February 15-18, 2009 Washington State Convention Center Seattle ...

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WHAT IS THE EFFECT OF DIFFERENT INDISPENSABLE AMINO ACID IMBALANCED
DIETS ON TROPICAL FISH PACU Piaractus mesopotamicus ?
Rodrigo Takata, Maria Célia Portella, Thiago M. de Freitas, Karolina Kwasek and Konrad Dabrowski
Sao Paulo State University - Aquaculture Center
Via Prof. Paulo Donato Castellane
14884-900 Jaboticabal, SP, Brazil
portella@caunesp.unesp.br
Under practical farming conditions, feed formulations that include plant proteins may result in disproportionate amounts and
deficiencies of indispensable (essential) amino acid (IDAA). The pacu, Piaractus mesopotamicus, is a native species extensively
cultured in Brazil and frequently subjected to disproportionate amounts of IDAA in commercial diets. The present study
aimed to investigate how disproportional amounts of IDAA in diets for juvenile pacu affects the growth and survival when
IDAA-imbalanced diets are provided in subsequent meals. The experiment was carried out for 56 days. Four isonitrogeneous
and isolipidic diets were used: casein-gelatin-based diet (protein control), FAA-based diet (with all indispensable amino acids),
(-)Lys diet (devoid of Lys, His, Ile, Phe and Trp and (-)Arg diet (devoid of Arg, Thr, Val, Leu and Met). Amino acids were
supplied in the form of L-free amino acids in FAA, (-) Lys and (-)Arg diets. Fish were fed four times per day at 4-hour intervals
and the feed schedule (treatment) used were: (-)Lys(-)Arg group, fish were fed 4 meals of (-)Lys, (-)Arg, (-)Lys and (-)Arg
diets each day throughout the experiment; (-)Lys(-)Lys group, fish were fed 2 meals of the (-)Lys diet as first two meals in the
morning and then 2 meals of the (-)Arg diet in the afternoon; (-)Lys/(-)Arg group, fish were fed four meals of the (-)Lys diet and
the (-)Arg diet on alternate days; FAA and Protein diets (controls); fish were fed FAA-based balanced and casein-gelatin based
diets, respectively, each day throughout the experiment. Mortality was monitored and moribund fish were removed to avoid
cannibalism. Growth performance was assessed by using mean individual weight. Fish fed the protein diet showed the highest
(P