T/NAASS 173-2026 Active Group standards

T/NAASS 173-2026 Code of practice for Two or even more Lamb Identification of Tan Sheep

Publish Date: 2026-01-15 Implement Date: 2026-01-25 For services related to genuine standard inquiry, procurement, translation, and other related services in China, please Contact Us

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Basic Information

Standard Code: T/NAASS 173-2026

Standard Type: Group standards

Standard Status: Active

is_force_gb: no

CCS Name: -

ICS Name: Animal husbandry and breeding

Publish Date: 2026-01-15

Implement Date: 2026-01-25

Scope

This standard specifies the definitions and terminology, production performance, grade evaluation, breeding requirements, and technical points of file recording for the identification of Tan sheep twin lamb breeds. This standard is applicable to the identification and grade evaluation of Ningxia Tan sheep twin lamb breeds. 3 Terms and Definitions The following terms and definitions are applicable to this document. Tan sheep twin lambs: Tan sheep that can produce two or even more lambs in a single pregnancy. 4 Production Performance Reproductive Performance Male sheep reach sexual maturity at the age of 6 to 7 months, and female sheep reach sexual maturity at the age of 7 to 8 months. The initial mating age of male and female sheep is 1.5 years, with a gestation period of 149 to 156 days and a lambing rate of 154-169%. 5 Grade Evaluation Evaluation Methods Evaluation shall be conducted in accordance with GB/T 2033, GB/T 27534.4, and NY/T 1236. Evaluation Frequency Evaluation shall be conducted three times according to the growth and development stages: initial evaluation within 3 hours after lamb birth, evaluation of two-colored lambs at 35 days of age, and evaluation of finished lambs at 18 months of age. Evaluation Content 5.3.1 Initial Lambs Evaluation items include natural length of wool strands, number of bends in wool strands, flower patterns, physical development, and initial weight. 5.3.2 Two-Colored Lambs Evaluation items include types of flower tufts, number of bends in wool strands, flower patterns, physical development, weight, proportion of bends in wool strands, wool strand compactness, color characteristics, and presence of physical defects. 5.3.3 Finished Lambs Evaluation items include physical constitution, physique, weight, color characteristics, wool strand length, and presence of physical defects. Evaluation Grade 5.4.1 Initial Lambs Grade evaluation shall be conducted in accordance with Table 1. Table 1: Grade Evaluation of Initial Lambs Grade