow hooves; the face is smooth, with some individuals having brown hair on the face, small erect ears, a prominent bridge of the nose, and a white nose; the skin under the neck has no longitudinal wrinkles, the skin of the body is wrinkle-free, thin, pink, and elastic; the entire body is covered with white wool, with the wool growing from near the line connecting the eyes to near the line connecting the legs, from near the wrist joint on the forelimbs to near the hock on the hind limbs; the wool tufts have obvious wavy curves; most rams have large spiral horns, most ewes are hornless, some have small horns, and some individuals may have a small number of spots on the head and limbs.

[0042] The growth performance of the semi-fine wool sheep obtained in this embodiment is as follows: the average birth weight of male lambs is 2.55 kg, and the average birth weight of female lambs is 2.20 kg; the average weaning weight of male lambs is 6.0 kg, and the average weaning weight of female lambs is 5.0 kg; the average weight of rams at six months of age is 15.0 kg, and the average weight of ewes at six months of age is 13.5 kg; the average weight of rams at 1.5 years of age is 33.00 kg, and the average weight of ewes at 1.5 years of age is 30.00 kg; the average weight of adult rams is 43.0 kg, and the average weight of adult ewes is 32.0 kg.

[0043] The wool properties of the semi-fine wool sheep obtained in this embodiment are as follows: the wool is fine and uniform in length, with consistent crimp, medium or large crimp, medium density, obvious crimp, moderate grease content, and white or milky white color; the shearing yield of adult rams is 3.0–3.75 kg / year, the shearing yield of adult ewes is 2.45–2.89 kg / year, the wool fineness is 47–50 count, the clean wool yield is ≥64.21%, and the pure white wool rate is ≥92.75%.

[0044] In this embodiment, the semi-fine wool sheep are raised using a daytime grazing and nighttime supplementary feeding method. The nighttime ambient temperature in the pen is no lower than 0℃, and the humidity is 30%–50%. Nighttime supplementary feeding includes supplementary concentrate and supplementary silage. Specifically, two hours after grazing, the sheep are supplemented with concentrate at a rate of 200–250g per sheep. The concentrate comprises the following components in parts by weight: 50 parts corn, 13 parts soybean meal, 12 parts wheat bran, 1.8 parts dicalcium phosphate, 1.1 parts edible salt, and 4.0 parts sheep compound premix. The silage comprises the following components in parts by weight: 70–75 parts corn stalks and 25–30 parts alfalfa.

[0045] The compound premix for sheep comprises the following components in parts by weight: 72 parts calcium carbonate, 12 parts dicalcium phosphate, 7.5 parts ferrous sulfate, 0.8 parts copper sulfate, 1.0 part zinc oxide, 5.0 parts manganese sulfate, 0.032 parts sodium selenite carrier premix, 0.12 parts potassium iodide, and 0.20 parts cobalt chloride.

[0046] It should be noted that this embodiment is a breeding scheme for a semi-fine wool sheep intermediate strain without introducing Xinjiang fine wool sheep sires, which mainly obtains a semi-fine wool sheep strain with a wool fineness of 47-50 count; Example 1 is a scheme to further introduce Xinjiang fine wool sheep sires on the basis of Bianciluozang crossbred sheep, and obtain a semi-fine wool sheep strain with a wool fineness of 56-58 count through crossbreeding fixation from F0 to F5 generations and selection of this breed.

[0047] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that conventional adjustments, substitutions, or equivalent transformations can be made to the parent selection, hybridization combinations, generational breeding, trait screening, and feeding and management conditions described in the present invention without departing from the technical concept and essence of the present invention; all such adjustments, substitutions, or equivalent transformations should fall within the scope of protection defined by the claims of the present invention. Molecular identification methods, wool fineness measurement methods, body weight measurement methods, feeding and management operations, and other conventional livestock breeding techniques not described in detail in the present invention can all be implemented using techniques known in the art.

