Initial Weight (initial + weight)

Distribution by Scientific Domains

Kinds of Initial Weight

  • average initial weight
  • g initial weight
  • mean initial weight


  • Selected Abstracts


    Severe blunt trauma in dogs: 235 cases (1997,2003)

    JOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue 6 2009
    Stephen A. Simpson DVM
    Abstract Objective , To evaluate population characteristics, injuries, emergency diagnostic testing, and outcome of dogs with blunt trauma requiring intensive care in an urban hospital. Design , Retrospective study 1997,2003. Setting , All data obtained from the University of Pennsylvania , Matthew J. Ryan Veterinary Hospital. Animals , Dogs admitted to the intensive care unit for treatment following blunt trauma. Interventions , None. Measurements and Main results , Of the 235 dogs that met inclusion criteria, 206 (88%) survived and 29 (12%) did not survive. Blunt vehicular trauma accounted for 91.1% of cases. Mild hyperglycemia and hyperlactatemia was common in both survivors and nonsurvivors. The chest was the most common region traumatized and the prevalence of polytrauma was 72.3%. Initial weight, vital signs, PCV, total plasma protein, BUN, glucose, lactate, acid-base status, and electrolytes did not differ between survivors and nonsurvivors. Nonsurvivors were significantly more likely to have had head trauma (P=0.008), cranium fractures (P<0.001), recumbency at admission (P<0.001), development of hematochezia (P<0.001), clinical suspicion of acute respiratory distress syndrome (P<0.001), disseminated intravascular coagulation (P<0.001), multiorgan dysfunction syndrome (P<0.001), development of pneumonia (P<0.001), positive-pressure ventilation (P<0.001), vasopressor use (P<0.001), and cardiopulmonary arrest (P<0.001). Conclusions , Outcome of severe blunt trauma in dogs treated with intensive care is very good. Despite the high survival rate, several features associated with poor outcome were identified. Neither admission lactate nor glucose was able to predict outcome. [source]


    The effect of weight loss by energy restriction on metabolic profile and glucose tolerance in ponies

    JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 5 2008
    S. Van Weyenberg
    Summary In nine initially obese ponies, a weekly weight loss according to 1% of their ideal body weight was evaluated for its impact on insulin sensitivity and metabolic profile. Weight loss was obtained solely through energy restriction, initially at 70% of maintenance energy requirements, but to maintain constant weight loss, feed amount had to be decreased to 50% and 35% of maintenance energy requirement during the course of the trial. An oral glucose tolerance test (OGTT) was performed at weeks 0, 10 and 17. Fasted blood samples were taken on weeks 0, 3, 10, 17 for analysis of triglycerides (TG), non-esterified fatty acids (NEFA), creatine phosphokinase (CPK), lactate dehydrogenase (LDH), T3, T4 and leptin. Total average weight loss was 18.2%. When the OGTT was performed at weeks 0, 10 and 17, ponies had lost 0.22%, 9.9% and 16.3% of their initial weight respectively. Weight loss was associated with a decreased AUC for glucose and insulin. Moreover, greater % weight loss was associated with a significantly lower glucose peak and a lower area under the curve (AUC glucose). The lower glucose response after an OGTT in lean ponies was not the result of an increased insulin secretion, but an improved insulin sensitivity. Restricted feeding led to mobilization of TG and NEFA and to a reduced basal metabolism, with lower LDH, CPK, T3 and leptin. In conclusion: in obese Shetland ponies, weight loss at a rate of 1% of ideal body weight per week through restricted energy intake, ameliorated insulin sensitivity. [source]


    Manufacturing, mechanical characterization, and in vitro performance of bioactive glass 13,93 fibers

    JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2006
    E. Pirhonen
    Abstract Fibers were manufactured from the bioactive glass 13,93 by melt spinning. The fibers were further characterized by measuring their tensile and flexural strength, and their in vitro performance was characterized by immersing them in simulated body fluid, which analyzed changes in their mass, their flexural strength, and surface reactions. The strength of glass fibers is highly dependent on fiber diameter, test method, and possible surface flaws, for example, cracks due to abrasion. In this study, the thinnest fibers (diameter between 24 and 33 ,m) possessed the highest average tensile strength of 861 MPa. The flexural strength was initially 1353.5 MPa and it remained at that level for 2 weeks. The Weibull modulus for both tensile and flexural strength values was initially about 2.1. The flexural strength started to decrease and was only ,20% of the initial strength after 5 weeks. During the weeks 5,40, only a slight decrease was detected. The flexural modulus decreased steadily from 68 to 40 GPa during this period. The weight of the samples initially decreased due to leaching of ions and further started to increase due to precipitation of calcium phosphate on the fiber surfaces. The mass change of the bioactive glass fibers was dependent on the surface area rather than initial weight of the sample. The compositional analysis of the fiber surface after 24 h and 5 weeks immersion did confirm the initial leaching of ions and later the precipitation of a calcium phosphate layer on the bioactive glass 13,93 fiber surface in vitro. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006 [source]


    A Spatial Economic Analysis of Urban Land Use and Obesity,

    JOURNAL OF REGIONAL SCIENCE, Issue 3 2005
    Andrew J. Plantinga
    Households maximize utility defined over housing, weight, and food subject to a fixed time budget allocated to commuting, calorie expenditure, and work. Our model explains the observed correspondence between high obesity rates and low development densities, but implies that these are determined endogenously in a spatial market equilibrium. We study the sorting of residents by attributes such as income, initial weight, and weight preferences, and examine the impacts on weight and density of urban design modifications that lower the costs of calorie expenditure. [source]


    Chemical composition and nutritive value of peach palm (Bactris gasipaes Kunth) in rats

    JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2005
    Pascal Leterme
    Abstract The peach palm (Bactris gasipaes Kunth) is the starchy fruit of a palm tree widely cultivated in Central and South America. The present study aimed at determining its chemical composition and its nutritive value in rats. The average chemical composition of 17 samples was as follows: 410 g kg,1 water and, in g kg,1 of dry matter (DM), 54 g crude protein, 114 g oil, 39 g neutral detergent fibre, 716 g starch, 21 g sugars and 18 g ash. The main variability was observed for the oil (60,180 g kg,1 DM) and starch (590,780 g DM) contents. The proteins contained, on average, in g kg,1 of proteins, 49 g lysine, 13 g methionine, 19 g cysteine, 39 g threonine and 7 g tryptophan. The mineral fraction contained, per kg DM: 1.0 g Ca, 0.8 g P, 0.6 g Mg, 0.3 g Na, 44 mg Fe, 4 mg Cu and 10 mg Zn. The digestibility of four peach palm genotypes was determined in rats fed a diet composed of 350 g kg,1 of peach palm and 650 g of a control diet based on maize and soybean meal. The digestibility of DM, energy, starch and protein of peach palm alone reached, on average 91, 87, 96 and 95%, respectively. No difference was observed between varieties, except for starch (p < 0.05). On average, peach palm contained 51 g of truly digestible protein kg,1 DM and 3.691 kcal digestible energy kg,1 DM. A growth trial was also carried out for 1 month on rats (initial weight: 78 g) fed a diet containing 0, 200, 400, 600 or 800 g peach palm kg,1, at the expense of a diet composed of maize starch and casein. The growth rate of the rats decreased (p < 0.05) as the peach palm concentration increased. The growth decrease was due to a decrease (p < 0.05) in DM intake and to the lower quality of the peach palm protein. It is concluded that peach palm is mainly an energy source for humans and animals. It is poor in protein and minerals but can be consumed in large amounts. Copyright © 2005 Society of Chemical Industry [source]


    Influence of Starvation on Flesh Quality of Farmed Dentex, Dentex dentex

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2010
    María Dolores Suárez
    Dentex (mean initial weight 324 ± 5 g) from a fish farm were divided into two groups (control and fasted). At the end of experimental period (5 wk), dentex were sampled for gross muscle composition and quality analysis. For post mortem muscle analysis, after death, fish were kept in a cold chamber at 4 C, and muscle samples were taken at 4 (prerigor state), 24 (rigor state), and 82 (postrigor state) h after slaughtering. In each fish, textural and biochemical parameters were determined. During starvation, there was a drastic reduction in muscle lipid content and a relative increase of the proteolysis. There were little qualitative changes in the fatty-acid profile of muscle lipids, although a significant increase in n3/n6 ratio in the starved dentex was detected. Starved fish also showed higher muscle firmness, but no differences in pH and water holding capacity were observed. Total and myofibrillar protein and collagen content increased significantly in starved dentex. Firmness during post mortem storage was significantly higher in starved fish, compared with control group. Preslaughtering feeding status showed decisive influence on the evolution dentex muscle quality parameters during cold storage. [source]


    Evaluation of Glycerol from Biodiesel Production as a Feed Ingredient for Channel Catfish, Ictalurus punctatus

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2010
    Menghe H. Li
    Glycerol is the main by-product of biodiesel production from vegetable oils and animal fats. It has been evaluated as an energy source for several farm animals. A study was conducted to examine the effects of various levels of glycerol in channel catfish, Ictalurus punctatus, diets. Fish with mean initial weight of 6.8 ± 0.1 g were stocked in 110-L flow-through aquaria and fed practical diets containing 0, 5, 10, 15, and 20% glycerol for 9 wk. There were no significant differences in feed consumption, weight gain, feed efficiency ratio, and liver lipid level among fish fed diets containing 0, 5, and 10% glycerol. However, fish fed diets containing 15 and 20% glycerol had reduced weight gain, feed efficiency, and liver lipid content. Survival was not affected by dietary glycerol levels. Blood glucose level was significantly higher in fish fed 5% glycerol than fish fed other diets. Fillet protein and fat generally decreased and fillet moisture increased as dietary glycerol level increased. It appears that channel catfish can utilize about 10% glycerol in the diet without adverse effects on feed consumption, weight gain, feed efficiency ratio, hemoglobin, hepatosomatic index, and liver lipid. [source]


    Effects of the Prebiotics GroBiotic® -A and Inulin on the Intestinal Microbiota of Red Drum, Sciaenops ocellatus

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2009
    Gary Burr
    Two separate feeding trials examined the effects of dietary supplementation of the prebiotics GroBiotic® -A and inulin on growth performance and gastrointestinal tract microbiota of the red drum, Sciaenops ocellatus. In the first feeding trial, fish meal-based diets without prebiotics or supplemented with either GroBiotic® -A or inulin at 1% of dry weight were fed to triplicate groups of juvenile red drum (initial weight of 2.6 g) in 110-L aquaria operated as a brackish water (7 ppt) recirculating system for 8 wk. In the second feeding trial, soybean meal/fish meal-based diets supplemented with either GroBiotic® -A or inulin at 1% of dry weight were fed to triplicate groups of red drum (initial weight of 15.8 g) in 110-L aquaria operated as either a common recirculating water system or closed system with individual biofilters (independent aquaria) for 6 wk. Supplementation of the prebiotics in either feeding trial did not alter weight gain, feed efficiency ratio, or protein efficiency ratio of red drum fed the various diets. In the second feeding trial, the culture system significantly affected weight gain, feed efficiency ratio, and protein efficiency ratio although there were no effects of dietary treatments on fish performance or whole-body protein, lipid, moisture, or ash. Denaturing gradient gel electrophoresis (DGGE) analysis of the gastrointestinal tract microbial community showed no effect of the dietary prebiotics as the microbial community appeared to be dominated by a single organism with very low diversity when compared with other livestock and fish species. DGGE of the microbial community in the biofilters of the independent aquariums showed a diverse microbial community that was not affected by the dietary prebiotics. [source]


    Commercial-scale Validation of Temperature-step Rearing on Growth Physiology in Turbot, Scophthalmus maximus

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 5 2008
    Albert K. Imsland
    The aim of this study was to investigate the possible benefit of "temperature-steps" (T-steps) rearing for juvenile turbot (initial weight 15.1 g) under realistic production scale and to determine whether initial growth advantage is maintained throughout the rearing period to market size. One group (called T-step 22-19-16) of juvenile turbot was reared at three different temperatures, that is, 22 C (from 17 to 60 g) followed by 19 C (from 60 to 100 g) and 16 C (>100 g); another group (called T-step 19-16) at two temperatures, that is, 19 C (from 17 to 100 g) and lowered to 16 C (>100 g); and the third group (called C16) at one constant temperature, that is, 16 C. Relative growth was significantly higher in the two T-step groups, with the T-step 19-16 showing the highest overall growth. Feed conversion efficiency was highest in the 19-16 group. Only minor effects of the experimental rearing on blood physiology were found, with one notable exception of inverse relationship between plasma glucose and growth. Overall, these findings indicate that a short interval of rearing fish at high temperature during the early juvenile phase may have a long-term effect on biomass increment in turbot. This is an important finding for the turbot industry. [source]


