Another consequence of the restrictions against chemically synthesized
solvents is that it is difficult to reduce the content of indigestible
carbohydrates in organic plant feed ingredients, which have
been shown to reduce the nutritional value of conventional feed in
many fish species (e.g., Glencross, 2009; Krogdahl et al., 2010; Refstie
et al., 1999).
The objective of the present study was to examine the effects on
nutrient utilization and fish performance when gradually substituting
fish meal by a matrix of organic pea (Pisum sativum) protein concentrate
(PC), organic horsebean (Vicia faba) protein concentrate (HC),
and organic rapeseed (Brassica napus) protein concentrate (RS). The
three plant protein sources were chosen based on their, for plant protein
ingredients, relatively high protein content, and the matrix was
established to mirror the amino acid composition of high quality
fish meal.