IUCN / SSC Cat Specialist Group - Digital Cat Library |
|
||||||||||
|
||||||||||
|
|
| Tebet, J.M. | |
| Efeito da criopreserva‡Æo sobre a c‚lula esperm tica em trˆs esp‚cies de felinos: o gato-do-mato-pequeno, a jaguatirica, e o gato dom‚stico | |
| 2004 Full Book | |
The general aim of this study was to evaluate the effect of freezing/thawing procedure on the semen of three feline species, _Leopardus tigrinus _(n=5, 15 ejaculates), _L. pardalis _(n=5, 17 ejaculates) and _Felis catus _(n=10). Semen was obtained by electroejaculation (experiment 1 and 2) or directly from epididymal and _vasa deferentia _(experiment 2) and processed by the same protocol: centrifugation (300g/10min), extending with cryodiluent, loading into 0,25 mL straws (5 x 106 sptz) and storage at 5§C for one hour (<0,5§C/min), freezing in nitrogen vapor for 20 minutes and immersion. Thawing was achieved at 46§C for 15 minutes. Spermatozoa ultrastructure was analyzed to detect injuries caused by cryopreservation in the three species. _The first experiment _tested the difference on efficiency between two freezing extenders, TEG (7% glycerol) and MP-50 (3% glycerol + 2% dimetilformamide) utilized to freeze _L. tigrinus _and _L. pardalis _sperm. The results appointed that there weren't evident differences between the two cryodiluents, in both species. _L tigrinus _exhibited a high decrease on sperm progressive motility index (PMI) (mean 36.3). _L. pardalis _showed lighter declines on PMI (mean 18,1). Both species presented elevation in percentage of major deffects (mean 7.2 and 24.7 points, respectively) due to the increase of acrossomal injuries. Sperm contamination by urine was a remarkable fact to _L tigrinus _(53% of the ejaculates) and _L. pardalis _(59% of the ejaculates) what occasioned and caused loss of spermatic resistance to face the stress of cryopreservation. _The second experiment _studied domestic cats and tested the difference between two techniques of semen collection - the electroejaculation and the acquisition from epididymides and _vasa deferentia _- faced to cryopreservation in TEG (7% glycerol) diluent. Electroejaculation was followed by orchiectomy and epididymal acquisition of semen, in the same tom. There was no differences between the response of the spermatic cell obtained from the two techniques, faced to cryopreservation, except for sperm morphology, due to decline of distal droplets after freezing procedures (probably in response of semen centrifugation), in epididymal sˆmen. Despite of the achieved results, the evaluation of spermatic cell utrastructure revealed that, after cryopreservation, all the three species showed severe acrossomal damages, that might be a limiting factor for the semen fertility. |
|
 |
PDF files are only accessible to Friends of the Cat Group. Joining Friends of the Cat Group gives you unlimited access and downloads in the Cat SG Library for one year, and allows you to receive our newsletter Cat News (2 regular issues per year plus special issues). More information how to join here |
(c) IUCN/SSC Cat Specialist Group ( IUCN - The World Conservation Union) |