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Zhou Q.-C.,Ningbo University | Wang Y.-L.,Guangdong Ocean University | Wang H.-L.,Guangdong Evergreen Group Corporation | Tan B.-P.,Guangdong Ocean University
Aquaculture | Year: 2013

An 8-week feeding trial was conducted to determine the dietary threonine requirement of juvenile Pacific white shrimp, Litopenaeus vannamei. Six isonitrogenous and isolipidic practical diets (43% crude protein and 7.5% crude lipid) were formulated to contain graded dietary threonine levels ranging from 1.07% to 2.30% (dry weight). In all of the diets, the nitrogen content of the amino acids was kept the same by replacing threonine with a non-essential amino acid mixture. Each diet was randomly assigned to triplicate groups of 40 juvenile shrimp (approximately 0.53. g) that were fed 4 times daily to apparent satiation. The results indicated that significant difference was observed in the weight gain among all treatments. Maximum weight gain was obtained at 1.67% dietary threonine; however, weight gain did not significantly increase with further dietary threonine increases. The survival of the shrimps showed no significant differences among all treatments. Feed efficiency, protein efficiency ratio and protein productive value were also significantly influenced by the dietary threonine levels, and the trends were similar to those of growth performance. There were no significant differences among dry matter, crude protein, crude lipid or ash content in the whole body and muscle composition. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), superoxide dismutase (SOD) and phenoloxidase (PO) activities in hemolymph were significantly affected by dietary threonine levels. Shrimp fed the diet containing 2.30% threonine had higher AST and ALT values than those fed the other diets; however, the highest SOD and PO activities were observed at 2.05% dietary threonine. The optimal dietary threonine requirement, estimated by a broken-line model based on SGR, was 1.51% of the dry diet (corresponding to 3.53% of dietary protein on a dry-weight basis). Considering the threonine leaching loss in seawater within 30. min (duration of feeding each time), the threonine requirement for L. vannamei is 1.18% of dry diet (2.81% of the dietary protein). © 2013 Elsevier B.V.


Xie F.,Ningbo University | Zeng W.,Guangdong Ocean University | Zhou Q.,Ningbo University | Wang H.,Guangdong Evergreen Group Corporation | And 3 more authors.
Aquaculture | Year: 2012

An 8-week feeding trial was conducted to estimate the dietary lysine requirement of juvenile Pacific white shrimp, . Litopenaeus vannamei. Six isonitrogenous and isolipidic practical diets (40% CP and 7.5% lipid) containing graded dietary lysine levels ranged from 1.44 to 2.49% (dry weight) at about 0.3% increments were formulated. Equal amino acid nitrogen was maintained by replacing lysine with nonessential amino acid mixture. Triplicate groups of 40 juvenile shrimps (about 0.52. g initial weight) were fed one of the diets four times daily to apparent satiation. No significant differences were observed in survival rates of shrimps (97.50-100%, . P>. 0.05), but specific growth rate (SGR), weight gain (WG), feed efficiency, protein efficiency ratio and protein deposition ratio were significantly affected by different dietary lysine levels (P<. 0.05). There were no significant differences in whole body and muscle composition (crude lipid, crude protein and ash), except for the crude protein content of whole body. Urea nitrogen, total protein and the activity of SOD in hemolymph showed no significant differences (P>. 0.05). Triglyceride, Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) in hemolymph were significantly affected by dietary lysine levels (P<. 0.05). The optimal dietary lysine requirement estimated by broken-line model based on SGR was 2.05% of dry diet (4.93% dietary protein). Considering the lysine leaching loss in seawater within 30. min (duration of feeding each time), the lysine requirement for . L. vannamei is 1.64% of dry diet (3.95% of the dietary protein). © 2012 Elsevier B.V.


