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Zhou Q.-C.,Ningbo University | Wang L.-G.,Guangdong Ocean University | Wang H.-L.,Guangdong Evergreen Feed Industry Co. | Wang T.,Guangdong Evergreen Feed Industry Co. | And 2 more authors.
Aquaculture Nutrition | Year: 2013

An 8-week feeding trial was conducted to establish the dietary vitamin E requirement of juvenile cobia. The basal diet was supplemented with 10, 20, 30, 40, 60, 120 mg vitamin E kg-1 as all-rac-α-tocopheryl acetate. The results indicated that fish fed the diets supplemented vitamin E had significantly higher specific growth rate, protein efficiency ratio, feed efficiency and survival rate than those fed the basal diet. It was further observed that vitamin E concentrations in liver increased significantly when the dietary vitamin E level increased from 13.2 to 124 mg kg-1. Fish fed the basal diet had significantly higher thiobarbituric acid-reactive substances concentrations in liver than those fed the diets supplemented vitamin E. Fish fed the diets supplemented with 45.7 and 61.2 mg kg-1 vitamin E had significantly higher red blood cell and haemoglobin than those fed the basal diet, while fish fed the diets supplemented with 61.2 and 124 mg kg-1 vitamin E had higher immunoglobulin concentration than those fish fed the basal diet. Lysozyme and superoxide dismutase were significantly influenced by the dietary vitamin E level. The dietary vitamin E requirement of juvenile cobia was established based on second-order polynomial regression of weight gain and lysozyme to be 78 or 111 mg all-rac-α-tocopheryl acetate kg-1 diet, respectively. © 2012 Blackwell Publishing Ltd. Source


Zhou Q.,Ningbo University | Wang L.,Guangdong Ocean University | Wang H.,Guangdong Evergreen Feed Industry Co. | Xie F.,Ningbo University | Wang T.,Guangdong Evergreen Feed Industry Co.
Fish and Shellfish Immunology | Year: 2012

This study was conducted to evaluate the effects of dietary vitamin C on growth performance, hematologic parameters and innate immune responses in juvenile cobia, Rachycentron canadum. Seven practical diets were formulated to contain 0.0 (as the basal diet), 13.6, 27.2, 54.4, 96.6, 193.4 and 386.5 mg ascorbic acid equivalent kg -1 diet. Each diet was fed to triplicate groups of juvenile cobia with initial body weight of 5.5 g in 500-L cylindrical fiberglass tank. The results of 8 weeks feeding trial showed that typical vitamin C-deficient signs such as spinal deformation and body nigrescence were observed in the fish fed the basal diet. Fish fed the basal diet had significantly lower weight gain, specific growth rate (SGR), protein efficiency ratio (PER) and feed efficiency (FE) than those fed the diets supplemented with vitamin C, but no significant differences were observed among diets supplemented with vitamin C. However, survival rate was significantly affected by the dietary vitamin C levels, fish fed the basal diet had lower survival rate than those fed the diets supplemented with vitamin C. The ascorbic acid concentration in liver was correlated positively with the dietary vitamin C levels, however, the thiobarbituric acid reactive substances (TBARS) concentrations in liver was not significantly affected by the dietary vitamin C levels, although, fish fed the basal diet had the highest TBARS values among all treatments. The activities of serum lysozyme, superoxide dismutase (SOD), alkaline phophatase (AKP) and total immunoglobulin (Ig) were significantly influenced by the dietary vitamin C levels, fish fed the basal diet had lower lysozyme, SOD, AKP and total Ig than those fed diets supplemented with vitamin C. The serum glucose and triglyceride concentrations were significantly affected by the dietary vitamin C levels. Fish fed the basal diet had lower red blood cell and hemoglobin values than those fed the vitamin C supplemented diets. The challenge experiment with Vibrio harveyi showed that lower cumulative survival was in fish fed the unsupplemented diet, the cumulative survival were significantly increased with increase of the dietary ascorbic acid levels from 13.6 to 96.6 mg kg -1, while the cumulative survival reached plateau when dietary ascorbic acid levels increased from 96.6 to 386.5 mg kg -1. These results indicated that dietary vitamin C did significantly influence on growth performance and immune response of juvenile cobia. © 2012 Elsevier Ltd. Source


Huang X.-L.,Ningbo University | Xia M.-H.,Ningbo University | Wang H.-L.,Guangdong Evergreen Feed Industry Co. | Jin M.,Ningbo University | And 2 more authors.
Aquaculture Nutrition | Year: 2015

