Home About us Contact
|
Home About us Contact | ||
|
|
||
Energy Ratio (energy + ratio)
Selected AbstractsOptimum Dietary Protein Levels and Protein to Energy Ratios in Olive Flounder Paralichthys olivaceusJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2005Kang-Woong Kim The olive flounder Paralichthys olivaceus is one of the most commercially important fish species in Korea. In order to formulate better diets for cultured olive flounder we evaluated the optimum dietary protein requirements for larval, fry and juvenile olive flounder, and the optimum dietary protein to energy ratio for juvenile olive flounder. Results of four separate experiments suggested that the optimum dietary protein requirements were 60% in larvae (0.3 g), 46.4,51.2% in 4.1-g juvenile, and 40,44% in 13.3 g growing olive flounder. The optimum dietary protein to energy ratio based on weight gain, feed efficiency, specific growth rate, and protein retention efficiency was 27,28 mg protein/kJ 2 energy (35 and 45% CP for diets containing 12.5 and 16.7 kJ energylg diet, respectively). [source] Performance analysis of an industrial waste heat-based trigeneration systemINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 8 2009A. Khaliq Abstract The thermodynamic performance of an industrial waste heat recovery-based trigeneration system is studied through energy and exergy efficiency parameters. The effects of exhaust gas inlet temperature, process heat pressure, and ambient temperature on both energy and exergy efficiencies, and electrical to thermal energy ratio of the system are investigated. The energy efficiency increases while electrical to thermal energy ratio and exergy efficiency decrease with increasing exhaust gas inlet temperature. On the other hand, with the increase in process heat pressure, energy efficiency decreases but exergy efficiency and electrical to thermal energy ratio increase. The effect of ambient temperature is also observed due to the fact that with an increase in ambient temperature, energy and exergy efficiencies, and electrical to thermal energy ratio decrease slightly. These results clearly show that performance evaluation of trigeneration system based on energy analysis is not adequate and hence more meaningful evaluation must include exergy analysis. The present analysis contributes to further information on the role of exhaust gas inlet temperature, process heat pressure, ambient temperature influence on the performance of waste heat recovery-based trigeneration from a thermodynamic point of view. Copyright © 2009 John Wiley & Sons, Ltd. [source] Effect of protein : energy ratio in milk replacers on growth performance of goat kidsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 5-6 2002K-H. YEOM Two separate experiments were carried out to establish the effects of the protein : energy ratio in milk replacers on growth performance, plasma lipid concentrations and fatty acid composition in adipose tissue of male goat kids. In the first experiment there were 211 3-day- old goat kids and in the second experiment there were 121 kids aged 3,7 days. The animals were fed ad libitum for a period of 4 weeks on milk replacers containing either 11.5 or 9.5 g crude protein/MJ metabolizable energy. In essence, protein was exchanged with fat on a weight basis. Milk concentrations were increased from 160 to 190 g/l in experiment 1, from 150 to 180 g/l in experiment 2. There were significant increases in body weight and feed intake when the milk replacer with high protein : energy ratio was fed. Group mean average daily weight gain was 168 and 203 g for the groups with low and high dietary protein : energy ratio in experiment 1; for experiment 2 the values were 139 and 160 g. Average dry matter intake was 18 and 14% higher for the diet with high protein : energy ratio in experiments 1 and 2, respectively. There was no change in either feed conversion (feed : gain ratio) or energy conversion (weight gain : energy intake ratio). There were no consistent diet effects on plasma lipid concentrations. Dietary fatty acid composition was reflected by that of adipose tissue. The milk replacer with high protein : energy ratio produced a small increase in the contents of myristic and palmitic acid in adipose tissue. [source] Optimum Dietary Protein Levels and Protein to Energy Ratios in Olive Flounder Paralichthys olivaceusJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2005Kang-Woong Kim The olive flounder Paralichthys olivaceus is one of the most commercially important fish species in Korea. In order to formulate better diets for