LAUSR

Tissue oxidative stress has been associated with low productivity of beef cattle. Supplementation of animals with natural antioxidants added to the diet may be an alternative to improve the tissue oxidative status and the productivity of steers at finishing phase. The present study evaluated whether the addition to the diet of a blend (Mix) containing Baccharis dracunculifolia (40%), Tamarindus indica seed (40%), cashew nutshell oil (10%) and clove oil (10%) modifies the oxidative state in the plasma and liver of steers (Angus x Zebu) in finishing phase. Forty animals were randomly distributed into four groups (ten animal per group), which received Mix respectively at the daily dose of 0.0, 2.0, 4.0 and 6.0 g per animal during 84 days. Blood and liver were taken at slaughter of the animals. Blood samples were also taken before starting the supplementation and served as control. The ferric reducing ability of plasma (FRAP), thiol groups and protein carbonyl groups were measured as plasma parameters of oxidative stress. The levels of thiobarbituric acid reactive substances (TBARS), protein carbonyl groups, reactive oxygen species (ROS), glutathione and the activity of catalase and superoxide dismutase (SOD) were measured as hepatic parameter of oxidative stress. Plasma levels of protein carbonyl groups were 30% lower in the animals supplemented with 4.0 and 6.0 g Mix and FRAP was 20% higher in the animals supplemented with 6.0 g Mix (P < 0.05; compared to the 0.0 g). Hepatic levels of TBARS were 38% lower in animals supplemented with 6.0 g Mix (P < 0.05). The other parameters were not modified. In conclusion, the supplementation of steers with Mix improved the systemic oxidative status and may be a complementary alternative to the diet of these animals in the termination phase.