    Investigation of the Effects of Salinity and Dietary Protein Level on Growth and Survival of Pacific White Shrimp, Litopenaeus vannamei

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2007
    Martin Perez-Velazquez
    It is presumed that in hypo- and hypersaline environments, shrimp's requirements for some specific nutrients, such as protein, may differ from those known in the marine habitat; however, few investigations have been conducted in this area of study. In the present investigation, the effects of salinity and dietary protein level on the biological performance, tissue protein, and water content of Pacific white shrimp, Litopenaeus vannamei, were evaluated. In a 3 × 4 factorial experiment, juvenile shrimp with an average initial weight of 0.36 ± 0.02 g were exposed for 32 d to salinities of 2, 35, and 50 ppt and fed experimental diets with crude protein contents of 25, 30, 35, and 40%. A significant effect of salinity on growth of shrimp was detected, with the growth responses (final weight, weight gain) ranked in the order 2 ppt (3.87, 3.50 g) > 35 ppt (3.40, 3.04 g) > 50 ppt (2.84, 2.47 g). No effects of dietary protein level or an interaction between salinity and protein on growth of shrimp were observed under the experimental conditions of this study. Percent survival of shrimp fed the highest protein content (40%, survival of 74%) was, however, significantly lower than those of shrimp fed the other feeds (25, 30 and 35% protein, survival of 99, 91, and 94%, respectively), a result likely associated with the concentration of total ammonia nitrogen, which increased significantly at increasing protein levels. Final water content of whole shrimp was significantly lower in animals exposed to 50 ppt (70.8%) than in shrimp held at 2 (73.7%) and 35 ppt (72.3%). No effect of salinity, protein, or their interaction was observed on the protein content of whole shrimp. The results of the present study are in agreement with reports of superior and inferior growth of L. vannamei reared in hypo- and hypersaline environments, respectively, as compared to what is generally observed in seawater. [source]


    Effect of Diets Formulated with Native Peruvian Plants on Growth and Feeding Efficiency of Red Pacu (Piaractus brachypomus) Juveniles

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2006
    Maria E. Palacios
    We evaluated the effects of casein-based semipurified diets, alone or supplemented with native Peruvian plants, on growth, feed efficiency, and histology of the digestive tract of red pacu, Piaractus brachypomus, juveniles over an 8-wk feeding trial. Three tanks were randomly assigned to one of four casein,gelatin (40:8) diets containing a supplement of 15% wheat meal (control) or an identical level of substitution of three South American native plant as follows: camu-camu fruit (Myrciaria dubia), aguaje fruit (Mauritia flexuosa), or maca tuber meal (Lepidium meyenii). The fish (initial weight, 2.04 ± 0.06 g) were fed experimental diets at decreasing feeding rates from 4 to 2.6% of body weight. After 8 weeks of feeding, fish fed a diet supplemented with maca meal showed significantly higher (P < 0.05) weight gain, specific growth rate, protein efficiency ratio (PER), apparent net protein utilization (NPU), and instantaneous feed intake than fish fed other diets. Feed conversion ratio (FCR), PER, and NPU in fish fed the casein,gelatin diet supplemented with maca meal were among the best ever reported in the scientific literature, 0.64 ± 0.03, 3.13 ± 0.15 and 23.8 ± 2.0, respectively. The camu-camu meal had a negative impact on diet palatability and utilization, which resulted in slower growth. The stomach, intestine, pancreas, and pyloric caeca at the start and end of the experiment showed normal differentiation and appearance of cells and tissues. The liver parenchyma showed lipid infiltration and pigment accumulation in all samples at the initiation of the experiment and may be attributed to the period of decreased feed intake prior to the study. At the end of the study, similar histopathologies were recorded in all samples from the control and camu-camu groups. Normal liver histology (polyhedral hepatocytes with centrally located nuclei) was observed in two of three samples from the maca group and all the samples from the group that was fed the aguaje-supplemented diet. [source]


    Replacement of Fish Meal with Soybean Meal in the Production Diets of Juvenile Red Snapper, Lutjanus campechanus

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2005
    D. Allen Davis
    The replacement of fish meal with soybean meal in fish diets has met with varying degrees of success. Quite often, poor responses to high soybean meal diets are either due to shifts in the nutrient profile or a reduced palatability of the diet when fish meal is removed. The present research was designed to evaluate the replacement of menhaden fish meal with solvent-extracted soybean meal in practical diets containing 10% poultry by-product meal and formulated to contain 40% protein, 8% lipid, and a total sulfur amino acid content of > 3.0% of the protein. The response of red snapper (mean initial weight 10.9 g) to diets containing graded levels of fish meal (30,20, 10, 0%) as well as the response to a low fish meal diet (10%) without poultry by-product meal were evaluated over a 6-wk growth period. Significant (P± 0.05) differences in final mean weight, percent weight gain, and feed conversion were observed. Final weights (percent gain) ranged from 30.9 g (185.5%) for fish offered diets with 30% fish meal to 12.6 g (16.3%) for fish offered diets with 0% fish meal. Corresponding feed conversion efficiencies ranged from 60.1% to 7.7%. No significant differences were observed for survival between treatment means. Although there was a clear reduction in performance as the fish meal was replaced with soybean meal, the use of 10% poultry by-product meal or 10% fish meal resulted in similar performance of the fish. This is a good indication that poultry by-product meal does not have palatability problems and could be used as a substitute. The present findings suggest that replacing fish meal with high levels of soybean meal appears to reduce the palatability of the diet. While the cost reducing benefit, with respect to the replacement of fish meal, has been shown with other species, before high levels of inclusion can be efficiently utilized further research is needed to address the palatability problems observed with red snapper. [source]


    Pilot Production of Hatchery-Reared Summer Flounder Paralichthys dentatus in a Marine Recirculating Aquaculture System: The Effects of Ration Level on Growth, Feed Conversion, and Survival

