• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.3
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• pp.308-313
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• 2015

A $3{\times}3$ factorial study was conducted to investigate the effects of dietary protein and lipid levels on the growth, feed utilization and innate immunity of red seabream Pagrus major. Nine diets consisting of three protein levels (42%, 46% and 50% crude protein) and three lipid levels (10%, 14% and 18% crude lipid) were formulated. Triplicate groups of red seabream were fed the experimental diets to apparent satiation (5-6 times a day, from 08:00 to 18:00 h at 2-h intervals) for 10 weeks. At the end of the feeding trial, the weight gain and specific growth rate of fish fed P46L14 (46% protein and 14% lipid), P50L10 (50% protein and 10% lipid) and P50L14 (50% protein and 14% lipid) were significantly (P<0.05) higher than those of fish fed P42L18 (42% protein and 18% lipid). The feed conversion ratios (FCR) of the fish were affected by dietary lipid levels (P<0.039), but not dietary protein levels. The FCR tended to increase with increasing dietary lipid levels from 10% to 18% with the 46% and 50% protein levels. The weight gain, protein efficiency ratio, specific growth rate, feed intake and survival of fish were not affected by either dietary protein or lipid levels. Myeloperoxidase activity in the group fed P50L14 (50% protein and 14% lipid) was significantly higher than that in the group fed P42L10 (42% protein and 10% lipid) or P50L18 (50% protein and 18% lipid). However, the myeloperoxidase activity of fish was not affected by either dietary protein or lipid level. The fish fed P46L14 (46% protein and 14% lipid) and P46L18 (46% protein and 18% lipid) showed significantly higher superoxide dismutase activity than did the fish fed P46L10 (46% protein and 10% lipid), P50L10 (50% protein and 10% lipid) of P50L18 (50% protein and 18% lipid). In conclusion, the optimum protein and lipid levels for the growth and feed utilization of juvenile red seabream were 46% and 14%, respectively, and the optimum dietary protein to energy ratio was 27.4 g/MJ.

• Journal of Aquaculture
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• v.7 no.3
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• pp.165-175
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• 1994

Attempts were made to find out nitrogen and phosphorus loads to aquatic environment resulting from feeding Nile tilapia (Oreochromis niloticus). Two different size groups, small and large, were used. The average sizes of small and large tilapia were 65.2 g and 389.2 g respectively, and three kinds of commercial diets were used for each size. The 3 kinds of commercial diets for tilapia contained in average 33.8% crude protein ($5.4\%$ nitrogen) and $1.4\%$ total phosphorus. The load of nitrogen and phosphorus were measured by subtracting the amounts of nutrients retained in the body of fish from consumed nutrients. Sixty, five percentage of total feces was excreted within 24 hours after feeding at $23^{\circ}C$. Nitrogen content in the feces was higher in large fish than small ones. The apparent digestibility of dietary protein for small and large tilapia was $90.0\%$ and $89.7\%$, respectively. Availability of dietary phosphorus for small and large tilapia was $44.7\%\;and\;51.4\%$, respectively. The total load of nitrogen and phosphorus per 1 metric ton of tilapia production was 49.5kg and 6.3kg, respectively, for small ones with feed conversion ratio (FCR) of 1.4, and 61.3 kg and 13.4kg, respectively, for large ones with the FCR of 1.8. Nitorgen balance appeared that small and large tilapia excreted $7.1\%\;and\;9.9\%$ of consumed nitrogen through fecal-nitrogen and $55.5\%\;and\;62.3\%$ through urine and gills, retaining $37.4\%\;and\;27.8\%$ in the body, respectively. These results show that small fish pollute less than large fish, excreting less and retaining more nutrients in the body.

