Selenium in poultry nutrition and health

Description

Selenium (Se) is an essential dietary trace element participating in the regulation of various physiological functions in humans, farm animals and poultry through its incorporation into a range of selenoproteins. Low Se content in main feed ingredients is a common problem worldwide and dietary Se supplementation is a current practise in poultry and farm animal nutrition. Recent research clearly proved that sodium selenite, used for the last 40 years as a feed supplement, is not an optimal form of Se. However, use of organic selenium in animal/poultry diets can help meeting Se requirement and m. Read more... Abstract: Selenium (Se) is an essential dietary trace element participating in the regulation of various physiological functions in humans, farm animals and poultry through its incorporation into a range of selenoproteins. Low Se content in main feed ingredients is a common problem worldwide and dietary Se supplementation is a current practise in poultry and farm animal nutrition. Recent research clearly proved that sodium selenite, used for the last 40 years as a feed supplement, is not an optimal form of Se. However, use of organic selenium in animal/poultry diets can help meeting Se requirement and m Content: Intro About the author Table of contents Preface Abbreviations Chapter 1 Antioxidant systems in animal body 1.1 Introduction 1.2 Free radicals and reactive oxygen and nitrogen species 1.3 Three levels of antioxidant defence 1.4 Superoxide dismutase in biological systems 1.5 Superoxide dismutase in avian biology 1.6 Other antioxidant mechanisms 1.7 Oxidative stress and transcription factors 1.8 Vitagene concept development 1.9 Conclusions References Chapter 2 Molecular mechanisms of selenium action: selenoproteins 2.1 Introduction 2.2 The selenoprotein family 2.3 Selenocysteine: the functional selenium2.4 Glutathione peroxidases 2.5 Glutathione peroxidase activity effectors 2.6 GSH-Px and their biological roles 2.7 Thioredoxin reductases as a major part of the thioredoxin system 2.8 Iodothyronine deiodinases 2.9 Other selenoproteins 2.10 General conclusions References Chapter 3 Selenium in feed: organic selenium concept 3.1 Introduction 3.2 Selenium in soils and plants 3.3 Selenium absorption and metabolism 3.4 Selenium status and bioavailability 3.5 Effectors of selenium absorption, metabolism and bioavailability 3.6 Selenium sources for poultry3.7 Selenium-enriched yeast: pluses and minuses 3.8 SeMet and OH-SeMet 3.9 Chelated Se products 3.10 Nano-Se products 3.11 Conclusions References Chapter 4 Selenium deficiency in poultry 4.1 Introduction 4.2 Exudative diathesis 4.3 Nutritional pancreatic atrophy 4.4 Nutritional encephalomalacia 4.5 Nutritional muscular dystrophy 4.6 Impaired immunocompetence 4.7 Impaired thyroid hormone metabolism 4.8 Reduced fertility 4.9 Reduced egg production and quality 4.10 Decreased hatchability and increased embryonic mortality 4.11 Conclusions 6.9 Se-enriched eggs and meat as functional food6.10 Conclusions References Chapter 7 Selenium and immunity 7.1 Introduction 7.2 Immune system and its evaluation 7.3 Phagocyte functions 7.4 Antibody production 7.5 Lymphocyte functions 7.6 In vitro effects of selenium on immune cells 7.7 Disease resistance 7.8 Immunoprotective effects of Se in stress conditions 7.9 Molecular mechanisms of immunomodulating properties of selenium 7.10 Immunocommunication, free radicals and selenium 7.11 Conclusions References Chapter 8 Antioxidant-prooxidant balance in the gut 8.1 Introduction