Agriculture and Agri-Food Canada, Western College of Veterinary Medicine, Saskatoon, SK, Canada.
Theriogenology. 2011 Sep 15;76(5):891-9. doi: 10.1016/j.theriogenology.2011.04.020. Epub 2011 Jun 25.
The objective of this case report was to identify the cause of apparent idiopathic infertility in a Red Angus (beef) bull. Semen was collected by electroejaculation and submitted to a series of assays, including evaluation of sperm motility by computer-assisted sperm analysis (CASA), sperm morphology and DNA integrity, semen cryopreservation, AI, IVF, induction of the acrosome reaction, and determination of the level of sperm proteins associated with bull fertility potential. Total (92 ± 2%) and progressive (79 ± 4%) sperm motility; sperm concentration (1647 ± 429 × 10(6) sperm/mL); proportions of morphologically normal sperm (83 ± 6%) and DNA integrity (96 ± 2), and acrosome-intact sperm (64 ± 4%) exceeded minimum acceptable values. Frozen sperm had good total (58.7 ± 6.7%) and progressive (43.9 ± 9.2%) motility immediately after thawing. However, AI of 16 heifers resulted in no pregnancies and blastocyst production rate (following IVF using sperm from this infertile bull) was nearly identical to that produced using dead sperm (a control of parthenogenesis; 2 ± 2 and 2 ± 3%; respectively P < 0.05). Treatment with a calcium ionophore (A23187) failed to induce the acrosome reaction in sperm from the infertile bull (P < 0.05). Evaluation of several proteins associated with the fertility potential of bulls revealed that the level of Binder Sperm Protein-1 (BSP1), known to be associated with the capacitation process, was much greater on sperm from the infertile bull compared to that of his sire. In conclusion, we inferred that the idiopathic infertility in this bull was caused by a failure to complete the capacitation process.
本病例报告的目的是确定一头红安格斯（肉牛）公牛出现不明原因特发性不育的原因。通过电刺激法采集精液，并进行一系列检测，包括计算机辅助精子分析（CASA）评估精子活力、精子形态和 DNA 完整性、精液冷冻保存、人工授精、体外受精、顶体反应诱导以及与公牛生育力相关的精子蛋白水平的测定。总（92±2%）和前向（79±4%）精子活力；精子浓度（1647±429×10(6)精子/ml）；形态正常精子的比例（83±6%）和 DNA 完整性（96±2%），以及完整顶体的精子（64±4%）均超过最低可接受值。冷冻精子解冻后总活力（58.7±6.7%）和前向运动精子活力（43.9±9.2%）良好。然而，16 头小母牛的人工授精并未妊娠，且使用该不育公牛精子进行体外受精的囊胚产生率（与使用死精子的对照（孤雌生殖；2±2%和 2±3%；分别 P<0.05）几乎相同。钙离子载体（A23187）处理未能诱导不育公牛精子的顶体反应（P<0.05）。对与公牛生育力相关的几种蛋白的评估表明，与受精过程相关的结合精子蛋白-1（BSP1）在不育公牛的精子上的水平明显高于其父本。总之，我们推断该公牛的特发性不育是由于未能完成获能过程。