• Animal Bioscience
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• v.34 no.9
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• pp.1499-1513
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• 2021

Objective: The purpose of this meta-analysis was to evaluate the effect of dietary essential oils (EOs) on productive performance, nutrient digestibility, and serum metabolite profiles of broiler chickens and to compare their effectiveness as growth-promoting additives against antibiotics. Methods: Peer-reviewed articles were retrieved from Web of Science, Science Direct, PubMed, and Google scholar and selected based on pre-determined criteria. A total of 41 articles containing 55 experiments with 163 treatment units were eligible for analyses. Data were subjected to a meta-analysis based on mixed model methodology considering the doses of EOs as fixed effects and the different studies as random effects. Results: Results showed a linear increase (p<0.001) on body weight gain (BWG) where Antibiotics (FCR) and average daily feed intake decreased (p<0.001) linearly with an increasing dose of EOs. Positive effects were observed on the increased (p<0.01) digestibility of dry matter, crude protein, ether extract, and cecal Lactobacillus while Escherichia coli (E. coli) population in the cecum decreased (p<0.001) linearly. There was a quadratic effect on the weight of gizzard (p<0.01), spleen (p<0.05), bursa of fabricius (p<0.001), and liver (p<0.10) while carcass, abdominal fat, and pancreas increased (p<0.01) linearly. The dose of EOs linearly increased high density lipoprotein, glucose, protein, and globulin concentrations (p<0.01). In comparison to control and antibiotics, all type of EOs significantly reduced (p<0.001) FCR and tended to increase (p<0.1) BWG and final body weight. Cinnamaldehyde-compound was the only EOs type showing a tendency to increase (p<0.1) carcass weight, albumin, and protein of serum metabolites while this EOs together with EOs-Blend 1 decreased (p<0.01) E. coli population. Low density lipoprotein concentration decreased (p<0.05) with antibiotics and carvacrol-based compound when compared to the control group. Conclusion: This evidence confirms that EOs are suitable to be used as growth promoters and their economical benefit appears to be promising.

• Korean Journal of Poultry Science
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• v.45 no.4
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• pp.273-283
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• 2018

Two diet energy levels (high or low) and two bedding material (rice husk or saw dust) treatments were designed for either male or female slow-growing Korean meat-type chicken (Hanhyop 3) to make totally eight treatments for 11~75 d feeding trial. Body weight gain (BWG) were influenced by energy levels, sex of bird and bedding material type. There were interaction effect among those three factors. Feed intakes (FI) by male bird during each and overall periods were higher than those by female. Diet energy levels and bedding material affected the FI only during final 56~75 d period, of which FI of high energy diet was higher in male whereas that of low energy diet was higher in female. Although feed conversion ratio (FCR) was improved by high energy diet, the better FCR has dissipated during 41~75 d, when the most of overall BWG were achieved. Apparent total tract retention (ATTR) of nutrients were higher in male than those in female birds with exception on fat ATTR. Fat ATTR was improved when fed low energy diet regardless of the sex of birds. Both energy levels and sex of bird influenced the color of breast. Thiobarbituric acid reactive substances (TBARS) value of female thigh was higher than that of male. Levels of moisture and P in female thigh were lower although level of fat in female breast was higher than those in male, respectively. This study showed that diet energy levels for Hanhyop 3 chicken, especially during 41~75 d, should be differently formulated between male and female bird.

• Animal Bioscience
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• v.34 no.2
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• pp.295-305
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• 2021

