Reproduction in swine is mostly carried out through artificial insemination (AI). For this purpose, AI studs collect the ejaculates, analyse the sperm quality, dilute and package to produce seminal doses and ship them to sow farms to carry out the AI. Temperature is controlled during the process to avoid sperm damage. Semen is diluted in the extender in a one‐step or a two‐step process where the second can be isothermic (approximately 32°C) or hypothermic (room temperature 21–22°C). Both techniques are currently performed, and the latter could reduce time and costs, but the literature available comparing the processes is scarce and presents discrepancies. To date, there are no studies about its impact in fertility. This study compared hypothermic two‐step dilution (HTSD) and isothermic two‐step dilution (ITSD) in laboratory and field trial to elucidate whether HTSD has any effect. Ejaculates from 72 boars in nine AI studs were split and processed with both techniques using a high‐performance extender and evaluated in laboratory. Four farms inseminated 345 sows with samples of four of these AI studs, and their fertility and prolificacy were registered. Results show no significant differences between doses prepared by HTSD and ITSD technique, having no impact in laboratory results (percentage of motile sperm, short hypoosmotic swelling test (sHOST) and short osmotic resistance test (sORT), viable sperm, damaged acrosomes, sperm under early apoptosis, high mitochondrial membrane potential (p > .1), fertility (92.2% versus 94.1%, p = .45) or farrowing rate (15.8 ± 0.3 versus 16.1 ± 0.3 p = .46). In conclusion, our results suggest that HTSD of semen on extender could be safely implemented in AI studs under the conditions tested.

中文翻译：

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通过两步低温稀释制备的精液对母猪进行授精不会损害农场的繁殖性能。

猪的繁殖主要通过人工授精（AI）进行。为此，AI螺柱收集精液，分析精子质量，稀释和包装以产生精液，然后将它们运送到母猪场进行AI。在过程中控制温度，以避免精子受损。精液通过一步或两步稀释剂在稀释液中稀释，其中第二步可以是等温（约32°C）或低温（室温21–22°C）。两种技术目前都已执行，后者可以减少时间和成本，但是比较该过程的可用文献很少，并且存在差异。迄今为止，还没有关于其对生育力影响的研究。这项研究在实验室和现场试验中比较了低温两步稀释法（HTSD）和等温两步稀释法（ITSD），以阐明HTSD是否有效。将来自9个AI螺柱的72只公猪的射精进行分割，并使用高性能的扩展剂通过两种技术进行处理，并在实验室进行评估。四个农场向345头母猪授精了其中四个AI螺柱的样品，并记录了它们的繁殖力和繁殖力。结果显示，通过HTSD和ITSD技术制备的剂量之间没有显着差异，对实验室结果没有影响（活动精子的百分比，短期低渗性溶胀试验（sHOST）和短期渗透性抵抗试验（sORT），活精子，顶体受损，精子受精早期细胞凋亡，线粒体膜电位高（将来自9个AI螺柱的72只公猪的射精进行分割，并使用高性能的扩展剂通过两种技术进行处理，并在实验室进行评估。四个农场向345头母猪授精了其中四个AI螺柱的样品，并记录了它们的繁殖力和繁殖力。结果显示，通过HTSD和ITSD技术制备的剂量之间没有显着差异，对实验室结果没有影响（活动精子的百分比，短期低渗性溶胀试验（sHOST）和短期渗透性抵抗试验（sORT），活精子，顶体受损，精子受精早期凋亡，线粒体膜电位高（将来自9个AI螺柱的72只公猪的射精进行分割，并使用高性能的扩展剂通过两种技术进行处理，并在实验室进行评估。四个农场向345头母猪授精了其中四个AI螺柱的样品，并记录了它们的繁殖力和繁殖力。结果显示，通过HTSD和ITSD技术制备的剂量之间没有显着差异，对实验室结果没有影响（活动精子的百分比，短暂的低渗溶胀试验（sHOST）和短暂的渗透压耐受试验（sORT），活精子，顶体受损，精子受精早期细胞凋亡，线粒体膜电位高（p  > .1），生育率（92.2％对94.1％，p  = 0.45）或分娩率（15.8±0.3对16.1±0.3 p  = 0.46）。总之，我们的结果表明，在经过测试的条件下，可以在AI螺柱中安全地实施增量剂精液的HTSD。