Spirulina as a nutrient source in diets for growing sturgeon (Acipenser baeri)

The efficiency of diets with the inclusion of Spirulina for Siberian sturgeon weaning has been tested. Three isoproteic and isoenergetic diets were formulated with an increasing level of Indian strain Spirulina (SP 40%, SP 50% and SP 60%); the diets were tested against a control diet without microalgae. The results show that Spirulina inclusion improves growth and that an inclusion level of 50% gave the greatest growth rate, a better favourable feed conversion rate and the highest protein efficiency. The fatty acid composition of fillets showed differences between the experimental and control diets: an increase in the Spirulina level induces increases in palmitic and linoleic acids and a decrease in the myristic acid. The control diet was characterized by high levels of eicosapentaenoic and docosahexaenoic acids. At the end of the experiment, statistical differences appeared in the fatty acid profile of the sturgeon fillet, mainly concerning high content of monounsaturated fatty acid and polyunsaturated fatty acid in the sturgeon fillets. If the problems related to the high production costs are solved, Spirulina could prove a good partial substitute fish meal.