Name: | Description: | Size: | Format: | |
---|---|---|---|---|
1.05 MB | Adobe PDF |
Advisor(s)
Abstract(s)
The sustainability of the Aquaculture industry relies on optimising diets to promote
nitrogen retention and maximise fish growth. The aim of this study was to assess how different
dietary formulations influence the bioavailability and metabolic fate of distinct amino acids in
gilthead seabream juveniles. Amino acids (lysine, tryptophan, and methionine) were selected based
on their ketogenic and/or glucogenic nature. Seabream were fed practical diets with different protein
(44 and 40%) and lipid contents (21 and 18%): 44P21L, 44P18L, 40P21L, and 40P18L. After three weeks
of feeding, the fish were tube-fed the correspondent diet labelled with 14C-lysine, 14C-tryptophan,
or 14C-methionine. The amino acid utilisation was determined based on the evacuation, retention
in gut, liver, and muscle, and the catabolism of the tracer. The metabolic fate of amino acids was
mainly determined by their nature. Tryptophan was significantly more evacuated than lysine or
methionine, indicating a lower availability for metabolic purposes. Methionine was more retained in
muscle, indicating its higher availability. Lysine was mainly catabolised, suggesting that catabolism
is preferentially ketogenic, even when this amino acid is deficient in diets. This study underpins the
importance of optimising diets considering the amino acids’ bioavailability and metabolic fate to
maximise protein retention in fish.
Description
Keywords
Ketogenic Glucogenic Catabolism Amino acid bioavailability Nutrient flux
Citation
Publisher
MDPI