133 research outputs found
Logarithmic entropy--corrected holographic dark energy with non--minimal kinetic coupling
In this paper, we have considered a cosmological model with the non--minimal
kinetic coupling terms and investigated its cosmological implications with
respect to the logarithmic entropy-- corrected holographic dark energy
(LECHDE). The correspondence between LECHDE in flat FRW cosmology and the
phantom dark energy model with the aim to interpret the current universe
acceleration is also examined.Comment: 11 pages, 2 figures; Can. J. Phys. Vol. 90, 201
Comparison of Beluga (Huso huso) growth rate in brackish and fresh-water
Utilization of infertile coastal lands in the north Iran and Caspian Sea brackish water for reproduction and rearing of Beluga was the main objective of this study. To do so, 600 Huso huso fingerlings with an average weight of 4829 grams were reared in fiberglass tanks (1.9*1.9*0.53m), amounting to 25 fish per square meter. We used a random statistical design in two trials under similar conditions (feeding rate, stocking density etc.) over a rearing period of 80 days. Brackish water was transferred from the Caspian Sea and used in four tanks (Group I) and freshwater from the Sefidrood River was used in the remaining two tanks. Four replicates were used for experimental tanks and two were used for control tanks. Water flow in both groups was maintained at 0.2 to 0.5 liters per second. Results were analyzed statistically using one-way ANOVA and Duncan test. Mean water temperatures for brackish and freshwater treatments were 22.4±3.7 and 23.1±3/9 degrees centigrade respectively. Results of ANOVA on biometrical measurements during 71 rearing days indicated a significant difference in food conversion ratio (FCR) for the two treatments at 95% confidence level. After 71 days of rearing, FCR in Group 1 was 1.190.44, more suitable as compared to that in Group 2 (1.39±0.043). Fishes in Group 1 reached an average weight of 196.88 and those in Group 2 reached an average weight of 193.1g, indicating no significant difference in the final body weight of fishes in the two groups. Our observation showed better results for culture of Beluga in brackish water as compared to freshwater
Effects of dietary lysine and methionine supplementation on growth, nutrient utilization and carcass compositions in beluga, Huso huso, fed soy protein-based diet
A feeding trial was conducted to examine the effects of dietary supplementation of lysine and methionine on growth, nutrient utilization and carcass compositions in beluga, Huso huso. Four experimental soy protein based diets D0 (without lysine or methionine supplementation), D1 (lysine supplementation alone), D2 (methionine supplementation alone) and D3 (both lysine and methionine supplementation) were fed to triplicate groups. 240 fish with an average weight of 144.6 ± 4.64 g were fed the experimental diets for 12wk. L-Lysine and DL-methionine were added to the diets containing 344 g kg-1 soybean meals at 22.02 and 12.94 g kg-1 of dry diet respectively. Significant higher weight gain, specific growth rate, protein efficiency ratio, condition factor, feed efficiency ratio, whole muscle protein and protein apparent digestibility were observed in fish fed soya protein-based diet supplemented with both lysine and methionine than that of fish of other dietary groups. There were no significant differences among fish fed diet supplemented with either methionine or lysine. Growth performances, feed utilization, carcass composition and apparent digestibility coefficients of protein, lipid and dry matter of fish fed control diet was significantly lower than those of fish fed diet supplemented both lysine and methionine and supplemented with either methionine or lysine. It can be concluded that beluga, fingerlings effectively utilize the supplemental amino acids (L-Lysine at 22.02 g kg-1 dry diet and DL-methionine at 12.94 g kg-1 dry diet) in the diets containing 344 g kg-1 soybean meals for better carcass proximate compositions, growth performance and feed efficiency and utilization
Effect of different dietary protein to energy ratios (P/E) on growth performance and body composition of farmed Persian sturgeon (Acipenser persicus)
To improve Persian sturgeon nutrition and determine its nutritional requirements, a growth trial was conducted to measure optimum dietary protein to energy ratio in Persian sturgeon sub-yearlings. Four diets: H (P/E=21.33mg/kJ), N (P/E=20.24mg/kJ), L (P/E=19.22 mg/kJ) and M (P/E=18.26mg/kJ) were used in the experiment. Triplicate groups of fish were kept in 500L fiberglass tanks under homogenous culture conditions (dissolved oxygen, light and water flow rate) and fed with the experimental diets. Fish were fed to satiation four times per day during 130 one fourth ¬ days of experiment when the average water temperature and dissolved oxygen were 12.82 plus or minus 1.48 degree C and 9.55 plus or minus 0.18 mg/l respectively. Fish in all treatments grew fast and efficiently utilized the diets. Growth rate, FE, GR, SGR and PER increased with decreasing dietary protein to energy ratios. A higher growth was observed in the fishes fed with lower P/E ratios. Food intake and fatness coefficient increased with increasing dietary energy and decreasing P/E ratios. There were no significant differences in feeding efficiency (FE) and protein efficiency ratio (PER) in fish fed with diet N (high carbohydrate and low lipid content) and diet L (low carbohydrate and high lipid content). We conclude that the Persian sturgeon is able to use lipids and carbohydrates as non-protein sources of energy. The results of the present study demonstrated that the protein content and P/E ratio for optimum growth and efficient protein utilization in Persian sturgeon is 40% and 18.3-19.2 mg protein/kJ energy, respectively
