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Indispensable amino acid concentrations decrease in tissues of stomachless fish, common carp in response to free
Y Zhang1, K Dabrowski, P Hliwa
1School of Natural Resources, The Ohio State University, Columbus, Ohio, U.S.A..
Amino Acids
|May 31, 2006
Summary
Free amino acid diets do not support stomachless fish growth, leading to essential amino acid depletion. Protein-based diets are superior for larval fish nutrition and development.
Area of Science:
- Aquaculture
- Fish Nutrition
- Larval Fish Biology
Background:
- Formulated feeds for fish larvae often face nutritional inadequacy.
- Protein-based diets are traditionally used, but alternative sources are being explored.
- Stomachless fish present unique digestive challenges.
Purpose of the Study:
- To test if free amino acid (FAA) or dipeptide (PP) diets can resolve nutritional inadequacy in stomachless fish larvae.
- To compare nitrogen utilization from FAA, PP, and protein diets.
- To investigate the impact of different dietary amino acid forms on whole-body amino acid pools.
Main Methods:
- Larval and juvenile common carp (Cyprinus carpio L.) were fed diets with amino acids in FAA, PP, or protein (brine shrimp) forms.
- Postprandial whole-body free amino acid pools were analyzed.
- Changes in indispensable and dispensable amino acid concentrations were measured over time.
Main Results:
- Feeding FAA or PP diets resulted in decreased whole-body indispensable amino acid concentrations after meals.
- Histidine increased in all groups, but other indispensable amino acids decreased in FAA and PP groups compared to protein.
- Taurine was identified as a major free amino acid in larval freshwater fish, potentially indicating a conditional requirement.
Conclusions:
- Synthetic FAA and PP diets cannot sustain stomachless larval fish growth.
- These diets may lead to the depletion of indispensable and dispensable amino acids in fish.
- Diet formulations need adjustments to prevent amino acid excretion without protein synthesis.
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