The use of factorial modeling to determine the dietary requirements for essential elements in fishes

• Published in: Aquaculture 1995-05, Vol.133 (1), p.57-72
• Main Author: Shearer, Karl D.
• Format: Article
• Language: English
• Subjects: Animal aquaculture; Animal productions; Aquaculture; Biological and medical sciences; Brackish; Diet; dietary requirements; Essential elements; Feeding; Fish; Freshwater; Fundamental and applied biological sciences. Psychology; Marine; Modeling; nutrition; Pisciculture; Vertebrate aquaculture
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/0044-8486(94)00405-D

A factorial model is used to examine the relationship between the net requirement for an essential element in fish (the amount required for growth and replacement of endogenous loss) and the dietary concentration necessary to meet that requirement. Factors that affect the dietary requirement ( C), when stated as a concentration in the diet, are: the bioavailability of the element ( A), feed intake ( F), the amount of the element taken up from the water ( U), the requirement for new tissue synthesis ( G) and the amount of endogenous loss ( E). The model contains factors that can be empirically quantified but the relationships among these factors are determined deductively according to the equation C = [( G + E − U)/ A]/ F. Examples, using both real and hypothetical data, demonstrate how quantification of these factors and their incorporation into a factorial model will allow broader application of the currently available, empirically derived requirements.