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2005
    Patrick M. Carroll
    Pilot-scale trials were conducted to evaluate growout performance of hatchery-reared summer flounder fingerlings in a state-of-the-art recirculating aquaculture system (RAS). The outdoor RAS consisted of four 4.57-m dia × 0.69-m deep (vol. =11.3 m3) covered, insulated tanks and associated water treatment components. Fingerlings (85.1 g mean initial weight) supplied by a commercial hatchery were stocked into two tanks at a density of 1,014 fish/tank (7.63 kg/m3). Fish were fed an extruded dry floating diet consisting of 50% protein and 12% lipid. The temperature was maintained between 20 C and 23 C and the salinity was 34 ppt. Under these conditions, growth, growth variation (CVwt), feed utilization, and survival of fish fed to 100% and 82% of a satiation rate were compared. Due to clear changes in growth patterns during the study, data was analyzed in three phases. During phase 1 (d 1,d 196), fish showed rapid growth, reaching a mean weight of 288 g ± 105 and 316 g ± 102, with a CVwt of 0.36 and 0.32 and FCR's of 1.38 and 1.36 in the subsatiation and satiation groups, respectively. During phase 2 (d 196,d 454), fish displayed slower growth reaching mean weights of 392 g ± 144 and 436 g ± 121, with a CVwt of 0.37 and 0.28, and increasing FCR's of 3.45 and 3.12 in the subsatiation and satiation groups, respectively. During phase 3 (d 454,d 614), fish showed little growth reaching mean weights of 399 g ± 153 and 440 g ± 129, with a CVwt of 0.38 and 0.29 in the subsatiation and satiation groups, respectively. Over the entire growout period (d 1,d 614), feed conversion ratios were 2.39 and 2.37 and survival was 75% and 81 % in the subsatiation and satiation treatments, respectively. The maximum biomass density reached during the study was 32.3 kg/m3. The satiation feed rate was superior to the 82% satiation rate, since it maximized growth rates, with no effect on FCR. The higher CVwt in the subsatiation group suggests increased competition for a restricted ration led to a slower growth with more growth variation. The decrease in growth in phases 2 and 3 was probably related to a high percentage of slower growing male fish in the population and the onset of sexual maturity. This study demonstrated that under commercial scale conditions, summer flounder can be successfully grown to a marketable size in a recirculating aquaculture system. Based on these results, it is recommended that a farmer feed at a satiation rate to minimize growout time. More research is needed to maintain high growth rates through marketable sizes through all-female production and/or inhibition of sexual maturity. [source]


    Effects of Dietary Vitamin A on Juvenile Red Sea Bream Chrysophrys major

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2004
    Luis Hector
    A 55-d feeding experiment was conducted to evaluate the effects of dietary vitamin A on growth of juvenile red sea bream Chrysophrys major. Nine semi-purified diets with supplemental retinol palmitate at levels of 0, 300, 600, 1,500, 3,000, 4,500, 6,000, 15,000 and 30,000 retinol eq/kg diet, were fed twice daily to triplicate groups of 10 juveniles per tank with an initial weight of 1.178 ± 0.001 g. Weight gain and specific growth rate increased with the increase of supplemental retinol palmitate in the diet up to a level of 6,000 retinol eq/kg diet, beyond which those indices tended to decrease slightly or to plateau. Significantly lower weight gain and specific growth rate were observed in fish fed with 0 and 300 retinol eq/kg diet. No significant differences were found in survival rates among the different levels of supplementation. The crude protein, lipid, moisture and ash contents in the whole body were not affected by the different vitamin A supplemental levels. Besides the reduced growth, fish fed with low levels of vitamin A supplement showed no other signs of deficiency. No hypervitaminosis A symptoms were observed in fish fed on high levels of supplementation. Fish fed on diets with 0 and 300 retinol eq/kg diet showed a significantly lower content of vitamin A (as a total retinol) in the liver than those in groups fed with higher levels of supplementation. Vitamin A was stored in the liver mainly as retinyl esters. Total retinal content of the eye showed no significant differences among the treatments; however, fish fed with 0 and 300 retinol eq/kg of diet had slightly higher concentrations. According to the results of the mean weight gain, specific growth rate and liver retinol content, the requirement of dietary vitamin A for juvenile red sea bream was estimated to be between 1,500 and 6,000 retinol eq/kg. [source]


    Effects of Amylopectin/Amylose Starch Ratio on Growth, Body Composition and Glycemic Response of Sunshine Bass Morone chrysops × M. saxatilis

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2003
    Steven Rawles
    Manipulation of the ratio of amylopectin (,-[1,4] and ,-[1,6] linked glucose) to amylose (,-[1,41 linked glucose) starches in the carbohydrate fraction of the diet has been used to improve carbohydrate and lipid metabolism in mammalian models. A 10-wk feeding trial was conducted to determine the effect of dietary amylopectin/amylose ratio on growth and composition of growth of advanced sunshine bass (Morone chrysops × M. saxatilis) fingerlings (60 g, initial weight). Fish were fed cold-pelleted, semipurified, isonitrogenous (35% crude protein), isocaloric (3.6 kcaVg protein), isolipidic (5%) diets containing 25% carbohydrate. The carbohydrate fraction of the diets was composed of either glucose, dextrin, 100% amylopectin/0% amylose, 70% amylopectin/30% amylose, or 30% amylopectin/70% amylose. Diets differing in ratios of amylopectin/amylose were achieved by adjusting the proportion of high-amylopectin (100% amylopectin) to high-amylose (70% amylose) corn starch. Diets were fed to fish in quadruplicate 76-L tanks (seven fish/tank) connected to a brackish water (5-7%v) recirculating culture system with biofiltration. Weight gain ranged from 195 to 236% of initial weight (60 g) and was significantly greater (P < 0.1) for fish fed diets containing 25% carbohydrate as dextrin or as 70% amylose and significantly lower in fish fed diets in which carbohydrate was composed of 30% amylose, 100% amylopectin, or glucose. Feed efficiency ranged from 0.52 to 0.61 and was higher in fish fed the diet containing the highest concentration of amylose and lower in fish fed the diet containing glucose. Hepatosomatic index was highest (2.71) in fish fed the diet containing glucose and lowest (1.401.45) in fish fed diets containing high-amylose cornstarch. Intraperitoneal fat ratio was distinctly lower in fish fed diets containing some amylose as compared to those fed diets without amylose. Liver lipid was significantly lower (4.8%) in fish fed the diet containing glucose and almost twice as high (7.3-8.9%) in fish fed the diets containing any starch. Glycogen content of the liver decreased from approximately 12% in fish fed the diet containing glucose to 5% in fish fed the diets containing amylose. Muscle proximate composition and ratio were unaffected by the dietary treatments. Fasting levels (15 h) of blood glucose in fish reared for 10 wk on the diet containing glucose were significantly elevated (5.5 mmol/L) when compared to fasting levels of those that had been reared on diets containing starch (3.4-1.1 mmol/L). Fish fed the diet containing glucose exhibited maximum blood concentrations (14.6 mmoVL) 4 h postprandial then rapidly declined to nearly fasting levels within 8 h postprandial. In contrast, maximum plasma glucose concentrations in fish fed diets containing starch were roughly half (6.8-8.1 mmol/L) those of fish fed the diet containing glucose. Blood glucose in fish fed diets containing dextrin or predominantly amylopectin starch remained elevated longer than that of fish fed diets containing glucose or predominantly amylose starch. Glycemic response appeared to decrease with increasing dietary amylose content. These data suggest that feeding diets in which a greater portion of the starch is amylose may be a useful strategy for improving carbohydrate use in sunshine bass. [source]


