Bedford S J, Jasko D J, Graham J K, Amann R P, Squires E L, Pickett B W
Animal Reproduction and Biotechnology Laboratory, Colorado State University, Fort Collins, CO 80523, USA.
Theriogenology. 1995 Apr 1;43(5):955-67. doi: 10.1016/0093-691x(95)00045-a.
Three experiments were conducted to evaluate the effects of egg yolk and(or) glycerol added to a nonfat dried skim milk-glucose (NDSMG) extender on motion characteristics and fertility of stallion spermatozoa. In Experiment 1, ejaculates from each of 8 stallions were exposed to each of 4 extender treatments: 1) NDSMG, 2) NDSMG + 4% egg yolk (EY), 3) NDSMG + 4% glycerol (GL), and 4) NDSMG + 4% egg yolk + 4% glycerol (EY + GL). Samples were cooled at -0.7 degrees C/min from 37 to 20 degrees C; subsamples were then cooled at -0.05 or -0.5 degrees C/min from 20 to 5 degrees C. Percentages of motile spermatozoa (MOT) and progressively motile spermatozoa (PMOT) were determined at 6, 24 and 48 h after initiation of cooling. There was no overall effect (P > 0.05) of cooling rate. PMOT was highest (P < 0.05) for spermatozoa extended in NDSMG + GL at 48 h. At 24 and 48 h, MOT and PMOT were lowest (P < 0.05) for spermatozoa extended in NDSMG + EY. In Experiment 2, ejaculates from 8 stallions were exposed to each of 4 treatments: 1) NDSMG, 2) NDSMG + EY, 3) semen centrifuged in NDSMG and resuspended in NDSMG, and 4) semen centrifuged in NDSMG and resuspended in NDSMG + EY. Samples were cooled from 20 to 5 degrees C at each of 2 rates (-0.05, -0.5 degrees C/min). A detrimental interaction between seminal plasma and egg yolk was noted for PMOT at 6 h and for both MOT and PMOT at > or = 24 h postcooling. Experiment 3 determined if egg yolk or glycerol affected fertility. The seminal treatments were 1) NDSMG, 2) NDSMG + EY with previous removal of seminal plasma, and 3) NDSMG + GL. All samples were cooled to 5 degrees C and stored 24 h before insemination. Embryo recovery rates 7 d after ovulation were lower for mares inseminated with spermatozoa cooled in NDSMG + EY (17%, 4/24) or NDSMG + GL (13%, 3/24) extenders, than semen cooled in NDSMG (50%, 12/24). We concluded that egg yolk (with seminal plasma removal) or glycerol added to NDSMG extender did not depress MOT or PMOT of cooled stallion spermatozoa but adversely affected fertility.
进行了三项实验，以评估向脱脂干脱脂奶粉 - 葡萄糖（NDSMG）稀释剂中添加蛋黄和（或）甘油对种马精子运动特性和生育力的影响。在实验1中，8匹种马的射精分别接受4种稀释剂处理：1）NDSMG，2）NDSMG + 4%蛋黄（EY），3）NDSMG + 4%甘油（GL），4）NDSMG + 4%蛋黄 + 4%甘油（EY + GL）。样品以每分钟 -0.7摄氏度的速度从37摄氏度冷却至20摄氏度；然后子样品以每分钟 -0.05或 -0.5摄氏度的速度从20摄氏度冷却至5摄氏度。在冷却开始后6、24和48小时测定活动精子（MOT）和进行性活动精子（PMOT）的百分比。冷却速度没有总体影响（P>0.05）。在48小时时，在NDSMG + GL中稀释的精子的PMOT最高（P<0.05）。在24和48小时时，在NDSMG + EY中稀释的精子的MOT和PMOT最低（P<0.05）。在实验2中，8匹种马的射精分别接受4种处理：1）NDSMG，2）NDSMG + EY，3）精液在NDSMG中离心并重新悬浮于NDSMG中，4）精液在NDSMG中离心并重新悬浮于NDSMG + EY中。样品以两种速度（每分钟 -0.05、 -0.5摄氏度）中的每一种从20摄氏度冷却至5摄氏度。在冷却后6小时观察到精浆和蛋黄之间对PMOT有有害相互作用，在冷却后≥24小时对MOT和PMOT均有有害相互作用。实验3确定蛋黄或甘油是否影响生育力。精液处理为：1）NDSMG，2）预先去除精浆的NDSMG + EY，3）NDSMG + GL。所有样品均冷却至5摄氏度并在授精前储存24小时。用在NDSMG + EY（17%，4/24）或NDSMG + GL（13%，3/24）稀释剂中冷却的精子授精的母马，排卵后7天的胚胎回收率低于用在NDSMG中冷却的精液（50%，12/24）。我们得出结论，向NDSMG稀释剂中添加蛋黄（去除精浆）或甘油不会降低冷却的种马精子的MOT或PMOT，但会对生育力产生不利影响。
