Showing 338 results for Growth
Volume 0, Issue 0 (3-2023)
Abstract
Urban growth boundaries are considered one of the key tools for controlling and managing the physical development of metropolitan areas. Uncontrolled and unplanned expansion in these regions has become a major challenge for urban and regional planners and managers, as this process leads to the destruction of agricultural lands and natural resources. The aim of this research is to simulate and assess future changes in growth boundaries in the Isfahan metropolitan area with the goal of preserving environmental resources and controlling physical expansion. In this regard, by adopting a positivist approach that follows an analytical and measurement-driven process, satellite imagery was utilized to assess changes in the physical expansion of the Isfahan metropolitan area. Artificial neural networks and machine learning algorithms were employed to predict the extent of future physical growth, and the projected growth boundaries were delineated. The research findings indicate that the Isfahan metropolitan area has experienced significant uncontrolled expansion, particularly in terms of physical development, over recent decades, and the reduction of agricultural and natural lands has become one of its major challenges. Based on the conducted simulations, the proposed growth boundaries can serve as an effective tool for managing and planning urban-regional development and preventing further degradation of natural resources and lands.
Volume 0, Issue 0 (1-2024)
Abstract
Increasing need for drought adaptation measures to conserve water and sustain crop yield in water-scarce regions, driven by severe and recurrent droughts. Achieving sustainable production entails studying deficit irrigation as a means to enhance water productivity and selecting genotypes resilient to soil water deficits. In the present study, 17 different melon (Cucumis melo L.) genotypes collected from the Van Lake Basin and 3 hybrids and 1 standard melon cultivar for control purposes were used. The study was carried out under climate room conditions. Two different irrigation levels (I100: 100% full irrigation, I50: 50% deficit irrigation-DI) were applied in the study for deficit irrigation. The applications started with the emergence of the second true leaves of the plants and after one-month, different growth, nutrient, and enzyme contents of the seedlings were determined. In general, it was determined that deficit water application negatively affects seedling growth, and and root dry matter, stomatal width and density, potassium, APX and SOD enzymes, and MDA content increased, while the other examined parameters decreased. The genotypes of the Van Lake Basin melon were found to vary as a result of the findings.
Mr Hossein Aghilifar, Dr Khosrow Piraei, Dr Hashem Zare, Dr Mehrzad Ebrahimi,
Volume 0, Issue 0 (12-2024)
Abstract
Aim and Introduction
After the global economic recession in 2008-2009, the discussion about countercyclical and procyclical fiscal policies and their effects on the economy began. Countercyclical fiscal policy is applied to reduce economic fluctuations by adjusting government spending and taxes against the business cycle. The aim of this policy is to stabilize the economy and flatten its fluctuations. On the contrary, procyclical fiscal policy strengthens economic fluctuations in the direction of business cycles. On the other hand, fiscal sustainability refers to the government's ability to maintain expenditures, income and public debt at a certain level in the long term without jeopardizing economic stability or facing a fiscal crisis. A sustainable fiscal policy ensures that the government's debt in the long run is at a level proportional to the size of the economy. The main questions of this research are as follows:
- Is Iran's fiscal policy countercyclical or procyclical?
- Is Iran's fiscal policy sustainable?
- What is the effect of cyclical fiscal policy and fiscal sustainability on the Iranian economic growth?
- How is the mutual relationship between fiscal sustainability and cyclical fiscal policy in Iran?
Methodology
The evaluation of fiscal policy cyclicality and fiscal sustainability and their determinants have been previously researched. However, the effect of cyclical fiscal policy and fiscal sustainability on economic growth and their mutual relationship has not been covered. This research, has utilized Iran's 1970-2021 annual data and a state-space model with time-varying parameters and an autoregressive distributed lags model as well as Kalman filter method. Moreover, to evaluate Iran's cyclical fiscal policy and fiscal sustainability, the effect of cyclical fiscal policy and fiscal sustainability on economic growth have been investigated. The research also deals with the mutual effect between cyclical fiscal policy and fiscal sustainability in Iran.
