Antioxidant effect of plant extracts on oxidative stress in feedlot sheep fed a diet with high concentrate

Abstract

Cattle and sheep finishing diets generally contain high proportion of starch and alter the fermentation by modulating the production of fatty acids for better energy efficiency. However, the change in physiology may influence the redox homeostasis, causing oxidative stress, reducing its productive capacity and causing disease in the animal. Although some compounds possess antioxidant effect is not fully elucidated its efficiency in fighting free radicals. Based on the exposed problem the objective of the trial is to evaluate the influence of compounds extracted from plants and selenium in the control of oxidative stress and its effects on meat quality. The experiment will be conducted at the Animal Science Department of the Faculty of Animal Science and Food Engineering, University of São Paulo. Fourty eight Dorper x Santa Inês lambs 60 days old will be used. The animals will be distributed in a randomized block design in four treatments: control diet, control diet plus extract of Magnolia officinalis plants and Macleaya cordata (EP), control + selenium + vitamin E, and control diet more If + vit. E + EP. There will be four experimental periods of 14 days, 10 days of adaptation and four days of collection. Total antioxidant capacity, total oxidant capacity, glutathione peroxidase levels, catalase, hydrogen peroxide, malondialdehyde and superoxide dismutase, will be assessed in the blood, all using specific commercial kits. In the meat, aspects such as color, softness, pH, TBARS and shelf life will be evaluated. The variables analyzed will clarify the control of oxidative stress by the natural compound used, enabling a better understanding in animal physiology, as well as its influence on oxidative stability of the post-mortem meat. (AU)