• Journal of Life Science
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• v.22 no.10
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• pp.1392-1398
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• 2012

This study investigated the effects of diet of different forages on growth performance and carcass characteristics of Hanwoo steers. Twenty-one Hanwoo steers were randomly allocated to three groups (fed hay, reed, and reed with rice straw) of seven steers each. Initial and final body weights of control, T1, and T2 groups were 125.5, 128.3, 128.3 kg and 697.4, 614.6, 706.7 kg, respectively. Average daily gain tended to increase in controls (0.70 kg/d) and the T2 group (0.71 kg/d) but not as much in the T1 group (0.60 kg/d); however, there was no significant difference. DMI was not significantly different among the treatment groups, but T1 was relatively lower than the other groups. For the yield traits, carcass weight was not significantly different between controls and the T2 group but was greater in the T2 group compared to the T1 group (p<0.05). Back fat thickness and rib eye area were higher in controls and T2 compared to T1; yield grade (A:B:C, %) was greater in T1 (43:57:0) compared to the other groups (control 0:71:29; T2 29:42:29). For the quality traits, fat color and texture were not significantly different among groups. However, meat color and maturity were significantly greater in T1 compared to T2 (p<0.05). Marbling score and appearance rate of over 1st meat quality grade were greater in the control and T2 groups compared to the T1 group. Based on the results, growth performance, feed utilization, and carcass traits appeared to improve when roughage containing rice straw plus reed was offered. Therefore, reed is worth considering as a roughage source for fattening Hanwoo steers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.740-748
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• 2018

This study was conducted to investigate the effects of dietary supplementation of enzyme complex (metalloprotease and xylanase) on growth performance, carcass characteristics and meat storability of broiler chickens. The experiment utilized a 2 (basal and low spec diets) ${\times}$ 3 (0, 0.5 or 1 g/kg of enzyme supplementation) factorial arrangement. A total of 360 male Ross broilers were randomly assigned into the following six groups: BD-T0 (basal diet + enzyme complex 0 g/kg), BD-T1 (basal diet + enzyme complex 0.5 g/kg), BD-T2 (basal diet + enzyme complex 1 g/kg), LD-T0 (low spec diet + enzyme complex 0 g/kg), LD-T1 (low spec diet + enzyme complex 0.5 g/kg), LD-T2 (low spec diet + enzyme complex 1 g/kg). Feed and water were provided ad libitum for 42 days, during which time feed intake and body weight were measured at one-week intervals. After the feeding trial, chickens were slaughtered by exsanguination and samples were collected. Feed intake was lower in the enzyme supplemented groups than the non-supplemented groups (p<0.05), as were body weight and gain (p<0.05). Thus, the feed conversion ratio improved in the enzyme supplemented groups relative to the non-supplemented groups (p<0.05). The carcass rate and production index were also significantly improved by supplementation with enzyme complex (p<0.05). Finally, the thiobarbituric acid reactive substances (TBARS) values were lower in the enzyme supplementation groups after 6 storage days (p<0.05). In conclusion, dietary supplementation with enzyme complex including metalloprotease and xylanase improved growth performance, carcass characteristics, and storability of broiler chicken meat.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.277-285
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• 2021

This study was conducted to compare performance, carcass yield, and meat quality of 4 Korean indigenous commercial chickens (Hanhyup 3: G, Sorae 1: V, Woorimatdak 1: S, Woorimatdak 2: W). A total of 384 chickens were divided into 4 treatments with 4 Korean indigenous commercial chickens, 6 repetitions per treatment, and 16 birds per treatment (♀ 8 birds, ♂ 8 birds). For 12 weeks, body weight was significantly higher in G and V breeds than S and W breeds (P<0.01), but body weight gain lower in S breed (P<0.05). Feed conversion ratio was significantly higher in W breed at 8~10 wk of age (P<0.05). There was no significant difference on livability among four treatments. Carcass yield and fresh meat ratio were highest in V breed at 12 wk of age (P<0.05). On breast meat, shear force was lower in G breed (P<0.05), and higher in male than in female (P<0.05). Lightness (L^*) of breast meat was higher in female except V breed, and redness (a^*) was significantly higher in breed G (P<0.05). Yellowness (b^*) of breast meat was higher in G and V breeds, and higher in male than in female except breed G. In conclusion, G and V breeds showed superior performance, and S and W breeds showed superior meat quality.

