The present invention relates to the production and culture of undifferentiated spermatogonial stem cells that can be maintained long term and are feeder free. The resultant feeder-free populations can be used in any of a number of protocols including the generation of progeny bulls. The present invention includes novel methods required for the successful enrichment of bovine spermatogonial stem cells, novel cell lines and other components used for the same, as well as the resultant stem cell compositions.