cultured olive flounder we evaluated the optimum dietary protein requirements for larval, fry and juvenile olive flounder, and the optimum dietary protein to energy ratio for juvenile olive flounder. Results of four separate experiments suggested that the optimum dietary protein requirements were 60% in larvae (0.3 g), 46.4,51.2% in 4.1-g juvenile, and 40,44% in 13.3 g growing olive flounder. The optimum dietary protein to energy ratio based on weight gain, feed efficiency, specific growth rate, and protein retention efficiency was 27,28 mg protein/kJ 2 energy (35 and 45% CP for diets containing 12.5 and 16.7 kJ energylg diet, respectively). [source] Temperature dependence effective activation energy in Tl2Ba2CaCu2O8 thin filmPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 6 2006S. L. Liu Abstract By considering the competition of thermal activation and effective pinning, a general description of temperature dependence resistivity under magnetic fields has been deduced on high temperature superconductors. The temperature dependence resistivity is a function of the energy ratio of thermal actviation and pinning. Based on vortex glass phase transition analysis, the temperature dependence activation energy can be obtained from the resistivity transition under magnetic fields. It is found that the activation energy can be scaled onto a single parabola. The experiments on Tl-2212 thin film and other superconductors support our model. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effects of dietary starches and the protein to energy ratio on growth and feed efficiency of juvenile cobia, Rachycentron canadumAQUACULTURE NUTRITION, Issue 5 2010K.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] Dietary strategies to improve the growth and feed utilization of barramundi, Lates calcarifer under high water temperature conditionsAQUACULTURE NUTRITION, Issue 4 2010B. GLENCROSS Abstract Several dietary strategies to ameliorate poorer growth observed to occur at temperatures above the upper thermal optima were examined with juvenile barramundi (Lates calcarifer). A reference (REF) and three experimental diets, one with an increased protein to energy ratio (PRO), another with an increased level of the amino acid histidine (HIS) and a third with supplementation of dietary nucleotides (NUC), were each fed to fish at either 30 °C or 37 °C for a 28-day period. Growth was affected by both temperature and diet. Fish fed the PRO diet at 30 °C grew fastest, but not faster than those fed the NUC diet at the same temperature. The addition of the amino acid histidine to the diet did not improve growth rates at either temperature. At water temperatures of 37 °C, only the fish fed the PRO diet had growth rates equivalent to those of fish at the 30 °C temperatures. Other key factors including feed intake, feed conversion rate, nutrient and energy retention and plasma enzymology were also all affected by temperature and diet. This study shows that the use of a diet with an increased protein to energy ratio provides significant benefits in terms of reducing the impact of growth retardation at higher temperatures. [source] Growth performance and body composition of pacu Piaractus mesopotamicus (Holmberg 1887) in response to dietary protein and energy levelsAQUACULTURE NUTRITION, Issue 2 2010A.J.A. BICUDO Abstract Improper dietary protein and energy levels and their ratio will lead to increased fish production cost. This work evaluated effects of dietary protein : energy ratio on growth and body composition of pacu, Piaractus mesopotamicus. Fingerling pacu (15.5 ± 0.4 g) were fed twice a day for 10 weeks until apparent satiation with diets containing 220, 260, 300, 340 or 380 g kg,1 crude protein (CP) and 10.9, 11.7, 12.6, 13.4 or 14.2 MJ kg,1 digestible energy (DE) in a totally randomized experimental design, 5 × 5 factorial scheme (n = 3). Weight gain, specific growth rate increased and feed conversion ratio (FCR) decreased significantly (P < 0.05) when CP increased from 220 to 271, 268 and 281 g kg,1 respectively. Pacu was able to adjust feed consumption in a wide range of dietary DE concentration. Fish fed 260 CP diets showed best (P < 0.05) protein efficiency ratio and FCR with 11.7,12.6 MJ kg,1; but for the 380 CP-diets group, significant differences were observed only at 14.2 MJ kg,1 dietary energy level, suggesting that pacu favours protein as energy source. DE was the chief influence on whole body chemical composition. Minimum dietary protein requirement of pacu is 270 g kg,1, with an optimum CP : DE of 22.2 g MJ,1. [source] Evaluation