Determination of the best stocking density for rearing Huso huso
Effects of stocking density on growth, food conversion ratio, specific growth rate, percentage of body weight increase in Huso huso were studied in two phases. Juveniles below one year old with an average weight of 92.09±1.72 grams and stocking densities of 1.6, 2.8 and 4 kg/m^2 in 3 replicates for 100 days were reared as the phase one group. One year old Huso huso with an average weight of 918.13±21.87 grams and stocking densities of 1.5, 2.5, 3.5 and 4.5 kg/m^2 reared for 120 days in 2000 liter fiberglass tanks were the second phase. Results revealed negative impact of density on growth, percentage of body weight, and specific growth rate and food conversion ratio in both phases. In the first phase, lower stocking density (1.6 kg/m^2) showed significant increase in growth rate (P<0.05) as compared to 2.8 and 4 kg/m^2 stocking densities resulting in 42.3% and 61 % growth rate respectively. Fish kept at 4 kg/m2 density showed malformed caudal fins and injured body due to higher tensions and contacts. In the second phase, the growth rate of fish decreased with increase in stocking density where fish with lower density (1.5 kg/m^2) showed 7.2%, 15.6%, and 19.8% higher weight gain as compared to fish reared at 2.5, 3.5 and 4 kg/m^2 stocking density. Analyses showed that with increase in stocking density, feeding area per fish decreases and tension between fish increases that leads to lower feeding efficiency. Based on the results, the recommended optimum stocking density for Huso huso individuals up to 90 grams is 1.5-2 kg/m^2 and for fish individuals over 900 grams each the density should be kept at 2.5-3 kg/m^2
Determination of the best feeding ratio in Huso huso meat production cultured in fiber glass tanks
A two-phase random growth test was conducted to evaluate the effects of feeding rate on growth performance, food conversion ratio (FCR), specific growth rate (SGR), feeding efficiency and price index of reared Huso huso fingerlings in fiberglass tanks (2x2x0.53 cm). Rearing conditions such as diet, dissolved oxygen, light, water flow, fish density and feeding frequency were kept similar for the tanks. In the first phase, 180 fingerlings with a mean weight 867.86±17.42g were fed for 100 days in four treatments and three replications at feeding rates 1, 2, 3 and 4 percent of their biomass. In the second phase, also four treatments and three replications were applied to 84 Huso huso with a mean weight 2096.1±35.6g. In this phase, the fish were fed for 125 days with 0.75, I .5, 2.5 and 3 percent of their biomass. During rearing period, water temperature was 25.52±1.78 and 14.82±0.48 degrees centigrade and dissolved oxygen was 7.6±0.3 and 7.89±0.18 mg/lit, for the two phases respectively. The fishes were fed four times daily with a diet containing 40% protein, 13% fat and 9.9% ash. All treatments induced fast growth in the fish, but feeding ratios were different in their effects on the growth (P<0.05). Weight gain percentage, specific growth rate (SGR), food conversion ratio (FCR), feeding efficiency and price index indicated that lower feeding ratios were more effective in causing fish growth (P<0.05). So, increase in feeding ratio directly increased daily food consumption (D.F.C) and negatively affected the feeding efficiency, food conversion ratio, specific growth rate and price index (P<0.05). The results showed that in phase one, when the fish were given food as much as two percent of their body weight, one unit of meat was produced by consuming 1.92 units of food. In the second phase, feeding fish with 0.75 percent of their body weight resulted in producing one unit of fish meat per 1.82 units of food consumed. Also, in the two phases, application of higher than 50% feeding ratio increased costs while no significant trend in fish growth was detected. It can be concluded that regarding the water temperature, the optimal feeding rate for fishes weighing 850 to 1900 grams and those weighing 2050 to 3300 grams are 2 % and 1 % of body weight, respectively
Effects of supplemental dietary L-carnitine on growth and body composition of beluga (Huso huso) juveniles