• Journal of Life Science
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• v.21 no.5
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• pp.684-692
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• 2011

The present study furthered this research by determining the optimal level of inuloprebiotics derived from Korean Jerusalem artichoke to promote growth in broiler chickens. On hatch day, 320 male Ross 308 broilers were randomly allotted to four groups for a 35-day feeding regimen. The groups were a control (no supplementation), diet supplementation with antibiotics (8 ppm avilamycin), supplementation with 200 ppm inuloprebiotics, and supplementation with 250 ppm inuloprebiotics. Body weight and feed intake were comparably high in the two inuloprebiotics groups, and exceeded the values for the control and antibiotics groups. Body weight and feed intake was higher in chickens fed the antibiotics supplemented diet, compared to controls. There were significant differences among treatment groups. Feed conversion ratio during total experimental periods was significantly high in the control group compared to the inuloprebiotics-fed groups, but no significant difference was evident using antibiotics or inuloprebiotics dietary supplementation. Carcass weight, dressing percentage, and weight of breast and thigh muscle were significantly higher for inuloprebiotics-fed chickens, compared with control and antibiotic-fed chickens. Inuloprebiotics concentration was not significant, while antibiotics-fed chickens displayed significantly higher values than control chickens. Abdominal fat was significantly reduced (19.08%-23.30%) and blood immunoglobulin and the weight of the thymus and Bursa of Fabricius were significantly increased in chickens receiving inuloprebiotics-supplemented feed, compared to control and antibiotics fed groups. In the lower intestine, the viable counts of beneficial bacteria (Bifidobacteria and Lactobacillus) were significantly increased and counts of harmful bacteria (Escherichia coli and Salmonella sp.) were significantly decreased in the presence of the inuloprebiotics, compared to control and antibiotic. The present results support 200 ppm as an optimal level of Korean Jerusalem artichoke-derived inuloprebiotics as a dietary supplement to improve growth in broiler chickens.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.437-443
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• 2019

This study examined the productivity, blood characteristics, and cecal microorganisms with the addition of mixed enzymes in broiler chickens. Three hundred chickens (Ross 308) were assigned randomly to five treatment groups (control, 0.5 MXG, 1.0 MXG, 2.0 MXG, and 1.0 G) with three replications. Based on the results, the weight, feed intake, feed efficiency, and daily gain increased slightly by the treatment assignment. Carcass, stomach, and heart weights increased slightly in all treatment groups compared to the control. On the other hand, liver weight was significantly low by enzyme addition compared to the control group (p<0.05). The total number of appendix bacteria decreased significantly in all treatment groups compared to the control group (p<0.05). The total protein, blood urea nitrogen (BUN), and glucose level did not differ after treatment. On the other hand, the IgG level was significantly higher in the 1.0 MXG and 2.0 MXG groups than in the control group (p<0.05). In conclusion, the addition of a mixed enzyme (MXG) will improve the feed efficiency and IgG, as well as reduce the liver weight and total bacteria in broiler chickens.

• Korean Journal of Organic Agriculture
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• v.23 no.3
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• pp.523-534
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• 2015

