COMPARATIVE PHYSICOCHEMICAL AND BIOCHEMICAL CHARACTERIZATION OF BULL AND BOAR SEMEN

Abstract

There are numerous specialized studies of the physicochemical and biochemical aspects of bull and boar semen, but this paper highlights additional enzymatic activity of superoxide dismutase and glutathione peroxidase enzymes that behave as sperm defense mechanism against of oxygen free radicals(the protection of membrane lipids against oxidative damage). Such a comparative study was performed from a physicochemical (pH, buffering capacity) and biochemical (seminal fructose content, total protein, total lipids, total cholesterol and lactate dehydrogenase enzymatic activity, glutamate dehydrogenase, superoxide dismutase, glutathione peroxidase and acrosin activity) point of view for 10 samples of boar and bull seminal plasma. The investigation showed smaller values of total protein, fructose, lipids and total cholesterol in the boar seminal plasma samples than in the bull seminal plasma samples (the decrease was significant, P <0.05). LDH and GDH activity in bull sperm is increased compared to the boar (P< 0.05), which leads to the idea that the anaerobic degradation of fructose (fructolise) in which LDH is involved, as well as the oxidation of the amino acids where GDH is involved are both processes that take place more intensively in bull sperm than in the boar one. Acrozine of boar sperm cells showed an increased activity compared with that of bull sperm (P< 0.05), because the intracellular pH of boar sperm (7.3-7.9) is closer to the optimal action pH for this enzyme (8,0). SOD activity in both the sperm extract and the seminal plasma of the bovines is increased compared to the ones from boar samples(P<0.01), which explains the higher resistance to lipid peroxidation of the bovine sperm compared to all other animal species. Regarding glutathione peroxidase activity, similarly to SOD activity, it is greatly increased in the extract of bovine sperm compared to bovine seminal plasma. In the boar samples, no traces of glutathione peroxidase could be found.