Volume 66, 2014

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    Dietary Copper Requirement of Juvenile Oriental River Prawn Macrobrachium nipponense, and its Effects on Growth, Antioxidant Activities, and Resistance to Aeromonas hydrophila
    ( 2014) Kong, You-Qin ; Ding, Zhi-Li ; Du, Zhen-Yu ; Sun, Sheng-Ming ; Wang, Li-Gai ; Li, Er-Chao ; Chen, LI-Qiao
    The present experiment evaluated the effects of dietary copper (Cu) on growth, antioxidant activities, and susceptibility to Aeromonas hydrophila infection of juvenile Oriental river prawn Macrobrachium nipponense, as well as determining the optimal dietary copper requirement. Semi-purified diets containing seven graded levels of copper (2.8, 12.2, 20.9, 29.8, 43.1, 78.9 and 157.1 mg/kg diet) from CuSO4⋅5H2O were fed to juvenile prawn (initial weight 0.101±0.002 g). The weight gain of prawns fed with 2.8-78.9 mg/kg Cu was higher and they had lower feed conversion ratios than the group fed 157.1 mg/kg Cu. Cu concentrations in the hepatopancreas, muscle, and whole body in prawns tended to increase with increased dietary Cu concentration. Hepatopancreas Cu-Zn superoxide dismutase (Cu-Zn SOD) activity, glutathione peroxidase (GPx), and total antioxidant competence (T-AOC) were highest (P<0.05) in the 43.1 mg/kg Cu group. The hepatopancreas malondialdehyde (MDA) content was lower (P<0.05) in the prawns fed 29.8 mg/kg Cu than that in prawns fed 2.8, 12.2, 78.9 and 157.1 mg/kg Cu. After the feeding experiment, prawns were injected with A. hydrophila, and the cumulative mortality rate of the prawns fed with 20.9-43.1 mg/kg Cu was lower than the prawns fed with 2.8 and 157.1 mg/kg Cu. The optimum requirement of dietary Cu in juvenile prawns was estimated at 26.9-27.8 mg/kg diet based on cumulative mortality rate and whole-body Cu retention.
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    Vitrification of Common Carp (Cyprinus Carpio) Spermatozoa, Post-Thaw Sperm Quality, and Fertility
    ( 2014) Bozkurt, Yusuf ; Yıldız, Cengiz ; Yavaş, İlker
    The aim of this investigation was to test a new technology, vitrification, or ultra-rapid freezing of the spermatozoa of common carp, and to study the ability of glucose, BSA, and other cryoprotectants to protect these cells from cryo-injuries. Spermatozoa were isolated and vitrified using 10 different cryoprotectant solutions: (1) Glucose based medium (GBM) + 1% bovine serum albumin (BSA); (2) GBM + 1% BSA + 10% DMSO; (3) GBM + 1% BSA + 20% DMSO; (4) GBM + 1% BSA + 30% DMSO; (5) GBM + 1% BSA + 10% DMA; (6) GBM + 1% BSA + 20% DMA; (7) GBM + 1% BSA + 30% DMA; (8) GBM + 1% BSA + 10% methanol; (9) GBM + 1% BSA + 20% methanol; (10) GBM + 1% BSA + 30% methanol. Fertilization rates for vitrification experiments were low and the use of low concentrations of cryoprotectants yielded lower fertilization rates than the vitrification solutions containing high cryoprotectant concentrations. In conclusion, this study reported successful vitrification of common carp spermatozoa by direct transfer into liquid nitrogen.
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    Effect of Enzyme Supplementation to Soybean Meal Based Diets on Growth, Feed Conversion Ratio, Nutrient Digestibility, and Body Composition of Rainbow Trout Oncorhynchus mykiss, (Walbaum) Fry
    ( 2014) Yigi, Nalan Ozgur ; CiHangir, Esra ; Metin, Selin ; Koca, Seval Bahadir
    A 12 week feeding trial was conducted with rainbow trout Oncorhynchus mykiss, fry (3.98 ± 0.05 g, average initial weight) to determine the effects of supplemental exogenous enzymes on growth, digestibility, and body composition. Five diets were prepared adding pectinase, xylanase, cellulase enzymes, and a commercial enzyme complex, to diets containing 40% soybean meal. The experiment was conducted in triplicate in 15 tanks, each stocked with 45 juvenile fish. The results showed that addition of enzymes to diet containing 40% soybean meal had no significant effect on growth performance and feed conversion ratio. No significant differences were observed in the apparent lipid digestibility, apparent protein digestibility, and whole body composition among dietary treatments (P>0.05). In conclusion, the use of single or multi-components of commercial enzymes (tested in this case) are not sufficient to degrade the high levels of non-starch polysaccharides introduced into digestive tract by the diets containing soybean meal at the rate of 40%.
