• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.2B no.3
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• pp.90-94
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• 2002

The line start permanent magnet (LSPM) motor has been developed facilitate to the design of the synchronous motor. The rotor of this motor is composed of interior permanent magnets and aluminum bars instead of rotor windings. It is difficult to predict the performance characteristics accurately, because many characteristics are produced by the aluminum rotor bars and the permanent magnets. Therefore, in this paper the dynamic characteristics of the LSPM motor are described and compared via the time-stepped finite element method with those of the cage-type induction motor to find the characteristics of the permanent magnets and the rotor bars in the LSPM motor.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.3
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• pp.139-146
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• 2003

In this paper, the steady-state operating performance analysis for the three-phase squirrel cage rotor self-excited induction generator (SEIG) driven by a variable-speed prime mover (VSPM) in addition to a constant-speed prime mover (CSPM) is presented on the basis of an effective algorithm based on its frequency-domain equivalent circuit. The operating characteristics of the three-phase SEIG coupled by a VSPM and/or a CSPM are evaluated on line processing under the condition of the electrical passive load parameters variations with simple and efficient computation processing procedure in unregulated voltage control loop scheme. A three-phase SEIG prototype setup with a VSPM as well as a CSPM is implemented for the small-scale clean renewable and alternative energy utilizations. The experimental operating characteristic results are illustrated and give good agreements with the simulation ones.

• Korean Journal of Veterinary Research
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• v.58 no.4
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• pp.193-199
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• 2018

As animal welfare issue becomes important, the European Union bans conventional cages for laying hens from 2012. So the alternative housing systems like floor pens, aviaries or free range systems have been suggested. From 2011 to 2014, we monitored 20 welfare-oriented laying hen farms in South Korea to figure out serological status of major viral diseases. During this period, total 3,219 blood samples were collected from the randomly selected chickens to test and evaluate the hemagglutination inhibition titers for low pathogenic avian influenza, Newcastle disease and egg drop syndrome '76. A total of 2,926 blood samples were tested through enzyme linked immunosorbent assay (ELISA) to assess the serological status of infectious bronchitis (IB). The distribution of ELISA titers for IB was various from almost 0 to 20,000 through the all weeks of age. Also, the antibody coefficient of variation for most of the diseases in this study was higher than those of typical cage layers. As this study was the first surveillance for major avian viral diseases of the animal welfare-oriented farms in South Korea, the results obtained from this study will help to determine what information and resources are needed to maintain better biosecurity and to improve the health and welfare of laying hen flocks.

• Korean Journal of Poultry Science
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• v.39 no.4
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• pp.261-267
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• 2012

Different housing systems have considerable influence on performance in poultry production. Therefore, the present study was undertaken to investigate the impact of different housing systems on the performance, bone mineral density and egg yolk fatty acid composition in laying hen. Hy-line brown pullets (n=450) of 12 weeks age were randomly divided into 3 housing systems with 6 replicates of 25 birds in each room. A diet with 2,750 kcal/kg ME and 16.5% CP was assigned to all birds. The pullets provided free access to feed and water. Significantly (P<0.05) higher values for egg production, egg mass and feed conversion efficiency were found in battery cages, however egg weight, egg shell color and breaking strength was remarkably (P<0.05) higher in floor system. The albumin height and Haugh unit were significantly higher (P<0.05) in battery cages which was statistically similar to aviary housing system. The egg yolk fatty acids concentration of linoleic acid and linolenic acids were significantly higher in aviary and in floor system, respectively, however both values were lower in battery cages. Saturated and unsaturated fatty acid content (%) in egg yolk did not influence by any housing systems. Bone mineral density was significantly higher (P<0.05) in floor and aviary housing system than that of battery cage system. It was concluded that in battery cages the egg production and composition maximized, however higher bone mineral density and yolk fatty acids content can be improved in the laying hen reared on floor and aviary housing systems.

• Korean Journal of Poultry Science
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• v.46 no.4
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• pp.271-277
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• 2019

In recent years, consumers have recognized the issue of and expressed concern over farm animal welfare. Therefore, worldwide, chicken farms are transitioning from traditional caged breeding systems to welfare-oriented breeding systems. In this study, we further analyzed and compared the prevalence and protection rate of various diseases by challenging chickens under conventional and welfare-oriented breeding conditions with low pathogenic avian influenza. Ten chickens were randomly selected from each farm (conventional and welfare) from which Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) were identified and isolated. Additionally, low pathogenic avian influenza (LPAI) were challenged to broilers from each farm and samples were collected from these chickens using oral and cloacal swabs to investigate viral shedding and titer. The results showed that Mycoplasma infection did not significantly differ between breeding systems. Initially, LPAI viral shedding and titer significantly differed between breeding systems post-challenge, but as the experiment progressed, there was ultimately no significant difference.

• Korean Journal of Poultry Science
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• v.38 no.4
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• pp.305-313
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• 2011

This study was conducted to investigate the effects of housing systems on the productivity and physiological response as stress indicators in White Leghorn chickens. The chickens subjected to the conventional cages had a significantly lower viability, hen-housed egg production, egg weight and body weight compared with those to the floor pens. However, the hens housed in the conventional cages had a shorter day of the first egg and a greater egg quality compared with those housed in the floor pens. In addition, this study was also investigated to identify biological markers for assessing the physiological response of chickens under stress conditions. As biological markers, the amount of telomeric DNA was analyzed by quantitative fluorescent in situ hybridization on the nuclei of cells. The DNA damage rate of lymphocytes was also quantified by the comet assay. The amount of telomeric DNA of the lymphocytes, kidney and spleen was significantly higher in the chickens under floor pens than those under conventional cages. The DNA damage also increased in chickens raised under conventional cages, as compared to the chickens under floor pens. As results, we conclude that the chickens housed in conventional cages have a greater stressful status than those housed in floor pens.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.10
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• pp.1610-1616
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• 2020

