Cauda epididymis in mammals is known to store mature sperm largely in quiescent state for several weeks without significantly affecting fertility. Hence, the aim of this study was to evaluate the effects of mimicking cauda epididymal plasma (CEP)-like conditions in extender on liquid preservation of ram semen at 3–5°C. Four experiments were conducted in this study: (1) evaluation of physicochemical properties of ram CEP, (2) effect of hyperosmotic solution on sperm motility and functional membrane integrity (FMI), and the effects of (3) CEP-like hyperosmolality (390 vs. 360 mOsmol/kg) and (4) pH in extender (pH 6.5 vs. 6.8) on liquid preservation of ram semen. Sperm treatment with hyperosmotic solution (450 mOsmol/kg) resulted in a decline (P < 0.05) in mass motility (3.5 ± 0.2 vs. 4.3 ± 0.2) and FMI (30.4 ± 3.2 vs. 52.1 ± 2.1%) compared to that with isoosmotic solution (360 mOsmol/kg). Overall, sperm viability, acrosomal integrity, and progressive motility were similar (P > 0.05) while straight-line velocity (77.8 ± 3.1 vs. 71.3 ± 2.7µm/s), linearity (47.4 ± 0.4 vs. 39.5 ± 0.9%), straightness (79.7 ± 0.5 vs. 74.0 ± 0.5%) and beat cross frequency (28.6 ± 0.8 vs. 26.0 ± 0.5 Hz) were higher (P < 0.05) and FMI (65.7 ± 1.5 vs. 75.4 ± 1.1%) was lower (P < 0.05) following liquid-preservation in hyperosmotic extender compared to that in isoosmotic extender. Both total motility (83.3 ± 1.8 vs. 75.4 ± 1.5%) and progressive motility (51.7 ± 2.3 vs. 39.5 ± 1.9%) were higher (P < 0.05) at 48 h of storage in hyperosmotic extender compared to the control. Overall, the seminal attributes were similar (P > 0.05) between the two pH’s of the extender. In conclusion, semen extender having CEP-like osmolality but not the pH was superior to extenders having conventional osmolality and pH for liquid preservation of ram semen.

Abbreviations: AI: artificial insemination; ALH: amplitude of lateral head displacement; BCF: beat cross frequency; CASA: computer-assisted semen analyzer; CEP: cauda epididymal plasma; ELON: elongation; EYTF: egg yolk-Tris-citrate-fructose; FMI: functional membrane integrity; GLM: general linear model; GPC: glycerophosphatidylcholine; HOS: hypoosmotic swelling; LIN: linearity; pHe: external pH; PROG: progressive motility; S.E.M.: standard error of the mean; SLTF: soya lecithin-Tris-fructose extender; SP: seminal plasma; STR: straightness; VAP: average path velocity; VCL: curvilinear velocity; VSL: straight-line velocity; TM: total motility

已知哺乳动物的附睾马尾精子在静止状态下可将成熟的精子大量储存数周，而不会显着影响生育能力。因此，本研究的目的是评估在补充剂中模仿马尾附睾血浆（CEP）状条件对公羊精液在3–5°C保存的影响。本研究进行了四个实验：（1）评价ram CEP的理化性质，（2）高渗溶液对精子活力和功能性膜完整性（FMI）的影响，以及（3）CEP样高渗性（390）相对于360 mOsmol / kg）和（4）精液保鲜剂中的pH值扩展剂（pH 6.5对6.8）。用高渗溶液（450 mOsmol / kg）进行精子治疗导致质量运动性（3.5±0.2 vs. 4.3±0.2）和FMI（30.4±3.2 vs. 52.1±2）下降（P <0.05）。1％）与等渗溶液（360 mOsmol / kg）相比。总体而言，精子活力，顶体完整性和进行性运动相似（P> 0.05），直线速度（77.8±3.1 vs. 71.3±2.7µm / s），线性（47.4±0.4 vs. 39.5±0.9％），直线度（79.7±0.5 vs. 74.0±0.5％）和拍频（28.6±0.8 vs.26.0±0.5 Hz）较高（P <0.05），FMI（65.7±1.5 vs. 75.4±1.1％）较低（与等渗增量剂相比，高渗增量剂中保存液体后的P <0.05）。与对照组相比，在高渗增量剂中储存48 h时，总运动能力（83.3±1.8 vs. 75.4±1.5％）和进行性运动（51.7±2.3 vs. 39.5±1.9％）均较高（P <0.05）。总体而言，增量剂的两个pH值之间的精髓属性相似（P> 0.05）。结论，

缩写：AI：人工授精；ALH：头部横向位移幅度；BCF：拍子交叉频率；CASA：计算机辅助精液分析仪；CEP：马尾附睾血浆；ELON：伸长率；EYTF：蛋黄-柠檬酸-果糖；IMF：功能性膜完整性；GLM：一般线性模型；GPC：甘油磷脂酰胆碱；居屋：低渗性肿胀；LIN：线性度；pHe：外部pH；PROG：进行性运动；SEM：平均值的标准误；SLTF：大豆卵磷脂-Tris-果糖增量剂；SP：精浆；STR：直线度；VAP：平均路径速度；VCL：曲线速度；VSL：直线速度；TM：总运动