of practical diets containing different protein levels on gonad development of female redclaw crayfish Cherax quadricarinatusAQUACULTURE NUTRITION, Issue 4 2009H. RODRÍGUEZ-GONZÁLEZ Abstract The effect of five experimental diets with different crude protein content (220, 270, 330, 390 and 450 g kg,1) on gonad development of female Cherax quadricarinatus was tested under laboratory conditions. After 70 days, a significant linear relationship indicated that higher concentrations of protein and carbohydrates in the hepatopancreas were produced as the dietary crude protein increased (P < 0.05). There were significant responses of the gonadosomatic index, hepatosomatic index, biochemical composition of the gonad (protein, lipids, carbohydrates and energy) and frequency of secondary vitellogenic oocytes to dietary protein level, as indicated by significant fits of the quadratic equation to the observed experimental data. The optimal response of the criteria parameters corresponded to levels of crude protein in the range 284,355 g kg,1. Overall, 330 g kg,1 crude protein with a protein : energy ratio of 15.6 mg kJ,1 was considered the most adequate concentration of dietary protein for gonad development and biochemical composition in female redclaw crayfish. [source] Growth and haematology of pacu, Piaractus mesopotamicus, fed diets with varying protein to energy ratioAQUACULTURE RESEARCH, Issue 4 2009Álvaro José De Almeida Bicudo Abstract Haematopoiesis and blood cells' functions can be influenced by dietary concentration of nutrients. This paper studied the effects of dietary protein:energy ratio on the growth and haematology of pacu, Piaractus mesopotamicus. Fingerling pacu (15.5±0.4 g) were fed twice a day for 10 weeks until apparent saciety with diets containing 220, 260, 300, 340 or 380 g kg,1 crude protein (CP) and 10.88, 11.72, 12.55, 13.39, 14.22 MJ kg,1 digestible energy (DE) in a totally randomized experimental design, 5 × 5 factorial scheme (n=3). Weight gain and specific growth rate were affected (P<0.05) by protein level only. Protein efficiency ratio decreased (P<0.05) with increasing dietary protein at all levels of dietary energy. Daily feed intake decreased (P<0.05) with increasing dietary energy. Mean corpuscular haemoglobin concentration was affected (P<0.05) by DE and interaction between dietary CP and DE. Total plasma protein increased (P<0.05) with dietary protein and energy levels. Plasma glucose decreased (P<0.05) with increasing dietary protein. The CP requirement and optimum protein:energy ratio for weight gain of pacu fingerlings, determined using broken-line model, were 271 g kg,1 and 22.18 g CP MJ,1 DE respectively. All dietary CP and DE levels studied did not pose damages to fish health. [source] Estimating digestible protein requirements of silver perch, Bidyanus bidyanus MitchellAQUACULTURE RESEARCH, Issue 5 2001G L Allan Abstract In this study, we estimated requirements for digestible protein, using intact protein sources, at one digestible energy content. Using digestibility data for silver perch (Bidyanus bidyanus Mitchell) for a large number of ingredients, we formulated a ,summit' diet to contain between 1.4 and 1.8 times the ,expected requirements' for digestible essential amino acids (based on requirements for channel catfish, Ictalurus punctatus Rafinesque). A ,diluent' diet was formulated to contain 0.4,0.5 times the expected requirements of digestible essential amino acids. Both ,summit' and ,diluent' diets contained similar digestible energy (14.7 MJ digestible energy kg,1 for the summit and 13.4 MJ digestible energy kg,1 for the diluent). Six diets were prepared with the following amounts of summit,diluent diets: 100:0, 80:20, 60:40, 40:60, 20:80 and 0:100. A practical diet widely used by commercial farmers was also included as a control. Ten juvenile fish (2.1,2.6 g) were stocked into each experimental 70-L acrylic aquarium, and each dietary treatment was randomly assigned to five replicate aquaria. Fish were fed twice daily to apparent satiation for 54 days. Final individual fish weight ranged from 4,15.5 g. Results were analysed using intersecting linear regression analysis. The optimum digestible dietary protein for diets with 13.4,14.7 MJ digestible energy kg,1, after which protein deposition did not increase significantly, was 28%. Although this study did not determine requirements for individual amino acids, for diets with the digestible energy content used here, requirements for individual amino acids obviously did not exceed the content in the 28% protein diet. These contents