Objective: This study was to evaluate the effect of husbandry systems and strains on cecum microbial diversity of Jingyang chickens under the same dietary conditions. Methods: A total of 320 laying hens (body weight, 1.70±0.15 kg; 47 weeks old) were randomly allocated to one of the four treatments: i) Silver-feathered hens in enrichment cages (SEC) with an individual cage (70×60×75 cm), ii) Silver-feathered hens in free range (SFR) with the stocking density of 1.5 chickens per ten square meters, iii) Gold-feathered hens in enrichment cages (GEC), iv) Gold-feathered hens in free range (GFR). The experiment lasted 8 weeks and the cecum fecal samples were collected for 16S rDNA high throughput sequencing at the end of experiment. Results: i) The core microbiota was composed of Bacteroidetes (49% to 60%), Firmicutes (21% to 32%) and Proteobacteria (2% to 4%) at the phylum level. ii) The core bacteria were Bacteroides (26% to 31%), Rikenellaceae (9% to 16%), Parabacteroides (2% to 5%) and Lachnoclostridium (2% to 6%) at the genus level. iii) The indexes of operational taxonomic unit, Shannon, Simpson and observed species were all higher in SFR group than in SEC group while in GEC group than in GFR group, with SFR group showing the greatest diversity of cecum microorganisms among the four groups. iv) The clustering result was consistent with the strain classification, with a similar composition of cecum bacteria in the two strains of laying hens. Conclusion: The core microbiota were not altered by husbandry systems or strains. The free-range system increased the diversity of cecal microbes only for silver feathered hens. However, the cecum microbial composition was similar in two strain treatments under the same dietary conditions.

• Journal of Nutrition and Health
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• v.25 no.7
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• pp.543-554
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• 1992

True metabolizable energy(TME) is believed a better indicator for animal performance than apparent metabolizable energy (AME) for excluding the endogenous energy losses from excreta, However few researches have been conducted to compare superiority of any energy systems through practical animal feeding tests. Present study was to compare the energy systems in young chicks in terms of predictability of energy intake for the birds performances including body energy retention and of methodological accuracy by evaluating reproducibility and additi-vity of energy values of feed ingredients and compound diets. Five ingredients such as yellow corn wheat soybean meal fish meal and wheat bran were measured for their various biological energy values. in the first feeding trial chicks were restric-ted-fed the basal diet at 80, 60 and 40% on weight basis of the amount of feed ingested by chicks fed ad libitum the same diet. chicks in the second trial were also restricted-fed diets at levels of 80, 70, 60 and 50% on energy basis of the amount consumed by the basak duet group fed ad libitum The diets in the latter trial were however composed of differeent formulations from the basal diet. One-week-old Single Comb White Leghorn male chicks were individually alloted in a cage on 10 cages/treatment basis and fed the diets for 14 days. Individual carcass energy was measured after the feeding trials. Coefficients of variation of energy measurements were lesser for nitrogen-corrected AME and TME(AMEn & TMEn respectively) than AME and TME values suggesting taht reprodu-cibility of energy determinations by former systems could be better than the latters. The coeffi-cients for AME and TME were almkost of the same values. Additivity obtained by the rations between the calculated values and catual measurements appeared quite satisfactory for all the energy systems. Those of AME and TME however were relatively better than the other systems. Regression coefficient ${r}^2$ between energy intake by various systems and chick performances appeared higher for TME, AMEn and TMEn than AME implying that the former systems could provide better predictability for body weight gain and energy retention than the AME. The ${r}^2$ values for TME and AMEn particularly for body weight gain were on the average 0.967 and 0.960 respectively. In conclusion TME or AMEn can be recommended as choice for dietary energy system in terms of performance predictability of the birds and of procedural convenience for the measurements.

• Korean Journal of Pharmacognosy
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• v.17 no.4
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• pp.272-279
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• 1986

This study was conducted about the effect of Shihogesikungang-tang on the central nervous system and cardiovascular system for the investigation of its clinical effect based on the Oriental medicinal references. The results of this study were summerized as follows; Analgesic activity as evaluated by the writhing syndrome in mice was significantly noted. A decrease effect of the spontaneous movement as estimated by wheel cage method, muscle relaxant effect as evaluated by the rotor rod method and the prolonged effect of sleeping time induced by thiopental-Na were significantly shown in mice. A antipyretic activity in febrile rats induced by the endotoxin was recognized. Anti-inflammatory effect in carrageen-induced paw edema in rats was significantly noted. Negative inotropic action on the isolated heart of frogs was noted. A vasodilative action in rabbits peripheral blood vessels and hypotension in anesthetized rabbits were remarkably recognized.

• Korean Journal of Pharmacognosy
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• v.19 no.2
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• pp.141-151
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• 1988

The sedative, antipyretic, analgesic and anticonvulsive action, action on the isolated ileum in mice, retricting action on edema, action on blood pressure and respiration of Sipmidojuksan were evaluated. The results were as follows; sedative effects were recognized by the unbalanced effects of spontaneous momentum by wheel cage method, muscle relaxing action by rotor rod method and prolongation of sleeping hours. In mice, a significant antipyretic effect to endotoxin was recognized. Significant anagesic effects by acetic acid and Randall-Sellito method were recognized. Significant anticonvulsive effects to strychnine and picrotoxin were recognized. Spontaneous momentum of isolated ileum in mice was restricted, and relaxing effects on smooth muscle of digestive organ were noted by anti-acetylcholine, anti-barium chloride and anti-histamine effects. Significant antiedemic effects to carrageenin and histamine were recognized. Dilatation of blood vessels and decrease of blood pressure were noted.