Luna-Orozco J R, González-Ramos M A, Calderón-Leyva G, Gaytán-Alemán L R, Arellano-Rodríguez F, Ángel-García O, Véliz-Deras F G
Higher Education Unit Agricultural Technology and Marine Sciences, Center for Agricultural Technological Baccalaureate, No. 1, Coahuila, Mexico.
Graduated from Postgraduate Department of Agricultural Production, Autonomous Agrarian University Antonio Narro, Coahuila, Mexico.
Iran J Vet Res. 2019 Spring;20(2):126-130.
Sperm cryopreservation is an important tool for breed improvement, nonetheless, spermatozoids of rams are extremely sensitive to cryopreservation.
The present research was to compare a liposome-based (OptiXcell: OX) diluent, a commercial TRIS-egg yolk (Optidyl: OP) and a citrate egg yolk-based (CY) diluent on ovine semen quality through the cryopreservation process.
Semen was collected from four sexually mature Dorper rams during the natural breeding season. After collection, semen was evaluated and diluted in OX, OP or CY diluent and was cooled from 37°C to 4°C for 2 h (refrigerated semen, RS), after that semen-filled straws were placed in liquid nitrogen (LN) vapour for 10 min, then immersed into LN at -196°C (cryopreserved semen, CS) and stored until evaluation.
For fresh semen (FS), similar values (P>0.05) were obtained from the 3 diluents [motility (4.2 ± 0.3), viability (75.4 ± 3.2), hypo-osmotic swelling test (HOST) (59.2 ± 2.1), and normality (84.7 ± 3.5)]. The motility values were higher for RS with OX and CY (4.0 ± 0.2 and 3.6 ± 0.3, respectively) compared to OP (3.0 ± 0.21; P<0.05). The viability was reduced after refrigeration and freezing (P<0.05). Refrigerated semen viability was similar for OX (65%), CY (63%) and OP diluents (60%; P>0.05), but for frozen semen, viability was lower in the CY diluent (P<0.05). Membrane integrity (HOST) in OX (53.6 ± 1.7) was similar to that in OP (50.7 ± 1.5; P>0.05) but higher than in CY (48.7 ± 1.5; P<0.05).
No difference was found between the OX diluents and those made with egg yolk in terms of sperm parameters; however, the OX diluent was more efficient in protecting the integrity of membrane in freezing/thawing semen.
精子冷冻保存是品种改良的一项重要工具，然而，公羊的精子对冷冻保存极为敏感。
本研究旨在通过冷冻保存过程，比较基于脂质体的（OptiXcell：OX）稀释液、商用TRIS-蛋黄（Optidyl：OP）和基于柠檬酸盐蛋黄的（CY）稀释液对绵羊精液质量的影响。
在自然繁殖季节从四只性成熟的杜泊公羊采集精液。采集后，对精液进行评估，并分别用OX、OP或CY稀释液进行稀释，然后从37°C冷却至4°C 2小时（冷藏精液，RS），之后将装有精液的细管置于液氮（LN）蒸汽中10分钟，然后浸入-196°C的LN中（冷冻精液，CS）并储存直至评估。
对于新鲜精液（FS），三种稀释液的各项指标值相似（P>0.05）[活力（4.2±0.3）、存活率（75.4±3.2）、低渗肿胀试验（HOST）（59.2±2.1）和正常形态率（84.7±3.5）]。与OP稀释液（3.0±0.21；P<0.05）相比，OX和CY稀释的冷藏精液（RS）活力值更高（分别为4.0±0.2和3.6±0.3）。冷藏和冷冻后存活率降低（P<0.05）。OX（65%）、CY（63%）和OP稀释液（60%；P>0.05）的冷藏精液存活率相似，但对于冷冻精液，CY稀释液中的存活率较低（P<0.05）。OX稀释液的膜完整性（HOST）（53.6±1.7）与OP稀释液（50.7±1.5；P>0.05）相似，但高于CY稀释液（48.7±1.5；P<0.05）。
在精子参数方面，OX稀释液与蛋黄制成的稀释液之间未发现差异；然而，OX稀释液在冷冻/解冻精液过程中对保护膜完整性更有效。
