Zhejiang Fisheries Technical Extension Station

Hangzhou, China

Zhejiang Fisheries Technical Extension Station

Hangzhou, China
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Xiao J.-X.,Zhejiang University | Zhou F.,Zhejiang Fisheries Technical Extension Station | Yin N.,Zhejiang University | Zhou J.,Zhejiang University | And 4 more authors.
Aquaculture Research | Year: 2013

An 8-week feeding trial was conducted to evaluate compensatory growth of juvenile black sea bream, Acanthopagrus schlegelii (initial weight 9.56 ± 0.12 g) in fifteen 300 L indoors flow-through circular fibreglass tanks. Feeding regimes was designed as follows: the control group (fed continuously), and S1, S2, S3 and S4 groups experienced 1, 2, 3 and 4 days of feed deprivation and then refeeding for the remaining days per week respectively. Changes in body weight, specific growth rate (SGR), feed intake (FI) and feed efficiency ratio (FER) were examined biweekly during the trial. At the end of the cyclical feeding periods, survival was not significantly affected by feeding strategy (P > 0.05). Final body weight of fish in S1 group was significantly higher than the control group (P < 0.05) after an 8 weeks trial, and fish in the S2 group reached the same body weight of the control fish (P > 0.05), however, the growth data in the S3 and S4 groups could not catch-up with the control treatment (P < 0.05). In the first 4 weeks, SGR values of fish with feed deprivation more than 2 days per week were inferior to those of control group (P < 0.05); however, no significant differences of SGR were observed among the groups for the last 4 weeks (P > 0.05). FI increased significantly with the starvation days increasing during the whole feeding trial (P < 0.05). At the periods 2, 4 and 6 weeks, FER values increased significantly with increasing feed-deprivation days up to S2 group and then levelled off (P < 0.05); however, FER in S2 group was only higher than that in S0 and S1, but no significant differences were found among the other treatments at the end of week 8. Significant differences were found in apparent digestibility coefficients (ADCs) of dry matter and crude protein among the treatments, while ADCs of crude lipid were unaffected. Protein and lipid contents in whole body and dorsal muscle showed declining tendency with increasing food deprivation days, while moisture contents tended to increase (P < 0.05). Serum parameters were markedly affected by feeding regimes except for total protein concentration and thyroxine level. The present results indicated that starvation for 1 and 2 days per week of juvenile black sea bream could achieve over-compensation and complete compensation respectively. However, in case of longer term feed restriction regime, fish failed to obtain good growth performance. © 2013 John Wiley & Sons Ltd.

Ma J.,Zhejiang University | Ma J.,Marine Fisheries Research Institute of Shandong Province | Shao Q.,Zhejiang University | Xu Z.,Zhejiang University | Zhou F.,Zhejiang Fisheries Technical Extension Station
Journal of the World Aquaculture Society | Year: 2013

An 8-wk feeding trial was conducted to investigate the effects of dietary n-3 highly unsaturated fatty acids (n-3 HUFA) on growth, body composition, and fatty acid profiles of juvenile Acanthopagrus schlegeli. Three replicate groups of fish (initial mean weight: 8.08±0.09g, mean ± SD) were fed diets with different levels of n-3 HUFA (0.76%, HUFA0.76; 0.83%, HUFA0.83; 0.90%, HUFA0.90; 0.97%, HUFA0.97; 1.04%, HUFA1.04; 1.12%, HUFA1.12) at 12.9% of total lipid, with a constant eicosapentaenoic acid (EPA, 20:5n-3) to docosahexaenoic acid (DHA, 22:6n-3) ratio of about 2.1. Hepatosomatic index (HSI) and intraperitoneal fat (IPF) ratio were all linearly depressed by dietary n-3 HUFA levels (P < 0.05), and condition factor (CF) was not affected. Adipocyte diameter in IPF decreased with the elevation of dietary n-3 HUFA and significance occurred between group HUFA0.90 and HUFA1.12. Lipid content in dorsal muscle was significantly lowered by dietary n-3 HUFA compared to fish fed diet HUFA0.76. No significance was found in whole fish proximate composition. In liver, dorsal muscle and IPF, ∑SFA, 16:0 or ∑n-3 HUFA were all positively correlated with dietary n-3 HUFA, while DHA to EPA ratios remained constant in 2.68, 2.86, and 3.60, respectively. Fatty acid synthase (FAS, EC activities of all treatments remained constant at first and then were significantly elevated by dietary n-3 HUFA higher than 0.97% (P < 0.05). In contrast, hormone sensitive lipase (HSL, EC changed following an opposite tendency. Quadratic analysis based on weight gain rate (WGR) indicated that dietary n-3 HUFA requirement for juvenile black seabream was 0.94% of the diet in 12.9% lipid diets. © Copyright by the World Aquaculture Society 2013.