Findings
In this research, in order to evaluate the cyclical behavior of Iran's fiscal policy and obtaining the index, a state-space model with time-varying parameters, is estimated in which the real GDP logarithm coefficient varies over time. Then, in order to assess Iran's fiscal sustainability and obtaining the index, a state-space model with time-varying parameters is estimated. Finally, an autoregressive distributed lags model is utilized to estimate the effect of cyclical fiscal policy index and fiscal sustainability index on economic growth, as well as estimating the mutual effect between cyclical fiscal policy index and fiscal sustainability index.
Discussion and Conclusion
The findings of this research show: First, Iran's cyclical fiscal policy index estimated in all years is positive and has not recorded a negative number in any year, which means that the fiscal policy implemented in Iran during the period 1970-2021, was procyclical. In other words, the fiscal policy implemented in Iran has increased the range of fluctuations of cycles and for this reason, it has made the Iranian economy vulnerable to the economic shocks. Second, the estimated Iran's fiscal sustainability index is negative in most years so that the average fiscal sustainability index in the entire period is -0.068. This indicates the unsustainability of Iran's fiscal policy in the period 1970-2021. The trend of the smoothed changes of the time-varying parameter related to the fiscal sustainability index is also downward, which means that Iran's fiscal sustainability has been weakening over time and has moved in the direction of unsustainability. Third, Iran's cyclical fiscal policy index has had a negative effect on economic growth. In other words, procyclical behavior of Iran's fiscal policy has slowed down the economic growth rate. Fourth, Iran's fiscal sustainability index has a negative and significant effect on economic growth. Based on the estimated fiscal sustainability index, unsustainability is evident within Iran's fiscal policy. Therefore, unsustainability of Iran's fiscal policy has weakened economic growth. Fifth, Iran's fiscal unsustainability has increased the procyclical behavior of fiscal policy and as a result, exacerbated the fluctuations of economic cycles. Sixth, the increasing Iran's cyclical fiscal policy index reduces the reaction of the primary balance to the government debt. In other words, the increase in the procyclical behavior of the fiscal policy weakens Iran's fiscal sustainability
Volume 1, Issue 1 (3-2013)
Abstract
In order to determine effects of chicken and cattle manures in culture of Chlorococcum, an experiment was designed in six treatments including; 0.1, 0.4, 0.8 g/l of chicken manure and 0.1, 0.4, 0.8 g/l of cattle manure as completely randomize design with three replicates for 28 days. Results showed that the mean maximum density (87.1 × 105 cell/ml), specific growth rate (0.054 day-1), algal dry biomass (0.644 g/l), and chlorophyll a (9.42 mg/l) were obtained with 0.8 mg/l chicken manure. In order to compare performance of these manures with other culture media, second experiment with five treatments including; BBM (control) (Bold’s Basal Medium), BBM + soil extract, 0.8 g/l chicken manure, 0.8 g/l cattle manure and mixture of all treatment (BBM, BBM + soil extract, chicken manure and cattle manure) was designed as completely randomize design with three replicates for 15 days. Comparative results showed that BBM + soil extract had highest algal density (11.6 x 106 cells/ml), highest algal dry biomass (0.81 mg/ml), maximum SGR (0.13 /day), highest chlorophyll a (10.15 mg/l) and minimum doubling time (4.97 days). In conclusion, performance of BBM + soil extract was better in terms of biomass and growth parameters of Chlorococcum.
