Evaluation of dietary selenium, vitamin C and E as the multi-antioxidants on the methylmercury intoxicated mice based on mercury bioaccumulation, antioxidant enzyme activity, lipid peroxidation and mitochondrial oxidative stress

Author's accepted version (postprint).This is an Accepted Manuscript of an article published by Elsevier in Chemosphere on 18/01/2021.Available online: https://www.sciencedirect.com/science/article/pii/S0045653521001429?via%3DihubMercury (Hg) in high exposures can be a potent life threatening heavy metal that bioaccumulate in aquatic food-chain mainly as organic methylmercury (MeHg). In this regard, fish and seafood consumptions could be the primary sources of MeHg exposure for human and fish-eating animals. The objective of the present study was to elucidate the effects of dietary supplementation of some antioxidants on induced mercury toxicity in mice model. In this study, a 30-day long investigation has been conducted to evaluate the dietary effect of selenium (Se) in combination with vitamin C and vitamin E on methylmercury induced toxicity in mice. Total 54 mice fed the diets with three levels of Hg (0, 50 or 500 μg kg−1) and two levels of Se in combination with vitamin C and E (Se: 0, 2 mg kg−1; vitamin C: 0, 400 mg kg−1; vitamin E: 0, 200 mg kg−1) in triplicates. The results show that Hg accumulated in blood and different tissues such as muscle, liver and kidney tissues of mice on dose dependent manner. The bioaccumulation pattern of dietary Hg, in decreasing order, kidney > liver > muscle > blood. Superoxide dismutase levels in blood serum showed no significant differences in mice fed the diets. However, dietary antioxidants significantly reduced the levels of thiobarbituric acid reactive substances in mice fed the mercury containing diets. Cytochrome c oxidase enzyme activities showed no significant differences as the mercury level increases in liver and kidney tissues of mice. Kaplan-Meier curve showed a dose- and time-dependent survivability of mice. Cumulative survival rate of Hg intoxicated mice fed the antioxidant supplemented diets were increased during the experimental period. Overall, the results showed that dietary Se, vitamin C and vitamin E had no effect on reducing the mercury bioaccumulation in tissues but reduced the serum lipid peroxidation as well as prolonged the cumulative survival rate in terms of high Hg exposures in mice.acceptedVersio

Interactive effect of dietary gamma-aminobutyric acid (GABA) and water temperature on growth performance, blood plasma indices, heat shock proteins and GABAergic gene expression in juvenile olive flounder Paralichthys olivaceus

publishedVersio

The Optimum Feeding Frequency in Growing Korean Rockfish () Rearing at the Temperature of 15°C and 19°C

Two feeding trials were conducted to determine the optimum feeding frequency in growing Korean rockfish, (Sebastes schlegeli) reared at the temperatures of 15°C and 19°C. Fish averaging 92.2±0.7 g (mean±standard deviation [SD]) at 15.0±0.5°C and 100.2±0.4 g (mean±SD) at 19.0±0.5°C water temperature were randomly distributed into each of 15 indoor tanks containing 250-L sea water from a semi-recirculation system. A total of five feeding frequency groups were set up in three replicates as follows: one meal in a day at 08:00 hour, two meals a day at 08:00 and 17:00 hours, three meals a day at 08:00, 14:00, and 20:00 hours, four meals a day at 08:00, 12:00, 16:00, and 20:00 hours, and one meal every 2 days at 08:00 hour. Fish were fed at the rate of 1.2% body weight (BW)/d at 15°C and 1.5% BW/d at 19°C. At the end of 8 wks of feeding trial weight gain and specific growth rate were significantly higher at the fish fed groups of one meal a day and two meals a day at 15°C and fish fed groups of 1 meal every 2 days at 19°C were significantly lower than those of all other fish fed groups. Glutamic oxaloacetic transaminase and glutamic pyruvic transaminase of fish fed group at 1 meal every 2 days was significantly higher than those of all other fish fed groups in both experiments. Weight gain, specific growth rate and condition factor were gradually decreased as the feeding frequency increased. The results indicate that growing Korean rockfish 92 and 100 g perform better at 15°C than 19°C water temperature. As we expected, current results have indicated that a feeding frequency of 1 meal a day is optimal for the improvement of weight gain in growing Korean rockfish grown from 92 g to 133 g at 15°C and 100 g to 132 g at 19°C water temperature

