Evaluation of zinc supplementation in European sea bass (Dicentrarchus labrax) juvenile diets: Zinc requirements in sea bass (original) (raw)
Related papers
Evaluation of zinc supplementation in European sea bass (Dicentrarchus labrax) juvenile diets
Aquaculture Research, 2010
This study aimed to investigate the e¡ect of increased zinc dietary levels on the growth performance, feed utilization, immune status and induced wound healing in European sea bass (Dicentrarchus labrax). Fish weighing 10 g were fed ¢ve diets containing organic zinc at 30,70,110 and 150 mg kg À 1 diet and one inorganic zinc source (zinc oxide) at 150 mg kg À 1 diet for a period of 12 weeks. No signi¢cant (P40.05) di¡erences were found in the growth performance parameters (¢nal weight, speci¢c growth rate), immunological indices tested (respiratory burst activity in whole blood) and the wound-healing process. Zinc accumulation in the skin, vertebrae and liver increased signi¢cantly (Po0.01) with increased dietary zinc levels but not in muscle. The highest zinc concentrations were obtained in skin tissue, followed by vertebrae, liver and muscle tissue. Using the concentration of zinc in skin as a response criterion, broken-line analysis showed that the supplementation of 148 mg organic Zn kg À 1 diet seemed to be the optimum dietary zinc supplementation level for sea bass juveniles.
Dietary zinc promotes immuno-biochemical plasticity and protects fish against multiple stresses
Fish & Shellfish Immunology, 2017
The abiotic and biotic stress is an episode that effect on regulatory, neuron, endocrine and immune systems of animals including fish. The stress creates stimulatory and suppressive of immune system resulting in increases the incidence of infection. In view of these points, we have conducted an experiment to mitigate the stress through a nutritional approach through Zinc (Zn) supplementation in Pangasius hypophthalmus (initial weight-3.65 ±0.75 g). Three isocaloric and isonitrogenous diets with graded levels of zinc 0, 10 and 20 mg/kg were prepared and fed to seven different groups with each in triplicate. The experiment group as follows as normal water with control diet (Ctr/Ctr), Pb exposed and fed with the control diet (Ctr/Pb), control diet and exposed to Pb and temperature (Ctr/Pb-T), Zn 10 mg/kg fed without stressors (Zn-10 mg/kg), Zn 20 mg/kg fed without stressors (Zn-20 mg/kg), Zn 10 mg/kg fed and Pb and temperature exposed (Pb-T/Zn 10 mg/kg) and Zn 20 mg/kg fed and exposed to Pb and temperature (Pb-T/Zn 20 mg/kg). The lead (Pb) in treated water was maintained at the level of 1/20 th of LC 50 (4 ppm) and temperature at 34 °C in exposure groups. The neutraceuticals role of dietary Zn was studied in terms of antioxidative enzymes (catalase, superoxide dismutase, glutathione-S-transferase), stress markers (Heat shock protein 70, cortisol, acetylcholine esterase, blood glucose, Vitamin C), immunological parameters (Total protein, albumin, globulin, A/G ratio and NBT) and subsequent challenge with Aeromonas veronii biovar sobria. The antioxidative enzymes, stress markers, albumin were significantly (p<0.01) elevated, brain AChE and immuno-hematological parameters were significantly (p<0.01) decreased due to lead (Pb) and temperature exposure. The relative survival (%) was reduced due to the concurrent effect of Pb, high temperature stress and bacterial challenge. Zinc at the rate of 10 and 20 mg/kg was found to be restore the biochemical and immunological parameters against concurrent exposure to lead (Pb), temperature and pathogenic infection. Results obtained in the present study indicate that supplementation of 10 and 20 mg/kg of Zn in the diet has a definitive role in the mitigation of lead (Pb) and temperature exposure along with pathogenic infection in P. hypophthalamus.
