The aim of this study was to estimate the genetic parameters for the morphometric measurements of withers height (WH), thoracic circumference (TC) and cannon bone circumference (CBC) of Criollo horses, stratified for maternal and paternal effects. Statistical genetic design of factor crossings was used to evaluate the offspring of full siblings and half-siblings. Fifty stallions were selected (n = 50) who had been crossed with six mares each (n = 6), to provide 300 parental pairings in which two offspring were born per mare (n = 600). WH in females and TC in males were highly influenced by additive genetic effects, while the other morphometric measures were found to be closely related to the general effects of the environment. WH had the greatest additive genetic influence on female offspring (47.06%), while TC presented the greatest additive genetic influence on male offspring (58.73%). When comparing the parental influence on the morphometric characteristics evaluated, TC and CBC had greater additive genetic influence from maternal effects, regardless of offspring sex. However, the WH in female offspring showed greater maternal additive genetic contribution, while in males this characteristic presented greater paternal additive genetic influence. For WH in male offspring, narrow sense heritability ( h r 2 : 0.26) was more influenced by paternal effects, while for WH in females ( h r 2 : 0.47), TC in females ( h r 2 : 0.08) and males ( h r 2 : 0.59), and CBC in females ( h r 2 : 0.07) and males ( h r 2 : 0.05) the maternal effects were the most important. Therefore, the phenotypic expression of WH in males and females and TC in males is influenced by the additive genetic effect of the genes. On the other hand, the TC in female progenies and CBC in progenies of both sexes are closely related to the effects of the environment. The results obtained in this study could be useful in the selection process of Criollo horses.

中文翻译：

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克里奥马形态测量的遗传参数

本研究的目的是估计 Criollo 马肩高 (WH)、胸围 (TC) 和炮骨围 (CBC) 形态测量的遗传参数，根据母本和父本影响进行分层。因子交叉的统计遗传设计用于评估全兄弟姐妹和半兄弟姐妹的后代。选择了 50 匹公马 (n = 50)，每匹公马与六匹母马 (n = 6) 杂交，以提供 300 对亲本配对，其中每匹母马出生两个后代 (n = 600)。雌性的 WH 和雄性的 TC 受加性遗传效应的影响很大，而其他形态测量指标被发现与环境的一般效应密切相关。WH 对雌性后代的遗传影响最大（47.06%），而 TC 对雄性后代的遗传影响最大（58.73%）。在比较父母对所评估的形态特征的影响时，无论后代性别如何，TC 和 CBC 对母体效应的附加遗传影响都更大。然而，雌性后代的 WH 表现出更大的母系加性遗传贡献，而在雄性中，这种特征表现出更大的父系加性遗传影响。对于雄性后代的 WH，狭义遗传力 (hr 2 : 0.26) 受父本效应的影响更大，而对于雌性 WH (hr 2 : 0.47)、雌性 (hr 2 : 0.08) 和雄性 (hr 2 : 0.59) 的 TC ) 和 CBC 在女性 (hr 2 : 0.07) 和男性 (hr 2 : 0.05) 中，母体效应是最重要的。所以，WH 在雄性和雌性中的表型表达和在雄性中 TC 的表型表达受基因的加性遗传效应的影响。另一方面，雌性后代的TC和两性后代的CBC与环境的影响密切相关。本研究中获得的结果可用于克里奥马的选择过程。