Engormix/Poultry Industry/Technical articles

Fighting Oxidative Stress with Silvafeed® ATX

Published on: 8/6/2018
Author/s : Alejandro R Castillo, PhD. Emeritus Farm Advisor. University of California, Extension.
Use a blend of plant extracts as dietary antioxidant in animal production
The objective of this article is to provide an introduction on oxidative stress, some concepts and suggestions to improve the efficiency of dietary antioxidants, including Silvafeed® ATX blend of plant extracts. This article is based on many concepts recently published in some important reviews (e.g. Bradford et al., 2015; Salami et al., 2015; Salami et al., 2016, and Abdollah, A. et al., 2016), and some presentations at the Annual Poultry Science Association Symposium in 2017 (see references).
Mammals obtain energy by burning food through a complex process of nutrients digestion and absorption, cells respiration, and oxygen metabolism. This is a controlled metabolic process that generates different byproducts formed mainly in the mitochondria cells. These byproducts are named Reactive Oxygen Species or ROS. The most important ROS are free radicals (mainly oxygen or nitrogen), which are electronically unstable atoms or molecules capable of consuming electrons from any other molecules they come in contact with in an effort to achieve stability, sometimes damaging these other molecules. The animal is naturally endowed with an overwhelming biological antioxidant system to fight free-radicals that are continuously produced in the body cells. The Total Antioxidant Status or TAS is the natural antioxidant capacity of any organism and it is called the antioxidant defense system. Based on these concepts (ROS and TAS), there is a balance among the antioxidant defense system and the free radicals’ production. When the system is in equilibrium, TAS can manage ROS or free radical production. Table 1 describe the enzymes and nutrients (trace minerals) working for the TAS in the biological systems.
Table 1. Antioxidants in biological systems of animals. (Salami et al., 2016; adapted from Weiss, 2010)
Fighting Oxidative Stress with Silvafeed® ATX - Image 1
The oxidative stress develops when free radicals’ generation exceeds TAS or the body antioxidants capacity. Many different situations can affect the equilibrium between TAS and ROS and they are summarized in Table 2.
Table 2. Factors that impair the balance between TAS and ROS.
Fighting Oxidative Stress with Silvafeed® ATX - Image 2

The natural antioxidant system or TAS is based on three levels of defense. The first level is represented by the antioxidant enzymes in the cytosol and mitochondria described in Table 1. The second level is linked to the activity of natural antioxidants, for example Vitamin E, which perform part of the job detoxifying peroxyl radicals or “ROO*” in hydroperoxides or “ROOH”. Third level: the reactions of free radicals with biological molecules (DNA, proteins, lipids, etc.) may result in oxidative damage of these molecules, also potential cellular damage, and in extreme cases cells death. This level includes specific enzymes (e.g. HSP or heat shock protein family) involved in repairing molecules damage by free radicals.
There is a close relationship between different animal production stressors, particularly in hot climatic regions, like heat stress, oxidative stress, systemic inflammation and immunosuppression. Low, weak or unbalanced TAS has been linked to several disease states in animals and humans.
An antioxidant is a molecule that prevents or inhibits the oxidation of other molecules. Antioxidants can be classified in different ways; the simplest classification is: (a) Enzymatic: they can be synthetized in the body through metabolic process or supplemented in the diet from other sources (natural or synthetic). (b) Non-enzymatic: some are nutrients required by animals (minerals, vitamins, etc.), many others are not natural components of their body (carotenoids, some provitamins, proteins and non-protein N, natural polyphenols, etc.).
Vitamin E is probably the most used antioxidant in animal production. Its effects have been extensively researched, maintaining cell membrane integrity, prolonging shelf-life of muscle and facilitating immune response mechanisms. But as antioxidant, Vitamin E does not work alone, it is part of a coordinated antioxidant system which includes Vitamin C, and Se, Mn, Cu, Fe, and Zn as co-factors for selected antioxidant enzymes (SOD, GSH-Px, CAT, etc.). It is clear that under oxidative stress conditions there is a need of exogenous supplementation of antioxidants. However, a high dose of supplemented antioxidants in excess of animal requirements could act as prooxidants inducing oxidative stress by increasing the production of reactive free radicals or depleting the antioxidant defense system to cause cellular damage.
The use of antioxidants in livestock will be driven by the impact of modern intensive livestock practices which might elevate the exposure of animals to oxidative stress conditions. Nowadays, it is an increasing demand by consumers for the use of natural products in livestock production. Silvafeed® ATX is a blend of plant extracts, naturally rich in bioactive substances, exerting a strong enhancing effect to the antioxidant status of animal species under stress conditions, and a solution to partially replace the use of synthetic Vitamin E. Silvafeed® ATX is perfectly balance natural extract which acts as an efficient antioxidant by enhancing TAS after a short period of time and at low dosages.
Final message, balance dietary nutrients and antioxidants levels according to animal requirements and including different types of exogenous antioxidants. These are key factors to control or minimize oxidative stress and possible prooxidative effect that impairs animals’ performance and well-being.

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