Time filter

Source Type

Niu J.,Sun Yat Sen University | Chen X.,CAS South China Sea Fisheries Research Institute | Zhang Y.-Q.,Guangdong Yuehai Feed Group Co. | Tian L.-X.,Sun Yat Sen University | And 4 more authors.
Aquaculture International | Year: 2015

Juvenile Penaeus monodon weighing about 1.46 g were fed on a diet for 8 weeks at various daily feeding rates of 3, 4, 5, 6, 7, 8 and 9 % of their body weight (BW), and the growth, feed utilization, blood parameters and non-specific immunity were determined. Forty shrimp per tank were distributed into 28 500-L fiberglass tanks, and they were fed four times 1 day. After the 56-day trial, survival was over 90 % and was not significantly affected by feeding rates. Final weight, weight gain and specific growth rates gradually increased with increasing feeding rate up to 8 % and then kept constant. Feed conversion rate (FCR: 1.08–2.20) from 9 % feeding rate treatment was significantly higher than that from 3 to 7 % feeding rate treatments (P < 0.05) but without difference to 8 % feeding rate treatment. Protein efficiency ratio linearly decreased with the increase in feeding rate. The apparent digestibility coefficients for dry matter, protein (APD) and energy (AED) of 3 % and 4 % feeding rate treatments were significantly lower than that of 5–9 % feeding rate treatments (P < 0.05). Activities of plasma glutamic oxaloacetic transaminase and glutamic pyruvic transaminase and concentrations of plasma cholesterol, triacylglycerol and low-density lipoprotein were increased with increasing feeding rate. Superoxide dismutase activities in hepatopancreas of shrimp from 3 to 5 % feeding rate treatments were significantly higher than that of shrimp from 7 to 9 % feeding rate treatments (P < 0.05) but without significant difference with 6 % feeding rate treatment. Nonlinear regression analysis of SGR indicated that the optimum feeding rate of juvenile P. monodon is 7.5 % BW/day. © 2015 Springer International Publishing Switzerland Source

Li J.,Ocean University of China | Li J.,China University of Petroleum - East China | Zhang L.,Ocean University of China | Zhang L.,Guangdong Yuehai Feed Group Co. | And 5 more authors.
Aquaculture Nutrition | Year: 2010

A 9-week feeding experiment was conducted to determine the dietary biotin requirement of Japanese seabass, Lateolabrax japonicus C. Six isonitrogenous and isoenergetic purified diets (Diets 1-6) containing 0, 0.01, 0.049, 0.247, 1.238 and 6.222 mg biotin kg-1 diet were fed twice daily to triplicate groups (30 fish per group) of fish (initial average weight 2.26 ± 0.03 g) in 18 fibreglass tanks (300 L) filled with 250 L of water in a flow-through system. Water flow rate through each tank was 2 L min-1. Water temperature ranged from 25.0 to 28.0 °C, salinity from 28.0 to 29.5 g L-1, pH from 8.0 to 8.1 and dissolved oxygen content was approximately 7 mg L-1 during the experiment. After the feeding experiment, fish fed Diet 1 developed severe biotin deficiency syndromes characterized by anorexia, poor growth, dark skin colour, atrophy and high mortality. Significant lower survival (73.3%) was observed in the treatment of deficient biotin. The final weight and weight gain of fish significantly increased with increasing dietary biotin up to 0.049 mg kg-1 diet (P < 0.05), and then slightly decreased. Both feed efficiency ratio and protein efficiency ratio showed a very similar change pattern to that of weight gain. Dietary treatments did not significantly affect carcass crude protein, crude lipid, moisture and ash content. However, liver biotin concentration (0-6.1 μg g-1) significantly increased with the supplementation of dietary biotin (P < 0.05), and no tissue saturation was found within the supplementation scope of biotin. Broken-line regression analysis of weight gain showed that juvenile Japanese seabass require a minimum of 0.046 mg kg-1 biotin for maximal growth. © 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd. Source

Pan Q.,Guangdong Medical College | Liu Y.,University of Hong Kong | Zhu X.,Guangdong Yuehai Feed Group Co. | Liu H.,Guangdong Medical College
Experimental and Therapeutic Medicine | Year: 2014