The effect of feed supplemented with L-carnitine at four levels of 0, 300, 600 and 900mg kg-1 on growth performance and body composition of beluga, H. huso, juveniles were evaluated in two separate trials. In the first trial, 180 juveniles (525±9gw) were fed with the test diet for a period of 71 days, and the trial extended to another 126 days in the second phase by randomly selecting 120 juveniles (870.7±32g) and rearing them with similar diets. All trials, in triplicates, were conducted in circular fiberglass tanks (200cm diameter, 40cm height).The fish were fed 4 times daily to apparent satiation. In the first phase, L-carnitine did not significantly affect mean final weight, feed conversion ratio (FCR) or specific growth rate (SGR) of the fish, however, the fish receiving 900mg kg-1 L-carnation showed better growth increment, SGR and feed efficiency (FE) than those in control group (p³0.05); neither did it significantly affect protein, lipid, moisture or ash as well as leptosomatic index (HSI) (p³0.05). The protein efficiency ratio (PER) was significantly affected by L-carnitine supplemented diet, particularly at 900mg kg-1(p£0.05). In the second phase, fish fed L-carnitine-supplemented diets produced significantly higher W2, SGR and PER than the control group (p£0.05), but HSI decreased significantly (P£0.05). At the end of the trial, the whole body composition of fish did not differ significantly among experimental treatments, but slightly reduced lipid content was observed at 600 and 900mg kg-1 L-carnitine (p£0.05).The results of this study indicated that supplementation of diets with 300-600mg carnitine kg-1 improved growth rate, feed utilization and stimulated protein-sparing effect in this species
Studying the correlation between serum level of 25-hydroxyvitamin D and glucose metabolism during pregnancy
There are conflicting ideas concerning the correlation between serum levels of 25- hydroxivatmin D and side effects of pregnancy. The present research seeks to study the correlation between lack of this vitamin and glucose metabolism in pregnancy. In this Cross-sectional research, as many as 330 women aging 18 to 35 in the 24th to 28th week of their pregnancy and fully aware of the process entered this project after their consent was gained. They underwent public screening for diabetes through 50-gram oral glucose challenge test (GCT). The serum level of HbA1C and 25-hydroxyvitamin D and analysis of urine for glucose were measured at the same time when the level of blood sugar was assessed. As for those people whose blood sugar 1 hour after receiving 50 g oral glucose was equal to or more than 140 mg/dl, the two-hour OGTT diagnosis test was carried out with 75 grams of glucose. The average levels of Vitamin D and HbA1C were compared with one another among the participants. Variables such as mother's age, parity, family history of diabetes, and BMI of mother were recorded in the checklists. Data was analyzed by SPSS20 software using T-test, Correlation, and K2 statistical methods. The average age of the mothers participating in this research and their average level of parity were 26.78 ± 4.5 and 1.89 ± 0.92 respectively. There were 48 cases (14.5) with pregnancy diabetes, while 282 cases (85.5) had no sign of diabetes. The serum level of vitamin D was above 30 ng/dl in 9 subjects (2.7), while this level was below 20 ng/dl in 321 people (93.7). A reverse significant correlation was observed between the serum level of vitamin D and average levels of HbA1C (p=0.006 and r=0.15). a significant difference was observed in Glucosuria between the diabetic and non-diabetic people (p=0.001) but it had no significant correlation between the level of vitamin D. Prevalence of vitamin D deficiency in this research is really high. The routine assessment of this vitamin before pregnancy and the necessity of correcting its deficiency and prescription of Vitamin D supplements and its effect on OGTT results,needs more researches
Proximate composition and fatty acids profiles of Artemia cysts and nauplii from different geographical regions of Iran
Artemia has been widely used in aquaculture as a suitable live food. The presence of highly unsaturated fatty acids is a key factor that determines the nutritional value and marketing of Artemia for shrimp, marine larvae, sturgeon and ornamental fish industries. To determine the variation in nutritional content in cysts, decapsulated cysts and nauplii of Artemia from three different biotopes of Iran, were tested for their protein, lipid, energy, and fatty acid profiles, particularly essential fatty acids. The cysts collected from Urmia, Maharlou and Meighan lakes, were rinsed, processed, decapsulated, hatched and then analyzed for proximate and fatty acid composition using standard methods. Statistical comparisons of the results revealed significant differences not only in proximate composition but also in fatty acid contents (p<0.05). The highest mean (±SD) level of protein (60.5±3.3%), lipid (18.60±1.1%) and energy contents (5448.3±10.4 Kcal/kg) were observed in Instar I nauplii hatched from Urmia Lake cysts, Instar I nauplii hatched from Maharlou Lake cyst and Instar I nauplii hatched from Urmia Lake decapsulated cyst, respectively. The highest content of DHA (0.78 mg/g DW) was observed in nauplii of cysts from Urmia Lake whereas it was around zero in other samples. The highest level of EPA (24.24 mg/g DW) was measured in nauplii from Maharlou Lake decapsulated cysts and the lowest (0.24 mg/g DW) was observed in Urmia lake cysts. The results revealed that the nauplii from decapsulated cysts of Maharlou Lake Artemia contained significantly higher levels of EPA and n-3 HUFA compared to others. Therefore, it is recommended to use it in aquatic larviculture
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