This study was conducted to investigate the effect of the duration of a flaxseed diet on fattening pigs' antioxidant defence mechanism in blood and tissues. Eighteen 20-week-old Landrace breed fattening pigs (BW 76.61 ± 2.30 kg) were divided into three groups of six animals. The control group was fed a basal diet. The FS3 group was fed the basal diet supplemented with 10% flaxseed for 3 weeks. The FS6 group received the same basal diet with flaxseed for 6 weeks. The total antioxidant capacity of the blood, measured as the total antioxidant status (TAS), total plasma antioxidant capacity (FRAP), reactive oxygen metabolites (dROMs) and total antioxidant capacity (PAT), was not affected by the flaxseed diet. The superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) activities were significantly decreased in the FS3 pigs in the heart (p < 0.05). However, in the FS3 group, the glutathione-S-transferase (GST) activity significantly increased compared to the control, but in the FS6 group, the activity was inhibited (p < 0.05). In the muscle, the CAT and GST activity was significantly decreased in the FS3 group (p < 0.05). The thiobarbituric acid reactive substance (TBARS) content was significantly reduced in the brain, muscle and heart in the FS3 group(p < 0.05). In FS6, the TBARS content significantly increased in the heart and brain (p < 0.05). Our results showed that the health effect of a flaxseed diet is significantly conditioned by the length of the flaxseed addition.
Keywords: antioxidant parameters; blood; flaxseed; pig; tissue.