Application of reproductive technologies to improve the utilization of superior sires in the pork production industry

人工授精（AI）的使用对养猪业的遗传改良产生了重大影响。然而，与其他畜牧业（如乳制品）不同，加拿大猪肉生产尚未充分实现人工智能可以提供的遗传收益和战略优势。这是由于：1)对公猪个体生育能力的评估无效，2)每窝产仔使用的精子数量过多。改善人工智能的这些低效率将为加拿大猪肉生产商在全球食品动物市场上带来重大优势。每次人工智能剂量的精子数量减少将增加对遗传优良公猪的使用。尽管30亿精子/人工智能剂量是行业标准，但我们小组和行业的最新数据表明，目前使用的公猪中，约有15-20%的公猪的生育能力不佳，尽管它们生产的精液质量“可接受”，可用于人工智能。当这些公猪的精液在低于30亿个精子/人工授精剂量时，其生育能力进一步受到损害，而其他公猪在人工授精剂量为15亿个精子时仍能保持生殖能力。识别和选择这些品种的能力将使该行业能够减少精子/人工智能剂量的数量，这意味着需要更少的公猪来满足人工智能的要求。因此，遗传价值较低和相对生产力较低的公猪可以被淘汰。此外，单次定时人工授精技术（FT-AI）与子宫颈后人工授精技术（PC-AI）相结合的开发和应用将通过减少产仔所需的精子数量，最大限度地提高优质公猪的影响。这项研究将提供新的工具和技术，以改善加拿大猪肉生产行业的育种管理实践，并确保高遗传价值的精英品种和终端品种之间的联系，这是经济上可持续发展的猪肉产业的基础。

The use of artificial insemination (AI) has had a major impact on genetic improvement in the swine industry. However, unlike other livestock industries (e.g. dairy), Canadian pork production has not fully realized the genetic gains and strategic advantages that AI can provide. This is due to: 1) ineffective evaluation of individual boar fertility, and 2) the excessive number of sperm used per litter born. Improving on these inefficiencies in AI would represent a major advantage to Canadian pork producers in a global food-animal marketplace. A reduction in sperm numbers per AI dose will enhance the use of genetically superior boars. Although 3 billion sperm/AI dose is an industry norm, recent data from our group and industry demonstrate that ~15-20% of boars currently in use demonstrate sub-optimal fertility, despite producing semen of "acceptable" quality for use in AI. The fertility of these boars is further compromised when their semen is inseminated at less than 3 billion sperm/AI dose, while other boars maintain reproductive capacity with AI doses of 1.5 billion sperm. The capacity to identify and select against these sires would allow the industry to reduce the numbers of sperm/AI dose, meaning fewer boars would be required to satisfy the requirements for AI. Boars of lesser genetic merit and lower relative productivity could thus be eliminated. Furthermore, development and application of single fixed-time artificial insemination techniques (FT-AI) in combination with post-cervical artificial insemination (PC-AI) techniques will maximize the impact of superior boars by reducing the number of sperm needed to produce a litter. This research will deliver novel tools and techniques that will improve breeding management practices in the Canadian pork production industry and ensure the link between the high genetic value of elite sires and terminal line progeny which are the foundation of an economically sustainable pork industry.