Oxidative Stress, Antioxidants, and Animal Function

Abstract

Reactive oxygen metabolites generated during normal metabolism and metabolism stimulated by xenobiotics can enter into reactions that, when uncontrolled, can impair performance of dairy cows. Direct effects include peroxidative changes in membranes and other cellular components. Indirectly, competitive consumption of reducing equivalents can interfere with important metabolic functions and divert glucose from other pathways by inducing the monophosphate shunt. Normally, the body is protected by a wide range of antioxidant systems working in concert. Metal catalysts of oxidative reactions are removed in intracellular fluids by metal-binding macromolecules. Superoxide dismutases, glutathione peroxidase, and catalase within cells remove superoxide and peroxides before they react with metal catalysis to form more reactive species. Finally, peroxidative chain reactions initiated by reactive species that escaped enzymatic degradation are terminated by chain-breaking antioxidants, including water-soluble ascorbate, glutathione, and urate and lipid-soluble vitamin E, ubiquinone, and beta-carotene. To optimize performance, oxidative stress in high producing cows must be controlled by supplying all known antioxidant nutrients and by minimizing effects of substances that stimulate reactive oxygen metabolites.

Administration of dexamethasone per os in finishing bulls. II. Effects on blood parameters used as indicators of animal welfare

“…The limited effect of dexamethasone on both oxidative stress parameters considered in this study (GPx and TAS) might be explained by the animal's attempt to maintain the balance between plasma pro-oxidant and antioxidant constituents (Miller et al, 1993;Bourdon and Blanche, 2001), which implies a dynamic response. For this reason, GPx and TAS do not appear to be useful biochemical tools for the detection of cattle treated illegally by corticosteroids.…”

Assessment of a natural dietary extract, titrated in phenylpropanoid glycosides, on blood parameters and plasma oxidative status in intensively reared Italian hares (Lepus corsicanus)

“…They play a protective role against ROS, thus reducing the lipoperoxides evidenced by the decrease in plasma MDA. The reduction in ROMs and lipid peroxidation (TBARS) can be due both to the direct action of the antioxidant verbascoside, which captures free radicals during the propagation of a chain reaction, and a phase-lock initiation of oxidation by inhibiting pro-oxidant enzymes (Miller et al, 1993;Kamiloglu et al, 2006). These results are in agreement with those reported by Corino et al (2007b) on weaned piglets fed a verbascosidesupplemented diet.…”

Antioxidative activity and protective effect of probiotics against high-fat diet-induced sperm damage in rats

“…It is proposed that dietary supplementation of probiotics with antimicrobial and antioxidant properties may be a promising strengthening agent for increasing pathogen resistance in animals. Reproduction is likely to fail long before life is endangered by deficiency of any required nutrient, including dietary antioxidants (Miller and Brzezinska-Slebodzinska, 1993). To date, no study has been found reporting on the effects of antioxidative probiotics on reproductive performance and oxidative status in animals, and only preliminary reports are available.…”