Effect of Long-Term Storage at Different Temperatures on the Quality of Liquid Boar Semen

In this study the effect of long‐term storage of liquid boar semen at different temperatures on motility, acrosome integrity and pH was investigated. Additionally, individual variation in sperm tolerance to storage at 10°C were examined. Beltsville Thawing Solution‐diluted AI doses from 16 randomly chosen Norwegian Landrace AI boars with proven fertility were split into subsamples and stored at 25, 20, 15 and 10°C, respectively. After 0, 24, 48, 72 and 96 h of storage, sperm motility, acrosome integrity and pH were determined. After 96 h, the initial percentage of motile sperm (77.8%) was significantly reduced to 52.2, 58.8, 50.9 and 42.8% by storage at 25, 20, 15 and 10°C, respectively. After an identical period of time, the percentage of acrosome intact sperm (95.8%) at time 0 became significantly reduced to 91.3, 91.3, 81.5 and 68.3% by storage at 25, 20, 15 and 10°C, respectively. The initial pH (7.21) decreased significantly to 6.96 and 7.06 after 96 h storage at 25 and 20°C, and increased not significantly to 7.25 for storage at 15°C and significantly to 7.29 at 10°C. In conclusion, the results from this study show that, according to the variables studied, 20°C is the least harmful of the four temperatures tested for the long‐term liquid storage of boar semen. Furthermore, remarkable differences in the individual resistance of boar semen to long‐term storage at 10°C were observed.     

Effect of Different Packages and Freezing/Thawing Protocols on Fertility of Ram Semen

A field trial was performed in order to evaluate the effect on fertility of different straw types, freezing protocols (one- or two-step) and thawing procedures (35°C and 70°C) using frozen–thawed ram semen. A total of 791 Norwegian Crossbred ewes were artificially inseminated during natural oestrus with semen collected from nine mature and proven Norwegian Crossbred rams. A milk-based extender was used for dilution. The ewes were allocated into one of the following three groups based on the different straw types and thawing temperatures: medium straw (0.5 ml) thawed at 35°C for 20 s (Med35), medium straw thawed at 70°C for 8 s (Med70) and mini straw (0.25 ml) thawed at 35°C for 15 s (Mini35). The semen to be frozen in mini straws was re-concentrated by centrifugation. Sperm number in each insemination dose was approximately 200 × 10⁶ spermatozoa. The fertility results [as 25-day non-return rate (NRR)] for Med35, Med70 and Mini35 were 53.1%, 50.8% and 58.3%, respectively, and the lambing rates 49.8%, 46.8% and 53.8%, respectively. No significant main effects were seen for straw type/thawing temperature (p = 0.17), ram (p = 0.06) or age of the ewe (p = 0.18) on NRR or lambing rates (p = 0.19, p = 0.16 and p = 0.27, respectively). Both NRR and lambing rate differed significantly among farms (p < 0.0001).     

Effect on Field Fertility of Addition of Gelatine,Different Dilution Rates and Storage Times of Cooled Ram Semen After Vaginal Insemination

In a field trial, 633 ewes from 24 farms were inseminated vaginally using liquid semen (150 × 10⁶ per dose) collected from 15 rams. The semen was either diluted with a milk‐based extender (M), filled in 0.2 ml straws and stored for 12 or 24 h (M12, M24) or diluted with M but with the addition of gelatine, filled in 0.5 ml straws and stored for 12 or 24 h (G12, G24). The hypothesis was that a larger volume and the addition of gelatine would prolong the survival of the spermatozoa. The ewes, aged between 6 months and 5.5 years, were allocated into four groups and inseminated after natural oestrus by the farmers themselves with a dose of 150 × 10⁶ spermatozoa. Inseminations in the groups (M12, M24, G12, G24) resulted in lambing rates of 69.6%, 63.6%, 69.4% and 58.3% (overall 65.2%), respectively. Farmer (p < .0002) had a significant effect on the lambing rate, while ram, age of the ewe and dilution rate/addition of gelatine/storage time had not. A pair‐wise comparison of the lambing rates between the four groups showed that significant lower results were only achieved for G24 compared with M12. None of the other comparisons showed significant differences. In conclusion, a higher dilution rate of the AI‐dose together with the addition of gelatine to the semen extender did not lead to improved fertility results after storage for 24 h when compared with standard AI‐doses used in Norway.     

