Cryopreservation of sperm is a routine technology in many livestock species, but not in swine. Frozen sperm must result in acceptable conception rates and produce 11-12 piglets/litter to be competitive with traditional cooled semen. The development of an extender that results in high post-thaw sperm quality and acceptable litter size requires identification of factors that markedly impact post-thaw semen quality. The present study aims to first identify factors in boar sperm cryopreservation that significantly impacts post-thaw sperm quality using an efficient, cost-effective, and relatively rapid approach. The Plackett-Burman experimental design is ideal for the screening of factors at their extreme, greatly reducing the amount of time and resources needed for a follow-up, full factorial design. Using commercial semen, a 9 factor, 12 run Plackett-Burman design was used on 10 boars split between 12 treatments. Via this method glycerol concentration, cooling rate, antioxidant supplementation with GameteGuard(Membrane Protective Technologies, Inc. Fort Collins, CO), and straw size were identified as highly influential factors that impact post-thaw sperm quality. Extender type, starting osmolality, sodium dodecyl sulfate addition, and stepwise addition of glycerol were also influential for some but not all post-thaw sperm parameters (p<0.05). Equilibration time in the straws before freezing was determined to have no impact on post thaw sperm quality parameters. Using the Plackett-Burman design, it can be concluded that four of the nine factors warrant detailed investigation in a full factorial experiments in development of boar sperm cryopreservation extenders.

中文翻译：

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一种新的公猪精子冷冻保存实验设计

精子冷冻保存是许多家畜的常规技术，但猪却不是。冷冻精子必须产生可接受的受孕率并产生 11-12 头小猪/窝才能与传统的冷却精液竞争。开发可提高解冻后精子质量和可接受产仔数的增量剂需要确定显着影响解冻后精液质量的因素。本研究旨在首先使用高效、经济且相对快速的方法确定公猪精子冷冻保存中显着影响解冻后精子质量的因素。Plackett-Burman 实验设计是筛选极端因素的理想选择，大大减少了后续全因子设计所需的时间和资源。使用商业精液，一个 9 因素，12 轮 Plackett-Burman 设计用于 10 头公猪，分为 12 个处理。通过这种方法，甘油浓度、冷却速率、GameteGuard 抗氧化剂补充剂（Membrane Protective Technologies, Inc. Fort Collins, CO）和吸管大小被确定为影响解冻后精子质量的高度影响因素。增量剂类型、起始渗透压、十二烷基硫酸钠添加和逐步添加甘油也对一些但不是所有解冻后精子参数有影响（p＜0.05）。经确定，冷冻前细管的平衡时间对解冻后的精子质量参数没有影响。使用 Plackett-Burman 设计，可以得出结论，九个因素中的四个需要在开发公猪精子冷冻保存延长剂的全因子实验中进行详细调查。