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Effects of Canola and Safflower Oil Supplementation in Diets, on Growth Performance and Fatty Acid Composition of Russian Sturgeon (Acipenser gueldenstaedtii Brandt, 1833)
Get PDFThe aim of this study was to determine the impact on growth performance and muscle fatty acid composition, of replacement of 50% fish oil (FO) with canola oil (CO) and safflower oil (SFO) in the diets of Russian sturgeon (Acipenser gueldenstaedtii). Two isoproteic (48%) and isolipidic (12%) diets were formulated combining two oil sources (50% fish oil + 50% canola oil or 50% fish oil + 50% safflower oil). The diets were fed to apparent satiation to triplicate groups for 15 weeks, twice a day. No significant differences were observed between the experimental groups fed CO and SFO diets in terms of weight gain, specific growth rate, feed conversion ratio, and protein efficiency ratio. The experimental groups fed CO and SFO diets did not show significant differences in terms of protein, lipid, ash, and moisture content in their muscle. There were no significant differences in muscle between total n-3 fatty acids but total n-6 fatty acids were significantly higher in SFO group (24.90%) than in CO group (21.30%). Total n-6 fatty acids were also higher than (20.43%) at the start. In conclusion, 50% replacement of FO by CO or SFO in Russian sturgeon diets had no negative effect on growth performance, feed efficiency and fatty acid composition in the muscle of this species
Efficacy of Alfalfa Saponins on Promoting Pigmentation by Astaxanthin in Blood Parrot Fish (Vieja synspila♀× Amphilophus citrinellus♂)
Get PDFThis study was conducted to evaluate the effect of alfalfa saponins on pigmentation induced by astaxanthin in 540 blood parrot fish (Vieja synspila ♀ × Amphilophus citrinellus ♂). The fish were divided into six treatment groups: basal diet; a diet supplemented with 3‰ astaxanthin; three diets with 3‰ astaxanthin plus 3‰, 6‰ or 12‰ alfalfa saponins respectively; and a diet supplemented with 4‰ alfalfa saponins alone. The fish were maintained in three aquaria per treatment. At 20, 40, 60, and 80 days, 6 blood parrot fish per aquarium were sampled. At the end of the experiment, the carotenoid content of scales, skin, and caudal fin in groups supplied with 3‰ astaxanthin plus alfalfa saponins were significantly higher than the control. The redness values, a*, of the body and caudal fins in these groups increased significantly. Conversely, the cholesterol and triglyceride content decreased significantly. Non-esterified fatty acid content and lysozyme activity were significantly higher in the three groups fed supplemented astaxanthin diets with the addition of alfalfa saponins, than the group fed a diet supplemented with 3‰ astaxanthin alone (P<0.05). The results show that the addition of alfalfa saponins to diets supplemented with astaxanthin, improves astaxanthin absorption and utilization
Effects of Dietary Surfactin Supplementation on Growth, Digestive Enzyme Activity, and Antioxidant Potential in the Intestine of Growth Retarded Marbled Eel (Anguilla marmaorata) at Elver Stage
Get PDFA 70 day trial was conducted to investigate the effects of surfactin on growth, digestive enzyme activity, and antioxidant potential in the intestine of growth retarded marbled eels (Anguilla marmorata) at the elver stage. Six hundred and forty marbled eels at elver stage were randomly divided into four treatment groups with four replicates per group, and 40 fish per replicate. The dietary surfactin level of the four experimental diets was 0, 25, 50, and 100 mg/kg, respectively. Final body weight, weight gain rate, survival rate, protease activity in the intestine, malondialdehyde level, total antioxidation capacity level, and activities of superoxide dismutase, and glutathione peroxidase in the intestine of fish, increased significantly with surfactin supplementation, and feed conversion rates improved significantly (P0.05). Results demonstrated that dietary surfactin supplementation could improve growth performance, some digestive enzyme activities, and antioxidant potential, in the intestine of growth retarded marbled eel at elver stage. Surfactin could be used as a dietary growth promoter for growth retarded eels
Identification of Relevant Biomarkers in Mercury Exposed Clam Venerupis philippinarum.
Get PDFThis study assessed the impact of four different concentrations (2.5, 5, 7.5, 10 μg/L) of mercury exposure on Manila clam Venerupis philippinarum based on the dynamic characteristics of antioxidant related enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), acid phosphatase (ACP), alkaline phosphatase (ALP), total glutathione content, and malondialdehyde (MDA) content at 24 h and 48 h post exposure.
The results showed that hemocyte SOD activity was inhibited while GR hemocyte activity significantly increased in the 2.5 μg/L group after 24 h. Hemocyte ALP activity and (GSH) content were also elevated at the 7.5 μg/L and 10 μg/L groups when exposed for 24 h, respectively. SOD activity, GR activity, ALP activity and GSH content in the hemocytes were relatively sensitive to different concentrations of mercuric mercury (Hg2+), suggesting that they may act as potential biomarkers in assessing environmental mercury exposure on Venerupis philippinarum. At different levels of exposure, antioxidant parameters showed differing responses in gill tissue, but no biomarkers were discovered in the samples examined. We found that hemocytes are more suitable biomarkers than proteins in gill tissue. Some hemocyte biomarkers are promising candidates for monitoring mercury pollution in marine clams
