02141naa a2200313 a 450000100080000000500110000800800410001910000220006024500770008226000090015952013070016865000280147565000210150365000190152465000090154365000170155265000100156965000160157965000180159565000220161365000200163565000290165565000100168465000240169465000110171865300160172970000180174577300640176315230972023-06-28       1996    bl uuuu     u00u1 u    #d1 aMAXWELL, W. M. C.  aRecent progress in the preservation of ram semen.h[electronic resource]  c1996  aAbstract: The processing and storage of ram semen reduce the motility and disrupt the membrane integrity of spermatozoa. It is generally assumed that these changes are detrimental and are associated with a loss of fertilising capacity. Despite many years of empirical research that has established a variety of methods for the processing, storage and insemination of spermatozoa, fertility is generally lower after cervical insemination with stored than fresh semen. The components of the sperm cell responsible for this low fertility are not clearly understood. However, recent evidence suggests that while many spermatozoa remain motile after storage, the membranes of the motile cells are destabilised to the point where they may not survive further ageing in the female tract after cervical insemination. These membrane changes are similar to the capacitation and acrosome reaction of spermatozoa. Thus, stored spermatozoa may require less capacitation time in the female tract, and may readily fertilise oocytes if placed in their immediate vicinity, as with in vitro fertilisation, tubal or even intrauterine insemination. It may be possible to prevent or reverse some of these membrane changes, for example using antioxidants, and thus improve fertility following cervical insemination of sheep.  aArtificial insemination  aCryopreservation  aFrozen storage  aRams  aReproduction  aSheep  aSpermatozoa  aArmazenamento  aCriopreservação  aEspermatozóide  aInseminação Artificial  aOvino  aReprodução Animal  aSêmen  aPreservacao1 aWATSON, P. F.  tAnimal Reproduction Sciencegv. 42, n. 1/4, p. 55-65, 1996.