    Effect of Dietary Protein Concentration and Stocking Density on Production Characteristics of Pond-Raised Channel Catfish Ictalurus punctatus

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2003
    Menghe H. Li
    Diets containing 28% and 32% crude protein were compared for pond-raised channel catfish Ictalurus punctatus stocked at densities of 14,820, 29,640, or 44,460 fish/ha. Fingerling channel catfish with average initial weight of 48.5 g/fish were stocked into 30 0.04-ha ponds. Five ponds were randomly allotted for each dietary protein ± stocking density combination. Fish were fed once daily to satiation for two growing seasons. There were no interactions between dietary protein concentration and stocking density for any variables. Dietary protein concentrations (28% or 32%) did not affect net production, feed consumption and weight gain per fish, feed conversion ratio, survival, processing yields, fillet moisture, protein and ash concentrations, or pond water ammonia and nitrite concentrations. Fish fed the 32% protein diet had slightly but significantly lower levels of visceral and fillet fat than fish fed the 28% protein diet. As stocking density increased, net production increased, while weight gain of individual fish, feed efficiency, and survival decreased. Stocking densities did not affect processing yield and fillet composition of the fish. Although highly variable among different ponds and weekly measurements, ponds stocked at the highest density exhibited higher average levels of total ammonia-nitrogen (TAN) and nitrite-nitrogen (NO2 -N) than ponds stocked at lower densities. However, stocking density had no significant effect on un-ionized ammonia-nitrogen (NH3 -N) concentrations, calculated based on water temperature, pH, and TAN. By comparing to the reported critical concentration, a threshold below which is considered not harmful to the fish, these potentially toxic nitrogenous compounds in the pond water were generally in the range acceptable for channel catfish. It appears that a 28% protein diet can provide equivalent net production, feed efficiency, and processing yields as a 32% protein diet for channel catfish raised in ponds from advanced fingerlings to marketable size at densities varying from 14,820 to 44,460 fish/ha under single-batch cropping systems. Optimum dietary protein concentration for pond-raised channel catfish does not appear to be affected by stocking density. [source]


    Dietary Lipid Utilization by Juvenile Summer Flounder Paralichthys dentatus

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2003
    T. Gibson Gaylord
    The ability of juvenile summer flounder Paralichthys dentatus to utilize dietary lipid as energy, and the effect of dietary lipid on weight gain and body composition was investigated in a 12-week feeding trial. Diets were formulated to provide 55% crude protein from herring meal and casein. Menhaden oil was added to produce diets with 8, 12, 16 or 20% total lipid while providing 16.0 kJ available energy/g dry diet. The diet containing 20% total lipid supplied 16.7 kJ available energy/g dry diet due to the high levels of protein and lipid. An additional diet was included to reproduce currently available commercial diet formulations for flounder, providing 55% crude protein supplied solely from herring meal and 16% total dietary lipid. Juvenile summer flounder (initial weight 23 g) were stocked into triplicate aquaria in a closed, recirculating system maintained at 20 C. Fish were fed 2% of body weight each day divided into two equal feedings. Upon termination of the study, effects of dietary lipid on weight gain, body condition indices, and proximate composition were determined. Weight gain (96,149% of initial weight), feed efficiency ratio values (0.43,0.48). fillet yield, and whole-body composition all were unaffected by dietary lipid level. High levels of dietary lipid did increase the lipid content in the finray muscle, as fish fed diets containing 16 and 20% dietary lipid had significantly higher lipid levels than fish fed the diet containing 8% lipid. No apparent protein sparing effect of lipid was observed. These data indicate that currently available commercial feeds for summer flounder may be over-formulated and show a need for further research to determine specific and accurate nutritional information for this species. [source]


    Evaluation of Experimental and Practical Diets for Walleye Stizostedion vitreum

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2002
    Anant S. Bharadwaj
    Culture of walleye Sfizostedion vitreum is one of the largest components of public sector aquaculture in the eastern U.S. and there is increasing interest in private sector culture. However, the nutritional requirements of walleye are unknown and experimental diets for use in quantifying nutritional requirements have not been identified. We formulated four experimental and four practical diets and fed those to triplicate groups of walleye with an initial weight of 13 g per fish. The experimental diets contained either casein (CAS), casein + gelatin (CG), casein + arginine (CA), or casein + gelatin + crystalline amino acids (CGAA) as sources of amino acids. The practical diets were formulated to mimic salmon grower (SG) and trout grower (TG) diets, a fish meal-free diet for trout (TFMF), and a walleye grower (WG) diet. Fish were fed twice daily to satiation for 9 wk. Feed consumption, percent weight gain, specific growth rates, feed efficiency, protein efficiency ratio, and protein retention efficiency were not significantly different among fish fed CGAA, SG, and TG, but those values were significantly higher than in fish fed other diets. Weight gain of fish fed CGAA was approximately 80% of that in fish fed SG and 91% of that in fish fed TG. Protein retention efficiency of fish fed CGAA was approximately 69% and 81% of that observed for fish fed SG, and TG, respectively. In general, the carcasses of fish fed diets CGAA, SG and TG had significantly lower moisture and ash concentrations, and higher lipid levels than fish fed other diets. There were no significant differences in carcass protein concentration, muscle proximate composition, or liver lipid concentration among treatments. Livers from fish fed all diets were characterized by microvesicular degeneration and glycogen accumulation in hepatocytes. Results from the study indicate that CGAA can be used as a basal experimental diet in future nutritional research with juvenile walleye and confirms the benefits of trout and salmon grower diets. Fish meal-free diets formulated around the requirements for rainbow trout were consumed at approximately 80% of the values in fish fed TG and SG, but weight gain was approximately 20% of that in fish fed TG and SG. It appears the nutritional requirements for walleye are different than those of rainbow trout. [source]