The aim of this study was to investigate the effect and mechanism of action of chloral hydrate on the peptidoglycan (PGN)-induced inflammatory macrophage response. The effect of chloral hydrate on the production of tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) by murine peritoneal macrophages with PGN-stimulation was investigated. In addition, RAW264.7 cells transfected with a nuclear factor-κB (NF-κB) luciferase reporter plasmid stimulated by PGN were used to study the effect of chloral hydrate on the levels NF-κB activity. Flow cytometry and western blotting were performed to investigate the expression levels of toll-like receptor 2 (TLR2) in the treated RAW264.7 cells. It was identified that chloral hydrate reduced the levels of IL-6 and TNF-α produced by the peritoneal macrophages stimulated with PGN. The levels of NF-κB activity of the RAW264.7 cells stimulated by PGN decreased following treatment with chloral hydrate, which was associated with a reduction in the expression levels of TLR2 and reduced levels of TLR2 signal transduction. These data demonstrate that chloral hydrate reduced the magnitude of the PGN-induced inflammatory macrophage response associated with lower expression levels of TLR2. Source

Zhu X.,Sun Yat Sen University | Zhu X.,Guangdong Yuehai Feed Group Co. | Davis D.A.,Auburn University | Roy L.A.,Auburn University | Samocha T.M.,Texas AgriLife Research Center
Journal of the World Aquaculture Society | Year: 2013

Three sources of soybean meal (SBM) were biochemically characterized and evaluated in diets for juvenile Litopenaeus vannamei. Three biological techniques were utilized to evaluate the nutritional quality of the meals including an outdoor growth trial as well as determination of in vivo apparent digestibility and in vitro digestibility including pepsin digestibility (0.0002%), pH Stat degree of hydrolysis, and immobilized digestive enzyme assay (IDEA). The growth trial was conducted over a 10-wk period using soybean meal as the primary protein source with each meal being included at 54-58% of the diet based on an equal protein inclusion. At the conclusion of the growth trial there were no significant differences between the test diets indicating equivalent biological availability under practical conditions. The in vivo digestibility trial utilized chromic oxide as the inert marker and 70:30 replacement techniques resulted in typical results. Apparent protein digestibility (APD) and apparent energy digestibility (AED) of the diets ranged from 66.8 to 80.2% and 65.4 to 74.7%, respectively. Ingredient digestibility values for protein and energy ranged from 78.8 to 93.5% and 60.5 to 85.0%, respectively. One of the three SBM evaluated had numerically lower protein digestibility and significantly lower energy digestibility than the other two meals. © Copyright by the World Aquaculture Society 2013. Source

Zhu X.Z.,Sun Yat Sen University | Liu Y.-J.,Sun Yat Sen University | Tian L.X.,Sun Yat Sen University | Mai K.S.,Ocean University of China | And 6 more authors.
Aquaculture Nutrition | Year: 2010

A 8-week feeding experiment was conducted to evaluate the effect of different dietary protein and lipid levels on growth and energy productive value of juvenile Litopenaeus vannamei, at 30 and 2 ppt, respectively. Nine practical diets were formulated to contain three protein levels (380, 410 and 440 g kg-1) and three lipid levels (60, 80 and 100 g kg-1). Each diet was randomly fed to triplicate groups of 30 shrimps per tank (260L). The effects of salinity and an interaction between dietary protein level and lipid level on growth and energy productive value of shrimp were observed under the experimental conditions of this study. At 30 ppt seawater, shrimp fed with 440 g kg-1protein diets had significantly higher weight gain (WG) than those fed with 380 g kg-1 protein diets at the same dietary lipid level, and the 60g kg-1 lipid group showed higher growth than 80 g kg-1and 100 g kg-1 lipid groups at the same dietary protein level. At 2 ppt seawater, the growth of shrimp was little affected by dietary protein treatments when shrimp fed the 80 and 100 g kg-1 lipid, shrimp fed the 80 g kg-1 lipid diets had only slightly higher growth than that fed 60and 100 g kg-1 lipid diets when fed 380 and 410 g kg-1 dietary protein diets. A significant effect of salinity on growth of shrimp was detected with the growth responses at 30 ppt 2ppt (P< 0.05). Final body lipid content, body protein content and energy productive value of shrimp was significantly higher in animals exposed to 30 ppt than in shrimp held at 2 ppt. © 2009 Yong Jian Liu, Shi Xuan Zheng Journal compilation © 2009 Blackwell Publishing Ltd. Source

Discover hidden collaborations