猪精液液态保存的研究进展

猪的人工授精主要使用液态保存精液 ,此法保存精子的存活率高、功能受损较小、授精繁殖率较高且操作简便。体外液态保存猪精液时 ,不仅要注意猪精子对温度变化敏感的特性 ,还要考虑酸碱度、离子的种类和强度、渗透压、过氧化损伤和微生物污染等对精子的影响 ,要向稀释液中添加各种保护成分 ,维持精子的存活和功能。目前主要是比较和改进各种稀释液 ,建立准确的精子质量评价方法 ,提高受精率     

Liquid Storage of Goat Semen in Chemically Defined Extenders

The suitability of certain commercial and self‐made chemically defined extenders for liquid storage of goat semen was tested and the effects of storage temperatures, dilution rates and sperm washing and pH of extenders on the goat sperm during liquid storage were observed. Semen was collected from nine goat bucks of the Lubei White and Boer breeds using an artificial vagina. Each ejaculate after initial evaluation was diluted with a specific extender, cooled and stored at a desired temperature. Stored semen was evaluated for sperm motility and other parameters every 24 or 48 h of storage. The ranking order of the existing milk‐ and yolk‐free extenders in sustaining goat sperm motility was Androhep > Zorlesco > Beltsville thawing solution > the Tris–glucose medium. The new extender (mZA) which was formulated based on Zorlesco and Androhep was more suitable for goat sperm than Androhep. The mZAP extender with Bovine Serum Albumin (BSA) replaced with polyvinyl alcohol (PVA) worked as efficiently as the mZA in maintaining sperm motility, membrane integrity, acrosome intactness and capacitation status. Goat sperm motility was best maintained at 5°C during liquid preservation, but decreased significantly as the temperature increased. When semen was sixfold diluted, sperm motility was maintained longer (p < 0.05) after centrifugation, but sperm motility did not differ between the centrifuged and non‐centrifuged groups when semen was 11‐fold diluted. When the extender pH was adjusted from 6.6 to 6.04, the efficiency increased significantly in both Androhep and mZAP. A forward sperm motility of 34% was maintained for 9 days when buck semen was 11‐fold diluted and stored at 5°C in mZAP, with pH adjusted to 6.04. It is concluded that for liquid storage of buck semen, the mZA extender was more suitable than other extenders; BSA can be replaced with PVA in mZA; centrifugation to remove seminal plasma can be omitted by adequate dilution; and the storage temperature and pH of extenders affected sperm motility significantly.     

Effect of Docosahexaenoic Acid on Quality of Cryopreserved Boar Semen in Different Breeds

During the cryopreservation process, the level of polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), in the sperm plasma membrane decreases significantly because of lipid peroxidation, which may contribute to sperm loss quality (i.e. fertility) of frozen–thawed semen. The aim of this study was to investigate the effect of supplementation of DHA (fish oil) in freezing extender II on frozen–thawed semen quality. Semen from 20 boars of proven motility and morphology, were used in this study. Boar semen was split into four groups, in which the lactose–egg yolk (LEY) extender used to resuspend the centrifuged sperm pellet was supplemented with various levels of fish oil to reach DHA level of 1X (group I, control, no added fish oil), 6X (group II), 12X (group III) and 18X (group IV). Semen solutions were frozen by using a controlled rate freezer. After cryopreservation, frozen semen was thawed and evaluated for progressive motility, viability by using SYBR‐14/Ethidiumhomodimer‐1 (EthD‐1) staining and acrosome integrity by using FITC‐PNA/EthD‐1 staining. There was a significantly higher (p < 0.001) percentage of progressive motility, viability and acrosome integrity in DHA (fish oil) supplemented groups than control group. Generally, there seemed to be a dose‐dependent effect of DHA, with the highest percentage of progressive motility, viability and acrosome integrity in group‐III. In conclusion, supplementation of the LEY extender with DHA by adding fish oil was effective for freezing boar semen as it resulted in higher post‐thaw plasma membrane integrity and progressive motility.     

不同稀释液对公猪精液常温保存效果的研究

 为提高猪精液的保存效果,设计了3种常温保存稀释液配方,并对保存后的精子进行了顶体染色,为猪精液常温保存技术及稀释液配方的研究提供参考依据。结果表明：当精子活率为50％与30％时,配方Ⅱ的精子保存时间均显著高于（P<0.05）配方Ⅰ与配方Ⅲ,且配方Ⅱ所保存精子的总存活时间也显著高于（P<0.05）配方Ⅰ与配方Ⅲ;在精液保存24h后,3种配方保存的精子顶体完整率均在95％以上,且差异不显著（P>0.05）,配方Ⅱ对精子的常温保存效果要优于配方Ⅰ与配方Ⅲ。     

维生素E对绵羊鲜精及冻精精液品质的影响

日粮中添加维生素E可以提高绵羊鲜精的活率 ,对照组和试验组的活率分别为 0 72± 0 0 7和 0 78± 0 0 6(P <0 0 5 ) ,显著改善鲜精精液品质。采用两步稀释法在绵羊冷冻精液稀释液中添加维生素E ,可以极显著降低冷冻对精子顶体的冷刺激损害程度 ,试验组的活率 ( 0 43 5± 0 0 2 0 )极显著高于对照组 ( 0 3 65± 0 0 2 6) (P <0 0 1) ,精子顶体的总异常率试验组 ( 3 3 72 % )极显著低于对照组 ( 4 4 3 5 % ) (P <0 0 1) ,其中试验组顶体膨胀率和脱落率与对照组分别为 1 2 8%±0 5 8%、2 3 0 8%± 1 45 %与 2 68%± 0 5 9%、2 8 96%± 3 14 %。冷冻精液品质显著改善。     

