A feeding trial was conducted to investigate the effect of partial fish meal (FM) replacement by dietary soybean meal (SBM) on the growth and protein and lipid metabolism of the juvenile Japanese flounder. Four isonitrogenous and isolipidic diets (Diets 1-4) were formulated containing 47% protein and 9% lipid with different SBM inclusion (Diet 1, 11%; Diet 2, 16%; Diet 3, 24%; and Diet 4, 41%). The fish were fed to satiation twice daily for a feeding period of 56 days. The weight gain rate (WGR) and protein efficiency ratio of fish fed Diet 4 were significantly lower than those fed Diets 1, 2, and 3, and feed conversion ratio in the group fed Diet 4 was significantly higher than that in the groups fed Diets 1, 2, and 3. Hepatosomatic indices showed the similar trend as WGR, and the value (1.75%) for Diet 1 was significantly lower than that (1.96-2.2%) for other diets. There were no differences in whole body moisture, crude protein, crude lipid, and ash content among all treatments. With increasing dietary SBM level, serum triglyceride (TG), cholesterol (CHO), and low-density lipoprotein cholesterol (LDL-C) concentrations increased, whereas the serum total protein (TP) and high-density lipoprotein cholesterol (HDL-C) concentrations decreased. Compared with Diet 1, the serum TG, CHO, and LDL-C concentrations of fish fed Diet 4 significantly increased by 78, 37, and 36%, respectively, while the TP and HDL-C concentrations decreased by 14 and 33%, respectively. No significant differences in condition factor, blood urea nitrogen concentration, and alanine and aspartate aminotransferase activities were observed among the dietary treatments. These results indicated that dietary SBM inclusion above 24% could adversely affect the growth and protein and lipid metabolism of Japanese flounder.

Using 0.5% chromic oxide as an external indicator, apparent digestibility coefficients (ADCs) were determined for 12 protein feed ingredients (fish meal [FM], blood meal [BM], meat‐and‐bone meal [MBM], poultry byproduct meal [PBM], shrimp head meal [SHM], squid visceral meal [SVM], soybean meal [SBM], rapeseed meal [RM], cottonseed meal [CM], peanut meal [PM], corn gluten meal [CGM], and brewer's yeast [BY]) fed to Pacific white shrimp Litopenaeus vannamei (mean initial weight ± SD = 4.45 ± 0.21 g). The shrimp were randomly allocated to thirty‐nine 150‐L tanks (20 shrimp/tank) and were hand‐fed a reference diet or test diet (70% reference diet and 30% test feed by weight) twice daily to satiation. Feces were collected by siphoning. The observed range of ADCs of the 12 ingredients was 48.6–87.0% for dry matter, 55.7–92.3% for crude protein, 2.1–92.5% for crude lipid, 52.1–79.9% for phosphorus, and 51.1–97.2% for gross energy. Relatively high ADCs were observed for dry matter in FM (87.0%) and MBM (76.5%); for crude protein in FM (90.9%), SBM (92.3%), and PM (88.8%); for crude lipid in FM (92.5%) and SVM (88.5%); and for phosphorus (79.9, 72.7, 72.5, and 78.5%) and gross energy (97.2, 82.3, 84.0, and 84.6%) in FM, MBM, PBM, and BY. The ADCs of amino acids for the 12 ingredients were 86.7–97.4% (FM), 58.4–98.8% (BM), 46.9–99.6% (MBM), 54.8–95.4% (PBM), 79.0–100.0% (SHM), 58.3–93.0% (SVM), 60.7–99.4% (SBM), 62.6–99.6% (RM), 52.9–91.4% (CM), 60.1–99.9% (PM), 15.6–97.8% (CGM), and 30.3–98.4% (BY). Fish meal, SBM, and PM showed high average ADCs for total amino acids (>90%). Crude protein ADCs corresponded with amino acid ADCs. Resultant digestibility data may provide more accurate information pertinent to formulating commercial feeds for Pacific white shrimp.