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    Effects of Mannan Oligosaccharide (MOS) on the Survival, Physiological, and Immunological Response of the Black Tiger Prawn (Penaeus monodon Fabricius, 1798) when Challenged with two Different Stressors
    ( 2014) Sang, Huynh Minh ; Thuy, Nguyen Thi Thanh
    Two trials were conducted to determine the effects of mannan oligosaccharide (MOS) on the resistance of the black tiger prawn (Penaeus monodon) to two different stressors, bacterial infection by Vibrio alginolyticus, and the environmental pollutant ammonia (NH3). Prawns were fed two different diets, 0% (control diet) and 0.15% MOS, for 8 weeks prior to exposure to the stressors. They were then tested for survival, physiological, and immunological parameters, as indicators of health status. When the two groups were exposed to NH3 and bacterial infection, survival of prawns fed the MOS diet was significantly higher (P<0.05) than prawns fed the control diet. Similarly, the wet hepatosomatic index (Hiw), dry hepatosomatic index (Hid), hepatopancreatic moisture content (HM), total hemocyte count (THC), and granular cell percentage (GC%), of the MOS fed prawns was significantly higher (P<0.05) than in prawns fed the control diet. Bacteremia of the MOS fed prawns was lower (P<0.05) than the control diet-fed prawns after bacterial infection. Findings demonstrated the potential of MOS to improve the survival, health status, and immunity of black tiger prawns when challenged with bacterial infection and NH3 exposure.
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    Effects of Dietary Emodin Supplementation on Growth Performance, Non-Specific Immune Responses, and Disease Resistance to Aeromonas hydrophila in Juvenile Wuchang Bream (Megalobrama amblycephala)
    ( 2014) Zhang, Yuan-yuan ; Liu, Bo ; Ge, Xian-ping ; Liu, Wen-bin ; Xie, Jun ; Ren, Ming-chun ; Zhou, Qun-lan ; Sun, Sheng-ming ; Cui, Yan-ting ; Chen, Ru-li ; Pan, Liang-kun
    An 8-week feeding trial was conducted to investigate the effects of dietary emodin supplementation on growth, non-specific immunity, and protection against Aeromonas hydrophila infection in juvenile Megalobrama amblycephala. A basal diet was supplemented with 0 (control), 15, 30, 60 and 120 mg emodin/kg to formulate five experimental diets. Each diet was randomly allocated to triplicate tanks of fish in a circulating water system (initial average weight 3.49±0.045g, 25 fish per tank). At the end of the feeding trial, fish fed the diet supplemented with 0 and 120 mg emodin/kg had lower weight gain (WG) and specific growth rate (SGR) than those in the other treatment groups, but no significant differences were observed among diets supplemented with emodin from 15 to 60 mg/kg. A significant increase on feed conversion ratio (FCR) of fish fed diet supplemented with 120 mg emodin/kg was observed. The white blood cell count (WBC), respiratory burst activity, superoxide dismutase (SOD) activity, myeloperoxidase (MPO) activity, malondialdehyde (MDA) content, and tumor necrosis factor-α (TNF-α) activity first increased and then decreased with increase of the dietary emodin levels. Fish fed the 30 mg emodin/kg supplemented diet had higher WBC, respiratory burst activity, SOD and TNF-α activity, and lower MDA content, than fish fed diets supplemented with 0 and 120 mg emodin/kg. In the bacteria challenge experiment with A. hydrophila, fish fed a diet supplemented with 30 and 60 mg/kg had a lower cumulative mortality rate than the control group. These results indicated that appropriate dietary emodin supplementation (especially 30 mg emodin/kg diet) could enhance the growth and immune responses of fish and improve resistance to infection by A. hydrophila.
