[The influence of semen preparation and culture medium on the success of IVF in cattle].

The effect of two semen-preparation methods and the presence and absence of capacitation-inducing supplements in the fertilization medium on IVF-results were examined in a 2 x 2 factorial design. In vitro matured oocytes were fertilized either with transmigrated (TM) or with swim-up (SU) prepared native semen. In the first group, the fertilization medium contained 0.8 microgram/ml heparin, 1.2 micrograms/ml hypotaurine and 0.2 microgram/ml epinephrine. However, in the second group, no capacitation-inducing or motility-enhancing substances were used. After SU-treatment, the supplements were necessary to obtain sufficient fertilization results. In the second group (non-supplemented medium), the percentages of penetrated and fertilized oocytes were decreased significantly (P < 0.001). By contrast, transmigrated semen required no additional supplementation of the fertilization medium. The penetration and fertilization rates of this semen-preparation method were equal in both groups.