Effect of Different Levels of Glycerol and Cholesterol‐Loaded Cyclodextrin on Cryosurvival of Ram Spermatozoa

This study was conducted to determine the optimum level of glycerol and cholesterol‐loaded cyclodextrin (CLC) in a Tris‐based diluent for cryopreservation of ram spermatozoa. Ram semen was treated with 0, 1.5, 3 or 4.5 mg CLC/120 × 10⁶ cells in Tris‐based diluents containing 3, 5 or 7% glycerol in a factorial arrangement 3 × 4 and frozen in liquid nitrogen vapour. Sperm motility, viability (eosin–nigrosin staining) and functional membrane integrity (hypo‐osmotic swelling test) were assessed immediately after thawing (0 h) and subsequently after 3 and 6 h at 37°C. There was an interaction between CLC and glycerol on the functional membrane integrity (p < 0.05). In the presence of 3% glycerol, the highest functional membrane integrity (32.2%) was found in the spermatozoa treated with 1.5 mg CLC/120 × 10⁶ sperm. Post‐thaw sperm motility was highest in 1.5 mg CLC immediately after thawing (40.5%) and after 3‐h (30.6%) incubation at 37°C (p < 0.05). Viability of spermatozoa was higher in all CLC treatments than in the untreated samples, and it was highest (33.9%) in the spermatozoa treated with 1.5 mg CLC (p < 0.05). These data indicate that the addition of cholesterol to sperm membranes by 1.5 mg CLC/120 × 10⁶ cells may allow the use of a lower concentration of glycerol (3%), which is sufficient to mitigate the detrimental effects of freezing and thawing.     

中草药添加剂对种公羊精液品质和耐冻性的影响

为探索中草药添加剂对种公羊精液品质的影响,用当归(Radix angelicae sinensis)、党参(Radix codonop sis)、黄芪(Radix astrag ali)、淫羊藿(Herba epimedii)、菟丝子(Semen cuscutae)等19味中草药复方配伍作饲料添加剂,按每头种公羊饲料量1%的比例饲喂3周,对种公羊的性反应和精液品质进行分析研究。结果表明:饲喂中草药添加剂后公羊性反应时间显著缩短;射精量、精子密度较对照显著和极显著提高;每次射精有效精子数达到61.64×109,比对照组增加2.36倍,差异极显著(P<0.01);精子头部畸形率较对照组降低8%(P<0.05);饲喂1周对精液质量有明显改善,饲喂3周至停药1周后可延缓精子质量下降的速度;且饲喂后种公羊的冻后精子活率和精子复苏率较对照和饲喂前显著提高(P<0.05),分别增加38.7%和28.9%。该复方中草药添加剂适用于高频度采精种公羊,可改善公羊的精液品质,提高人工授精过程中精液保存质量,有利于进一步发挥优良公羊的种用价值。     

不同药物配方对公猪精液常温保存效果研究

为提高猪精液的保存效果,为猪精液常温保存技术及稀释液配方的研究提供参考依据,设计了3种常温保存希释液配方,并对保存后的精子进行了顶体染色。结果表明：当精子活率为50%与30%时,配方Ⅱ的精子保存时间均显著高于配方Ⅰ与配方Ⅲ（P〈0.05）,且配方Ⅱ所保存精子的总存活时间也显著高于配方Ⅰ与配方Ⅲ（P〈0.05）。上述结果表明,配方Ⅱ对猪精液的常温保存效果要优于配方Ⅰ与配方Ⅲ。     

不同药物配方对公猪精液常温保存效果研究

为提高猪精液的保存效果,为猪精液常温保存技术及稀释液配方的研究提供参考依据,设计了3种常温保存希释液配方,并对保存后的精子进行了顶体染色.结果表明:当精子活率为50%与30%时,配方Ⅱ的精子保存时间均显著高于配方Ⅰ与配方Ⅲ(P＜0.05),且配方Ⅱ所保存精子的总存活时间也显著高于配方Ⅰ与配方Ⅲ(P＜0.05).上述结果...     