Zhou Q.-C.,Ningbo University | Zeng W.-P.,Guangdong Ocean University | Wang H.-L.,Guangdong Evergreen Group Corporation | Wang T.,Guangdong Evergreen Group Corporation | And 2 more authors.
Aquaculture | Year: 2012

An 8-week feeding trial was conducted to evaluate the dietary arginine requirement of juvenile Pacific white shrimp, Litopenaeus vannamei. Six isonitrogenous and isolipidic practical diets (41% crude protein and 7.5% crude lipid) were formulated to contain graded dietary arginine levels ranging from 1.44 to 2.74% (dry weight) in approximately 0.3% increments. In all of the diets, the nitrogen content of the amino acids was kept the same by replacing arginine with a non-essential amino acid mixture. Each diet was randomly assigned to triplicated groups of 40 juvenile shrimp (approximately 0.50. g) 4 times daily to apparent satiation. The results indicated that the specific growth rate and weight gain were significantly influenced by the dietary arginine levels. Maximal specific growth rate and weight gain occurred at 2.32% dietary arginine; however, specific growth rate and weight gain did not significantly increase with further increases in dietary arginine from 2.51% to 2.74%. Feed efficiency, protein efficiency ratio and protein productive value were also significantly affected by the dietary arginine levels, and the trends were similar to those of growth performance. No mortality was observed among all treatments. There were no significant differences among crude protein, crude lipid and ash content in the whole body and muscle composition. The total protein in hemolymph was significantly affected by dietary arginine levels, however, there were no significant differences in urea nitrogen, triglycerides and cholesterol in the hemolymph among all treatments. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), superoxide dismutase (SOD), arginase and nitric oxide synthase (NO) activities in the hemolymph were significantly affected by dietary arginine levels. The optimal dietary arginine requirement estimated by two slope broken-line model based on SGR was 2.32% of the dry diet (corresponding to 5.66% of dietary protein on a dry weight basis). Considering the arginine leaching loss in seawater within 30. min (duration of feeding each time), the arginine requirement for L. vannamei is 1.96% of dry diet (4.77% of the dietary protein). © 2012 Elsevier B.V.


Zhou Q.-C.,Ningbo University | Zeng W.-P.,Guangdong Ocean University | Wang H.-L.,Guangdong Evergreen Group Corporation | Xie F.-J.,Ningbo University | And 2 more authors.
Aquaculture | Year: 2012

An 8-week feeding trial was conducted to determine the dietary arginine requirement of juvenile yellow grouper . Epinephelus awoara. Six isonitrogenous and isolipidic diets (43% crude protein and 10% lipid) were formulated to contain six graded dietary arginine levels ranging from 2.01 to 3.27% (dry weight) in about 0.3% increments. In all diets, amino acid nitrogen contents were kept the same by replacing arginine with a non-essential amino acid mixture. Each diet was randomly assigned to triplicated groups of 20 juvenile fish (about 4.23. g) twice daily to apparent satiation. The results indicated that the specific growth rate and weight gain at different dietary arginine levels were all significantly different. Maximal weight gain and specific growth rate occurred at 2.83% dietary arginine, however, weight gain and specific growth rate did not significantly increase with further increase in dietary arginine from 2.83% to 3.27%. Feed efficiency and protein efficiency ratio were not significantly affected by the dietary arginine levels. No mortality was observed at any diets. The dietary arginine levels significantly affected condition factor and hepatosomatic index, however, viscerosomatic index and muscle ratio were not significantly influenced by the dietary arginine levels. Crude protein, crude lipid and ash content in the muscle and dry matter in the whole body were significantly affected by the dietary arginine levels; fish fed with the 2.83% arginine diet had a higher crude protein content than fish fed with the other diets. There were no significant differences in red blood cell count, hemoglobin content and hematocrit among all treatments. Total nitric oxide synthase, inducible nitric oxide synthase in liver, and total nitric oxide synthase in plasma were significantly influenced by the dietary arginine levels. The essential amino acid concentrations in the muscle were significantly affected by the dietary arginine levels; however, there was no significant difference in essential amino acid concentrations in the liver. Quadratic regression analysis on specific growth rate and weight gain against dietary arginine levels indicated that the optimal dietary arginine requirement was estimated to be 2.8% of the diet (corresponding to 6.5% of dietary protein on a dry weight basis). © 2012 Elsevier B.V.