Lu J.,Zhejiang University | Hua Y.,Zhejiang University | Fu W.-Z.,Zhejiang University | Zhou F.,Zhejiang Fisheries Technical Extension Station | And 4 more authors.
Turkish Journal of Fisheries and Aquatic Sciences | Year: 2014

Four experimental diets were formulated to evaluate the effect of coated lysine (Lys) and methionine (Met) supplemented in mixture protein diets of juvenile black sea bream, Acanthopagrus schlegelii. Fish meal (FM) was the main protein source in control diet, and 21.2% FM was replaced by the mixture of soybean protein concentrate, meat and bone meal, and monosodium glutamate protein in replacement diets with coating Lys and Met were suppled at none (0%, 0%), low (1.7%, 1.1%) and high (5.0%, 3.4%) level (designated as NLM, LLM and HLM diet, respectively). Each diet was fed to triplicate groups of 20 fish (initial mean weight, 4.13 ± 0.16g) twice a day to apparent satiation for 8 weeks, in a flow-through system. Results showed that amino acid supplementation significantly improved weight gain and specific growth rate in these mixture protein diets groups, and the fish fed with HLM diet showed comparable growth with the control group. Feed efficiency ratio (FER), protein efficiency ratio (PER), and crude protein and Met content in dorsal muscle were significantly affected by diet amino acid level. The highest apparent digestibility coefficients appeared in HLM group but the values showed insignificant difference with the control group. Serum activities of aspertate aminotransferase and alanine aminotransferase in control group were lower than those of in other treatments. Fish fed with NLM and LLM diets had higher triglycerides concentration than those of fed the HLM and FM diets. Furthermore, the feed cost of the various feed treatments were evaluated, and the three test diets were all lower than the control diet. The present study indicated that 21.2% FM in black sea bream diet can be successfully replaced by mixture protein with sufficient coated Lys (5.0%) and Met (3.4%) supplemented. © Published by Central Fisheries Research Institute (CFRI) Trabzon, Turkey.

Zhou F.,Zhejiang Fisheries Technical Extension Station | Ding X.-Y.,Zhejiang Fisheries Technical Extension Station | Feng H.,Zhejiang Fisheries Technical Extension Station | Xu Y.-B.,Zhejiang Fisheries Technical Extension Station | And 3 more authors.
Aquaculture | Year: 2013

A feeding trial was conducted to determine the optimum dietary protein requirement of a new Japanese strain of juvenile Chinese soft-shell turtle, Pelodiscus sinensis. Five iso-energetic diets were formulated to contain graded protein levels of 340, 370, 400, 430 or 460gkg-1 diet and fed to triplicate groups of turtles (mean initial weight, 3.70±0.05g) for eight weeks. The turtles were reared in 350-L indoor plastic containers (15 turtles/container) provided with aerated freshwater. For each graded increase of dietary protein up to 430gkg-1 diet, growth performance of the soft-shell turtles increased significantly. No further growth increase was observed beyond this dietary protein level. The highest feed efficiency and protein productive value were observed in P. sinensis fed the 430gproteinkg-1 diet. In general, the apparent digestibility coefficients (ADC) of dry matter, crude protein and gross energy increased significantly with increasing dietary protein levels. No significant differences were observed in the ADC of crude lipid among all experimental groups. Turtle whole-body protein content increased significantly from 15.2% to 16.8% with a corresponding decrease in moisture content (75.5% to 74.2%) when fed increasing dietary protein levels. The lowest concentrations of serum protein and cholesterol were observed in turtles fed 340 or 460gproteinkg-1 diet. Aspartate transaminase activity in turtles fed 340gproteinkg-1 diet was significantly higher compared to those fed 400 or 430gproteinkg-1 diet. Broken-line regression analysis indicated that juvenile P. sinensis (Japanese strain) requires 422.0gproteinkg-1 diet for optimum growth. © 2013 Elsevier B.V.

Zhou F.,Zhejiang Fisheries Technical Extension Station | Wang Y.-Q.,Zhejiang University | Ding X.-Y.,Zhejiang Fisheries Technical Extension Station | Ng W.-K.,Universiti Sains Malaysia | And 2 more authors.
Aquaculture Research | Year: 2016

An 8-week experiment was conducted to evaluate the effects of dietary fish meal (FM) replaced by soybean protein concentrate (SPC) on Japanese strain of soft-shelled turtle, Pelodiscus sinensis juveniles. Diets were formulated to replace FM protein by SPC at 0, 15, 30, 45, 60 or 60% supplemented with phytase (2000 FTU kg-1) (designated as S0, S15, S30, S45, S60 and S60P, respectively), and each diet was fed to triplicate groups. The results showed that the growth was significantly lower when dietary SPC replaced more than 45% FM. The turtles fed the S15 or S30 diet showed comparable feed and protein utilization efficiency compared with the S0 group, whereas more than 30% replacement of FM adversely affected these values. Increasing dietary SPC levels significantly lowered the apparent digestibility coefficients (ADC) of dry matter, protein, lipid, phosphorus and gross energy. Whole-body protein, ash and phosphorus content showed a declining trend when dietary SPC levels increased, while body lipid and moisture content were unaffected. When the turtles were fed diets with increasing levels of SPC, serum total protein concentration, alkaline phosphatase and catalase activities decreased with a corresponding increase in glutamic pyruvic transaminase activity. Turtles fed the S60P diet showed comparable growth performance and feed utilization efficiency to the S40 group, and were superior to the S60 group. The present study showed that SPC could successfully substitute for 30% FM protein in the diets for P. sinensis juveniles, and the maximum effective substitution may be greater if exogenous phytase was added. © 2016 John Wiley & Sons Ltd.

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