are useful as an estimate of ,recommended levels' for silver perch diets with 13.4,14.7 MJ digestible energy kg,1. The proximate composition of fish was affected by diet. Whole body protein and moisture increased, whereas lipid content decreased with increasing dietary protein content (and increasing protein,energy ratio and decreasing lipid). Fish size was also affected by diet; however, the changes in whole carcass proximate composition also occurred for fish fed diets 60:40, 80:20 and the summit diet which were a similar final weight. [source] Turbulent stresses as a function of shear rate in a local disk modelASTRONOMISCHE NACHRICHTEN, Issue 1 2009A.J. Liljeström Abstract We present local numerical models of accretion disk turbulence driven by the magnetorotational instability with varying shear rate. The resulting turbulent stresses are compared with predictions of a closure model in which triple correlations are modelled in terms of quadratic correlations. This local model uses five nondimensional parameters to describe the properties of the flow. We attempt to determine these closure parameters for our simulations and find that the model does produce qualitatively correct behaviour. In addition, we present results concerning the shear rate dependency of the magnetic to kinetic energy ratio. We find both the turbulent stress ratio and the total stress to be strongly dependent on the shear rate (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effects of dietary starches and the protein to energy ratio on growth and feed efficiency of juvenile cobia, Rachycentron canadumAQUACULTURE NUTRITION, Issue 5 2010K.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] Effects of dietary protein to energy ratios on growth and body composition of juvenile Chinese sucker, Myxocyprinus asiaticusAQUACULTURE NUTRITION, Issue 2 2010Y.C. YUAN Abstract A growth experiment was conducted to investigate effect of dietary protein to energy ratios on growth and body composition of juvenile Myxocyprinus asiaticus (initial mean weight: 10.04 ± 0.53 g, mean ± SD). Nine practical diets were formulated to contain three protein levels (340, 390 and 440 g kg,1), each with three lipid levels (60, 100 and 140 g kg,1), in order to produce a range of P/E ratios (from 22.4 to 32.8 mg protein kJ,1). Each diet was randomly assigned to triplicate groups of 20 fish in 400-L indoors flow-through circular fibre glass tanks provided with sand-filtered aerated freshwater. The results showed that the growth was significantly affected by dietary P/E ratio (P < 0.05). Fish fed the diets with 440 g kg,1 protein (100 and 140 g kg,1 lipid, P/E ratio of 31.43 and 29.22 mg protein kJ,1) had the highest specific growth rates (SGR) (2.16 and 2.27% day,1, respectively). However, fish fed the diet with 390 g kg,1 protein and 140 g kg,1 lipid showed comparable growth (2.01% day,1), and had higher protein efficiency ratio (PER), protein productive value (PPV) and energy retention (ER) than other groups (P < 0.05). No significant differences in survival were found among dietary treatments. Carcass lipid content was positively correlated with dietary lipid level, but irrespective of protein level and inversely correlated with carcass moisture content. Carcass protein contents increased with increasing dietary lipid at each protein level. The white muscle and liver composition showed that lipid increased with increasing dietary lipid level (P < 0.05). Dietary protein concentrations had significant effect on condition factor (CF), hepatosomatic index (HSI) and viscerosomatic index (VSI) (P < 0.05). However, dietary lipid concentrations had no significant effect on CF, HSI (P > 0.05). Based on these observations, 440 g kg,1 protein with lipid from 100 to 140 g kg,1 (P/E ratio of 29.22 to 31.43 mg protein kJ,1) seemed to meet minimum requirement for optimal growth and feed utilization, and lipid could cause protein-sparing effect in diets for juvenile Chinese sucker. [source] Growth and body composition of juvenile white shrimp, Litopenaeus vannamei, fed different ratios of dietary protein to energyAQUACULTURE NUTRITION, Issue 6 2008Y. HU Abstract A 10-week feeding experiment was conducted to evaluate the effect of different protein to energy ratios on growth and body composition of juvenile Litopenaeus vannamei (initial average weight of 0.09 ± 0.002 g, mean ± SE). Twelve practical test diets were formulated to contain four protein levels (300, 340, 380 and 420 g kg,1) and three lipid levels (50, 75 and 100 g kg,1). Each diet was randomly fed to triplicate groups of 30 shrimps