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Submitted to: Cryopreservation of Fish Sperm
Publication Type: Book / Chapter Publication Acceptance Date: 3/15/1999 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Efforts to freeze spermatozoa began in the mid-1800's with the report of Mantegazza (1866). Modern cryobiology on the other hand began over 100 years later, with the report that glycerol provided spermatozoa with protection during freezing to -79 C and through subsequent thawing by Polge, Smith, and Parks (1949). Although the various mammalian and avian species react quite differently to freezing and thawing, most species have been frozen and thawed on a research scale, but few have been frozen for commercial practice. Some of the greatest advances in genetic improvement in the livestock industry has been made with cattle, where modern cryobiology came together with artificial insemination. Artificial insemination in livestock was fairly well advanced in1949, making use of stored liquid semen for delivery to farms. Consequently dairy cattle of the world enjoy the widest possible application because freezing bull spermatozoa is considered state of the art for all species. It is particularly useful in cattle due to the benefits with respect to a long generation interval. Currently 500 to 700 straws of semen can be prepared from one bull ejaculate compared to 300 to 500 just 15 years ago. This considerable improvement in efficiency is due to improved sperm harvest methods, and a better under understanding of processing, freezing and thawing procedures. Compatibility of frozen semen with management of the dairy herd is advantageous as is the fact that selection of bulls on the basis of milk production of their daughters is an advantage that is not necessarily repeatable with other species. No other species seems to have so many things going for it with respect to propagation. |