    Growth and Feed Utilization of the Tilapia Hybrid Oreochromis mossambicus×O. niloticus Cultured at Different Salinities under Controlled Laboratory Conditions

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2001
    Manuel García-Ulloa
    Fish (2.32 g mean initial weight) were grown in 113-L aquaria at salinities of 0.5, 17 and 32 ppt at a density of 20 fish per tank. Mean specific growth, food conversion, and food consumption were determined at each salinity. There was no significant difference (P > 0.05) in growth among the treatments, although feed conversion and feed consumption were significantly improved (P , 0.05) when fish were grown at 17 and 32 ppt. [source]


    Effects of dietary starches and the protein to energy ratio on growth and feed efficiency of juvenile cobia, Rachycentron canadum

    AQUACULTURE NUTRITION, Issue 5 2010
    K.A. JR WEBB
    Abstract Optimization of the protein to energy ratio in juvenile cobia (Rachycentron canadum) would allow the production of diets that maximize growth without the addition of excess energy that may increase costs or even be detrimental to the health of the fish. During a 6-week growth trial, juvenile cobia (5.6 ± 0.5 g fish,1 initial weight) were fed five isonitrogenous and isolipidic diets containing various protein to energy ratios using starch as the energy source. At the end of the trial, some fish were analysed for body composition characteristics while the rest were used to examine the excretion of dietary starch in the feces. Survival and growth were not significantly affected, but feed efficiency (ranging from 0.64 to 0.94) and daily consumption (ranging from 45.3 to 64.1 g kg,1 of body weight d,1) were affected. No reduction in consumption due to excess energy was noted. Analysis of the fecal carbohydrate data showed a linear relationship between dietary inclusion and excretion of carbohydrates with no sign of reaching saturation. Results of this study suggest that cobia can utilize dietary carbohydrates up to at least 340 g kg,1 of dry diet with an optimal protein to energy ratio of approximately 34 mg protein kJ,1metabolizable energy. [source]


    Influence of dietary lipid/protein ratio on survival, growth, body indices and digestive lipase activity in Snakehead (Channa striatus, Bloch 1793) fry reared in re-circulating water system

    AQUACULTURE NUTRITION, Issue 5 2010
    M. ALIYU-PAIKO
    Abstract Nine isoenergetic (18.5 kJ g,1) diets were formulated in a 3 × 3 factorial design to contain three protein levels (350, 400 and 450 g kg,1) for each of three lipid levels (65, 90 and 115 g kg,1), respectively, and fed twice daily for 8 weeks to fish of mean initial weight 3.34 ± 0.02 g reared in a re-circulatory water system. Temperature, pH and dissolved oxygen (DO) were maintained within the range 28,30 °C, 5.6,6.8 and 4.82,6.65 mg L,1 respectively throughout. Results show that fish survival was better in the groups fed 65 g kg,1 lipid while growth performance (% weight gain, WG; specific growth rate, SGR) and nutrient utilization (feed conversion ratio, FCR; protein efficiency ratio, PER; protein intake, PI) in the 65/450 and 90/450 g kg,1 treatments were similar and significantly (P < 0.05) higher than in fish fed the other lipid/protein ratio combinations. The body indices monitored (Hepatosomatic index, HSI and viscerosomatic index, VSI) were similar among the treatments whereas intestinal lipase activity was not significantly (P < 0.05) affected by increase in dietary lipid and protein levels. Carcass composition showed that dietary protein level affected body protein content positively in the 65 and 90 g kg,1 lipid treatments, but dietary lipid level did not affect body lipid content. A lipid/protein ratio of 65/450 g kg,1 is considered adequate for good growth performance and survival of Channa striatus fry. [source]


    Response of rainbow trout (Oncorhynchus mykiss) to varying dietary astaxanthin/canthaxanthin ratio: colour and carotenoid retention of the muscle

    AQUACULTURE NUTRITION, Issue 5 2010
    G. CHOUBERT
    Abstract Rainbow trout with an average initial weight of 160 g were fed during 42 days diets containing varied keto-carotenoids astaxanthin (Ax)/canthaxanthin (Cx) ratio, as follows: Ax 100% : Cx 0%; Ax 75% : Cx 25%; Ax 50% : Cx 50%; Ax 25% : Cx 75% and Ax 0% : Cx 100%. Muscle colour and carotenoid muscle retention were studied. Colour parameter values for mixed astaxanthin,canthaxanthin-fed fish were intermediate between those obtained for Ax 0% : Cx 100% fed fish group and for Ax 100% : Cx 0% fed fish group. Concerning muscle carotenoid retention, it has been observed that as the level of canthaxanthin in diet increased, the muscle total carotenoid retention decreased. In the mean time, as the level of canthaxanthin in diet increased, the muscle astaxanthin retention decreased while that of canthaxanthin increased. The results reported here provide further evidence of non-beneficial effects in terms of muscle colour and muscle carotenoid retention of the use of varying dietary astaxanthin/canthaxanthin ratio for feeding rainbow trout compared to values obtained for astaxanthin-only feed. [source]


    Effects of the commercial probiotic Lactobacillus casei on the growth, protein content of skin mucus and stress resistance of juveniles of the Porthole livebearer Poecilopsis gracilis (Poecilidae)

