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Number of results: 5
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Abstract

In individual dogs, despite good quality of raw sperm, some parameters are significantly changed after thawing, which cannot be predicted. We therefore investigated whether motility parameters objectively obtained by CASA, membrane integrity (MI), cell morphology or a combination are suitable to improve the prediction of bad post-thaw quality. For this purpose 250 sperm analysis protocols from 141 healthy stud dogs, all patients introduced for sperm cryopreservation, were evaluated and a Classification and Regression Tree (CART) -analysis performed. The sperm was routinely collected, analysed, and frozen by using a modified Uppsala system. After thawing, data were routinely examined by using CASA, fluorescent microscopy for membrane integrity (MI) and Hancock’s fixation for evaluation of cell morphology. Samples were sorted by post-thaw progressive motility (P) in good (P > / = 50%, n=135) and bad freezers (P<50%, n=115). Among bad freezers, 73.9% showed in addition post-thaw total morphological abberations of >40% and/or MI <50%. Bad freezers were significantly older than good freezers (p<0.05). Progressive motility (P), velocity curvilinear (VCL), mean coefficient (STR), and linear coefficient (LIN) were potential predictors for post-thaw sperm quality since specifity was best (85.8%) and sensitivity (75.4 %) and accuracy (80.4 %) good. For these objectively measured raw sperm parameters, cut-off values were calculated allowing prediction of bad post-thaw results with high accuracy: P = 83.1 % VCL = 161.3 µm/sec, STR = 0.83 %, and LIN = 0.48 %. Raw sperm samples with values below these cut off values will have below average post-thaw quality with a probability of 85.8%. We conclude that VCL, P, STR and LIN are potential predictors of the outcome of sperm cryopreservation, when combined.
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Abstract

In this study the quality of total RNA, isolated from fresh spermatozoa, was compared between boars with good and poor semen freezability (GSF and PSF, respectively). Semen from 3 boars with GSF exhibited significantly higher total motility, mitochondrial function, plasma membrane integrity and reduced lipid peroxidation compared with 3 boars with PSF after cryo- preservation. There were variations in the quality of RNA isolated from spermatozoa of boars with GSF and PSF. Boars with GSF exhibited mainly full-length, intact RNA, whereas substantial amounts of degraded RNA were detected in spermatozoa from boars with PSF. Further under- standing of the biological relevance of RNAs in sperm function is critical to improve the freezabil- ity of boar semen.
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Abstract

The aim of this study was to measure the NO level in boar semen held in a liquid state and to determine its putative relation to spermatozoa motility, plasma membrane integrity, mitochondrial membrane potential and ATP content. Generally, the percentage of spermatozoa which generated nitric oxide gradually increased, while NO level in the surrounding medium declined during the liquid preservation. NO generation in semen preserved in BTS was higher as compared to those in Androhep®Plus. We demonstrated the positive correlation between the NO level in fresh spermatozoa and their quality. We also showed negative correlation between nitric oxide level in spermatozoa preserved in BTS and sperm cells motility as well as plasma membrane integrity. Results obtained in this study confirm that NO may affect sperm physiology in a dualistic manner.
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