|Lim, Chhorn - Auburn University|
|Lee, Cheng-sheng - Oceanic Institute|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 12/1/2013
Publication Date: 7/17/2015
Citation: Lim, C.E., Webster, C.D., Lee, C. 2015. Feeding Practices and Fish Health. In: Lim, C. E., Webster, C. D., Lee, C., editors. Dietary Nutrients, Additives, and Fish Health. Hobokon, NJ: Wiley Blackwell. p. 333-347.
Technical Abstract: Over the past three decades, the aquaculture industry has expanded rapidly throughout the world and is expected to continue to grow in the years to come due to the unpredictability and high cost of harvesting fish from the oceans as well as the increased demand for fish as a result of rapid population growth, increased disposable income and preferences for fish over other animal protein for personal, cultural and health reasons. World food fish production from aquaculture has expanded at an annual average rate of 8.8% from 1980 to 2010, but has slowed to an annual growth rate of 6.3% from 2010 to 2012. Paralleling the growth of the industry has been a trend toward intensification of culture practices where fish are stocked at high densities aiming to obtain higher yield per unit area. In contrast to extensive and semi-intensive culture system where fish derive all or most of their nutritional needs from natural pond-food organisms, fish reared under intensive production systems depend largely or solely on compounded feeds and are subjected to more stressful conditions (poorer water quality) leading to growth reduction, immune suppression and susceptibility of infectious diseases. It has generally been recognized that among other factors, adequate nutrition and good feeding practices are two most important requisites for sustainable, successful fish production in intensive culture operations. Without adequate intake of nutritionally balanced diets fish are unable to grow optimally, reproduce, and maintain the ability to withstand stress and resist disease-causing agents. However, many problems are encountered in feeding fish as compared to feeding terrestrial animals. Fish are not fed on an ad libitum basis as are with domestic animals. Because fish are fed in the water, feed that is not consumed within a reasonable time period represents not only an economic loss, but also causes environmental degradation which can bring about stress, poor growth, susceptibility to diseases, low survival and poor harvest. Until now, the feeding of fish is still an art rather than a science because the feeder, not the fish, determines how much, how often, when, how to, and where to feed. It is commonly known that feeding levels may influence the nutritional status of fish, which could ultimately affect their immune system function and resistance to infectious microorganisms. Underfeeding or overfeeding can directly or indirectly result on poor growth performance, and increase the susceptibility of fish to stress and disease-causing agents. However, sparse research has examined the effects of feeding allowances in relation to fish health. This chapter attempts to provide an overview of the effects of feeding practices on the immune responses and disease resistance in fish. The effects of winter feeding on disease resistance as well as feeding of diseased fish will also be presented.