Published in Scientific Papers. Series D. Animal Science, Vol. LVIII
Written by Monica-Elena BURAC, Manuela PASCAL, Adriane WOEHL WENIGERKIND, Alin BÎRȚOIU
The aim of this paper was to compare two non-animal macromolecules (methyl cellulose and hydroxyethyl-starch) as an alternative to bovine serum albumin supplement in the bull sperm capacitation medium. Attention was paid to the rate of penetrated oocytes and to the polyspermic fertilization in order to assess the effect of these substances on bull semen capacitation.435 class one and two oocytes were matured in TCM -199supplemented with bovine serum albumin (3mg/ml) and FSH (0.88 mg/ml) for 24 hours at 38.5°C, 5% CO2 in saturated humidity. 21 straws from one single bull ejaculate were used. Sperm motility was assessed using Sperm Vision 3.7® (Minitübe, Germany) before the separation process. Sperm preparation was done on a commercial density gradient medium (BoviPure®, Nidacon, Sweden). Three groups were formed: the bovine serum albumin group (BSA at 6mg/ml), the methyl cellulose group (MC at 0.1mg/ml) and the hydroxyethyl-starch group (HES at 10mg/ml). Matured oocytes were co-incubated for 18 hours with the sperm (38.5°C, 5% CO2 in saturated humidity). After 18 hours, the oocytes were denuded, fixated and stained with acetoorcein in order to assess the penetration and pronuclear formation.77.80%±14.82% of the oocytes in the BSA group were not-penetrated, 22.20%±14.82% were penetrated and3.37%±2.37% were with polyspermy. In the MC and HES group respectively, 71.18%±21.66% and 60.23% ± 23.04% of the oocytes were not-penetrated, 28.82%±21.66% and 39.77%±23.04% werepenetrated and8.71%±6.3% and 13.74%±8.87% were with polyspermy. The physical characteristics of methyl cellulose and hydroxyethyl-starch were considered suitable for the in vitro production; they are all white powder, colourless and odourless in aqueous solution. The results showed that, there are no significant differences (p < 0.05) between methyl cellulose and bovine serum albumin regarding the penetration rate and the polyspermic fertilization, thus making methyl cellulose suitable to be used as an alternative supplement to the capacitation medium for bull semen.
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bovine serum albumin
