Early development: protein and arginine requirements in four species of cultivated fish (rainbow trout, turbot, bream, bass)
European Network for the Dissemination of Aquaculture
RTD Information (Q5CA-2000-30105) and previously FAIR-3837, Aquaflow ref. :
TL2003-180
Essential amino acids (or EAA) are not synthesised by
the organism in sufficient quantity to perform proteic synthesis and ensure
the physiological functions in which they are involved. They must therefore
be provided by nutrition. This is the case for arginine. Nutritional protein
requirements are high in teleostian fish with, however, important
differences between species. In view of the current expansion in
aquacultural production and the environmental implications of nitrous waste,
it has become necessary to precisely define the requirements of protein and
EAA for each species of fish.
The objective of this study was to evaluate the
requirements in nitrogen (N) and in arginine (Arg) for the maintenance and
growth of four species of fish at an early stage of development: a fresh
water fish (rainbow trout) and three marine species (turbot, bream and
bass). On this basis animals with an initial weight of 5 to 7g were fed
during 4 to 6 weeks with feed in which the N and Arg content varied from 0
to 8% and 0 to 3% respectively in dry matter. For each species, the N and
Arg requirements for maintenance and growth were calculated from the
relation expressing the daily nitrogen gain according to the quantities of N
and Arg absorbed.
The N requirement necessary for maintenance is of the
same order in trout and bass (respectively 38 and 45mg/kg PM*/day).
This requirement is twice as high in the bream (85mg/kg PM/day) and three
times as high in turbot (127mg/kg PM/day). The N requirement necessary for a
1g nitrogen gain is lower for turbot and trout (respectively 2.2 and 2.3g/g
N gain) than bass and bream (2.5 and 2.6g/g N gain). The data obtained
equally demonstrate that the Arg requirement necessary for maintenance is
nil for the trout, turbot and bass or very low for bream. The Arg
requirement necessary for a 1g nitrogen gain is very close for the three
marine species (1.04 to 1.11g) and slightly lower (0.86g) for trout.
In conclusion, turbot appears to have a higher
nitrogen requirement for maintenance than the three other species, which
could explain the high total protein requirement in this species. The
results obtained equally suggest that the endogenous synthesis of Arg
although reduced, appears sufficient for maintaining the nitrogen balance.
The Arg requirement for growth seems somewhat higher for the marine species.
The requirements concerning other development stages as well as other EAA
will need to be evaluated.
*PM=((initial weight)0.75+(final weight)0.75)/2
Source: Fournier, V., Gouillou-coustans M.F., Métailler,
R., Vachot, C. , Guedes, M.J., Tulli, F., Oliva-Teles, A., Tibaldi, E., and
Kaushik, S. J. 2002. Protein and arginine requirements for maintenance and
nitrogen gain in four teleosts. British
Journal of Nutrition, 87, 459-469.
For
more information, contact :
S.
Kaushik
Laboratoire de Nutrition des Poissons
Unité mixte INRA-IFREMER
64310 Saint-Pee-sur-Nivelle - France
Tel.: 00 33 (0)5 59 51 59 90
Fax: 00 33 (0)5 59 54 51 52
E-mail: kaushik@st-pee.inra.fr