Twenty four Holstein steers (average body weight $714{\pm}13.60kg$) were used in this experiment to determine the effect of supplementing of microbial culture and coated vitamin-C on growth performances and carcass characteristics in finishing Holstein steers. Holstein steers were randomly assigned to feeding groups of control group (Con, 12 kg of basal diet/head/day), microbial culture group (MC, 12 kg of basal diet + 30 g of microbial culture/head/day) and coated vitamin-C group (CVC, 12 kg of basal diet + 10 g of coated vitamin-C/head/day). MC and CVC groups were higher in ADG compared to control (P<0.05). FCR was also lower in MC and CVC groups than control group (P<0.05). Back fat thickness, rib-eye area, marbling score, meat color and yield index were not changed by supplementing microbial culture and coated vitamin-C. MC group was higher for maturity compared to control and CVC group (P<0.05). CVC group was higher for fat color compared to control and MC group (P<0.05). Based on the results obtained from the current study, supplementation of microbial culture and coated vitamin-C as an alternative to antibiotic might increase growth performances and enhance carcass characteristics in finishing Holstein steers. However, more studies are needed to find out the optimum supplementing period of microbial culture or coated vitamin-C for high quality meat production from Holstein steers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.566-572
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• 2021

A methodology for the identification and coordinates estimation of air cavities under urban ground or sandy soil using its natural poles and natural resonant frequencies is presented. The potential of this methodology was analyzed. Simulation models of PEC (Perfect Electric Conductor)s with various shapes and dimensions were developed using an EM (Electromagnetic) simulator. The Cauchy method was applied to the obtained EM scattering response of various objects from EM simulation models. The natural poles of objects corresponding to its instinct characterization were then extracted. Thus, a library of poles can be generated using their natural poles. The generated library of poles provided the possibility of identifying a target by comparing them with the computed natural poles from a target. The simulation models were made assuming that there is an air cavity under urban ground or sandy soil. The response of the desired target was extracted from the electromagnetic wave scattering data from its simulation model. The coordinates of the target were estimated using the time delay of the impulse response (peak of the impulse response) in the time domain. The MP (Matrix Pencil) method was applied to extract the natural poles of a target. Finally, a 0.2-m-diameter spherical air cavity underground could be estimated by comparing both the pole library of the objects and the calculated natural poles and the natural resonant frequency of the target. The computed location (depth) of a target showed an accuracy of approximately 84 to 93%.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.3
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• pp.326-332
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• 2015

Analyzing electromagnetic properties in plasma medium, it is difficult to numerically solve electromagnetic problem with thin plasma. In this paper, subcell Maxwell-Boltzmann FDTD method was proposed which is combined with Maxwell-Boltzmann FDTD and subcell FDTD method for analyzing plasma and electrically thin materials, respectively. Calculations of reflection coefficient and absorption rate error were performed by using 1D FDTD method. Reflection coefficient computed by applying the proposed method is in agreement with analytic solution. Absorption rate error analyzed by employing the proposed method is 1/10 times less than one by using conventional method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.9
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• pp.1847-1853
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• 2011

Analysis of an indoor propagation channel has conventionally used the ray-tracing method. But, in this paper, we had modelling the channel for three dimensional indoor structure by the finite difference time domain method for three dimensional full wave analysis. An excitation signal of the FDTD method used plane wave. The plane wave was excited using the total field/scattered field method. And absorbing boundary condition used the perfectly matched layer method with 7 layers. An living room for the simulation of indoor channel modeling is surrounded the wall that be composed of the wood, the conductor, the glass and concrete. When there are furniture in the living room or not, it were simulated, respectively. As simulation results, we could identify the fading effect of multipath at indoor propagation environment, calculated mean excess delay and rms delay spread for the receiver design.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.207-212
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• 2015

Continuous, high-quality supply of electrical energy is the backbone of any modern economy. Any equipment operating at a power station must be reliable and safe. All major power supply components such as transformers, cables, generators, and switchgear need to be kept in perfect operating condition. The lifetime of power cables, used as the main means of transferring electric power, is understood to be about 30 years, from the time of manufacturing. The dielectrics between two conductors of a cable must be able to withstand electrical stresses from high-voltage input. This condition should be verified throughout the lifetime of the cable system. Several techniques, such as VLF-tan${\delta}$, partial discharge, and insulation resistance are used in order to determine the operating conditions of cables. In this paper, we present our work on insulation resistance to diagnose cables in operation at the Western Power station in Taean, Chungcheong Namdo Province, South Korea. As a result we have found cables the life time of which is 38 years.