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[EBOOK] Nutrition and Fish Health, Chhorn Lim and Carl D. Webster, Published by Food Products Press

Aquaculture constitutes a vital and rapidly growing segment of agriculture worldwide. New technological advances and increased demand for fish as a source of animal protein are expected to accelerate the industry’s growth in the near future. As the industry continues to expand, the culture methods have become more intensive for the purpose of producing higher yields per unit area. Infectious disease is the major cause of economic loss in intensive culture operations. In the United States, current methods for disease treatment are limited to a number of government-approved antibiotics or chemothera-peutics that are marginally effective. Some of the problems arising from the use of the drugs, either by means of medicated diets or water treatments, are high cost, creation of antibiotic-resistant pathogens, required withdrawal period, and environmental contamination. For these reasons, aquaculturists are interested in developing cost-effective preventive measures that can prevent the outbreak or reduce the severity of epizootics. One such preventive measure is the development of various nutritional strategies that might lessen or eliminate diseases, something which is currently being examined by the aquaculture industry.

The significance of nutrition as a key factor in maintaining the health of humans and other animal species, including fish, has been recognized for many years. Earlier research on the relationships between nutrition, immune response, and disease resistance has focused on humans and other terrestrial animals. In the past two decades, however, attempts to conduct similar studies utilizing fish have met with limited success due to an incomplete understanding of the immune response in fish. Evidence from either unintentional or intentional infection of fish occurring in some of these nutritional investigations appears to indicate that most, if not all, dietary nutrients have an influence on immune function and disease resistance. A deficiency or excess of any nutrient could have a profound effect on the infection and survival of fish, largely through its effects on host defense mechanisms. Other factors such as nutrient bioavailability and interactions, the presence of immunostimulants and toxins, and feeding management also influence fish health. This clearly demonstrates the potential role that nutrition can play in improving immune response and disease resistance in fish.

This book should be useful for nutritionists, disease specialists, feed for-mulators, students, extension specialists, and aquaculturists. It begins with an overview of diseases affecting warm-water and cold-water fish and shrimp viral diseases. Nutritional strategies affecting the health of marine and baitfish and nutritional deficiencies in commercial aquaculture settings are provided. Immune system functions and disease resistance in fish are presented to provide the readers with a better understanding of the effects of dietary nutrients (ascorbic acid, iron, and other minerals, and lipids and fatty acids); additives and contaminants (immunostimulants and mycotoxins); and feed allowance as they relate to fish health. The impacts of dietary lipids and environment on the stress tolerance of fish and altering environmental tolerances of fish through dietary modifications are also presented. The use of vaccines as a management strategy to prevent diseases of aquatic species is also included to provide a balanced description of disease preventive measures.

The information contained in this book is by no means complete. Moreover, it is apparent from this book that fish immunonutrition is a relatively young discipline. It is hoped, however, that this book will fulfill its intended purpose to provide a better understanding of and put into perspective the complex interrelationship between nutrition and fish health, as well as to accelerate research in this area. It is also hoped that future aquaculture diets will be formulated to provide not only optimum growth and feed efficiency but also improved fish health.

[EBOOK] Nutrition and Fish Health, Chhorn Lim and Carl D. Webster, Published by Food Products Press

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