This study evaluated the effect of dietary thiamin on growth performance, feed utilization and non-specific immune response for juvenile Pacific white shrimp, Litopenaeus vannamei. Six isonitrogenous and isolipidic practical diets were formulated with graded thiamin levels of 6.9, 32.7, 54.2, 78.1, 145.1 and 301.5 mg kg-1 of dry diet, respectively. Each diet was randomly assigned to triplicate groups of 30 juvenile shrimp and provided four times each day to apparent satiation. Weight gain (WG) and specific growth rate (SGR) of the shrimp were significantly influenced by the dietary thiamin levels, the maximal WG and SGR occurred at 54.2 mg kg-1 dietary thiamin level. However, with further increase in dietary thiamin level from 54.2 to 301.5 mg kg-1, the WG and SGR significantly decreased. Shrimp fed the 54.2 mg kg-1 thiamin diet exhibited higher feed efficiency, protein efficiency ratio and protein productive value than those fed the other diets. Dry matter and protein content in whole body were significantly affected by the dietary thiamin levels. Thiamin concentration in hepatopancreas significantly increased when the dietary thiamin level increased from 6.9 to 145.1 mg kg-1. The total protein, glucose, triacylglycerol and cholesterol contents in hemolymph were not significantly affected by the dietary thiamin levels. Dietary thiamin had significantly influenced superoxide dismutase, catalase and lysozyme activities in hemolymph. Results of this study indicated that the optimal dietary thiamin requirements estimated using a two-slope broken-line model based on WG and thiamin concentration in hepatopancreas were 44.66 and 152.83 mg kg-1, respectively. © 2014 John Wiley & Sons Ltd. Source


Xia M.-H.,Ningbo University | Huang X.-L.,Ningbo University | Wang H.-L.,Guangdong Evergreen Feed Industry Co. | Jin M.,Ningbo University | And 2 more authors.
Aquaculture Nutrition | Year: 2015

This study investigated the effects of dietary niacin on growth performance, feed utilization and non-specific immune response in juvenile Pacific white shrimp. Six isonitrogenous and isolipidic practical diets were formulated with graded niacin levels of 10.9, 65.8, 121.2, 203.4, 387.5 and 769.3 mg kg-1 of dry diet, respectively. Results indicated that per cent weight gain (WG), specific growth rate (SGR), feed efficiency (FE), protein efficiency ratio (PER) and protein productive value (PPV) were significantly influenced by the dietary niacin levels. The maximum WG and SGR occurred at 121.2 mg kg-1 niacin diet. However, survival and proximate composition of whole body were not significantly affected by the dietary niacin levels. Dietary niacin levels had no significant effects on the total protein, glucose, triacylglycerol and cholesterol contents in the haemolymph. The activity of catalase and lysozyme in the haemolymph was significantly affected by dietary niacin levels. Based on a two-slope regression analysis of SGR against dietary niacin level, the dietary niacin requirement of juvenile Pacific white shrimp was 109.6 mg kg-1. © 2015 John Wiley & Sons Ltd. Source


Xu Z.,South China Normal University | Wang A.,South China Normal University | Wang H.,Guangdong Evergreen Feed Industry Co. | Zhang H.,Guangdong Evergreen Feed Industry Co.
Israeli Journal of Aquaculture - Bamidgeh | Year: 2016

High prices and unsustainable supply have rendered the use of high levels of fish oil in aquafeeds problematic. In the present study, an eight-week feeding trial was conducted to evaluate the replacement of fish oil with less expensive and more sustainable soybean oil in a practical diet containing 17% fish meal, which is widely used in China for Pacific white shrimp Litopenaeus vannamei. Five diets with five levels of fish oil replacement (0%, 25%, 50%, 75%, and 100%) by soybean oil were fed to shrimp for 56 days. At the end of the trial results obtained after analysis of the shrimp showed that shrimp fed diets containing 50% fish oil and 50% soybean oil displayed no significant differences in weight gain, specific growth rate, survival, and feed conversion ratio. Quantitative polymerase chain reactions revealed that the expression levels of fatty acid binding protein and fatty acid synthase, two critical genes in fat metabolism, gradually decreased with increased levels of soybean oil in diets. Fatty acid profiling showed that complete replacement of fish oil with soybean oil affected fatty acid content in shrimp muscles, including monounsaturated fatty acid, polyunsaturated fatty acid, and highly-unsaturated fatty acid, as well as the ratio of n-3/n-6 polyunsaturated fatty acids. The expression of two genes decreased with increased soybean oil level in diets. The growth results indicate that soybean oil can be used to replace 50% fish oil in this practical diet for Litopenaeus vannamei without adverse effects on shrimp growth performance. © 2015, Israeli Journal of Aquaculture - Bamidgeh. All rights reserved. Source

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