Hybrid sturgeon 'AL' diets

In this experimentation, corn gluten (CG) and pea meal (PM) were tested as potential protein sources in hybrid sturgeon âALâ. One hundred and twentyâeight hybrid sturgeons âALâ (Acipenser naccarii A Acipenser baeri) (initial body weight 364.8 ± 4.5âg) were utilized with four experimental diets and four replicates each; the experimental design was 4 A 4. Four isonitrogenous [crude protein=40% dry matter (DM)] and isoenergetic (gross energy=20âMJâkgâ1 DM) diets were formulated containing different levels of CG with or without PM and tested against a control diet that was fish meal (FM) based. Diets were as follows: CG55 contained 55% of corn gluten; diet CG55PM25 contained 55% CG and 25% PM; diet CG45PM25 contained 45% of corn meal and 25% of PM; and diet FM was control, based on FM. Fish fed with the PM diet showed lower values of feed conversion ratio (FCR) and specific growth rate (SGR) (FCR=4.53 ± 2.51 in the CG55PM25 diet; FCR=4.09 ± 1.45 in the CG45PM25 diet; SGR=0.20 ± 0.07 in the CG55PM25 diet; SGR=0.19 ± 0.11 in the CG55PM25 diet). The results of tissue proximate composition confirmed the results obtained from productive traits. This study indicates that CG meal but not PM could be utilized as a substitute of FM in hybrid sturgeon âALâ nutrition

Effects of Spirulina and plant oil on the growth and lipid traits of white sturgeon (Acipenser transmontanus) fingerlings

The aim of this research was to evaluate the efficiency of diets with Spirulina and plant oils (POs) inclusion for white sturgeon weaning and their effects on the fatty acid (FA) composition of fish flesh. Three isoproteic (45%) and isoenergetic (21 MJ kg−1 DM) diets were formulated: one fish meal-based diet integrated with fish oil (FMO) and two 40% Spirulina meal-based diets integrated with corn (SPC) or soybean (SPS) oils respectively. One hundred and thirty-five white sturgeon fingerlings (mean weight 17.5 g) were stocked randomly in nine fibreglass tanks. At the end of the trial, which lasted 71 days, the growth performance traits and somatic indexes were determined. The chemical composition, gross energy and FA profile were determined on the fish fillets. No significant effects were observed for the growth performances or fillet chemical composition. The FA profile of the fillets reflected those of the diets. In particular, the fillets of the fish fed with the SPC and SPS diets were lower in n-3 FA, due to the substitution of fish oil (FO) with POs. It is possible to replace FO and meal in sturgeon; therefore, Spirulina meal integrated with POs could be a good alternative to sturgeon diet

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

The e⁄ciency 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 e⁄ciency. The fatty acid composition of ¢llets showed diierences 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 diierences appeared in the fatty acid pro¢le of the sturgeon ¢llet, mainly concerning high content of monounsaturated fatty acid and polyunsaturated fatty acid in the sturgeon ¢llets. If the problems related to the high production costs are solved, Spirulina could prove a good partial substitute ¢sh meal

Partial replacement of fish meal by T-Iso in gilthead sea bream (Sparus aurata) juveniles diets

The aim of this study was the evaluation of microalga Isochrysis sp. T-Iso in partial substitution of fish meal and the study of the effects on gilthead sea bream (Sparus aurata) perform- ances and chemical composition of fillets. The results show that the microalga T-Iso nutrients support growth better than control diets, and the chemical composition of sea bream fillets also meets the needs of consumers for healthy diets. T-Iso resulted highly digestible, and support the best perform- ances of fish fed on 70% alga diet probably due to its high protein efficiency in comparison to other diets. The presence of a high quantity of cyclic isoprenoid could explain this high efficiency of T-Iso. Gilthead sea bream fed on 70% T-Iso showed fillets with a low level of protein and a high level of fat; moreover, their somatic indexes were higher than those of fish fed other diets. Highest percentage T- Iso diet showed the highest amount of the sum of saturated fatty acids, mainly due to myristate and palmitate. On the contrary, the sum of polyunsaturated decreases, mainly because of the reduction of EPA and DHA amounts. If the mass production economical problems are solved, T-Iso will represent a good solution in partial substitution of fish meal