Abstract

The basic technique for freezing cattle, sheep and goat embryos is briefly described. The number of offspring born from each transferred thawed embryo is usually satisfactory but extensive pre and post freezing culling of embryos means that the technique is usually inefficient compared with unfrozen embryos. Research to improve results continues and the 54 and 64% embryo survival/embryo frozen obtained from minimally selected sheep embryos at Ruakura is most encouraging. The technique is being used for the international export of cattle embryos. Its major advantage is that it enables the export of genetic material which could not otherwise be obtained by the importing country. Its use should increase as embryo survival rates increase and particularly if it is established as an effective means of infectious disease control.

JDB, Ward, KJ Bremner, and R Kilgour

Proceedings of the New Zealand Society of Animal Production, Volume 43, , 171-174, 1983