Priority Research Centre for Reproductive Science, University of Newcastle, Callaghan, New South Wales, Australia.
Nuffield Department of Women's and Reproductive Health, University of Oxford, Oxford, UK.
Biol Reprod. 2022 May 17;106(5):854-864. doi: 10.1093/biolre/ioac031.
Breeding soundness examinations for bulls rely heavily on the subjective, visual assessment of sperm motility and morphology. Although these criteria have the potential to identify infertile males, they cannot be used to guarantee fertility or provide information about varying degrees of bull fertility. Male factor fertility is complex, and the success of the male gamete is not necessarily realized until well after the spermatozoon enters the oocyte. This paper reviews our existing knowledge of the bull's contribution from a standpoint of the sperm's cargo and the impact that this can have on fertilization and the development of the embryo. There has been a plethora of recent research characterizing the many molecular attributes that can affect the functional competence of a spermatozoon. A better understanding of the molecular factors influencing fertilization and embryo development in cattle will lead to the identification of biomarkers for the selection of bulls of superior fertility, which will have major implications for livestock production. To see this improvement in reproductive performance, we believe incorporation of modern technology into breeding soundness examinations will be necessary-although many of the discussed technologies are not ready for large-scale field application. Each of the 'omics fields discussed in this review have shown promise for the identification of biomarkers of fertility, with certain families of biomarkers appearing to be better suited to different evaluations throughout a bull's lifetime. Further research is needed for the proposed biomarkers to be of diagnostic or predictive value.
种公牛的繁殖健康检查在很大程度上依赖于精子运动和形态的主观、视觉评估。尽管这些标准有可能识别出不育的雄性，但它们不能用于保证生育能力或提供关于公牛生育力不同程度的信息。雄性因素生育力是复杂的，雄性配子的成功并不一定在精子进入卵子后很久才实现。本文从精子货物的角度回顾了我们对公牛贡献的现有知识，以及这对受精和胚胎发育的影响。最近有大量研究描述了许多可能影响精子功能能力的分子特征。更好地了解影响牛受精和胚胎发育的分子因素，将导致能够识别出具有更高生育力公牛的生物标志物的出现，这将对畜牧业生产产生重大影响。为了看到这种繁殖性能的提高，我们认为有必要将现代技术纳入繁殖健康检查中——尽管许多讨论的技术还没有准备好大规模应用于现场。本综述中讨论的每个“组学”领域都显示出了鉴定生育力生物标志物的潜力，某些生物标志物家族似乎更适合在公牛的一生中进行不同的评估。需要进一步的研究来使提出的生物标志物具有诊断或预测价值。
