Oxidative stress in farmed minks with self-biting behavior

Self-biting behavior (SBB) is a serious behavioral disorder in farmed minks, but little is known about the biological basis of this disorder. The present study examined for the first time the hepatic and cerebral oxidative stress biomarker levels in SBB minks and compared them with those in normal ones to study the association of oxidative stress and SBB in minks. Calcium-activated adenosine triphosphatase (Ca2+ATPase) activities were also determined to investigate whether the Ca2+ pump in brain is affected. Twenty male SBB minks and 20 male normal minks were chosen in December. The brain and liver of each mink were harvested immediately after slaughter to test oxidative stress biomarkers. All parameters were determined by using a spectrophotometer. Our findings were as follows: SBB minks produced more malondialdehyde with 51% increase in brain (P < 0.01) and 22% increase in liver (P < 0.01) compared with normal minks. Similarly, the hepatic and cerebral protein carbonyls in SBB minks were 18.5% (P < 0.01) and 30% higher (P < 0.001), respectively. Glutathione peroxidase activities in brain and catalase activities in both tissues of SBB minks were markedly lower than those of normal group (P < 0.01). However, SBB minks had higher total superoxide dismutase (SOD), Cu/Zn-SOD, and Mn-SOD activities in both tissues (P < 0.05 or P < 0.01). Significant depletion of glutathione and vitamin E levels were observed in SBB minks (P < 0.01 or P <0 .05). Calcium-activated adenosine triphosphatase activities in the brain of SBB minks were inhibited (P < 0.01). Our results supported the oxidative stress hypothesis in minks with SBB.