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    Use of Lactic Acid Bacteria from Nile tilapia Oreochromis niloticus as Probiotics for Sustainable Production and Improvement in Fish Welfare
    ( 2014) L.C, Nwanna ; Ajani, E. K. ; Bamidele, S. F.
    Two studies were conducted to investigate the effectiveness of lactic acid bacteria (LAB) from the intestine, gills, and skin of Nile tilapia Oreochromis niloticus as probiotics to promote growth, bolster the immune system, and improve general fish welfare. Results of the first study including LAB characterization indicated four major strains in the three organs as Lactobacillus fermentum (60.0%), L. brevis (16.7%), L. acidophilus (13.3%) and L. xylosus (10.0%). Safety tests of these LAB isolates conducted on some samples of the fish confirmed that they were non-pathogenic. In the second study L. fermentum, which showed the greatest promise as a probiotic, was used at different dilution levels to prepare diets for feeding O. niloticus juveniles weighing 18.1±0.1g. Diets 1-5 contained 0 colony forming unit (cfu)/g, 103cfu/g, 105cfu/g, 107cfu/g and 109cfu/g of L. fermentum, respectively. The feeding trials in fish fed diets 1-5, resulted in growth from the initial weight of 18.1g to 32.0e, 46.0a, 44.3b, 43.9c and 40.8d g, respectively. Inclusion of L. fermentum in the diets increased carcass protein, pack cell volume, hemoglobin, RBC, and reduced glutamate (P<0.05). Challenge tests conducted on the fish using pathogenic Pseudomonas aeruginosa indicated that the diets supplemented with L. fermentum improved fish immune responses. In conclusion, the studies revealed that LAB from O. niloticus can act as probiotics to improve growth, immune responses, and fish welfare.
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    Comparative Study of Antibacterial Properties of Emodin and Enrofloxacin Against Aeromonas hydrophila
    ( 2014) Ren, Mingchun ; Chen, Ruli ; Zhou, Qunlan ; Pan, Liangkun
    Antibacterial properties of emodin, extracted from rhubarb, and enrofloxacin, against Aeromonas hydrophila, were assessed in this study. The minimum inhibitory concentration (MIC) values of emodin and enrofloxacin to fight A. hydrophila WJ2011BJ44 were found to be 100ug/ml and 9.375ug/ml, respectively. To understand the mechanisms of action of emodin and enrofloxcain against A. hydrophila we studied antibacterial activity, bacterial membrane permeability, and ultrastructure of A. hydrophila cells treated with emodin, enrofloxacin individually, and the combination of both. The results shown in the growth curve of A. hydrophila treated with different concentrations (from 0 MIC to 4 MIC) of emodin and enrofloxacin were similar and stable, and there was no significant difference in the growth curve of different treatment groups. There were significant differences in the K+ concentration among all treatment groups from 1 h to 8 h after incubation compared with the control. The highest K+ concentration was observed in the emodin+enrofloxacin group from 1 h to 8 h after incubation. PI fluorescence signal of untreated A. hydrophila cells and A. hydrophila cells treated with emodin, or enrofloxacin individually, or the combination of both were 0.89, 11.4, 13.98 and 18.3, respectively. The mortality of A. hydrophila cells treated with the combination of emodin and enrofloxacin was greatest compared with other groups. These results indicated that 2 MIC emodin, 2 MIC enroflxacin, and combination of 1 MIC emodin and 1 MIC enrofloxacin can inhibit the growth of A. hydrophila, increase bacterial membrane permeability, and damage cell membrane integrity. The combination of 1 MIC concentration emodin and 1 MIC concentration enrofloxacin produced the best antibacterial activity against A. hydrophila *
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    Effect of Feeding Frequency on Growth Rate, Body Composition and Gastric Evacuation of Juvenile GIFT Strain of Nile Tilapia (Oreochromis niloticus)
    ( 2014) Bin, Chen ; Qi, Peng ; Bin, Wu ; Bo, Luo ; Wen, Liang $Jian, Feng
