Although useful spermatozoa cryopreservation techniques have been established, long‐term equilibration seems to be required before freezing the spermatozoa of many species, including dogs. The fertility of cryopreserved dog spermatozoa from five males for a reduced equilibration period (0, 30, 60, 120 and 180 min) in a skim milk (SM)‐based extender containing raffinose was evaluated in the present study. When the sperm was diluted with the extender at room temperature (RT) and cryopreserved without equilibration, the proportion of total motile spermatozoa (TMS) after thawing was lower (27%) than when the sperm was equilibrated for 30 min (33%), 60 min (32%), 120 min (44%; p < .05) or 180 min (29%). The proportion of TMS increased as the equilibration time increased and peaked at 120 min. Acrosome integrity was significantly lower in the cryopreserved spermatozoa that had not undergone the initial equilibration than in the equilibrated spermatozoa (p < .05). The normal rate of acrosomes increased with the extension of the first equilibration and peaked at 120 min. When frozen–thawed spermatozoa that had been diluted at RT and subjected to an initial equilibration lasting 60 or 180 min were transcervically inseminated into recipients, there were no differences in the delivery rate, litter size or breeding efficiency. In the cryopreservation of canine spermatozoa using a SM‐based extender, even if the initial equilibration time was shortened to 60 min, the results were comparable to those obtained when the conventional method (with an initial equilibration time of 180 min) was used.

中文翻译：

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使用脱脂乳基补充剂和较短的平衡时间冷冻保存精子。

尽管已经建立了有用的精子冷冻保存技术，但在冷冻包括狗在内的许多物种的精子之前，似乎需要长期平衡。在本研究中，评估了五只雄性的低温保存的狗精子在含有棉子糖的脱脂乳（SM）增量剂中的平衡期缩短（0、30、60、120和180分钟）的繁殖力。当精子在室温（RT）下用增量剂稀释并冷冻而不平衡时，解冻后总活动精子（TMS）的比例（27％）比精子平衡30分钟（33％）时要低， 60分钟（32％），120分钟（44％; p <.05）或180分钟（29％）。随着平衡时间的增加，TMS的比例增加，并在120分钟达到峰值。未进行初始平衡的冷冻保存的精子的顶体完整性显着低于平衡的精子（p <.05）。顶体的正常比率随着第一次平衡的延长而增加，并在120分钟达到峰值。当将经冷冻融化的精子在室温下稀释并持续60或180分钟的初始平衡后，经子宫颈经受精后，其分娩率，窝产仔数或繁殖效率没有差异。使用基于SM的补充剂对犬精子进行冷冻保存时，即使将初始平衡时间缩短至60分钟，其结果也可以与使用传统方法（初始平衡时间为180分钟）获得的结果相媲美。