Improvements in the ability to freeze semen have been achieved by reducing the amount of glycerol, using only the sperm-rich fraction with the addition of L-glutamine at 80 mM and replacing hen egg yolk with quail egg yolk. Pregnancy rates obtained with semen frozen in these conditions (AI daily until ovulation, 600 million spermatozoa) improved from 0 to 38% after glycerol removal (Trimeche ''et al'', 1998; Tibary ''et a''l, 2006). | Improvements in the ability to freeze semen have been achieved by reducing the amount of glycerol, using only the sperm-rich fraction with the addition of L-glutamine at 80 mM and replacing hen egg yolk with quail egg yolk. Pregnancy rates obtained with semen frozen in these conditions (AI daily until ovulation, 600 million spermatozoa) improved from 0 to 38% after glycerol removal (Trimeche ''et al'', 1998; Tibary ''et a''l, 2006). |