Even though artificial insemination is a simple technique that has been practiced for over a century, it has long been carried out under poor conditions due to an inadequate understanding of repro- ductive physiology and antagonistic socio-ethical attitudes. Accor- dingly, until fairly recently it was a medical act with a limited scientific basis which was practised more or less clandestinely. The development of semen preservation has totally changed the conditions of artificial insemination, especially in regard to flexibility and safeguards in its application. Although the use of fresh...