The changes in common carp blood after short-term zinc exposure
Environmental Science and Pollution Research, 2003
Blood zinc level, hematological parameters and blood cell morphology were evaluated in common carp immediately after 3 h exposure to 20 mg dm -3 of zinc (Zn0), and in 24, 48 and 96 hours after the end of it (Zn24, Zn48, Zn96). Blood zinc level in the non-exposed fish was 8 mg dm -3, reached a maximum of 20 mg dm -3 in Zn48, while it dropped to 9 mg dm -3 in Zn96. Zinc caused a stress reaction in fish indicated by an increase in hematocrit value in Zn0, and elevated plasma glucose level and trombocytosis which persisted until the end of the experiment. Zinc-exposed fish showed an increased frequency of abnormal erythrocytes, and a compensatory release of immature erythrocytes to the blood stream. In zinc-treated fish, leukocyte count initially increased and subsequently decreased significantly below the control level due to a drop in lymphocyte number. Lymphocyte viability was reduced, and abnormal lymphocytes appeared. A decreased count of juvenile neutrophiles, and reduced phagocyte activity also occurred. The results indicate possible zinc-induced disturbances in both specific and non-specific immune mechanisms.
Biology
Since Asian sea bass is one of the economically most important fish, aquaculture conditions are constantly optimized. Evidence from feeding studies combined with the current understanding of the importance of zinc for growth and immune defense suggest that zinc supplementation may be a possible approach to optimize aquacultures of Asian sea bass. To investigate the effects of zinc deficiency and zinc supplementation, cells from Asian sea bass were incubated in culture medium with different zinc contents. The expression of genes, important for zinc homeostasis, redox metabolism, and growth hormones was analyzed using RT-PCR. Zinc deficiency induced the expression of certain zinc transporters (ZIP14, ZIP10, ZIP6, ZIP4, ZnT4, ZnT9) as well as of SOD1, IGF I and IGF II, while expression of ZnT1 and metallothionein (MT) was reduced. Zinc supplementation decreased the expression of ZIP10, while expression of ZnT1 and MT were elevated. No differences in the effects of zinc supplementation ...
International Aquatic Research, 2017
This study investigated the effect of dietary Zn levels on growth performance, feed utilization, and hematological parameters of juvenile Siberian sturgeon (Acipenser baerii, Brandt 1869). The five semipurified diets were formulated by adding 0, 5, 10, 20, and 40 mg Zn kg-1 diet in the form of zinc sulfate (ZnSO 4) to provide the actual dietary value of 14.7, 20.8, 27.3, 37.7, and 46.4 Zn kg-1 diet, respectively. The results showed that dietary Zn elevating level significantly improved the growth and feed utilization of the fish (p \ 0.05), but not the hepatosomatic index (p [ 0.05). Erythrocyte number, hemoglobin concentration, and hematocrit were increased with raising dietary Zn level (p \ 0.05), whereas a regular trend was not observed in blood indices, including MCV, MCH, and MCHC. A significant increase was also found in the leucocyte number followed by their differential counts, except for eosinophil percentage. The broken line regression model indicated optimal dietary Zn level for growth maximization of fish was estimated to be 29.15 mg Zn kg-1 diet. In spite of well correlation with dietary Zn level, no break point was observed to estimate the juvenile Siberian sturgeon requirement based on the erythrocyte numbers.
The present study was carried out to investigate the effect of sublethal zinc (Zn) concentrations on the growth, biochemical variables, and Zn residues in common carp, Cyprinus carpio L.. Fish (18.1 – 19.1 g) were exposed to 0.0 (control), 5.0 and 10.0 mg Zn/L for 7, 14, 28, and 56 days. At each time interval and each treatment, fish were collected, weighed and sampled to measure the growth, biochemical variables, and Zn residues in whole-fish body. Growth performance was significantly reduced with increasing Zn concentrations. However, fish exposed to 10.0 mg Zn/L for 56 days grew lower than that of the control group. Likewise, the optimum feed intake and feed conversion ratio were obtained at control group at 56 days. Furthermore, glucose, AST, ALT, creatinine, and cortisol increased significantly with increasing Zn concentration and exposure time, with maximal values at 56 days. Meanwhile, the highest values of serum protein and lipids of were obtained in the control fish reared for 56 days, whereas the lowest values were observed in fish exposed to 10.0 mg Zn/L for 56 days. The content of whole-body moisture and total ash increased significantly, while crude protein and total lipid contents decreased significantly with increasing Zn concentrations. In addition, Zn exposure increased Zn residues in fish body; however, Zn bioaccumulation in fish body was Zn dose and time dependant. The present study revealed that the growth and health status of common carp were deteriorated by Zn toxicity.