Optimum dietary processed sulfur (Immuno-F) level has antibiotic effects on the growth, hematology and disease resistance of juvenile olive flounder, Paralichthys olivaceus

Author's accepted version (postprint).This is an Accepted Manuscript of an article published by Elsevier in Animal Feed Science and Technology on 19/07/2021.Available online: https://www.sciencedirect.com/science/article/pii/S0377840121002212?via%3DihubA great deal of research has been focused on feed additives that can boost the immune system of cultured fish since the food and drug administration (FDA) banned the use of antibiotics as feed supplementations in 2017. Sulfur is generally an essential element for the growth of animals, and sulfur-containing compounds are known to have anti-oxidant and anti-bactericidal effects. Although dietary sulfur has many potentials as a functional additive as well as an antibiotic replacer, it can also be toxic when supplemented at the high levels. Thus, it is necessary to determine the optimum amount in fish diet to exert positive effects on immune responses. Hence, an 8-week feeding trial was conducted to evaluate the optimum dietary processed sulfur (Immuno-F) level to replace antibiotic oxytetracycline (OTC) in juvenile olive flounder based on growth performance, hematology, and disease resistance. Each of 20 fish averaging 12.6 ± 0.17 g (mean ± SD) were randomly allocated into 8 groups of three tanks, and fed one of the eight isonitrogenous and isocaloric (crude protein 46.7 %, 160 kJ g−1) experimental diets formulated by supplementing Immuno-F at 0 ppm (Cont), 25 ppm (F25), 50 ppm (F50), 250 ppm (F250), 500 ppm (F500), 1000 ppm (F1000) and 2000 ppm (F2000), or oxytetracycline 4000 ppm (OTC4000). Weight gain and specific growth rate of fish fed F25, F500, and OTC4000 diets were significantly higher than those of fish fed F1000 and F2000 diets. In addition, superoxide dismutase, lysozyme and myeloperoxidase activities were not significantly different between sulfur and OTC supplemented groups. However, serum triglyceride levels of fish fed F1000 diet were significantly higher than those of fish fed F25, F50, F250, F500 and OTC4000 diets. In challenge test against Edwardsiella tarda at the 6th day, cumulative survival rates of fish fed F50 diet were slightly higher than those of fish fed F250-F2000 diets. Therefore, these results indicate that dietary processed sulfur at 50 ppm supplementation could replace antibiotic (OTC) in juvenile olive flounder.acceptedVersio

Re-evaluation of the optimum dietary protein level for maximum growth of juvenile barred knifejaw Oplegnathus fasciatus reared in cages

Abstract We determined the optimum dietary protein level in juvenile barred knifejaw Oplegnathus fasciatus in cages. Five semi-purified isocaloric diets were formulated with white fish meal and casein-based diets to contain 35, 40, 45, 50, and 60 % crude protein (CP). Fish with an initial body weight of 7.1 ± 0.06 g (mean ± SD) were randomly distributed into 15 net cages (each size: 60 cm × 40 cm × 90 cm, W × L × H) as groups of 20 fish in triplicates. The fish were fed at apparent satiation level twice a day. After 8 weeks of feeding, the weight gain (WG) of fish fed 45, 50, and 60 % CP diets were significantly higher than those of fish fed 35 and 40 % CP diets. However, there were no significant differences in WG among fish fed 45, 50, and 60 % CP diets. Generally, feed efficiency (FE) and specific growth rate (SGR) showed a similar trend as WG. However, the protein efficiency ratio (PER) was inversely related to dietary protein levels. Energy retention efficiency increased with the increase of dietary protein levels by protein sparing from non-protein energy sources. Blood hematocrit content was not affected by dietary protein levels. However, a significantly lower amount of hemoglobin was found in fish fed 35 % CP than in fish fed 40, 45, 50, and 60 % CP diets. Fish fed 60 % CP showed the lowest survival rate than the fish fed 35, 40, 45, and 50 % CP diets. Broken-line analysis of WG showed the optimum dietary protein level was 45.2 % with 18.8 kJ/g diet for juvenile barred knifejaw. This study has potential implication for the successful cage culture of barred knifejaw