Volume 1, Issue 1 (3-2013)
Abstract
In this study, the effect of fructooligosaccharide as a prebiotic on the growth and density of lactobacillus in intestine of stellate (Acipenser stellatus) has been investigated. To do this, 90 individuals of stellate fingerlings (ten in each replications) were prepared with an average weight of 30.16 ± 0.14 gr from International Sturgeon Research Institute. This study was carried out in a completely randomized design with three replications in fiberglass tanks with 2000 liters volume. They were fed with feed containing 0, 1 and 2 percents of fructooligosaccharide (Raftilos P95, Sigma Company). Results indicated that feed with one percent fructooligosaccharide had a significant effect (P < 0.05) on weight gain, SGR, FCR, FE, PER and HI. The number of colonies regarding to lactobacillus showed a significant increase compared to the control (in one percent fructooligosaccharide). Results indicated that fructooligosaccharide as a prebiotic (in level of one percent in feed) caused good growth capabilities and feed efficiency through increasing the density of lactobacillus in intestine.
Volume 1, Issue 2 (6-2012)
Abstract
The life table parameters of Schizaphis graminum (Rondani) (Hemiptera: Aphididae) on four commercial cultivars of wheat (Kohdasht, Pastor, Tajan and Zagros) were determined in laboratory conditions. Fertility life table were constructed using age-specific survivorship (lx) and age-specific fecundity (mx) and subsequently analyzed using jackknife method and ANOVA. There were significant differences among pre-imaginal period and adult longevity of the aphid on the four wheat cultivars. The highest mortality occurred at first nymphal instar on all of wheat cultivars tested. The life expectancy (ex) of one-day-old adults was estimated to be 23.5, 24.6, 30.36 and 26.83 days on Kohdasht, Pastor, Tajan and Zagros, respectively. The gross reproductive rate was significantly higher on Tajan (102.39 ± 1.42 females/female/generation) compared with other three cultivars. The net reproductive rate (R0) significantly differed on different wheat cultivars examined. The R0-value was highest on Tajan (82.21 ± 1.21) and lowest on Zagros (38.23 ± 0.63 females/female/generation). The highest and lowest values of the intrinsic rate of increase (rm) were 0.276 ± 0.002 (on Pastor) and 0.222 ± 0.001 day-1 (on Zagros), respectively. The finite rate of increase (l) differed significantly among four wheat cultivars, ranging from 1.25 ± 0.00 (on Zagros) to 1.32 ± 0.00 days-1 (on Pastor). Doubling time ranged from 2.51 ± 0.02 (on Pastor) to 3.12 ± 0.02 days (on Zagros). The longest mean generation time (T) of the aphid was obtained on Tajan cultivar. The results showed that the Zagros cultivar had the highest antibiotic effect on population growth of S. graminum.
Volume 1, Issue 2 (6-2013)
Abstract
Logistic regression (LR) was used to model urban growth between the years 1987 and 2001 in Gorgan city, north east of Iran. Three groups of variables including economic-social, land use and biophysical variables were used in the modeling practice. Using covariance of the independent variables, distance to administrative and sporting centers plus distance to cities were removed. ROC (Relative Operating Characteristic) value for LR was 0.87 that confirmed success of the modeling method. Using maps of urban growth probability predicted by the LR model, urban distribution patterns for the years 2010, 2020, 2030, 2040 and 2050 were created. Land use maps for the years 2001-2050 were created using urban probability pattern maps and the base land use map of the year 1987. We used landscape metrics at class and landscape levels to compare the urban growth effects on other land use types present in the area. The comparison showed that urban development influences agriculture and pasture land use types more than other land uses. Also, we found that the landscape in the study area has undergone fragmentation and will become more fragmented and heterogeneous over time. Urban growth creates higher urban patchiness and increases the number of pasture and agricultural patches. The information thus obtained is helpful in more effective management of the area.
Volume 1, Issue 2 (7-2014)
Abstract
Background: Henoch-Schönlein purpura (HSP) is an lgA mediated small vessel systemic vasculitis disease in children. The etiology and pathogenesis of HSP disease remain unknown. However, environmental and genetic risk factors could play important roles in susceptibility to HSP disease. In this study we investigated the association of 5՛-untranslated region polymorphism (-634G/C) of VEGF gene with HSP among Iranian Azeri Turkish population. Methods: Thirty unrelated Iranian Azeri Turkish children with HSP and fifty healthy unrelated subjects without HSP and other inflammatory diseases were enrolled in this population. -634G/C polymorphism of VEGF gene was genotyped by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) technique. Results: The distribution of CC genotype in VEGF -634G/C polymorphism statistically showed a significant difference in HSP patients in compare to that of control group (P= 0.009). Conclusions: The CC genotype of VEGF -634G/C polymorphism could be associated with susceptibility to HSP disease in Iranian Azeri Turkish ethnic group.
