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The effect of fish meal (FM) substitution with fermented soybean meal (FSBM) in the diets of the carnivorous marine fish, black sea bream, Acanthopagrus schlegelii, was investigated. An 8-wk feeding trial was conducted with black sea bream (11.82 ± 0.32 g; mean initial weight) in indoor flowthrough fiberglass tanks (25 fish per tank). Six isonitrogenous and isoenergetic diets were formulated, in which FM was replaced by FSBM at 0% (control diet), 10% (FSBM10), 20% (FSBM20), 30% (FSBM30), 40% (FSBM40), or 50% (FSBM50), respectively. Each diet was fed to triplicate groups of fish twice daily to apparent satiation. The results showed that there was no difference in survival of black sea bream during the feeding trial. Fish fed the FSBM10 or FSBM20 diet showed comparable growth performance compared with fish fed the control diet (P > 0.05), whereas more than 30% replacement of FM adversely affected weight gain and specific growth rate (P < 0.05). Feed intake was significantly lower for fish fed the FSBM50 diet compared with fish fed the control diet. Feed conversion ratio (FCR) tended to increase with increasing dietary FSBM with the poorest FCR observed for fish fed the FSBM50 diet. Protein efficiency ratio and protein productive values showed similar patterns. Apparent digestibility of nutrients significantly decreased with increasing dietary FSBM level. With the exception of protein content, no significant differences in whole body and dorsal muscle composition were observed in fish fed the various diets. Fish fed the FSBM50 diet had significantly lower intraperitoneal ratio than fish fed the control or FSBM10 diet. Hepatosomatic index and condition factor were unaffected by dietary treatments. This study showed that up to 20% of dietary FM protein could be replaced by FSBM protein in the diets of juvenile black sea bream.

Effects of dietary LL-carnitine were studied in juvenile black sea bream (Sparus macrocephalus). The semipurified basal diet [crude protein 450 g kg )1 dry matter (DM); crude lipid 126 g kg )1 DM] was formulated to choose white fishmeal as the protein source and fish oil plus corn oil (1 : 1) as the lipid source. Six diets (control + diets 1-5) containing 0.1, 0.12, 0.16, 0.24, 0.39 and 1.1 g of L L-carnitine kg )1 diet were fed to triplicate groups of black sea bream (initial weight 13.10 ± 0.05 g) for 8 weeks. At the end of the feeding trial, growth performance, body composition and antioxidant status were determined. The results showed that relative growth rate (RGR) was significantly improved by the elevation of dietary L L-carnitine level from 0.1 to 0.24 g kg )1 , but decreased with further increment (P < 0.05). Lipid content decreased significantly (P < 0.05) in the dorsal muscle whereas increased (P < 0.05) in the liver with the addition of dietary L L-carnitine. Dietary

An 8‐wk experiment was conducted to determine the optimal protein requirement of juvenile black sea bream, Sparus macrocephalus, (initial weight 13.13 ± 0.21 g, mean ± SD) in 18 300‐L indoor flow‐through circular fiberglass tanks provided with sand‐filtered aerated seawater. Six isoenergetic diets were formulated to contain varying protein levels ranging from 31.95 to 48.53% at about 3% protein increments by substituting corn oil and α‐starch for fish meal. Each diet was assigned to triplicate groups of 20 fish in a completely randomized design. Twenty uniform‐sized fish were stocked in a 300‐L indoor flow‐through circular fiberglass tank. After the feeding trial, weight gain and specific growth rate (SGR) increased with increasing levels of dietary protein up to 41.8% (P < 0.05) and both showed a declining tendency thereafter. Survival could not be related to dietary treatments. Both condition factor and protein efficiency ratio declined while dietary protein levels increased (P < 0.05). The highest and the lowest values of hepatosomatic index were found in fish fed 31.9 and 41.8% protein diets (P < 0.05), respectively, and showed no significant difference among other treatments (P > 0.05). Feed efficiency ratio (FER) improved as dietary protein level increased, with the maximum FER in the 41.8% protein diet, although this was not significantly different from the 45.2% protein diets. Apparent digestibility coefficients (ADCs) of main ingredients of diets tended to improve as the protein level increased, although they decreased to a different extent at higher levels of dietary protein. The highest ADC values of organic matter and protein were both found for fish fed 41.8% protein diet, while lipid and energy were at 38.5 and 45.2% protein diet, respectively. The whole‐body protein content was positively correlated with dietary protein levels, while lipid content was negatively correlated. The muscle crude protein and crude lipid contents were significantly affected (P < 0.05) by dietary protein level, while moisture and ash showed no significant differences (P > 0.05). Dietary protein levels had significant influences on plasma parameters (P < 0.05). The concentrations of total cholesterol, triacylglyceride, alanine transaminase, and aspartate transaminase significantly reduced with dietary protein level except plasma total protein contents which presented reverse trend. Analysis of dose (protein level)–response (SGR) with second‐order polynomial regression suggested that the optimal dietary protein requirement was 41.4%.

