Karlau Ayelen, Azcona Florencia, Molina Antonio, Trigo Pablo, Sánchez-Serrano Juan Pablo, Demyda-Peyrás Sebastián
Departamento de Producción Animal, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Calle 60 y 118 s/n, La Plata 1900, Argentina.
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-CCT La Plata, Calle 8 1467, La Plata 1900, Argentina.
Animals (Basel). 2025 Sep 17;15(18):2720. doi: 10.3390/ani15182720.
The Peruano de Paso is a horse breed renowned for its smooth gait, traditionally selected based on breeders' empirical knowledge. Recently, the frequency of chestnut horses, a recessive trait, has increased substantially within the official studbook. This study evaluated whether preference for chestnut coat colour has influenced morphological traits and genetic diversity within the breed. A total of 8376 records of seven morphological traits, collected by the Peruano de Paso Breeders Association over eight years, were analysed, along with a pedigree including 41,357 individuals. Morphological traits were studied through univariate genetic models that considered potential heterogeneity of additive genetic variance between chestnut and non-chestnut horses. Results indicated moderate to high heritability estimates across traits. No significant differences were observed between groups, except for croup width, with heritability of 0.28 ± 0.08 in chestnuts and 0.44 ± 0.08 in non-chestnuts. Genetic correlations between groups could not be precisely estimated due to limited data. The main effect of selection for chestnut coat colour was a reduction in genetic variability, an increase in inbreeding and relatedness. However, this selection has had little impact on morphology, indicating that the traits valued by breeders remain almost unaffected despite the loss of diversity.
秘鲁 Paso 马是一种以步态平稳而闻名的马种，传统上是根据育种者的经验知识进行选育的。最近，栗色马（一种隐性性状）在官方种马登记簿中的出现频率大幅增加。本研究评估了对栗色毛色的偏好是否影响了该品种的形态特征和遗传多样性。分析了秘鲁 Paso 马育种协会在八年内收集的总共 8376 条关于七个形态特征的记录，以及包含 41357 个个体的系谱。通过单变量遗传模型研究形态特征，该模型考虑了栗色马和非栗色马之间加性遗传方差的潜在异质性。结果表明各性状的遗传力估计值为中等至高。除了臀部宽度外，两组之间未观察到显著差异，栗色马的遗传力为 0.28±0.08，非栗色马的遗传力为 0.44±0.08。由于数据有限，无法精确估计两组之间的遗传相关性。选择栗色毛色的主要影响是遗传变异性降低、近亲繁殖和亲缘关系增加。然而，这种选择对形态几乎没有影响，这表明尽管多样性丧失，但育种者所重视的性状几乎未受影响。