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The effects of fructooligosaccharide (FOS) on growth performance, immunity and predominant autochthonous intestinal microbiota of shrimp (Litopenaeus vannamei) fed diets with fish meal (FM) partially replaced by soybean meal (SBM) were evaluated. After acclimation, shrimps (1.82 ± 0.01 g/kg) were allocated into 15 tanks (25 shrimps per tank) and fed five different diets including positive control diet (C0, containing 250 g/kg FM and 285 g/kg SBM), control diet (C, containing 125 g/kg FM, 439 g/kg SBM) and three experimental diets supplemented with 1.0 g/kg FOS (T1), 2.0 g/kg FOS (T2) and 4.0 g/kg FOS (T3) to control diet (C) respectively. Shrimps were fed diets to apparent satiation three times per day, and 15 shrimps from each aquarium were randomly sampled and analysed at the end of the 6-week feeding trial. The results showed that FBW, WGR, SGR and SR decreased, while FCR and FI increased significantly in control (C) compared with positive control (C0). Besides, significantly decreased trypsase and lipase activities, and SOD, AKP and ACP activities were recorded in control (C) compared with positive control (C0). On the other hand, significantly improved SGR and decreased FCR were observed in groups T1, T2 and T3 compared with control (C). Moreover, lipase and amylase activities enhanced significantly in group T3 compared with the control (C), while GOT and GPT activities dropped significantly with the increment supplementation of FOS in diets. Compared with the control (C), SOD activity enhanced significantly and MDA level decreased significantly in groups T2 and T3, and improved AKP and ACP activities were observed in group T3. In addition, dietary FOS improved the microbial diversity, and suppressed several potential pathogens, such as Vibrio tubiashii, Vibrio parahaemolyticus and Photobacterium damselae-like strains in the intestine of shrimp. Overall, these results proved FOS could relieve the side effects induced by SBM and supported the use of 2.0-4.0 g/kg FOS in shrimp diets with FM partially replaced by SBM. K E Y W O R D S Fructooligosaccharide, growth performance, immunity, intestinal microbiota, Litopenaeus vannamei | 195 HU et al.

The apparent digestibility coe⁄cients (ADCs) of dry matter, crude protein, crude lipid, ash, phosphorus, gross energy and amino acids of 10 selected ingredients for juvenile hybrid tilapia (7.05 AE 0.09 g) were determined using 0.5% Cr 2 O 3 as an inert indicator. The feed ingredients tested in this study were corn gluten meal (CGM), corn byproduct, corn germ meal (CG), soybean meal (SBM), fermented soybean meal (FSM), soy protein concentrate (SPC), soy protein isolate, malt sprouts (MS), ¢sh meal (FM) and earthworm meal (EM). The test diets were prepared by incorporation of 30% test ingredients into the reference diet. Reference and test diets were fed to the ¢sh and the faecal samples were collected using a faecal collection column attached to the ¢sh-rearing tanks. The ADCs for dry matter, crude protein, crude lipid, ash, phosphorus and gross energy were 41.7^98.9%, 90.6^99.6%, 73.1^98.8%, 34.1^98.6%, 49.5^99.6% and 45.4^99.7% respectively. Soy protein isolate, FM and EM had higher dry matter, crude protein and gross energy ADCs. Corn byproduct and EM had higher crude lipid ADCs, and CG and EM had higher phosphorus ADCs. Corn germ meal had the highest ash ADC, while CGM had the highest value for gross energy. The lowest dry matter, crude protein, lipid and gross energy ADCs occurred in MS, while the lowest ash and phosphorus ADCs occurred in SPC. The amino acid ADCs ranged from 83.3% to 100%, exhibiting a positive correlation with crude protein digestibility for a given test ingredient. The feed ingredient digestibility of this study may provide useful information about nutrient and energy utilization to facilitate formulation of least-cost practical diets for hybrid tilapia. Ã Mineral premix (values are in g kg À 1 mineral premix): MgSO 4 Á 7H 2 O, 25.3; ZnSO 4 Á 7H 2 O, 21.5; KI, 0.20; FeSO 4 Á 7H 2 O, 73.9; CuSO 4 Á 5H 2 O, 6.3; MnSO 4 Á H 2 O, 14.8; CoCl 2 , 0.2; Na 2 SeO 3 , 0.7 and NaCl, 0.4. wVitamin premix (values are in g kg À 1 vitamin premix): retinoic acid, 50.0; vitamin D 3 , 0.025; allrac-a-tocopherol, 40.0; vitamin K 3 , 5.0; thiamin, 5.0; ribo£avin, 2.5; pyridoxine, 5.0; cyanocobalamin, 0.025; pantothenic acid, 25.0; nicotinamide, 60.0; biotin, 0.5; folic acid, 2.5 and inositol, 200.0; asorbic acid, 25.0.Aquaculture Research, 2010 Hybrid tilapia apparent digestibility X-H Dong et al.