    The specific objectives of this study were to determine the optimum feeding frequency in juvenile GIFT (Genetically Improved Farmed Tilapia) strain of Nile tilapia (Oreochromis niloticus), for growth rate, body composition, and gastric evacuation, as well as to investigate the passage of a single meal through the stomach in order to establish gastric evacuation rate. Six treatment groups of juvenile GIFT were fed to satiation with extruded feed, at 6 feeding frequencies: four, three, and two meals a day, and four meals, three, and two meals, every 2 days, for 6 weeks respectively. Each treatment (n=20) was replicated three times. As feeding frequency decreased, the growth rate of the juvenile GIFT decreased gradually. The feed intake of fish fed two meals a day was significantly lower than that of fish fed three meals a day (P <0.05), whereas the feed efficiency ratio of fish fed two meals a day was significantly higher than that of fish fed three meals a day (P<0.05). As feeding frequency decreased, moisture content of fish body increased and the fat and protein contents decreased gradually. Hepatosomatic indices of fish fed two, and three meals a day, were not statistically different to each other or to the remaining groups. The livers of all fish were normal. Gastric evacuation of the fish was best evaluated with the square root model. It was estimated that gastric feed contents gradually decreased and reached the prefeeding level within 15 h. Evacuation of 80% would require 9 h which appeared to correspond with the return of appetite. Our results suggest that two meals a day are optimal for growth performance of juvenile GIFT Nile tilapia.
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    Growth and Hemato-Immunological Response to Dietary i-Carrageenan in Labeo rohita (Hamilton, 1822) Juveniles
    ( 2014) Kumar, Vikash ; Kumar, Saurav ; Pandey, P.K. ; Raman, R.P. ; Prasad, K. Pani ; Roy, Suvra ; Kumar, Abhay ; Kumar, Kundan
    The study was performed over a period of 60 days to evaluate the effect of dietary carrageenan on growth, hematology, biochemistry, and innate immunity in rohu Labeo rohita. A basal diet supplemented with iota (i)Carrageenan at 5, 10 and 20g/kg was fed to three different groups of fish for 60 days. The fish were examined 15, 30, 45, and 60 days after commencement of the study. Parameters for growth (absolute growth, specific growth rate, and percentage weight gain), hematology (total erythrocyte count, total leucocyte count, thrombocyte count and hemoglobin value), biochemistry (total serum protein, albumin, globulin and albuminglobulin ratio), and innate immunity (nitroblue tetrazolium NBT, and myeloperoxidase MPO, activity) were monitored to assess the effect of the iCarrageenan based diet in L. rohita. All the parameters examined (growth, hematology, biochemistry, and innate immunity) increased significantly (P<0.05) in carrageenan-fed groups compared to the control group. However, the highest values for those parameters were found on the 60th day in the group which was fed a 10 g/kg i-Carrageenan diet. The study suggests that a 10 g/kg diet of i-carrageenan enhances immunity and the overall health status in L. rohita.
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    Chemical composition and fatty acid profile of Trans-Andean Shovelnose catfish Sorubim cuspicaudus
    ( 2014) Prieto-Guevara, Martha Janeth ; Pájaro, Cristina Morelo ; Doria, Yuly Yabrudy ; Atencio-Garcia, VictorJulio
    Chemical composition and fatty acid profile were studied in larvae and adult Trans-Andean shovelnose catfish muscle. The chemical composition in dry matter of the larvae and the food they consumed were: moisture, 89.2%, 91.8%; protein, 79.8%, 70.6%; ethereal extract, 7.8% 7.2%; and ash, 12.7% and 14.5%, respectively. In adult muscle there were no significant differences between sexes in the percentages of moisture, protein, ethereal extract, and ash. Similarly, there was no statistical difference between sexes for monounsaturated fatty acids and polyunsaturated fatty acids. A significant difference between the sexes was found in the fatty acid profile which showed a predominance of saturated fatty acids. This study demonstrated that there is a great similarity in the chemical composition of the species. The percentage of protein and variation in ethereal extract and ash content was dependent upon the composition of its food. These results provide basic information for formulating adequate nutritional diets to meet the requirements of Neotropical fish.