Volume 1, Issue 3 (9-2013)
Abstract
Fish larvae have a high requirement of amino acid (AA) for energy production and growth. This study was aimed to increase knowledge of AA profile during feral carp larval ontogeny and estimate larval AA requirements. Larvae were collected randomly at 1, 3, 7, 11, 15, 19, 26 and 33 days post hatch for growth and AA analysis. The composition of total AA changed significantly during ontogeny. The essential AA profile of marine carp showed low correlation with rotifers (R2=0.22). High correlation was found between dry food and early larval ages (R2≥0.7) but was lower in late stage (R2≥0.37). At day 7, when larvae were fed on rotifers, methionine seemed to be the limiting AA and when larvae were fed dry food at day 11, 15, 19, 26 and 33, arginine seemed to be the limiting AA. Larval indispensible AA profile can be used as index of the IAA requirements of carp larvae. Supplementation of larval diet used with limiting AA is one way for compensating the deficient amino acid.
Volume 1, Issue 4 (12-2013)
Abstract
An 84-day feeding trial was carried out onfingerling (4.44 ± 0.06 g) rainbow trout (Oncorhynchusmykiss, Walbaum, 1792) to evaluate the effect of dietary supplementation with a commercial prebiotic GroBiotic®-A (G-A) on the growth, feed efficiency, haematology and immunlogical parameters. Ttreatments containing various inclusions of G-A (0 %, 0.5 %, 1.0 %, 1.5 %, 2.0 %, 2.5 %, and 3.0 %) were added to a commercial fish dietand were fed twice daily at 2-6 % of body weight. The highest weight gain (WG), specific growth rate (SGR) and average daily gain (ADG) were obtained in fish fed the diet containing 2.5 % G-A followed by 3.0 % inclusion (P<0.05). The highest feed efficiency (FE), protein efficiency ratio (PER) and net protein utilization (NPU) were also recorded in the 2.5 % G-A inclusion (P<0.05). Survival was significantly higher (P<0.05) in fish fed with 2 % and 2.5 % G-Asupplement (P<0.05). Although higher Hb, haematocrit, RBC, WBC, MCH, MCHC, MCV, lymphocytes, and neutrophils were observed at all G-A supplemented diets, the differences among themwerenot significant (P>0.05). On the other hand,significantly higher differencee (P<0.05) in lysozyme and immunoglobulin (IgM) concentrations wereobserved in 2.5% G-A inclusion. The results of this study indicated that 2.5 % G-A inclusionhad a better performance on growth and haematoimmunological parameters in rainbow trout fingerling.
