The present study was conducted on 1,002 reproductive records of 430 Jersey crossbred cattle, descended from 57 sires and 198 dams, maintained at the Eastern Regional Station of ICAR‐National Dairy Research Institute, Kalyani, Nadia, West Bengal, India to investigate the influence of direct genetic, maternal genetic and maternal permanent environmental effect on three most important reproductive traits viz., number of service per conception (NSPC), days open (DO) and calving interval (CI) of Jersey crossbred cattle. Six single‐trait animal models (including or excluding maternal genetic or permanent environmental effects) were fitted to analyse these traits, and the best model was chosen after testing the significant increase in the log‐likelihood values when additional parameters were added in the model. Direct heritability estimates for NSPC, DO and CI from the best model were 0.10, 0.14 and 0.20, respectively. The maternal permanent environmental (c²) effects on reproductive traits accounted for almost negligible fraction of the total phenotypic variance in this study. The maternal genetic effects (m²) also contributed very little (0%–3%) to the total phenotypic variance except for CI where it was important and accounted for 20% of phenotypic variance. A significantly large negative genetic correlation was observed between direct and maternal genetic effects for all traits, suggesting the presence of antagonistic relationship between dam's direct additive component and daughter's additive genetic component. Results suggest that both direct and maternal effects were important only for CI but not for other traits. Therefore, both direct additive effects and maternal genetic effect need to be considered for improving this trait by selection.

中文翻译：

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动物模型评价探讨母源遗传和母源永久环境对泽西杂交牛繁殖性能的影响

本研究对 430 头泽西岛杂交牛的 1,002 份繁殖记录进行，这些牛是 57 头公牛和 198 头母牛的后代，保存在印度西孟加拉邦纳迪亚 Kalyani 的 ICAR-国家乳制品研究所东部地区站，以调查直接遗传、母系遗传和母系永久环境对三个最重要的生殖特征的影响，即.，泽西杂交牛的每次受孕服务数 (NSPC)、开放天数 (DO) 和产犊间隔 (CI)。拟合六个单性状动物模型（包括或不包括母体遗传或永久环境影响）来分析这些性状，并在测试模型中添加额外参数时对数似然值的显着增加后选择最佳模型。来自最佳模型的 NSPC、DO 和 CI 的直接遗传力估计值分别为 0.10、0.14 和 0.20。在本研究中，母体永久环境 (c ² ) 对生殖性状的影响几乎可以忽略不计。母体遗传效应（m ²) 对总表型方差的贡献也很小 (0%–3%)，除了 CI 很重要，占表型方差的 20%。在所有性状的直接和母系遗传效应之间观察到显着的显着负遗传相关性，表明母系的直接加性成分和女儿的加性遗传成分之间存在拮抗关系。结果表明，直接效应和母体效应仅对 CI 重要，对其他特征不重要。因此，通过选择来改善这一性状，需要同时考虑直接加成效应和母本遗传效应。