    AQUACULTURE NUTRITION, Issue 4 2010
    L.H.H. HERNANDEZ
    Abstract A 11-week feeding trial was carried out to determine the effects of the probiotic bacteria Lactobacillus casei from the commercial product Yakult® on the growth performance, proximal composition, protein content of skin mucus and stress resistance of juvenile Porthole livebearer Poeciliopsis gracilis. Triplicate groups of 15 juveniles per tank with an initial weight of 47 ± 9 mg (mean ± standard deviation) were fed with Artemia nauplii enriched with the probiotic, by using the bacteria cells plus the fermented milk (group ProN) and the other (group ProC) by using only the bacterial cells, eliminating the fermented milk by centrifugation. A control of fish was set up, by feeding non-enriched Artemia nauplii. Growth performance and survival rates did not show significantly differences among the treatments and control group, but a slightly tendency of higher values for body weight, weight gain and specific growth rate was observed in the juveniles of ProC treatment. Whole body proximate composition did not show significant differences among the groups, but higher values of protein and lipid contents were observed in the groups fed with the probiotic. Content of protein in the skin mucus were significantly higher in the ProC treatment than control group. Recovery rates after an air-dive test were significantly higher on the fish fed with the probiotic cells than the control group. These results show that L. casei might be used as a probiotic for fish and would help during the culture of juvenile of the Porthole livebearer P. gracilis. [source]


    Effect of dietary protein levels on growth performance and whole body composition of summerling and winterling spotted barbel (Hemibarbus maculates Bleeker)

    AQUACULTURE NUTRITION, Issue 4 2010
    J.-M. CHEN
    Abstract Six test diets with protein levels varying from 250 to 500 g kg,1 were fed to six triplicate groups of summerling (initial weight: 1.56 g) and seven test diets with protein levels varying from 200 to 500 g kg,1 were fed to seven triplicate groups of winterling (initial weight: 9.49 g) for 8 weeks. Weight gain (WG) and feed efficiency (FE) of summerling significantly increased with increasing dietary protein levels from 250 to 350 g kg,1 and slightly declined, but without statistical significance at a dietary protein level of 400 g kg,1, then further significantly decreased with increasing protein levels to 450 and 500 g kg,1; WG of winterling increased significantly with increasing dietary protein levels from 200 to 300 g kg,1 (P < 0.05), and above this level, WG had a tendency to decrease with increasing dietary protein levels. Winterling fed diets with 300 and 400 g kg,1 of dietary protein had significantly higher FE than those fed other diets. WG data analysis by quadratic regressions showed that the optimum dietary protein levels required for the maximum growth of summerling and winterling were 374 and 355 g kg,1 of dry diet respectively. Protein efficiency ratio of both summerling and winterling negatively correlated with levels of dietary protein. The whole body moisture, protein, lipid and ash of summerling after being fed various test diets for 8 weeks were significantly different among treatments (P < 0.05). The whole body moisture and fat of winterling were also significantly affected by dietary protein levels (P < 0.05), while the whole body protein and ash of winterling were not (P > 0.05). [source]


    Effects of various corn distillers by-products on growth, feed efficiency, and body composition of channel catfish, Ictalurus punctatus

    AQUACULTURE NUTRITION, Issue 2 2010
    M.H. LI
    Abstract A study was conducted to examine the use of corn distillers' by-products in diets and the effects of additional dietary fat on channel catfish, Ictalurus punctatus, performance. Juvenile channel catfish (initial weight: 12.6 g per fish) were stocked in flow-through aquaria and fed one of six practical diets for 9 weeks. Fish fed the control + fat diet consumed more diet and had higher feed efficiency ratio (FER) than fish fed the control diet, but weight gain was not significantly different between fish fed these two diets. Fish fed the diet containing 300 g kg,1 distillers dried grains with solubles (DDGS) consumed more diet and gained more weight, but had similar FER compared with fish fed the control + fat diet. The diet containing 200 g kg,1 high-protein distillers grains (HPDDG) resulted in similar diet consumption, weight gain and FER as the control + fat diet. Fish fed the diet containing 100 g kg,1 distillers solubles (DS) consumed more diet, but had similar weight gain and FER compared with fish fed the 300 g kg,1 DDGS diet. The presence of distillers solubles in the diet (300 g kg,1 DDGS, 100 g kg,1 DS, 100 g kg,1 EDS diets) appears to increase diet consumption, weight gain, and FER over the control diets with or without additional fat. [source]


    The potential of land animal protein ingredients to replace fish meal in diets for cuneate drum, Nibea miichthioides, is affected by dietary protein level

    AQUACULTURE NUTRITION, Issue 1 2010
    Y. WANG
    Abstract A net pen experiment was carried out to examine the effect of dietary protein level on the potential of land animal protein ingredients as fish meal substitutes in practical diets for cuneate drum Nibea miichthioides. Two isocaloric basal (control) diets were formulated to contain 400 g kg,1 herring meal but two different digestible protein (DP) levels (400 versus 350 g kg,1). At each DP level, dietary fish meal level was reduced from 400 to 280, 200, 80 and 0 g kg,1 by incorporating a blend that comprised of 600 g kg,1 poultry by-products meal (PBM), 200 g kg,1 meat and bone meal (MBM), 100 g kg,1 feather meal (FEM) and 100 g kg,1 blood meal (BLM). Cuneate drum fingerling (initial weight 42 g fish,1) were fed the test diets for 8 weeks. Fish fed the test diets exhibited similar feed intake. Final body weight, feed conversion ratio and nitrogen retention efficiency was not significantly different between fish fed the basal diets containing 350 and 400 g kg,1 DP. Weight gain decreased linearly with the reduction of dietary fish meal level at the 350 g kg,1 DP level, but did not decrease with the reduction of dietary fish meal level at the 400 g kg,1 DP level. Results of the present study suggest that fish meal in cuneate drum diets can be completely replaced with the blend of PBM, MBM, FEM and BLM at the 400 g kg,1 DP level, based on a mechanism that excessive dietary protein compensate lower contents of bio-available essential amino acid in the land animal protein ingredients relative to fish meal. [source]


    Complete replacement of fish meal by porcine and poultry by-product meals in practical diets for fingerling Nile tilapia Oreochromis niloticus: digestibility and growth performance