Volume 2, Issue 1 (6-2013)
Abstract
Cell concentrations and growth rate of Dunaliella salina Teodoresco in light intensities e. g. 50 and 150 µmol. photons.m-2.s-1 and temperatures 25 ± 0.5 and 31 ± 0.5 oC (Mean ± SD) were studied. The algae was isolated from the Urumieh Lake and cultured in various treatments (n=12). Algae cells were counted regularly using Thoma counting chamber in 3 replicates on daily basis. The curve of changes in population was plotted. The specific growth rate (SGR; d-1) was calculated and compared within treatments by means of two ways ANOVA Analysis. The highest cell concentration (Mean ± SD) 4.8 ± 0.6 × 10 6 cell.ml-1 was observed in light intensity of 150 µmol. photons.m-2.s-1 and temperature 25 ± 0.5 oC. The minimum cell concentration (2.8 ± 0.3 × 10 6 cell.ml-1) was observed in light intensity of 50 µmol. photons.m-2.s-1 and temperature 31 ± 0.5 oC. Specific growth rate showed significant differences in various treatments (P
Volume 2, Issue 1 (6-2013)
Abstract
The effects of various levels of the commercial dietary supplement, Hoplite containing glucan, on growth performance, body composition and intestinal microbiota in white fish, Rutilus frisii kutum fry were investigated. 25 white fish fry (mean weight=1 ± 0.15 g) were stocked in each experimental tank (100 L). The fry were fed experimental diets supplemented with 0, 0.5, 1 and 2% Hoplite to apparent satiation, 3 times a day for 60 days. Biometry was performed every two weeks. Mean dissolved oxygen concentration, pH and water temperature recorded during the experiment were 5.0±0.1 mg/l, 7.8±0.2 and 24.4±0.11 ºC, respectively. At the end of the trial period, growth parameters, body composition and intestinal microbiota were studied. Results indicate that fry fed 0.5 and 1% glucan exhibited highest weight gain (WG), specific growth rate (SGR) and final body weight (FBW) which were significantly different (P
Volume 2, Issue 1 (6-2013)
Abstract
A 4 × 4 factorial design was conducted to quantify the optimumrncarbohydrate ⁄ lipid ratio to minimize the dietary protein level in growingrnbeluga, Huso huso (initial weight 891.9 ± 33.4 g, mean ± SD). Fish were fedrnwith sixteen experimental diets formulated to contain four protein levels (35,rn40, 45 and 50%) and four dietary carbohydrate ⁄ lipid ratios of 0.8, 1.1, 1.4,rnand 1.7 for 108 days. At the end of trial, there were no significant differencesrnin growth parameters among fish fed with 35, 40 and 45% protein levels. Nornsignificant difference in growth parameters and feed efficiency (FE) wasrnalso observed when dietary carbohydrate ⁄ lipid ratios decreased from 1.7 torn1.1 within the same energy level (P > 0.05). The highest carcass proteinrncontent was observed in fish fed 0.8 and 1.4 carbohydrate to lipid ratio (P
Volume 2, Issue 1 (4-2012)
Abstract
Nowadays the urban growth pattern of cities is growing dramatically; and current suburbs of cities will form the inseparable components of the main city in the near future. In all cities of world vertical and horizontal urban growth have been one of the most important factors noticed by urban managers and planners. Urban growth is a spatial - structural process that refers to the increased importance of towns and cities as a concentration of population within a particular economy and society. Increase in urban points as quantitative issue shows itself in the forms of increase in population of cities and development in built up area scale. The unorganized physical growth of cities is due to their physical discrete and separate development which is mostly in form of forming individual and separate parts. Hence, analysis of the current physical status, and prediction of the future development of cities due to its influence on the politics and management of city and human resources, is of great importance. Regarding the numerous factors affecting the inharmonic physical urban growth, the present article has investigated the rate of urban horizontal growth from two aspects of area and direction.The research method in this article is analytical- comparative and with respect to the evolution of the physical- spatial pattern of Tabriz metropolitan in the 1956-2006 period. Shannon’s Entropy model is utilized for evaluation of the rate of the urban horizontal growth diversity. In order to use this model first we draw the complete and detailed plan of Tabriz city in concentric buffers with width of one kilometer between years 1956-2006 using Auto Cad software and the physical gravity center of Tabriz city which is the same center of cultural- historical part has been considered as basis for buffering modulation, and Sectoral- Geographical model is used for specification of urban growth directions. . In the next phase center of city gravity has drawn in the form of circle with determined diameter and the center of this circle was considered as basis for modulation of geographical sectors and sectoral buffering in 12 geographic directions. The attained results of analyzing the research findings has shown that the sprawl growth and diversity of inharmonic development has occurred in Tabriz metropolitan. The maximum of this rate has happened on the year 1996 and directions of horizontal urban growth are completely coincided on the margins of main connection corridors of city.
