practice implies certain limits to the feed (reviewed by Mente et al.,
2011). Following the European Union's regulation No. 834/2007 on
organic production and labeling of organic products (EU, 2007), it is
not allowed to add synthetic amino acids to the feed or to use chemically
solvent related purification methods of the plant ingredients. It
is therefore necessary, when formulating an organic diet, to blend a
selection of different vegetable protein sources with high protein contents
and complementary amino acid profiles, since optimization of
the amino acid profile of organic feed must be based on the protein
sources alone. An optimized amino acid profile can only be obtained
by combining a number of plant protein ingredients as no single agricultural
crop can provide a suitable amino acid composition (Gaylord
et al., 2010; Kaushik, 1990).