Aquaculture, 2020
The present study aimed to evaluate the optimal dietary micronutrient supplementation of plant-based diets for juvenile European sea bass. A 90-day feeding trial was performed, where fish were fed a high fishmeal (FM) based diet (62% DM; positive control) or low FM diets (12.5% FM and krill meal), supplemented with increasing levels of a micronutrient mixture (Nutrient Package, NP) consisting of vitamins, minerals and other micronutrients. The supplementation levels ranged from 0% (no supplementation, negative control) to 400%, where 100% supplementation level corresponded to the requirement levels recommended for other fish species. Fish growth and feed performance (SGR, DGI, FCR, PER) were significantly impaired at levels NP0 and NP25 compared to the FM control. Body Fe and Zn concentrations were positively affected by the graded levels of the NP, while Mn and Se concentrations remained stable. Growth parameters were particularly correlated to body Fe and Zn, while immune parameters were mainly correlated to body Zn. Significant immunosuppression was evidenced (concerning the respiratory burst activity) when low FM diets were not supplemented with NP. High inclusion levels of the NP showed a negative impact on lysozyme activity. Histological examinations did not reveal any significant effects on gills, gut and liver morphology. At identical NP supplementation level (50%), fish fed low and high FM diets showed similar growth and innate immunity suggesting that long-term feeding with plantbased diets do not significantly affect the fish when adequate minerals and vitamins supplementation is provided. Quadratic regression analysis showed that the inclusion of the NP between 260 and 300% improves growth and immune parameters of fish fed low-FM diets as well as Zn body incorporation. Overall, the present study suggested the positive impact of NP supplementation of PM-based diets on both fish growth and health but future NP could include less Mn, more Fe, closer to levels obtained in fish fed FM (245 mg•kg −1), and Zn at 122 mg•kg −1 .
Effects of different levels of dietary zinc on the gilthead,Sparus aurata during the growing season
Biological Trace Element Research, 1996
Gilthead were fed three diets. Diet A was the control diet, whereas diets B and C were supplemented with 300 and 900 mg Zn/kg, respectively. Fish fed with diet C, at the end of the experiment, showed the lowest weight. Zinc concentrations presented the higher values in gills, liver, and kidney. Muscle and brain had the lower mean values and showed a tight control of zinc levels. These results reinforce the hypothesis that zinc in the CNS should be strictly controlled in order to maintain the functional role of the metal. Significant differences in tissue zinc concentrations were obtained between fish fed different amounts of zinc, the metal concentrations being higher in tissues of fish fed diet C. The tissue decrease of zinc, found at the end of the experiment, may depend on a lower feed consumption or on different zinc requirements during the cold season. These changes, even if not univocal among the three diets, may be associated with the life cycle of fish. Furthermore, copper concentrations were little affected by the different concentrations of zinc in the three diets; liver and kidney presented the highest concentrations; liver showed a significant decrease in copper content at the end of the experiment. We conclude that: zinc concentrations of the diet may affect the gilthead weights and the tissual metal content; and zinc concentrations in the diets, depending on the growth rate, may be varied depending on the season.
Zinc gluconate and zinc sulphate as dietary zinc sources for Atlantic salmon
2001
Dierent chemical forms of essential minerals and trace elements supplemented to feed may show dierent bioavailability in ®sh. The present experiment was performed to compare an organic zinc form (Zn-gluconate) with zinc sulphate as dietary zinc sources for Atlantic salmon. Triplicate groups of ®sh were fed commercial ®sh meal based diets supplemented with either a low zinc level (50 mg Zn kg )1 ) or medium zinc level (180 mg Zn kg )1 ) as zinc gluconate or zinc sulphate for 6 months. Growth, mortality and feed conversion were recorded through the experiment. Fish were sampled initially and every month for zinc status analyses measured as whole-body zinc concentration. After 4 and 6 months, vertebral zinc concentration was measured and serum zinc was analysed at the end of the experiment. There were no dierences in growth or mortality during the experiment. The results showed a signi®cant eect of dietary zinc supplementation level on zinc status in ®sh for both zinc forms. However, there were no dierences in zinc status between groups given dierent zinc forms. In conclusion, the present experiment showed that zinc sulphate and zinc gluconate are equally ecient as zinc supplements in salmon feeds within the concentrations normally found in salmon feed.