A comparison of BoviPure® and Percoll® on bull sperm separation protocols for IVF

In the present study, we have examined the effect of density gradient preparations BoviPure® and Percoll® on bull sperm separation and the in vitro fertilization (IVF) and culture (IVC) results. Frozen/thawed semen from five simmental bulls were pooled. Sperm quality parameters such as sperm motility, concentration, membrane activity (HOS assay), membrane integrity (SYBR-14/PI assay) and acrosomal status (EthD-1/FITC-PSA assay) were evaluated before and after sperm processing for IVF using BoviPure® and Percoll® density gradient separations. The results of the evaluated parameters before sperm processing were: motility 50%, concentration 82.33 × 106 spz/mL, membrane activity 39.05%, membrane integrity 42.97% and the acrosomal status 46.90% of the live spermatozoa with intact acrosomes. After sperm processing with BoviPure® and Percoll® the motility was 66.67 and 64.17%, the concentration was 25.50 × 106 and 27.67 × 106 spz/mL, the membrane activity was 53.78 and 56.58%, the membrane integrity was 70.85 and 68.76% of and the acrosomal status was 74.16 and 67.46% of the live spermatozoa with intact acrosomes, respectively. Percentages were referred to the total number of spermatozoa. There were significant differences (P < 0.05) between the evaluated parameters before and after sperm processing for both separation protocols. We found no significant differences (P > 0.05) regarding sperm evaluation parameters between the protocols. A total of 492 oocytes were matured and fertilized in vitro and cultured in SOFaaBSA in six replicates. The cleavage (D2) and blastocysts (D7) rate were significantly higher (P < 0.05) for the BoviPure® group compared to the Percoll® group: 75.80 and 28.21%; 61.58 and 20.83%, respectively. However, the number of hatched blastocysts (D10) did not differ significantly between sperm separation protocols (P > 0.05). Our results indicate that both protocols gave suitable sperm for IVF. This finding and the similarity between those two density gradient preparations suggests that BoviPure® is a good alternative for sperm separation in bovine IVF.