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Improvement of yield and food conversion in salmonids and maricultured fish

Objective

The evolution of the world fishery harvest has now reached a stationary phase. Although the production of fish through aquaculture has increased significantly over the past decade, it will be insufficient to meet future needs unless production is dramatically increased. Among the limiting factors in commercial fish farming are the length of the production cycle and the feed costs. Improvement in feed conversion efficiency and acceleration of growth rate are therefore highly desirable.

The aim of this programme is to develop a treatment in fish farming, based on the oral administration of an encapsulated fish protein, in order to improve the yield, the production costs and the quality of salmonids and maricultured fish. All the relevant data necessary for assessing its farm scale feasibility will be accumulated. The different partners will collaborate in developing a suitable encapsulation procedure and in defining a delivery system for the protein, produced by recombinant techniques, suitable for oral administration in fish. They will thus develop, through small scale experimentation, an efficient treatment which can be used in typical fish farming conditions and assess the improvement of quality of the fish flesh. Different fish species will be studied: trout, salmon, sea bass, and sea bream. The last part of the programme consists of a farm scale trial campaign in different countries of the European Community allowing the accumulation of the data needed to evaluate the economic interes of such a treatment.
The aim of this work was to develop a treatment in fish farming, based on the oral administration of a liposome encapsulated fish protein, to improve the yield, production costs and the quality of salmonids and maricultured fish.
Eurogentec has studied several expression vectors carrying tilapia or rainbow trout growth hormone (GH) complementary deoxyribonucleic acid (cDNA) in Escherichia coli and Saccharomyces cerevisiae. The characteristics of each system have been compared in order to select the expression system presenting the highest potential for GH production. Cell culture conditions and growth kinetics have been optimized for the selected expression system. Fermenter capacity has been optimized for the selected expression system. An integrated process has been developed for cell lysis, inclusion bodies preparation and solubilisation, rfGH renaturation and purification. The purity of the recombinant tGH preparations is over 95 % and the protein is biologically fully active. Ultrasensitive radioimmunoassay (RIA) and radioreceptorassay (RRA) using recombinant trout somatotropin have been developed. The stability of rfGH in various aqueous and organic solution suitable for encapsulation has been investigated by RIA. Several formulations of lyophilised rfGH have been developed.

The aim of this work was to develop a treatment in fish farming, based on the oral administration of a liposome encapsulated fish protein, to improve the yield, production costs and the quality of salmonids and maricultured fish.
The salmonid growth hormone (GH) radioimmunoassay developed at the INRA has been widely used in the monitoring of the biological activity of recombinant fish somatotropins (rfGH) during the optimization process of the renaturation and purification of rfGH. Results demonstrate that recombinant trout GH is biologically fully active in terms of binding to its receptors.

The aim of this work was to develop a treatment in fish farming, based on the oral administration of a liposome encapsulated fish protein, to improve the yield, production costs and the quality of salmonids and maricultured fish.
Trials began at the University of Stirling to determine the efficacy and effects of recombinant trout rowth hormone (GH) on Atlantic salmon held in sea water. Feeding rate was controlled, and growth and food conversion efficiency were monitored. Following the final injection, 10 fish per group were collected in order to determine the effects of treatment on relative food intake and body composition. The remaining fish are being ongrown to measure subsequent growth and food conversion efficiency.

The aim of this work was to develop a treatment in fish farming, based on the oral administration of a liposome encapsulated fish protein, to improve the yield, production costs and the quality of salmonids and maricultured fish.
The absorption and transepithelial transfer in the rainbow trout gut of 2 proteic markers (ferritin and horseradish peroxydase) have been studied. The localisation of the absorption site of the markers and the different steps of their transepithelial transfer have been determined. The results obtained have been extended to somatotropins. Recombinant trout somatotropins (rtGH) and bovine somatotropin (bGH) have been administered by the anal route and their intestinal absorption studied by immunocytochemistry.
The evolution of world fishery harvest has now reached a stationary phase. Although the production of fish through aquaculture has increased significantly over the past decade, it will be insufficient to meet future needs unless production is dramatically increased. Among the limiting factors in commercial fish farming are the lenght of the production cycle and the feed costs. Improvement in feed conversion efficiency and acceleration of growth rate are thereforce highly desirable.

The aim of this program is to develop a treatment in fish farming, based on the oral administration of a liposome encapsulated fish protein, in order to improve the yield, the production costs, and the quality of salmonids and maricultured fish. All the relevant data necessary for assessing its farm scale feasibility will be accumulated. The different partners will collaborate in developing a new encapsulation procedure based on liposomes and in defining a delivery system for the protein, produced by recombinant techniques, suitable for oral administration in fish. They will thus develop, through small scale experimentation, an efficient treatment which can be used in typical fish farming conditions and assess the improvement of quality of the fish flesh. Different fish species will be studies : trout, salmon, sea bass, and see bream. The last part of the programme consists of a farm scale trial campaign in different countries of the European Community allowing the accumulation of the data needed to evaluate the economic interest of such a treatment.

Coordinator

Société Européenne de Biotechnologie SA
Address
14,Rue Bois Saint-jean
4102 Seraing
Belgium

Participants (6)

Biocompatibles Ltd
United Kingdom
Address
Brunel Science Park Kingston Lane
UB8 3PQ Uxbridge
Institut National de la Recherche Agronomique (INRA)
France
Address
147 Rue De L'université
75341 Paris
UNIVERSIDADE DE LISBOA
Portugal
Address
Campo Grande
1699 Lisboa
UNIVERSITE DE LIEGE*ULG
Belgium
Address
Place Du 20 Aout 7
4000 Liege
UNIVERSITE DE PARIS-SUD XI
France
Address
Rue Georges Clemenceau 15
91405 Orsay
UNIVERSITY OF STIRLING
United Kingdom
Address

FK9 4LA Stirling