Transformation of a short-term boar semen extender into a long-term boar semen extender by using penicillamine

This study aimed to convert a short-term semen extender into a long-term semen extender by adding penicillamine (PEN). Semen samples were collected from six boars, diluted at a concentration 3 × 109 spermatozoa/100 ml, and divided into eight groups as follows: BTS, Merck III®, Androstar® Plus, PEN 0.125 mM, PEN 0.25 mM, PEN 0.5 mM, PEN 1.0 mM, PEN 2.0 mM. All the diluted semen samples were stored at 18 °C and were examined for progressive motility, viability, acrosome integrity, pH and osmolarity on days 0, 1, 3, 5 and 7 after storage. The level of the total anti-oxidative capability (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) were also measured for antioxidant activities. Fertility tests on a commercial pig farm was also conducted. On days 0, 1 and 3 of storage, no statistically significant differences in all the parameters among the extenders was observed. On day 5, the semen diluted with PEN at a concentration of 0.25 mM and Androstar® Plus could maintain progressive motility reach of 70.0% and 76.0%, respectively (P < 0.01). On day 7, the semen diluted with PEN at a concentration of 0.25 mM maintained progressive motility (70.0%) and acrosome integrity (85.7%) which is comparable to long-term semen extenders (Androstar® Plus) (P < 0.01). For the antioxidant activities, the level of the T-AOC, SOD and MDA varied depended on the PEN concentrations . The results of the fertility test were not different among the groups. To conclude, adding PEN at 0.25 mM in the BTS extender is able to transform a short-term semen extender into a long-term extender.