Maximini L, Fuerst-Waltl B, Gredler B, Baumung R
Department of Sustainable Agricultural Systems, Division of Livestock Science, University of Natural Resources and Applied Life Sciences, Vienna, Austria.
Reprod Domest Anim. 2011 Feb;46(1):e102-4. doi: 10.1111/j.1439-0531.2010.01645.x.
Using pedigree data, the inbreeding coefficients of 715 Austrian dual-purpose Simmental (Fleckvieh) bulls stationed in two artificial insemination (AI) centres in Upper and Lower Austria were calculated and incorporated in statistical models for the analysis of semen quality. Five semen quality parameters (volume, concentration, motility, number of spermatozoa per ejaculate and percentage of viable spermatozoa) of approximately 30,000 ejaculates, used in two separate data sets, were investigated. The mixed model included the fixed effects age class of the bull, bull handler, semen collector, month and year of collection, number of collection per bull and day, time interval since last collection, the linear continuous effect of the inbreeding coefficient of the bull, interactions between age class and month, and age class and interval since last collection, respectively, as well as the random effect of the bull and the random residual effect. Non-linear effects of inbreeding were significant for motility only. Despite the quite low inbreeding coefficients (mean 1.3%), all semen quality traits showed inbreeding depression, in four of the five traits significantly in at least one of the data sets. The magnitude of inbreeding depression was small, which might partly be caused by the low inbreeding levels and a potential pre-selection of the bulls in the AI centres. However, monitoring of inbreeding depression on fertility traits is recommended to avoid unrecognized deterioration of such traits.
利用系谱数据，计算了驻扎在奥地利上奥地利州和下奥地利州两个人工授精（AI）中心的715头奥地利兼用西门塔尔牛（弗莱维赫牛）的近亲繁殖系数，并将其纳入统计模型以分析精液质量。对两个独立数据集中约30000份射精样本的五个精液质量参数（体积、浓度、活力、每次射精的精子数量和活精子百分比）进行了研究。混合模型包括公牛的固定效应年龄组、公牛饲养员、精液采集员、采集月份和年份、每头公牛每天的采集次数、自上次采集以来的时间间隔、公牛近亲繁殖系数的线性连续效应、年龄组与月份之间的相互作用以及年龄组与自上次采集以来的时间间隔之间的相互作用，以及公牛的随机效应和随机残差效应。近亲繁殖的非线性效应仅对活力有显著影响。尽管近亲繁殖系数相当低（平均1.3%），但所有精液质量性状均表现出近亲繁殖衰退，在五个性状中的四个性状中，至少在其中一个数据集中显著衰退。近亲繁殖衰退的程度较小，这可能部分是由于近亲繁殖水平较低以及人工授精中心对公牛的潜在预选。然而，建议监测生育性状的近亲繁殖衰退情况，以避免此类性状出现未被识别的恶化。