per tank (260 L). The water temperature was 28.5 ± 2 °C and the salinity was 28 ± 1 g L,1 during the experimental period. The results showed that the growth was significantly (P < 0.05) affected by dietary treatments. Shrimps fed the diets containing 300 g kg,1 protein showed the poorest growth. However, shrimp fed the 75 g kg,1 lipid diets had only slightly higher growth than that fed 50 g kg,1 lipid diets at the same dietary protein level, and even a little decline in growth with the further increase of dietary lipid to 100 g kg,1. Shrimp fed the diet with 420 g kg,1protein and 75 g kg,1 lipid had the highest specific growth rate. However, shrimp fed the diet with 340 g kg,1 protein and 75 g kg,1 lipid showed comparable growth, and had the highest protein efficiency ratio, energy retention and feed efficiency ratio among dietary treatments. Triglycerides and total cholesterol in the serum of shrimp increased with increasing dietary lipid level at the same dietary protein level. Body lipid and energy increased with increasing dietary lipid level irrespective of dietary protein. Results of the present study showed that the diet containing 340 g kg,1 protein and 75 g kg,1 lipid with digestible protein/digestible energy of 21.1 mg kJ,1 is optimum for L. vannamei, and the increase of dietary lipid level has not efficient protein-sparing effect. [source] Carbohydrate utilization by juvenile silver perch, Bidyanus bidyanus (Mitchell).AQUACULTURE RESEARCH, Issue 2 2003Abstract The ability of juvenile silver perch (Bidyanus bidyanus) to utilize dietary raw wheat meal, raw wheat starch, gelatinized wheat starch and dextrin as energy sources to spare protein for growth was quantified. Energy utilization and protein sparing were assessed by comparing the weight gain, energy retention efficiency, protein retention and body composition of silver perch that had been fed a series of diets in which the basal diet (low carbohydrate) was systematically replaced with graded levels of each carbohydrate ingredient or an inert diluent, diatomaceous earth. The protein content decreased as the carbohydrate content increased, giving four different protein to energy ratios for each of the four carbohydrate sources (except for the 60% inclusion level, at which only three carbohydrate sources were tested). Silver perch were efficient at utilizing carbohydrate for energy to spare protein. Silver perch fed diets containing up to 30% wheat meal, raw wheat starch, gelatinized wheat starch or dextrin exhibited similar growth, protein retention and energy retention efficiency to the fish fed the basal diet. Weight gain of silver perch fed diets containing wheat meal or carbohydrates at 45% inclusion content had significantly reduced weight gain when compared with fish fed the basal diet. However, protein retention and energy retention efficiency were similar or better. Whole-body protein levels of silver perch remained constant regardless of carbohydrate sources, and there was no evidence of increasing whole-body lipid concentrations for fish fed diets with up to 60% dietary carbohydrate. Silver perch were more efficient at utilizing processed starch (either gelatinized starch or dextrin) than wheat meal or raw wheat starch. [source] Effect of the protein/energy ratio on the growth of Mediterranean yellowtail (Seriola dumerili)AQUACULTURE RESEARCH, Issue 11 2008Ana Tomás Vidal Abstract Yellowtails weighing 490 g were fed five experimental diets with different protein/energy ratios, 24.6, 26.9, 28.9, 31.8 and 35.8 g MJ,1, for 152 days. The energy content was similar in all the diets and the protein and lipid levels were 40/26, 45/26, 50/18, 50/26 and 55/18 %CP/%CL respectively. The final weight and SGR were lower in fish fed diets with a lower PD/ED ratio (24.6 and 26.9 g MJ,1), and the mortality of fish fed diet 24.6 g MJ,1 was higher. In fact, only fish that consumed diet 35.8 g MJ,1 had a haematocrit and a normal erythrocyte number similar to that in healthy yellowtail. No differences appeared in feed intake and feed conversion ratio. Digestible energy ingestion was similar for all the diets and digestible protein intake was also low for 24.6 compared with 35.8 g MJ,1. The meat composition was similar for fish fed all the diets, but the profiles of muscle fatty acids indicated an increasing content of saturates and n-3 HUFA, while the levels of monounsaturates decreased, corresponding to an increase in the PD/ED relation. The economic conversion ratio and economic profit index were not different for fish fed the experimental diets. [source] | |||||||||||||