Objective: The objectives of this study were to compare the effects of normal and low protein content (PC) of starter diet supplemented or not with blends of branched-chain amino acids (BCAAs) on growth performance of broilers under summer conditions and to investigate whether these effects altered some quality traits and the characteristics of gastrointestinal tract. Methods: A total of 768 mixed-sex broiler chicks (Ross 308, one-d-old) with an average initial body weight (BW) of 47.6±1.03 g were allocated into six treatments with four replications in 2×3 factorial arrangement. Factors were: PC, normal (N, 22% to d 15); and low (L, 20% to d 15); and added BCAA blends, L-leucine, L-isoleucine, and L-valine at zero (0L:0I:0V); 1.0, 0.25, and 0.25 (4L:1I:1V); or 1.0, 0.25, 0.75 (4L:1I:3V) g/kg of diet. Hence, six dietary treatments were named as N0L:0I:0V, N4L:1I:1V, N4L:1I:3V, L0L:0I:0V, L4L:1I:1V, and L4L:1I:3V. Average indoor temperature and humidity were 32.8℃±1.7℃ and 61.1%±4.12%, respectively. Results: BW, feed conversion ratio (FCR) and carcass weight were not affected by PC, BCCA and their interaction (p>0.05). The L diets decreased the water holding capacity of the breast (p = 0.002) and thigh (p = 0.050) meats and dressing percentage (p = 0.005) compared to the N diets. The 4L:1I:1V diet decreased breast yield compared to the 0L:0I:0V diets (p = 0.041). The effect of PC on feed intake, mortality and gastrointestinal trait weight were depended on the L:I:V ratios under summer conditions due to interactions between factors (p<0.05). The FI and mortality of L4L:1I:1V broilers were lower than those of N4L:1I:1V birds (p<0.05). Conclusion: It was concluded that the blends of BCAAs used failed to improve performance and to promote breast yields, because diets with normal or with reduced protein supplemented or not with BCAAs up to d 15 produced a similar BW and FCR in broilers raised in hot-climate conditions.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.651-659
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• 2022

This study was conducted to investigate the effects of different water temperatures (8, 11, 14 and 17℃) on growth, survival and hematological parameters of juvenile chum salmon(Oncorhynchus keta) for eight weeks. At the end of the experiment, at 14℃, the final body weights of the O. keta group were the highest compared to the other groups. Also, the O. keta showed a higher tendency in the 14℃ group than the 8, 11, and 17℃ groups in terms of growth performances, including specific growth rate (SGR), feed conversion ratio (FCR), feed efficiency (FE), weight gain (WG), and condition factor (CF). The survival rate (SR) was 100% at 8 and 11℃ groups, 96% at 14℃ group and 98% at 17℃ group. In the plasma components, the alanine aminotransferase (ALT) was significantly decreased at 17℃ group, whereas there was no significant change in the albumin (ALB), total protein (TP), sodium (Na⁺), potassium (K⁺) and chloride (Cl^-) levels. Among the whole-body composition of salmon, moisture, crude protein, and ash were not significantly affected by water temperature. However, crude lipid in the 8℃ group was significantly higher than in other water temperature groups. The results of this study demonstrated that the optimal temperature to stable growth performance for juvenile O. keta was 14℃.

• Animal Bioscience
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• v.36 no.11
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• pp.1709-1717
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• 2023

Objective: A pivotal study was designed to investigate the effect of Hydroxy (HYC) Cu, Zn, and Mn on egg quality and laying performance of chickens under tropical conditions. Methods: A total of 1,260 Babcock White laying hens (20-wk-old) were randomly assigned to one of 4 treatments with 15 replicates of 21 hens each in a Randomized Complete Block Design. The birds were reared for 16 weeks and were fed the corn-soybean meal diets supplemented with one of the following mineral treatments: T1, inorganic (INO, 15 ppm CuSO4, 80ppm MnSO4 and 80 ppm ZnO); T2, Hydroxy-nutritional level (HYC-Nut, 15 ppm Cu, 80 ppm Mn, 80 ppm Zn from Hydroxy); T3, Hydroxy-Low (HYC-Low, 15 ppm Cu, 60 ppm Mn, 60 ppm Zn from Hydroxy); T4, Hydroxy plus inorganic (HYC+INO, 7.5 ppm HYC Cu+7.5 ppm CuSO4, 40 ppm HYC ZnO+40 ppm ZnSO4, 40 ppm HYC Mn+40 ppm MnSO4). The egg production was recorded daily, while the feed consumption, feed conversion ratio (FCR) and egg mass were determined at the end of each laying period. The egg quality parameters were assayed in eggs collected over 48 h in each laying period. Results: Overall, no significant effect of treatments was observed on percent egg production, egg weight and FCR (p>0.05). Feed intake was significantly lower in birds fed Hydroxy plus inorganic (p<0.05) diet. The supplementation of HYC-Low significantly increased the egg mass compared to the other treatments (p<0.05). HYC supplementation alone or in combination with INO elicited a positive effect on shell thickness, shell weight, shell weight per unit surface area, yolk colour, albumen and yolk index for a certain period (p<0.05), but not throughout the whole laying period. Conclusion: Dietary supplementation of HYC-Low (15-60-60 mg/kg) showed similar effects on production performance and egg quality characteristics in laying hens as compared to 15-80-80 mg/kg of Cu-Zn-Mn from inorganic sources. This indicates that sulphate based inorganic trace minerals can effectively be substituted by lower concentration of hydroxyl minerals.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.2
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• pp.27-34
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• 2024