    AQUACULTURE NUTRITION, Issue 1 2010
    C. HERNÁNDEZ
    Abstract The apparent digestibility coefficients (ADC) of poultry by-product meal-pet food grade (PBM) and porcine meal (PM) were determined for fingerling male Nile tilapia. ADC for protein were 98.1% and 92.3% in PBM and PM, and 87.1% and 79.4% for energy. PBM and PM were then used as complete replacements for fish meal (FM) in practical diets for Nile tilapia formulated to contain equal digestible protein (300 g kg,1) and energy (16.74 MJ per 100 g) on an as-fed basis. Fingerlings (mean initial weight ±SD, 9.5 ± 0.015 g) were fed for 8 weeks on one of the four diets: FM-, PBM- or PM-based and a commercial feed. The ADC for protein in control and PBM diets (89.7% and 87.9%) were significantly higher than those for the control diet (81.96%). Growth performance and feed utilization were statistically similar between fish fed control and PBM diets, whereas the PM diet exhibited significantly lower performance compared with the control. However, the PM diet showed similar results to the commercial reference diet. Survival and feed conversion ratio were not significantly influenced by replacement of FM with either PBM or PM. The results indicated that PBM and PM can effectively replace FM in practical diets for fingerling Nile tilapia. [source]


    Growth performance and tissue mineral content of juvenile grouper (Epinephelus coioides) fed diets supplemented with various levels of manganese

    AQUACULTURE NUTRITION, Issue 6 2009
    C.-X. YE
    Abstract This study was conducted to investigate the effect of dietary manganese (Mn) on growth, vertebrae and whole-body Mn content of juvenile grouper, and to examine the effect of dietary Mn on copper (Cu), iron (Fe), zinc (Zn), calcium (Ca), phosphorus (P) and magnesium (Mg) content of vertebrae and whole body. Seven casein-gelatin-based diets were supplemented with 0, 5, 10, 15, 20, 50 and 1000 mg kg,1 of Mn from MnSO4·H2O. Grouper with an initial weight of 12.9 ± 0.4 g were fed to satiation with one of the seven diets for 8 weeks. Growth was not significantly affected by dietary Mn supplements. Vertebrae Mn increased from 31.7 to 118.1 mg kg,1 dry weight with dietary Mn supplement increasing from 0 to 50 mg kg,1 (y = ,0.0002x3 + 0.0162x2 + 1.3903x + 26.27, R2 = 0.9561, where y is the vertebrae Mn content and x is the dietary Mn content). Whole-body Mn increased from 2.5 to 7.8 mg kg,1 wet weight with dietary Mn supplement increasing from 0 to 50 mg kg,1 (y = 0.00001x3 , 0.00107x2 + 0.11054x + 2.24615, R2 = 0.9080, where y is the whole-body Mn content and x is the dietary Mn content). Dietary Mn had no significant effect on vertebrae Fe, Ca, P and Mg content, and whole-body Cu, Zn and Mg content. However, vertebrae Zn and whole body Ca, P were highest in fish fed diet supplemented with 15 mg kg,1 of Mn. Based on this, Mn supplement of 15 mg kg,1 might be the optimum when the basal diet contained 4 mg kg,1 of Mn. Fish fed diet supplemented with 1000 mg kg,1 of Mn did not show any gross abnormality or change in feeding behaviour, but Mn contents of vertebrae and whole body were as high as 695.1 mg kg,1 dry weight and 42.5 mg kg,1 wet weight, respectively. Also, whole body Fe decreased significantly when Mn supplement was up to 1000 mg kg,1. [source]


    Effect of methionine on intestinal enzymes activities, microflora and humoral immune of juvenile Jian carp (cyprinus carpio var. Jian)

    AQUACULTURE NUTRITION, Issue 5 2009
    L. TANG
    Abstract An 8-week feeding experiment was conducted to determine the effect of dietary methionine supplementation on intestinal microflora and humoral immune of juvenile Jian carp (initial weight of 9.9 ± 0.0 g) reared in indoor flow-through and aerated aquaria. Eight amino acid test diets (350 g kg,1 crude protein, CP), using fish meal, soybean-condensed protein and gelatin as intact protein sources supplemented with crystalline amino acids, were formulated to contain graded levels of methionine (0.6,22.0%) at a constant dietary cystine level of 3 g kg,1. Each diet was randomly assigned to three aquaria. Growth performance and feed utilization were significantly influenced by the dietary methionine levels (P < 0.05). Maximum weight gain, feed intake occurred at 12 g kg,1 dietary methionine (P < 0.05). Methionine supplementation improved hepatopancreas and intestine weight, hepatosomatic and intestine index, intestinal ,-glutamyltransferase and creatine kinase activity, Lactobacillus count, Bacillus count, lysozyme activities, lectin potency, sim-immunoglobulin M content, addiment C3,C4 contents and serum total iron-binding capacity and declined Escherichia coli and Aeromonas counts. Quadratic regression analysis of weight gain against dietary methionine levels indicated that the optimal dietary methionine requirement for maximum growth of juvenile Jian carp is 12 g kg,1 of the dry diet in the presence of 3 g kg,1 cystine. [source]


    Dietary pyridoxine requirement of juvenile Jian carp (Cyprinus carpio var. Jian)

    AQUACULTURE NUTRITION, Issue 4 2009
    W. HE
    Abstract In a 80-day feeding trial, a total of 1050 juvenile Jian carp (Cyprinus carpio var. Jian) with an average initial weight of 10.71 ± 0.05 g were fed semi-purified diets containing seven graded levels of pyridoxine (0.20, 1.71, 3.23, 4.96, 6.32, 8.58 and 12.39 mg pyridoxine kg,1 diet). Results indicated that with increasing dietary pyridoxine levels up to 4.96 mg kg,1 diet, percent weight gain (PWG) and specific growth rate (SGR) were improved, and no differences were found with further increase of pyridoxine levels. Feed intake also followed the similar pattern to that observed with PWG and SGR when dietary pyridoxine levels were ,6.32 mg kg,1 diet. But feed efficiency and protein efficiency ratio were not affected by pyridoxine levels. Crude protein of carcass, productive protein value and plasma ammonia concentration were improved with increasing dietary pyridoxine levels up to 4.96 mg kg,1 diet. Amylase activities in the intestine were improved with increasing dietary pyridoxine levels up to 4.96 mg kg,1 diet, but protease and lipase activities in the intestine were not affected by pyridoxine levels. Na+, K+ -ATPase and Gamma-glutamyl transpeptidase activities in proximal intestine, mid intestine (MI) and distal intestine (DI) were lowest when fed the diet containing 1.71 mg pyridoxine kg,1 diet. The alkaline phosphatase activities in MI and DI followed the same pattern. The dietary pyridoxine requirement of juvenile Jian carp based on PWG estimated by broken line model was 6.07 mg pyridoxine kg,1 diet. [source]