[Separation techniques ro achieve vital and reproduction competent equine spermatozoa populations--a survey]

Equine ejaculates are significantly characterized by widely varying parameters especially in those of practical relevance for equine Al. Therefore it is of interest for practical purposes to get subpopulations of concentrated, vital, and competent spermatozoa from the origin ejaculates. Special preparation of the donor stallions will stabilize sperm output. Fractionated semen collection from stallions supplies sperm enriched seminal fractions very useful to work with further in semen preservation. Most important to achieve a concentrated sperm subpopulation are semen manipulations post ejaculation represented conventionally in semen centrifugation. In the last decade alternative measurements have been introduced. Above all semen filtration using glasswool-sephadex and more recently membrane techniques gave good results indicating that these new techniques may replace semen centrifugation in the future. This article gives a survey of the different starting points and methods for separation of vital and concentrated sperm subpopulations of equine semen.