Evaluation of protein quality in microbound starter diets made with decapsulated cysts of Artemia and fishmeal for fish larvae
A.
Garcia-Ortega, E.A. Huisman, P. Sorgeloos, J. Verreth-2001
Journal of the World Aquaculture Socity, 32(3):
317-329 (from Current Contents)
Abstract :
The protein quality of carboxymethylcellulose
microbound diets (MBDs) made with decapsulated cysts of Artemia and/or
fishmeal as protein sources was used as an indicator of their suitability as
starter feed for fish larvae. Studies on the proximate, fatty acid and amino
acid composition, in vitro protein digestibility, diet solubility, and
protein structure were combined with an in vivo feeding experiment with
African catfish Clarias gariepinus larvae to evaluate the protein quality of
the MBDs and a commercial diet. The growth of catfish larvae was higher when
fed Artemia-based MBDs than with fishmeal-based MBDs. despite the higher
protein and amino acid content of the latter. The in vitro protein
digestibility was high for all the MBDs in comparison to a commercial diet.
Differences were found in the protein molecular weight among the diets. Most
of the proteins in the fishmeal-based diets had low molecular weight in the
range between 7.4 and 49.2 kDa. The Artemia-based MBDs had larger protein
fractions between 29.4 and 82 kDa. Decapsulated cysts improved the
utilization of the MBDs when used in combination with fishmeal. Besides the
effect of chemical attractants, the explanation for the positive effect of
Artemia has yet to be elucidated. However, attention should be given to
interactions between nutrients (e.g., protein-lipid) in live food, which
might have an effect on the functional properties of food proteins.
(Ctr Invest Alimentac & Desarrollo, Unidad
Mazatlan, Apartado Postal 711, Mazatlan, Sinaloa, Mexico, e-mail: agarcia@victoria.ciad.mx)