Volume 2, Issue 1 (9-2011)
Abstract
Abstract:
In recent years, extension of Artemia applications in aquaculture and decreasing of natural resource, lead many of related studies to the distribution of Artemia population and new resource assessment studies. Urmia Lake as one the biggest habitat for Artemia because of ecological variations in the regions in which of its differentiations in cyst biometry and Artemia, moreover some genetic variations suggested to have some several Artemia populations in the Lake. In this project Artemia cyst samples were collected from 5 ecological stations of the Lake Urmia. The cyst hatching and the nauplii breeding up to adult Artemia stage were done according to optimum conditions in laboratory. Growth rate and survival of larva in days of 3, 5, 7, 11, 15, 20 of rearing period were measured in feeding with a complex of Dunaliella tertiolecta and Lanzy PZ for a period of 20 days in 75 and 150 ppt. Data and its statistical analysis revealed that according to previously records the growth rate of the Artemia was influenced by increasing the salinity from 75 to 150 ppt survival and growth rate of Artemia have been influenced by water salinity (P<0.05) but increasing the salinity only in two population of Bari and Eslami led decreasing of survival. The produced cysts in two salinity showed that Artemia population can produce the cysts with different diameter and there were not any statistic correlations between the salinity and populations. The Dandrogarm of population statistic analysis emphasized that according to growth rate and survival parameters and among populations under this test there were 4 different populations of Artemia urmiana in which had interesting differentiations in growth rate and survival.
Keywords: Artemia, Survival, Growth rate, Salinity, Urmia Lake.
Volume 2, Issue 2 (6-2013)
Abstract
The effect of various host plants including chickpea (varieties Arman, Hashem, Azad and Binivich), common bean (variety Khomein), white kidney bean (variety Dehghan), red kidney bean (variety Goli), cowpea (variety Mashhad), and tomato (variety Meshkin) on the reproductive performance and growth indices of the cotton bollworm, Helicoverpa armigera (Hübner) was determined under laboratory conditions (25 ± 1°C, 65 ± 5% RH and a 16:8 h light:dark photoperiod). The highest rate of gross fecundity, gross fertility, net fecundity, net fertility, mean daily eggs and mean daily fertile eggs were observed on chickpea Arman (2947.8 ± 7.8, 2933.0 ± 7.8, 2404.2 ± 7.1, 2392.2 ± 7.1, 170.9 ± 0.4, and 170.1 ± 0.4 eggs female-1, respectively), whereas the lowest values of these parameters were on tomato Meshkin (847.5 ± 9.2, 673.8 ± 7.3, 225.5 ± 2.6, 179.3 ± 2.1, 67.9 ± 0.7 and 54.3 ± 0.5 eggs female-1, respectively). The development index of overall immature stages varied from 1.10 to 1.57, with the minimum on tomato Meshkin and the maximum on chickpea Arman. Also, the fitness and standardized insect-growth indices were highest (0.349 ± 0.009 and 0.058 ± 0.001 gr day-1) and lowest (0.052 ± 0.001 and 0.013 ± 0.000 gr day-1) on chickpea Arman and tomato Meshkin, respectively. The Weibull model sufficiently described the shape of the survivorship curve of adult H. armigera from life-table data. A significant fit was obtained with the Weibull model for H. armigera in all experimental host plants. The results of reproductive performance, growth indices and the cluster analysis showed that tomato Meshkin was partially resistant to H. armigera.
Volume 2, Issue 2 (9-2013)
Abstract
Aquaculture production is often accompanied by some stressors which undesirable effects on growth and physiological function. Music is one of the cases that could eliminate or reduce the effects of stressors. The purpose of this study was to determine the effect of Iranian traditional music on growth, reproduction and behaviour of zebra cichlid (Pseudotropheus zebra). Fish with an average weight 5.5 0.18 g were put under both music and silence treatment with the number of 2 fish/aquarium with 3 replicates for 4 weeks. Fish under music treatment were put twice a day and every 30 minutes under the Iranian traditional music. At the end of this period, suitable conditions for fish were created to spawning. The results showed no significant differences in growth parameters, but 50 percent of fish during the 2-week were spawned in music treatment. However, only 16.6 percent of fish under silent treatment were spawned. Of eggs and spawn time, significant differences were observed between two groups. When is music being played, the fish were found mainly along approach the speakers, while the distribution of fish treated silence was uniform. The results of present study showed that use of music can affect physiological function of fish, which have more tranquility and less stress on fish.