Zhou Q.-C.,Ningbo University | Zhao J.,Ningbo University | Li P.,The National Renderers | Wang H.-L.,Guangdong Evergreen Group Corporation | Wang L.-G.,Ningbo University
Aquaculture | Year: 2011

A 10-week feeding trial was conducted to evaluate the potential use of poultry by-product meal (PBM) as a partial replacement of fish meal protein in the commercial diets for juvenile cobia. Five isonitrogenous (approximately 45%) and isolipidic (about 11%) diets were formulated to contain graded levels of PBM, and fish meal protein was replaced with a pet food-grade PBM at 15, 30, 45, 60% level (PBM15, PBM30, PBM45, PBM60, respectively) without lysine and methionine supplementation. The reference diet (PBM0) contained fish meal and soybean meal as protein sources. Each diet was fed to groups of 20 juvenile cobia initially averaging approximately 5.8. g in triplicate 500-l tanks twice daily to apparent satiation. The results showed that growth performance and survival for fish fed PBM-supplemented diets were not significantly lower compared to fish fed the reference diet (P> 0.05). However, protein efficiency ratio and feed efficiency ratio were significantly affected by the replacement level of fish meal protein with PBM, fish fed the PBM30 and PBM45 diets had higher PER and FER than fish fed the reference diet and the other diets. The condition factor, viscerosomatic index and intraperitoneal fat ratio were not significantly affected by the dietary treatments, however, fish fed the PBM45 diet had a higher hepatosomatic index than fish fed the other diets. There were no significant differences in moisture, crude lipid, ash, calcium and phosphorus content in whole body among all treatments, but the fish fed the reference diet had higher crude protein in whole body than fish fed the PBM-supplemented diets. There were no differences in liver superoxide dismutase, catalase, glutathione S-transferase and glutathione peroxidases activities among fish fed the experimental diets. Hematocrit, hemoglobin, red blood cell and total immunoglobulin were not significantly affected by the replacement level of fish meal protein with PBM. With the exception of plasma glucose content, there were no significant differences in plasma triglyceride, cholesterol and total protein concentration in fish fed the experimental diets. The results of this study indicated that good quality terrestrial PBM can successfully replace fish meal in the commercial diets for cobia, and the optimal level of fish meal replacement with PBM was determined by quadratic regression analysis to be 30.75% on the basis of maximum protein efficiency ratio. © 2011 Elsevier B.V.


Ding X.,CAS South China Sea Fisheries Research Institute | Li Z.-J.,CAS South China Sea Fisheries Research Institute | Yu M.-C.,Guangdong Evergreen Group Co. | Wang H.-L.,Guangdong Evergreen Group Co. | Chen Y.-Q.,CAS South China Sea Fisheries Research Institute
Chinese Journal of Ecology | Year: 2010

Six strains of Bacillus spp. were isolated and screened from the environment of aquaculture, and their protease and amylase activities were determined. Based on the determination of the activities of the two digestive enzymes, the strain ZD 02 was selected as test object, and its heat-stability was evaluated. The strain ZD 02 identified as Bacillus subtilis had higher tolerance to high temperature. Its survival rate at 90°C for 10 min, 95°C for 5 min, and 100°C for 5 min was 93%, 93%, and 82%, respectively. At 95°C and 100°C for 2 min, the survival rate of the strain was less affected. Moreover, the survival rate of ZD 02 remained 94% at 102°C after adding other feed materials and manufactured into grains. Then, the ZD 02 was cultured through fermentation, and applied to the intensive culture of Litopenaeus vannamei. Three experimental groups were installed. In control group, only basal diet provided by Guangdong Evergreen Group Co., Ltd. was added; in group A, basal diet amended with 0.3% B. subtilis was supplied; in group B, 0.3% B. subtilis was applied on the basis of unchanged cost of diet description. The results showed that the survival rate of L. vannamei in experimental groups A and B was higher than that in control group (P<0.05). Compared with the control, the output of groups A and B increased by 43.0% and 36.7% (P<0.05), production value increased by 35.4% and 21.0% (P<0.05), feed conversion ratio decreased by 9.9% and 8. 7%, (P<0.05), expenses inclu- ding regulation substances of aquaculture, medicines, and energy expending were economized by 21.3% and 22.3%, respectively (P<0.05). No significant differences were observed in the survival rate, output, production value, feed conversion ratio, and such expenses as medicines and energy expending between groups A and B (P>0.05). The results demonstrated that the reasonable application of B. subtilis in aquaculture could promote the output and production value of L. vannamei.

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