Replacing Fish Meal In Rainbow Trout (Oncorhynchus MyKiss) Diets

The effects of Ohio State University (OSU) meal (a mixture of blood meal, meat and bone meal, poultry by-products and feather meal), as partial or total replacement of fish meal was investi- gated. Thirty-two fish tanks, each containing 30 rainbow trout (initial mean weight 1.93 g), were fed one of 10 diets (the control had only two replicates) containing a different quantity of OSU meal for 14 weeks. The trout fed the diets containing 20% or 40% OSU meal grew similarly to the trout fed the fish meal based diet. Total replacement of the fish meal caused a significant reduction in growth (p<0.05) only at the 47% protein level and not at the 36%. The results of this study suggest that diets containing up to 75% OSU meal and 25% fish meal are sufficient for good growth in rainbow trout fry

Effects of the Dietary Microbial Phytase Supplementation on Bioavailability of Phosphorus in Juvenile Olive Flounder Paralichthys olivaceus Fed Soybean Meal based Diets

Abstract An 8 weeks feeding trial was carried out to evaluate the effects of dietary microbial phytase (P) supplementation on nutrient digestibility, and body composition in juvenile olive flounder Paralichthys olivaceus fed soybean meal-based diets. Seven experimental diets were formulated to be isonitrogenous and isocaloric to contain 50.0% crude protein (CP) and 16.7 kJ of available energy/g with or without dietary phytase supplementation. White fish meal (FM) provided 92.4% of the total protein in the basal diet (S 0 ), in the other 6 diets, 30% or 40% FM protein was replaced by soybean meal: 70% FM + 30% soybean meal (S 30 ); 70% FM + 30% SM + 1000 U phytase/kg diet (S 30 P 1000 ); 70% FM + 30% SM + 2000 U phytase/kg diet (S 30 P 2000 ); 60% FM + 40% SM (S 40 ); 60% FM + 40% SM + 1000 U phytase/kg diet (S 40 P 1000 ); and 60% FM + 40% SM + 2000 U phytase/kg diet (S 40 P 2000 ). After two weeks of the conditioning period, triplicate groups of 25 fish initially averaging 6.15 ± 0.04 g (mean ± S.D.) were randomly distributed into the aquarium and were fed one of the experimental diets for 8 weeks. After feeding trial, supplementation of phytase significantly improved the apparent digestibility coefficients of phosphorus in flounder diets (P&lt;0.05) containing 30% and 40% soybean meal regardless the levels. However, phytase had no significant influence on growth performance and whole body composition of fish. Based on the experimental results, we conclude that dietary supplementation of phytase could improve the apparent digestibility coefficient of phosphorus in olive flounder

Effects of replacing dietary fish oil with beef tallow on growth performance, serological parameters, and fatty acid composition in juvenile olive flounder, Paralichthys olivaceus

This study evaluated the effects of replacing fish oil (FO) with beef tallow (BT) in juvenile olive flounder, Paralichthys olivaceus (3.93 ± 0.07 g), over 8 weeks. Seven diets, consisting of 0, 25, 50, 75, and 100% replacement of FO with BT and 63 and 75.9% replacement supplemented with docosahexaenoic acid (DHA) at 0.9 and 1.1% of 100 g diet, respectively, were distributed into 21 tanks in a semi‐recirculation system with 15 fish per tank. The replacement of FO with BT at the given levels showed no significant changes (p > .05) in growth performance and whole‐body proximate composition. Fish fed the diet of 75.9% replacement with 1.1% DHA supplementation showed the best performance in these measurements among the treatments. Plasma glutamic pyruvic transaminase, cholesterol, high‐ and low‐density lipoproteins, and total protein were not significantly influenced by the replacement of FO with BT. The FO replacement generally resulted in a reduction of eicosapentaenoic acid, DHA, and n‐3/n‐6 polyunsaturated fatty acid ratio in the whole body, whereas the DHA supplementation recovered the level of DHA and the n‐3/n‐6 ratio to those observed in the group fed the 0% replacement diet. Taken together, BT along with DHA supplementation can potentially be a cost‐effective alternative for FO in olive flounder culture