Volume 2, Issue 2 (4-2000)
Abstract
In a field experiment the effect of five planting densities (100, 175. 250, 325 and 400
plants in"2 ) with or without foliar application of chlormequat chloride (2-till o methyltrimethyl
uminonion chloride, CCC) on growth, development and grain yield of winter
barley (cv Valfajr) was studied. The results indicated that Increasing plant density
hastened the rate of apical development and stem elongation. This pattern continued
up to the beginning of rapid stem elongation phase (Zadoks growth stage 32).
However, during the rapid stem elongation and ear growth, the pattern was reversed
i.e. it had become slightly in favor of the lower densities. Increasing plant density up
to 25(1 plants in"2 increased the grain yield, however, from 250 to 400 plants m"2 there
was no significant change in grain yield. It appeared that the higher planting
densities, i.e. 250 to 400 plants m~- were in a range around the supposed "optimum"
density. Foliar application of CCC slowed down the rate of apical development and
stein elongation in all plant densities, hut without any significant effect on its spikelet
initiation rate. Such retardation of development in CCC-treatecl plants was initially
associated with lower dry weight accumulation. However, this trend was reversed
before anthesis, as the CCC- treated plants had accumulated more dry matter by anthesis,
and gave a higher grain yield. The interactive effect of CCC and plant density is
worthy of further exploration.
Volume 2, Issue 3 (12-2013)
Abstract
The effect of Artemia urmiana nauplii enriched with flaxseed oil on growth performance, survival and fatty acid composition of severum, Cichlasoma severum, larvae (0.3 mg initial weight) was investigated through a completely randomized block design with two treatments, viz., (1) larvae fed with plain nauplii, (2) larvae fed with nauplii enriched with flaxseed oil, in three replications. Results of the first biometry (day18th), showed a significantly higher survival rate in treatment 1 (81.87±0.29%) than treatment 2 (68.83±1.62%) (P<0.05), but there were no significant differences in the specific growth rates, the average weight and length gains between treatments (P>0.05). At the end of the second period of the experiment (day36th), significant differences in growth performance and survival rate was recorded between treatment 1 (97.82 ± 1.09%) and treatment 2 (91.16± 1.34%) (P>0.05). The larvae was also found to convert n-3fatty acids to EPA and DHA.
Volume 2, Issue 3 (12-2013)
Abstract
Separate or combined effects of inulin and mannan oligosaccharide supplements on the growth, survival, body composition and salinity resistance of kutum roach (Rutilus frisii kutum) fry (410 ± 19 mg) were investigated for 45 days in 40-liter tanks containing 30 individuals. Fish were fed 7 to 12% body weight with a commercial diet (35% protein and 12% lipid) supplemented with 0 (control), 5 g kg-1 inulin, 5 g kg-1 MOS and 2.5 g kg-1 inulin + 2.5 g kg-1 MOS in a totally randomized design trial in triplicate. A general enhanced growth performance and feed efficiency were observed in fish fed on diet containing 5 g kg-1 MOS (p<0.05). There were no significant differences in survival rate among treatments (p>0.05). NO significant difference was observed in body composition, but protein and lipid contents in the whole body increased in fish fed with 5 g kg-1 MOS and control group. In general, the fish fed 5 g kg-1 MOS had the highest survival index after 48 hours exposed to salinity stress (15 ppt). Results showed 5 g kg-1 MOS could improve growth performance, survival and salinity stress resistance of kutum fry.