Claims

1. A method for breeding dual-purpose (wool and meat) semi-fine wool sheep suitable for cold environments, characterized in that, Includes the following steps: S1. Using the local Tibetan sheep breed of the river valley type in the Shigatse agricultural area as the maternal line, and using Tsigai sheep, Romni sheep and border area Leicester sheep as the paternal line respectively, crossbreeding was carried out to obtain Tsigai-Tibetan hybrid sheep, Romni-Tibetan hybrid sheep and border-Tibetan hybrid sheep; S2. Crossbreed the Cizang hybrid sheep with the Luozang hybrid sheep to obtain the Ciluozang hybrid sheep; crossbreed the Luozang hybrid sheep with the Bianzang hybrid sheep to obtain the Bianluozang hybrid sheep; S3. Crossbreed the Tsilozang crossbred sheep with the Bianluozang crossbred sheep to obtain the Biantsilozang crossbred sheep with a wool fineness of 46-52 count; S4. Crossbreeding with Bianciluozang crossbred sheep as the female parent and Xinjiang fine wool sheep as the male parent to obtain the F0 generation of semi-fine wool sheep with a wool fineness of 54-58 count; S5. The semi-fine wool sheep F0 generation is cross-fixed and continuously selected for generations up to the F5 generation to obtain semi-fine wool sheep with a wool fineness of 56-58 count; S6. Continue to breed semi-fine wool sheep with wool fineness of 56-58 count to obtain a dual-purpose semi-fine wool sheep breed with consistent phenotype.

2. The breeding method according to claim 1, characterized in that, The ewes among the Tszang-Tibetan hybrid sheep, Lozang-Tibetan hybrid sheep, and Bian-Tibetan hybrid sheep obtained in step S1 meet the following conditions: Birth weight is over 2.2kg, weaning weight at three months of age is over 5.25kg, and adult ewe weight is 32-35kg; The head is white or has some brownish-yellow hair, the coat is white, the back and loin are straight, the body is medium-sized, there are no horns, the head is narrow and long, the neck is slender and long, the body is narrow and long, and the limbs are thin and long.

3. The breeding method according to claim 1, characterized in that, In step S2, the crossbreeding of Cizang and Luozang hybrid sheep includes crossbreeding Cizang hybrid rams with Luozang hybrid ewes, and / or crossbreeding Cizang hybrid ewes with Luozang hybrid rams.

4. The breeding method according to claim 1, characterized in that, In step S2, the crossbreeding of Luozang hybrid sheep and Bianzang hybrid sheep includes crossbreeding of Luozang hybrid sheep rams and Bianzang hybrid sheep ewes, and / or crossbreeding of Luozang hybrid sheep ewes and Bianzang hybrid sheep rams.

5. The breeding method according to claim 1, characterized in that, In step S3, the crossbreeding of Tsering crossbred sheep and Bianluozang crossbred sheep includes crossbreeding a Tsering crossbred ram with a Bianluozang crossbred ewe, and / or crossbreeding a Tsering crossbred ewe with a Bianluozang crossbred ram.

6. The breeding method according to claim 1, characterized in that, In step S4, before using the Bianciluozang hybrid sheep as the maternal parent, the horn type genotype of the Bianciluozang hybrid sheep maternal parent is tested, and individuals with the horn type genotype pp are selected as the maternal parent and crossbred with the Xinjiang fine wool sheep paternal parent.

7. The breeding method according to claim 1, characterized in that, In step S5, during the cross-fixation process of the semi-fine wool sheep from generation F0 to generation F5, each generation is selected for breeding based on the fineness of the wool, and individuals with a wool fineness of 56-58 counts are selected to enter the next generation for breeding.

8. The breeding method according to claim 1, characterized in that, In step S6, during the breeding of this breed, the growth performance of candidate semi-fine wool sheep individuals is measured, and they are selected for breeding according to the following growth performance indicators: The average birth weight of male lambs was 2.60 kg, and the average birth weight of female lambs was 2.30 kg. The average weaning weight of male lambs was 6.35 kg, and the average weaning weight of female lambs was 5.25 kg. The average weight of rams at six months of age was 15.80 kg, and the average weight of ewes at six months of age was 13.84 kg. The average weight of adult rams is 45.50 kg, and the average weight of adult ewes is 33.80 kg.

9. The breeding method according to claim 1, characterized in that, In step S6, during the breeding of this breed, the wool performance of candidate semi-fine wool sheep individuals is tested, and they are selected for breeding according to the following wool performance indicators: The wool yield of adult rams is 3.0-3.75 kg / year, and the wool yield of adult ewes is 2.45-2.89 kg / year. The wool has a fineness of 56-58 count, a clean wool yield of ≥64.21%, and a pure white wool color rate of ≥92.75%.

10. The breeding method according to claim 1, characterized in that, The semi-fine wool sheep are raised by grazing during the day and supplementing with feed at night. The ambient temperature in the pen at night is not lower than 0℃ and the humidity is 30%-50%. Nighttime supplementary feeding includes supplementary concentrate and supplementary silage. Specifically, supplementary concentrate should be given at a rate of 200-250g per animal two hours after the animals are brought into the pen. The silage comprises the following components in parts by weight: 70-75 parts corn stalks and 25-30 parts alfalfa.

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