This study was conducted to examine the feasibility of using Fe-activated wood-derived biochar as a conductive filler for manufacturing cement-based strain sensor. To evaluate the compressive and electrical properties of cement composite with 3% Fe-activated biochar, three cubic specimens of size 50 x 50 x 50mm³ and three prismatic cement-based sensors of size 40 x 40 x 80mm³ were prepared respectively. The four-probe method of electrical resistance measurement was used for cement-based sensors. For cement-based sensors with FE-activated biochar, the conductive performance such as electrical resistance and impedance under different water content and repeated compression was investigated. Results showed that the fractional changes in the DC electrical resistivity of cement-based sensors increase with increasing time and the maximum fractional changes in the resistivity decrease with increasing the moisture contents during 900s. At moisture content of 7.5% range, the conductive performance of cement composite including 3% Fe-activated biochar as a conductive filler showed the most stable, while the strain detection ability tended to decrease somewhat as the repeated compressive stress increased between repeated compressive strain and fractional change in resistivity (FCR).

• Fisheries and Aquatic Sciences
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• v.5 no.2
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• pp.103-107
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• 2002

A 6-week feeding trial was conducted to investigate the effects of six different dietary animal protein sources on growth and body composition of olive flounder, Paralichthys olivaceus in recirculating system. White fish meal (WFM), flounder muscle (FLM), carp muscle (CM), blood meal (BM), squid liver powder (SLP) and casein (CA) were used as the main animal protein sources in the six experimental diets. Fish averaging $2.9\pm0.03g$ $(mean\pm SD)$ were distributed to each aquarium as a group of 15 fish and were fed one of the six experimental diets to each treatment of triplicate groups. After 6-week of the feeding trial, fish fed white fish meal (WFM) and flounder muscle (FLM) diets showed a significant higher weight gain $(WG\%)$ (P<0.05) than those of fish fed the CM, BM, SLP and CA diets. Fish fed BM diet showed the lowest WG among all the dietary treatments. Feed conversion ratio (FCR) and protein efficiency ratio (PER) showed the similar trend as WG. Hematocrit and hemoglobin were not affected by the dietary treatments. Fish fed the FLM and CM diets showed significant higher survival rate than those of fish fed BM diets, and there was no significant difference in survival of fish fed WFM, FLM, CM, SLP and CA diets. These results indicated that WFM and FLM are the best dietary protein sources tested in olive flounder.

• Journal of Hydrogen and New Energy
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• v.18 no.4
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• pp.382-390
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• 2007

To check the feasibility of SMART(Steam Methane Advanced Reforming Technology) system, an experimental investigation was performed. A fluidized bed reactor of diameter 0.052m was operated cyclically up to 10th cycle, alternating between reforming and regeneration conditions. FCR-4 catalyst was used as the reforming catalyst and calcined limestone(domestic, from Danyang) was used as the $CO_2$ absorbent. Hydrogen concentration of 98.2% on a dry basis was reached at $650^{\circ}C$ for the first cycle. This value is much higher than $H_2$ concentration of 73.6% in the reformer of conventional SMR (steam methane reforming) condition. The hydrogen concentration decreased because the $CO_2$ capture capacity decreased as the number of cycles increased. However, the average hydrogen concentration at 10th cycle was 82.5% and this value is also higher than that of SMR. Based on these results, we could conclude that the SMART system can replace SMR system to generate pure hydrogen without HTS (high tempeature shift), LTS (low temperature shift) and $CO_2$ separation process.