GB/T 2033-2026Livestock and poultry breeds (synthetic lines) - Tan sheep (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part

1.Structure and Drafting Rules of Standardization Documents". Drafting. This document replaces GB/T 2033-2008 "Tan Sheep". Compared with GB/T 2033-2008, the main differences are structural adjustments and editorial changes. In addition, the main technological changes are as follows:

---Some terms and definitions have been deleted, added, and modified, specifically including. the deletion of "Tan sheep lambskin", "Tan lambskin", "Tan fur", and "Tan milk" (referring to lambskin from the Tan sheep). "Lamb meat" and "Tan lamb meat" were added; "two-hair skin" was added; the definitions of "two-hair lamb", "flower spike", "string of flowers", and "soft large flower" were changed (see section [number]). Chapter 3 (Chapter 2 of the.2008 edition);

---The varietal origin and characteristics have been changed (see Chapter 4,

3.1 of the.2008 edition);

---The description of body shape and appearance has been changed (see Chapter 5,

3.2 of the.2008 edition);

---The body weight and body size indicators have been changed (see Chapter 6,

3.3.1 of the.2008 edition);

---Added performance indicators for fur (see 7.1);

---The wool production performance indicators have been changed (see 7.2,

3.3.3 in the.2008 version);

---The meat production performance indicators have been changed (see 7.3,

3.3.4 in the.2008 version);

1 Scope

GB/T 2033-2026 is the Chinese national standard covering the Tan sheep of Ningxia - a breed kept above all for the curled lambskin taken in the first weeks of life, with the coat characteristics, the body measurements and the performance that define a registered animal. It replaces GB/T 2033-2008 and has been in force since 1 October 2026. It was issued on 31 March 2026 and takes effect on 1 October 2026, replacing GB/T 2033-2008. The document is under the responsibility of the Ministry of Agriculture and Rural Affairs. This page is published from the official record of the 2026 edition; the clause text of a standard this recent is not yet in circulation, and the figures, limits and tables it contains are those of the document itself, delivered in full with the English translation.

This document specifies the origin and characteristics of the Tan sheep breed, its physical features, weight and body size, production performance and grading, and describes the testing methods. This document applies to the breed identification and grading of Tan sheep.

4.Variety origin and characteristics Tan sheep is a unique local sheep breed in my country, renowned for its double-wool pelts. It thrives in warm, arid, semi-desert, and desertified environments. Raised in suitable environments, these animals are characterized by their tolerance to roughage, strong disease resistance, and excellent meat quality and flavor. They are mainly produced in Yanchi County, Tongxin County, and Hongsipu County of Ningxia Hui Autonomous Region. It is also distributed in the district, Lingwu City, and the eastern foothills of the Helan Mountains, as well as in areas bordering Gansu Province, Shaanxi Province, Inner Mongolia Autonomous Region, and Ningxia.

5 Physical characteristics

5.1 Two-haired lambs The main coat types of Ermao lambs are wavy and large wavy, as shown in Appendix A, Figures A.1 to A.2.The wool is wavy, with tight strands and a distinctive pattern. The markings are clear, the coat is pure white with a pleasing sheen, and the tips of the hairs have a semi-circular or slightly curved shape. The main parts of the body show a consistent pattern, with 3 to 7 curves. The curved portion accounts for 1/2 to 3/4 of the total length of the wool strand, with the curvature evenly distributed on the same horizontal plane, and a few exhibiting twisting. (The text then abruptly shifts to unrelated details about the abdomen, neck, and hair.) The tail and limbs have short hair strands with few curls. The coat consists of medullated hairs and dimorphic hairs, with medullated hairs accounting for approximately 54% and dimorphic hairs accounting for approximately 46%. The diameter is 17.37µm±4.36µm, and the diameter of the two types of wool is 26.60µm±7.67µm. The physical characteristics of the two-wool lamb are shown in Appendix B, Figure B.1.

5.2 Adult sheep Medium-sized and robust. Rams have spiral horns that extend outwards, while ewes are generally hornless or have small horns. Most have brown, black, or yellow heads. Patches, slightly raised bridge of the nose. Ears come in three sizes. large, medium, and small. Straight back and loins, deep chest, straight limbs, and sturdy hooves. Wide tail base, tapering to a thin tip. Round, long, fat tail, inverted triangular in shape, hanging down past the hock. The body is covered in pure white fur, with long, soft medullated hairs and a moderate amount of non-medullated hairs; there are no dry or dead hairs. The rump is braided, and the forequarters and hindquarters show the same characteristics. See Figures B.2 to B.7 for the physical characteristics of adult sheep.

6 Body weight

The weight and body size of Tan sheep should meet the requirements in Table 1.

7 Production performance

7.1 Performance of fur The Tan sheep second wool hide is thin and tight, with a thickness of 0.78mm ± 0.05mm, a fresh hide weight of 0.92kg ± 0.25kg, and a semi-dried hide area of... 2253cm2±650cm2, characterized by distinct curvature of the hair strands, clear pattern, soft hair roots, lightness, warmth and beauty.

7.2 Wool production performance Shearing is done twice a year, in spring and autumn. In spring, adult rams produce

0.25 kg of wool, and ewes produce

0.31 kg of wool. The clean wool yield is... 66.9%±5.0%. The coat consists of medullated hairs, non-medullated hairs, and two types of hairs. Medullated hairs account for 7%, with a diameter of 44.87µm±10.18µm; non-medullated hairs... 78% of the hairs are of the first type, with a diameter of 19.07µm ± 5.85µm; the second type accounts for 15%, with a diameter of 34.13µm ± 8.62µm and a natural strand length of 8.00cm. above.

7.3 Meat production performance Lambs of Tan sheep aged 35-60 days had a pre-slaughter live weight of

2.15 kg and a carcass weight of

3.12 kg, with a dressing percentage of 47.50%±2.23%. Lambs fattened to 6-8 months of age had a pre-slaughter live weight of 38.92kg±7.90kg and a carcass weight of 18.86kg±

3.88 kg, slaughter rate 48.50% ± 1.71%.

7.4 Reproductive performance Rams reach sexual maturity at 6-7 months of age, and ewes at 7-8 months of age. The average age for first mating for both rams and ewes is

1.5 years. Most breeding occurs in the autumn. Estrus. The estrous cycle in ewes is 17-18 days, with estrus lasting 26-32 hours. Gestation lasts 149-156 days. Lambing rate... 101%~111%.

8 Rating

8.1 Assessment Subjects Newborn lambs, second-year lambs, and growing sheep (18 months old).

8.2 Assessment Time and Frequency Tan sheep are assessed three times throughout their lives. the initial assessment is the foundation, the second-year assessment is the focus, and the assessment of growing sheep is a supplement. The initial assessment is conducted at [time missing]. Lambs are assessed within 3 hours of birth, while second-generation lambs are assessed at 35 days of age, and growing lambs are assessed at 18 months of age.