The role of antioxidants in reproduction and fertility of poultry

For the majority of organisms on Earth, life without oxygen is impossible. Animals, plants and many microorganisms rely on oxygen for the efficient production of energy. However, the high oxygen concentration in the atmosphere is potentially toxic for living organisms. Recently free radical research has generated valuable information for further understanding not only detrimental, but also beneficial role of free radicals in cell signaling and other physiological processes. The benefit or harm of free radicals ultimately depend on the level of their production and efficiency of antioxidant defence. During evolution, living organisms have developed specific antioxidant protective mechanisms to deal with ROS. Therefore, the presence of natural antioxidants in living organisms is the major factor that enables their survival in an oxygen-rich environment. The protective antioxidant compounds are located in organelles, subcellular compartments or the extracellular space, enabling maximum cellular protection to occur. Natural antioxidants, including vitamin E, Se and carotenoids play important roles in avian reproduction by maintaining antioxidant defences of the spermatozoa and embryonic tissues. Optimal antioxidant supplementation is shown to be important to maintain high productive and reproductive performances of commercial poultry. Se is considered to be “chief-executive of the antioxidant defence system”. Indeed, it is considered to be an integral part of at least 25 selenoproteins expressed in various tissues of human and animals. It has been proven that Se participates in regulation of major physiological functions in human and animals including growth, development, spermatogenesis and embryonic development. The most fascinating part of Se-related research is coming from understanding a principal difference between various Se sources in the diet. The digestive system of animals, including birds, adapted to metabolise organic Se from plant-based feedstuffs during evolution. Therefore, inclusion of selenite or selenate in the diet is not the ‘natural’ situation and differences in assimilation, distribution and accumulation of Se in tissues depend on source of Se. A great body of evidence indicates that replacement of sodium selenite in the poultry diet by organic Se, in the form of Sel-Plex, can help to meet the optimal Se requirement and to increase fertility and hatchability. _________________________________________________________________________________