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Extender Used (extender + used)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Single layer centrifugation of stallion spermatozoa consistently selects the most robust spermatozoa from the rest of the ejaculate in a large sample size

EQUINE VETERINARY JOURNAL, Issue 7 2010
J. M. MORRELL
Summary Reasons for performing study: An improvement in sperm quality after single layer centrifugation (SLC) has been seen in previous studies using small sample sizes (for example, n = 10 stallions). There is a need to investigate whether this improvement is repeatable over several breeding seasons with a larger number of stallions (n , 30 stallions). Objective: To make a retrospective analysis of the results of SLC performed on more than 250 sperm samples (176 ejaculates) from 31 stallions in 3 consecutive breeding seasons. Methods: Sperm quality (motility, proportion of morphologically normal spermatozoa and the proportion of spermatozoa with undamaged chromatin) was assessed before and after SLC. Results: All parameters of sperm quality examined were significantly better in sperm samples after SLC than in their unselected counterparts (P<0.001 for each parameter). The yield of spermatozoa obtained after SLC was influenced by the type of extender used and also by the concentration of spermatozoa in the original ejaculate, with fewer spermatozoa being recovered when the loading dose contained a high concentration of spermatozoa. The optimal concentration was approximately 100 × 106/ml. Sperm concentration in the samples loaded on to the colloid influenced the sperm yield while the type of semen extender affected sperm quality and survival. Furthermore, the scaled-up SLC method was found to be suitable for use with a range of ejaculates, with similar sperm kinematics being observed for standard and scaled-up preparations. Conclusions: SLC consistently improved the quality of stallion sperm samples from a large number of ejaculates. The method could be scaled-up, allowing larger volumes of ejaculate to be processed easily from a wide range of stallions. [source]

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

REPRODUCTION IN DOMESTIC ANIMALS, Issue 3 2010
K Kaeoket
Contents 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. [source]

Effect of cryoprotectants, extenders and freezing rates on the fertilization rate of frozen striped catfish, Pangasius hypophthalmus (Sauvage), sperm

AQUACULTURE RESEARCH, Issue 10 2003
Samorn Kwantong
Abstract The effects of four cryoprotectants (methanol, MeOH; dimethyl sulphoxide, DMSO; dimethyl acetamide, DMA; and ethylene glycol, EG), three extenders (calcium-free Hanks' balanced salt solution, C-F HBSS, Hanks' balanced salt solution, HBSS and sodium chloride, NaCl) and two different freezing procedures (one- and two-step) on the cryopreservation of striped catfish (Pangasius hypophthalmus (Sauvage)) sperm were investigated. Sperm were frozen using a controlled-rate freezer in 250 ,L straws and stored for 2 weeks in a liquid nitrogen (LN2) container. They were then airthawed at room temperature, and fertilization, motility and viability were assessed. The highest fertilization rate of 41% (81% of control) was achieved with the combination of 12% DMSO and 0.9% NaCl using a one-step freezing procedure (10°C min,1). Also, DMA resulted in a higher fertilization rate (30% or 51% of the control) than MeOH (18% or 38% of the control) or EG (8% or 12% of the control). In addition, the three extenders used did not affect fertilization rates after cryopreservation with each cryoprotectant. There were no significant differences among the three cryoprotectant concentrations and between the one- and two-step freezing procedures. However, fertilization rates of cryopreserved sperm were significantly lower than the controls (P<0.05). The results of this study indicate that high fertilization rates of striped catfish eggs can be achieved using cryopreserved sperm when frozen at 10°C min,1 in DMSO or DMA with either 0.9% NaCl or C-F HBSS. [source]

Cryopreservation of sperm in marine fish

AQUACULTURE RESEARCH, Issue 3 2000
M. Suquet
Since the first work of Blaxter in 1953, fish sperm cryopreservation has been attempted on about 30 marine species. The present paper reviews the techniques used and the results published in these species. Particular attention is paid to the handling procedure of sperm before freezing, the problems of semen ageing and semen contamination with urine. The quality of frozen,thawed semen was evaluated using previously standardized biotests, such as a two-step motility activation technique adapted for the different species and fertilization assays using a discriminating insemination technique. Most extenders used in marine fish are saline or sugar solutions. From the investigated cryoprotectants, dimethyl sulphoxide (DMSO) generally leads to the best results. Cooling rates range from 8 °C to 99 °C min,1; the thawing rate is generally high. Compared with freshwater species, a high percentage of spermatozoa survives cryopreservation. Therefore, and because of the simplicity of the techniques, the cryopreservation of marine fish sperm is suited for application in aquaculture. [source]