Abstract
Protein digestibility by gastrointestinal homogenates of Dicentrarchus labrax, was investigated in 5 feeds in relation to their amino acids composition and their ability to sustain growth of D. labrax post larval juveniles. Gastric proteolysis was found to contribute <25% of the total proteolytic capacity. Correlation was found between intestinal proteolytic capacity and the feed protein content of three pairs of amino acids. The sum of basic amino acids, arginine + lysine in the feed protein exhibited a positive correlation with susceptibility to proteolysis. The sum of the acid amino acids glycine and proline showed a negative correlation. Comparison of the intestinal proteolytic enzymatic activities in 3 growth stages of this species revealed similar profiles. Post larval and large juveniles had similar proteolytic capacities when compared on the basis of equal activity on an artificial substrate of Trypsin. Specific growth rates of post larval fish fed on these 5 feeds correlated positively with their protein digestibility as measured with large juvenile's intestinal homogenates. The results suggest that in this species, the efficiency of feeds in sustaining growth at the post larval stage can be estimated by measuring the feed protein digestibility by the proteolytic system of larger sized juveniles.
| Original language | English |
|---|---|
| Pages (from-to) | 399-407 |
| Number of pages | 9 |
| Journal | Fish Physiology and Biochemistry |
| Volume | 14 |
| Issue number | 5 |
| DOIs | |
| State | Published - 1 Oct 1995 |
| Externally published | Yes |
Keywords
- Dicentrarchus labrax
- feeds
- growth rate
- post larvae
- proteolytic enzymes
ASJC Scopus subject areas
- Biochemistry
- Physiology
- Aquatic Science