不同稀释保护液对羊精子在4 ℃低温保存条件下品质影响的探索研究

Effect of Different Dilution Media on the Quality of Sheep Semen during LowTemperature Preservation at 4 ℃

摘要:

本研究旨在评估不同稀释保护液(含蛋黄、大豆卵磷脂、甘油等成分)在4 ℃条件下保存6 d对种公羊精子参数的影响,从而为种公羊鲜精低温延时保存技术提供科学依据,并提高优质种公羊的利用率。实验通过混合精液样本以消除个体差异,并将混合后的精液均分为三份,分别添加至三种不同的稀释保护液(Tris基础液+大豆卵磷脂、Tris基础液+蛋黄、牛奶+果糖)中进行等温稀释,使最终精子浓度达到40×10⁶个/mL。随后,将稀释后的精子分装至0.25 mL麦管中,并使用聚乙烯醇进行密封,储存于4 ℃恒温冰箱中。在储存后的0、72、120和144 h,采用计算机辅助精子分析系统(CASA)测定精子活力参数,并利用伊红染色技术评估精子顶体完整性和异常率。实验结果显示,在初始状态下,各组精子活力相近且未检出异常率;然而,随着储存时间的延长,精子活力逐渐降低,异常率逐渐上升。特别是在储存144 h后,牛奶+果糖组的精子活力最低,异常率最高;相比之下,Tris基础液+大豆卵磷脂组在短期内对精子活力的保持效果更佳,且精子异常率相对较低。因此,本研究表明,在4 ℃低温保存种公羊精子时,选择合适的稀释保护液对于维持精子活力和降低异常率至关重要,其中Tris基础液+大豆卵磷脂稀释保护液表现出较好的应用潜力。

Abstract:

This study aimed to evaluate the effects of different dilution media(containing egg yolk,soy lecithin,glycerol,etc.)on semen parameters of breeding rams after 6day storage at 4 ℃.The objective was to provide scientific evidence for the lowtemperature delayed preservation of fresh semen from breeding rams and improve the utilization rate of highquality breeding rams.Semen samples were mixed to eliminate individual differences,and the mixed semen was evenly divided into three portions and diluted with three different dilution media(Tris base solution+soy lecithin, Tris base solution+egg yolk,milk+fructose)at an isothermal condition to achieve a final sperm concentration of 40×10⁶/mL.Subsequently,the diluted semen was dispensed into 0.25 mL straws,sealed with polyvinyl alcohol,and stored in a constanttemperature refrigerator at 4 ℃.At 0,72,120 and 144 h after storage,sperm motility parameters were determined using a computer-assisted sperm analysis system(CASA),and sperm acrosome integrity and abnormality rates were assessed using eosin staining.The results showed that sperm motility was similar in all groups at the initial state,and no abnormalities were detected.However,with the extension of storage time,sperm motility gradually decreased,and the abnormality rate gradually increased.Particularly after 144 h of storage,the milk+fructose group exhibited the lowest sperm motility and the highest abnormality rate.In contrast,the Tris base solution+soy lecithin group showed better maintenance of sperm motility in the short term,with a relatively low sperm abnormality rate.Therefore,this study indicates that selecting the appropriate dilution media is crucial for maintaining sperm motility and reducing the abnormality rate during lowtemperature preservation of semen from breeding rams at 4 ℃.Among them,the Tris base solution+soy lecithin dilution media demonstrated good application potential.