Amino Acids and Proteins
2003; Elsevier BV; Linguagem: Inglês
10.1016/b978-012319652-1/50004-5
Autores Tópico(s)Aquaculture disease management and microbiota
ResumoPublisher Summary This chapter discusses the amino acids and protein requirements of fish. Proteins are the major organic material in fish tissue, making up about 65–75% of the total on a dry-weight basis. Fish consume protein to obtain amino acids. A regular intake of protein or amino acids is required because amino acids are used continually by the fish, either to build new proteins (as during growth and reproduction) or to replace existing proteins (maintenance). Inadequate protein in the diet results in a reduction or cessation of growth and a loss of weight due to withdrawal of protein from less vital tissues to maintain the functions of more vital tissues. Fish, like other animals, do not have a true protein requirement but have a requirement for a well-balanced mixture of essential or indispensable and nonessential or dispensable amino acids. Size and age, water temperature, and maintenance requirements affect the protein requirements of fishes. Various investigators have observed improved growth and feed efficiency when experimental diets for salmonids were supplemented with indispensable amino acids to simulate levels found in isolated fish protein or the respective eggs and whole-body tissue of the species being studied. The indispensable amino acid requirements of certain fish have also been shown to correlate well with the indispensable amino acid pattern of the whole-body tissue of that fish.
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