Enrichment of high-quality spermatozoa in bovine semen: relative effectiveness of three filtration matrixes

To be practical, any method for improving bull semen must yield a large qua ntity of motile spermatozoa. Some separation methods based on physical prop erties, e.g. filtration, chromatography, centrifugation, washing and poolin g, have been reported as satisfactory, but generally are not repeatable. Ne vertheless, filtration methods appear to allow the attainment of an accepta ble number of spermatozoa, thus allowing such a technique to he introduced in the production of standard bovine semen doses for artificial inseminatio n. The aim of this work was to evaluate systematically the relative effects : of three filtration matrixes (silica oxide, glass beads or Sephadex (TM)) on the improvement of whole ejaculate quality. Analysis of the type of mat rix and the volume and height of the filtration column was performed. The o nly characteristic of the columns that appears to influence ejaculate quali ty after filtering is the matrix volume. While all matrixes: produced impro vement of semen quality, Sephadex (TM) was better than the other matrixes t ested. An explanation for the mechanism of column filtration is proposed.