Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil; Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois Urbana Champaign, Urbana IL.
Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil.
J Equine Vet Sci. 2021 Oct;105:103719. doi: 10.1016/j.jevs.2021.103719. Epub 2021 Jul 18.
The present study aimed to compare semen parameters and fertility of cooled donkey semen extended in a commercially available skim milk (SKM) based extender and the same extender with cholesterol-loaded cyclodextrin (SKM-CLC). In Experiment 1, thirty-five ejaculates from seven jacks were split in SKM and SKM-CLC, extended at 50 million sperm/mL and stored at 5°C for 48 hours. Total motility (TM), progressive motility (PM), percentage of sperm with rapid motility (RAP) were assessed with CASA. Plasma membrane stability (PMS), and high mitochondrial membrane potential (HMP) were assessed with the combination of Yo-Pro and MitoStatusRed with flow cytometry. Semen was assessed before (0), 24 and 48h after cooling. In Experiment 2, two estrous cycles of 15 mares were used for fertility assessment. Mares were examined every other day by transrectal ultrasonography and had ovulation induced with 250 µg of histrelin acetate when a ≥35 mm follicle was first detected. Mares were randomly inseminated with semen obtained from one jack. Semen was extended in either SKM or SKM-CLC and cooled-stored for 24 hours. Pregnancy diagnosis was carried out 15-day post-ovulation. Data were analyzed with a mix model and Tukey's as posthoc and logistic regression model. Significance was set at P ≤ .05. There were no differences in TM, PM, RAP, PMS, and HMP for semen extended in either extender immediately before cooling (P > .05). There was a reduction in TM, PM, RAP, PMS, and HMP overtime across groups (P < .05); however, semen extended with SKM-CLC had superior TM, PM, RAP, PMS, and HMP than semen extended in SKM at 24- and 48-hours post-cooling (P < .05). Mares bred with semen extended in SKM had a lower conception rate (13%, 2/15 cycles) than cycles bred with SKM-CLC (47%, 7/15 cycles; P < .05). In conclusion, incorporating CLC into SKM extender improved cooling ability and fertility of donkey semen in horse mares. It remains to be determined if similar results can be obtained in clinical practice with mares and jennies.
本研究旨在比较在市售脱脂乳（SKM）基础 extender 和相同的 extender 中添加胆固醇负载环糊精（SKM-CLC）对冷却驴精液参数和生育力的影响。在实验 1 中，将来自 7 头公驴的 35 份精液分为 SKM 和 SKM-CLC，以 5000 万精子/ml 的浓度扩展，在 5°C 下储存 48 小时。使用 CASA 评估总活力（TM）、前向运动精子（PM）、快速运动精子比例（RAP）。使用 Yo-Pro 和 MitoStatusRed 结合流式细胞术评估质膜稳定性（PMS）和高线粒体膜电位（HMP）。在冷却前（0）、冷却后 24 和 48 小时评估精液。在实验 2 中，使用 15 匹母马的两个发情周期进行生育力评估。通过直肠超声每隔一天检查母马，并在首次检测到≥35mm 卵泡时使用 250μg 醋酸曲普瑞林诱导排卵。母马随机用来自 1 头公驴的精液授精。精液在 SKM 或 SKM-CLC 中扩展，冷却储存 24 小时。排卵后 15 天进行妊娠诊断。使用混合模型和 Tukey 作为事后检验和逻辑回归模型进行数据分析。显著性水平设为 P ≤.05。在冷却前（P >.05），在两种 extender 中扩展的精液的 TM、PM、RAP、PMS 和 HMP 没有差异。随着时间的推移，各组的 TM、PM、RAP、PMS 和 HMP 均呈下降趋势（P <.05）；然而，与在 SKM 中扩展的精液相比，在 SKM-CLC 中扩展的精液在冷却后 24 和 48 小时具有更高的 TM、PM、RAP、PMS 和 HMP（P <.05）。用 SKM 扩展的精液配种的母马受胎率（13%，15 个周期中的 2 个）低于用 SKM-CLC 扩展的精液配种的母马（47%，15 个周期中的 7 个；P <.05）。总之，在 SKM 中添加 CLC 可提高驴精液的冷却能力和马母马的生育力。在临床实践中，母马和母驴是否能获得类似的结果仍有待确定。