Cryopreservation of Ram Semen in Extenders Containing Soybean Lecithin as Cryoprotectant and Hyaluronic Acid as Antioxidant

A soybean lecithin‐based extender supplemented with hyaluronic acid (HA) was assayed for effectiveness to improve the quality of frozen–thawed ram semen. HA has not been tested yet in an extender containing soybean lecithin for freezing ram semen. Thus, the aim of this study was to analyse the effects of soybean lecithin at 1% or 1.5% along with HA at 0, 0.5 and 1 mg ml^‐1 in a Tris‐based extender on the motion characteristics, membrane integrity (HOST), viability, GSH peroxidase (GSH‐PX) activity, lipid peroxidation and acrosomal status after freezing–thawing. Semen was collected from four Mehraban rams during the breeding season and frozen in the six lecithin×HA extenders. The extender containing 1.5% lecithin supplemented with no HA yielded higher total motility (52.5%±1.6), viability (55.8%±1.6) and membrane integrity (44.5%±1.7), but the effects of the lecithin concentration did not reach signification. Linearity‐related parameters, ALH, BCF, lipid peroxidation, GSH‐PX activity, morphology and acrosomal status were not affected by the extender composition. In general, adding HA significantly decreased sperm velocity (1 mg ml^‐1 HA), total motility (only with 1.5% lecithin), viability (1 mg ml^‐1 HA for 1% lecithin; both concentrations for 1.5% lecithin) and membrane integrity. In conclusion, adding HA to the freezing extender supplemented with soybean lecithin failed to improve quality‐related variables in ram semen. Increasing the lecithin content could have a positive effect, but further studies are needed.     

采精种公羊调教技术探析

种公羊的采精调教是开展“绵羊常温人工授精技术”第一个步骤,也是最主要的环节,直接影响绵羊改良的生产目标。理论上较为简单,实际操作且有一定的困难,主要是操作方面细节性的掌握、调教程序及方法的熟练过程等。这项技术在甘肃省肉羊产业的发展中起到示范带动作用。     

Characterization and Evaluation of Semen in Growing Awassi Ram Lambs

This study was conducted to determine when semen can be collected and to characterize and evaluate the semen collected from growing Awassi ram lambs. Semen was collected regularly once a week for 20 months, starting at 11 months of age, from 14 Awassi ram lambs of milk and meat lines that accepted the artificial vagina. After each collection, the semen was evaluated in terms of its appearance, ejaculate volume, progressive motility, spermatozoa concentration and density. There were significant effects (p<0.01) for the age and weight of the lambs on ejaculate volume, progressive motility and spermatozoal concentration, while the types of birth and production line had no significant effects on these characteristics. Ejaculate volume and spermatozoal concentration increased significantly (p<0.01) with age, despite monthly variations. Progressive motility was similar throughout the year. Average values for ejaculate volume, progressive motility and sperm concentration were 1.2±0.5 ml, 75±10% and (4.0±1.6)×10⁹ sperm/ml, respectively. The highest positive and significant correlations were found between the semen characteristics (r = 0.29–0.68). On the other hand, a negative and significant (p<0.01) correlation (r = –0.66) was found between the spermiodensimeter readings and spermatozoal concentration, and the relationship could be represented by a linear equation Y = 7.85 – 0.07X ±0.37, where Y = expected concentration of sperm (units of 10⁹ sperm/ml) and X = spermiodensimeter reading. However the modest correlation coefficient indicates that the accuracy and precision of the resulting predictions will not be high. It was concluded that semen can be collected with a good quality from growing Awassi ram lambs at 11 months of age.     

稀释粉对猪精液常温保存效果的研究

为了开发猪精液常温保存新型稀释粉,通过检测精子活率、质膜完整性、顶体完整性以及超氧化物歧化酶(SOD)活性、过氧化氢(H2O2)和丙二醛(MDA)产生量等指标,分析常温保存稀释粉对猪精液的保存效果的影响。结果表明,在常温保存条件下,自配稀释粉保存猪精液5d时间内,精子活率平均为0.63,精子顶体完整率和质膜完整率分别达到78.4%和48.6%;SOD活力、H2O2产生量和MDA产生量分别是177.39IU/mL、86.28mmol/mL和9.36nmol/mL,可以在生产实践当中应用。     

烟酸和不同水平叶酸对肉仔鸡生产性能的影响

试验选用1日龄艾维茵商品代白羽肉鸡210只,随机分成7组,每个处理组3个重复,每个重复10只鸡。处理Ⅰ组为对照组,处理Ⅱ、Ⅲ、Ⅳ组叶酸的添加水平分别为0.75、1.5和3.0 mg/kg;处理Ⅴ、Ⅵ、Ⅶ组烟酸的添加水平为60 mg/kg,叶酸的添加水平分别为0.75、1.5和3.0 mg/kg。于21日龄时,以重复为单位逐个称重,记录耗料量,计算料重比。结果表明,在21日龄时,与对照组相比,日粮中添加不同水平的叶酸均可显著提高肉仔鸡的日增重和日采食量,降低料重比（P<0.05）;添加60 mg/kg烟酸和不同水平叶酸可极显著提高肉仔鸡的日增重（P<0.01）。