Center for Quantitative Genetics and Genomics, Aarhus University, Blichers Allé 20, PO Box 50, DK-8830 Tjele, Denmark.
Center for Quantitative Genetics and Genomics, Aarhus University, Blichers Allé 20, PO Box 50, DK-8830 Tjele, Denmark.
J Dairy Sci. 2021 Sep;104(9):10010-10019. doi: 10.3168/jds.2021-20403. Epub 2021 Jun 5.
Despite the importance of the quality of semen used in artificial insemination to the reproductive success of dairy herds, few studies have estimated the extent of genetic variability in semen quality traits. Even fewer studies have quantified the correlation between semen quality traits and male fertility. In this study, records of 100,058 ejaculates collected from 2,885 Nordic Holstein bulls were used to estimate genetic parameters for semen quality traits, including pre- and postcryopreservation semen concentration, sperm motility and viability, ejaculate volume, and number of doses per ejaculate. Additionally, summary data on nonreturn rate (NRR) obtained from insemination of some of the bulls (n = 2,142) to cows in different parities (heifers and parities 1-3 or more) were used to estimate correlations between the semen quality traits and service sire NRR. In the study, low to moderate heritability (0.06-0.45) was estimated for semen quality traits, indicating the possibility of improving these traits through selective breeding. The study also showed moderate to high genetic and phenotypic correlations between service sire NRR and some of the semen quality traits, including sperm viability pre- and postcryopreservation, motility postcryopreservation, and sperm concentration precryopreservation, indicating the predictive values of these traits for service sire NRR. The positive moderate to high genetic correlations between semen quality and service sire NRR traits also indicated that selection for semen quality traits might be favorable for improving service sire NRR.
尽管在人工授精中使用的精液质量对奶牛群的繁殖成功至关重要，但很少有研究估计精液质量性状的遗传变异程度。更少的研究量化了精液质量性状与雄性生育力之间的相关性。在这项研究中，使用了从 2885 头北欧荷斯坦公牛收集的 100088 次射精记录来估计精液质量性状的遗传参数，包括冷冻前和冷冻后精液浓度、精子活力和活力、射精量和每次射精的剂量数。此外，还使用了来自一些公牛（n=2142）对不同胎次（小母牛和 1-3 胎或更多胎次）的母牛进行授精的非返情率（NRR）汇总数据，以估计精液质量性状与种公牛 NRR 之间的相关性。在该研究中，对精液质量性状的遗传力估计为低至中度（0.06-0.45），表明通过选择性繁殖改善这些性状的可能性。该研究还表明，种公牛 NRR 与一些精液质量性状之间存在中度到高度的遗传和表型相关性，包括冷冻前和冷冻后精子活力、冷冻后精子活力和精子浓度，表明这些性状对种公牛 NRR 的预测价值。精液质量和种公牛 NRR 性状之间的中度到高度正遗传相关性也表明，选择精液质量性状可能有利于提高种公牛 NRR。
