The aim of this study was to locate SSTR5 polymorphisms and evaluate their association with growth traits in Hulun Buir sheep. The study followed up 884 Hulun Buir sheep from birth to 16 months of age, which were born in the same pasture and the same year, and a consistent grazing management strategy was maintained. The birth weight (BRW) was recorded at birth, and body weight (BW), body height (BH), body length (BL), chest circumference (ChC), chest depth (ChD), chest width (ChW), hip width (HW), and cannon circumference (CaC) were measured at 4 and 9 months of age. BW, BH, BL, ChD, HW, and CaC were also recorded at 16 months of age. Based on the growth traits, 233 sheep were selected as experimental animals. Sanger sequencing was performed, and seven single-nucleotide polymorphisms (SNPs) were identified. Association analyses of the SNPs and the growth traits were then conducted. Seven SNPs of the SSTR5 exhibited moderate polymorphism (0.25<PIC<0.5) and were consistent with the Hardy–Weinberg equilibrium. SNP7 (T989C, rs601836309) caused a change in amino acid sequences, while others did not cause any change. The genotypes of SNP1 (C186T, s400914340) were significantly associated with BW, ChW, and ChC at 4 months of age and with HW at 9 months of age (p<0.05). These genotypes also showed extremely significant association with CaC at 4 months of age (p<0.01). The genotypes of SNP7 exhibited a significant association with ChW and CaC at 4 and 9 months of age, respectively. Moreover, the genotypes of SNP3 (T384C, rs413380618)) and SNP4 (T537C, rs605867745) were significantly associated with CaC at 9 months of age (p<0.05). Linkage disequilibrium was observed among the seven SNPs with five haplotypes. However, these haplotypes were not associated with growth traits at different ages. In conclusion, SNP1, SNP3, SNP4, and SNP7 may serve as molecular markers for the growth traits of Hulun Buir sheep.

本研究的目的是找出SSTR5呼伦贝尔羊多态性及其与生长性状的关系评价。该研究对884只呼伦贝尔羊从出生到16月龄进行了跟踪调查，这些羊出生在同一牧场、同年，并保持一致的放牧管理策略。出生时记录出生体重（BRW）、体重（BW）、身高（BH）、体长（BL）、胸围（ChC）、胸深（ChD）、胸宽（ChW）、臀宽(HW) 和大炮周长 (CaC) 在 4 个月和 9 个月大时测量。还在 16 个月龄时记录了 BW、BH、BL、ChD、HW 和 CaC。根据生长特性，选取233只羊作为实验动物。进行桑格测序，鉴定出七个单核苷酸多态性 (SNP)。然后进行 SNP 和生长性状的关联分析。七个 SNPSSTR5表现出中等多态性（0.25<PIC<0.5）并且与Hardy-Weinberg平衡一致。SNP7（T989C，rs601836309）引起氨基酸序列的变化，而其他则没有引起任何变化。SNP1 的基因型（C186T，s400914340）与 4 月龄时的 BW、ChW 和 ChC 以及 9 月龄时的 HW 显着相关（p<0.05）。这些基因型还显示出与 4 个月大时的 CaC 极其显着的相关性（p<0.01）。SNP7 的基因型分别与 4 月龄和 9 月龄时的 ChW 和 CaC 显着相关。此外，SNP3（T384C，rs413380618））和SNP4（T537C，rs605867745）的基因型与9个月龄时的CaC显着相关（p<0.05）。在具有 5 个单倍型的 7 个 SNP 之间观察到连锁不平衡。然而，这些单倍型与不同年龄的生长特征无关。综上所述，SNP1、SNP3、SNP4、SNP7可作为呼伦贝尔羊生长性状的分子标记。