Aquila Foundation and the Center for Studies on Iberian Raptors, CERI Toledo, Spain.
Anim Reprod Sci. 2012 Mar;131(1-2):1-8. doi: 10.1016/j.anireprosci.2012.02.001. Epub 2012 Feb 9.
A comparative approach was used to evaluate semen cooling rates, thawing rates and freezing volume on the cryosurvival of avian sperm. Turkey (Meleagris gallopavo) and sandhill crane (Grus canadensis) sperm were cryopreserved with dimethylacetamide (DMA) concentrations ranging from 6% to 26%. Experiments evaluated the efficacy of (1) rapid, moderate and slow cooling rates, (2) rapid and slow thawing rates, and (3) final volume of semen frozen (0.2 mL compared to 0.5 mL). For crane sperm only, additional experiments were conducted to evaluate the effect of sucrose on cryosurvival. The functionality of frozen/thawed crane sperm was evaluated by fertility trials. For all studies, sperm viability was assessed using the nigrosin-eosin stain. Higher percentages of crane and turkey sperm maintained intact membranes when frozen with moderate or slow cooling rates compared to rapid cooling rates (P<0.05), regardless of DMA concentration. Turkey sperm viability was not affected by thawing rate at any DMA concentration (P>0.05). Crane sperm viability was only affected by thawing rate for the 24% DMA treatment, where moderate thawing was better than slow thawing (P<0.05). Sperm viability was not affected by the semen volume used for freezing for either species (P>0.05). The percentage of membrane-intact crane sperm at lower DMA concentrations was improved by addition of 0.1M sucrose (P<0.05) but not 0.29 M NaCl. The mean fertility rate from frozen/thawed crane semen was 57.5%, and 71.4% of the fertile eggs hatched. The viability of crane sperm was always greater than turkey sperm, regardless of cooling rate, thawing rate or volume of semen frozen. These data verify avian-specific differences in sperm cryosurvival, further emphasize the need for species specific studies to optimize cryopreservation protocols.
采用比较方法评估了精液冷却速率、解冻速率和冷冻体积对禽类精子冷冻保存的影响。火鸡（Meleagris gallopavo）和沙丘鹤（Grus canadensis）精子用二甲酰胺（DMA）浓度范围为 6%至 26%进行冷冻保存。实验评估了以下方面的效果：（1）快速、中度和缓慢冷却速率；（2）快速和缓慢解冻速率；（3）冷冻精液的最终体积（0.2 毫升与 0.5 毫升）。仅对鹤精子进行了额外的实验，以评估蔗糖对冷冻保存效果的影响。冷冻/解冻鹤精子的功能通过受精试验进行评估。对于所有研究，使用黑-曙红染色评估精子活力。与快速冷却速率相比，用中度或缓慢冷却速率冷冻时，更多的鹤和火鸡精子保持完整的膜，这与 DMA 浓度无关（P<0.05）。在任何 DMA 浓度下，解冻速率都不会影响火鸡精子活力（P>0.05）。只有在 24% DMA 处理中，鹤精子活力才受到解冻速率的影响，中度解冻优于缓慢解冻（P<0.05）。对于这两个物种，用于冷冻的精液量都不会影响精子活力（P>0.05）。在较低 DMA 浓度下，添加 0.1M 蔗糖可提高膜完整的鹤精子比例（P<0.05），但添加 0.29 M NaCl 则没有提高（P<0.05）。冷冻/解冻鹤精液的平均受精率为 57.5%，71.4%的可育卵孵化。无论冷却速率、解冻速率或冷冻精液体积如何，鹤精子的活力始终大于火鸡精子。这些数据验证了禽类精子冷冻保存中存在特定物种差异，进一步强调需要进行特定物种研究以优化冷冻保存方案。