An 8‐week growth trial was conducted to evaluate the effects of different levels of tributyrin supplementation in a high‐soya bean meal diet on juvenile black sea bream (11.30 ± 0.16 g). The positive control (PC) diet contained 45% fishmeal and 20% soya bean meal, while the negative control (NC) contained 12% fishmeal and 45% soya bean meal. Graded levels of tributyrin were added to the NC diet at 0.05% (TB 0.05), 0.1% (TB 0.1), 0.2% (TB 0.2), 0.4% (TB 0.4) and 0.8% (TB 0.8). Ultimately, the fish fed the PC diet had a higher weight gain and specific growth rate than the fish fed other diets. The fish fed the NC diet had the lowest growth, and TB 0.05–TB 0.2 diets increased growth performance while TB 0.4–TB 0.8 diets caused reduction in growth. Dietary tributyrin supplementation improved protease activity and enhanced antioxidant capacity. Compared with the fish fed the NC diet, the fish fed the tributyrin‐supplemented diets had improved gut morphology and structure, and the results were similar to those of the fish fed the PC diet. Furthermore, the analysis of the dose response with second‐order polynomial regression indicated that the optimum tributyrin supplementation for juvenile black sea bream is 2.24 g/kg in the 45% soya bean meal diet.

An 8-week feeding trial was conducted to determine the dietary arginine requirement of juvenile black sea bream Sparus macrocephalus in 18 350 L indoors £ow-through circular ¢breglass tanks. Six isonitrogenous and isoenergetic diets were formulated to contain graded levels of L-arginine (1.85%, 2.23%, 2.51%, 2.86%,3.20% and 3.46% dry diet) from dietary ingredients and crystalline arginine. Each diet was randomly assigned to triplicate groups of 25 juvenile ¢sh (10.51 AE 0.15 g) twice daily (08:00 and 16:00 hours) to apparent satiation. Results showed that the speci¢c growth rate (SGR) increased with increasing dietary arginine levels up to 2.51% and remained nearly the same thereafter. Feed e⁄ciency ratio, protein e⁄ciency ratio (PER) and protein productive value all showed an increasing tendency and then levelled o¡. Apparent digestibility coe⁄cients of dry matter, crude protein and gross energy signi¢cantly improved up to 2.86% arginine diet and decreased at di¡erent extents thereafter. Fish fed 1.85% arginine diet had signi¢cantly lower protein content in the whole body and dorsal muscle than those fed diets supplemented with or 42.86% of arginine. Lipid content decreased and lower value occurred at 3.46% of dietary arginine. The dietary essential amino acid composition in the whole body of the black sea bream was signi¢cantly in£uenced by dietary arginine. Arginine retention increased with an increasing dietary arginine level from 1.85% to 3.20%, then declined slightly at 3.46% arginine diet. Serum biochemical parameters were signi¢cantly a¡ected by the dietary arginine level except for the cholesterol content. Broken-line regression based on SGR and second-order polynomial regression based on PER indicated that the optimum dietary arginine requirements for juvenile black sea bream were 2.79% and 3.09% diet, corresponding to 7.74% and 8.13% of the dietary protein respectively. , 320 and p-aminobenzoic acid, 50. zOthers (%) : carboxymethylcellulose, 4; sodium dihydrogen phosphate, 2.5; k-carrageenan, 2.5; a-cellulose, 5.08; betaine, 0.3; Cr 2 O 3 , 0.5. ‰Values for the proximate analysis of the test diets are means of triplicate analyses. Optimum arginine requirement of black sea bream F Zhou et al. Optimum arginine requirement of black sea bream F Zhou et al. r 2010 The Authors Aquaculture Research r 2010 Blackwell Publishing Ltd, Aquaculture Research, 41, e418^e430 e421 Ã Values are presented as mean AE SD (n 5 3); values with di¡erent superscripts in the same row di¡er signi¢cantly (Po0.05).Survival (%) 5 100 Â ¢nal ¢sh number/initial ¢sh number; WG (weight gain) (%) 5 100 Â (FBWIBW)/IBW; SGR (speci¢c growth rate) (% day À 1 ) 5 100 Â (ln FBWln IBW)/day; CF (condition factor) (g cm À 3 ) 5 100 Â (live weight, g)/(body length, cm) 3 ; HSI (Hepatosomatic index) 5 100 Â (liver weight, g)/(body weight, g); FER (feed e⁄ciency ratio) 5 100 Â wet weight gain in g/dry diet fed in g; PER (protein e⁄ciency ratio) 5 weight gain in g/protein intake in dry basis in g; PPV (protein productive value) 5 g protein gain/g pr...

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