• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.135-137
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• 2003

The analyses of relationship between specific genes and economic traits were performed on the basis of the genetic characterization of Korean native chicken in this study. Three generation reference pedigree was established from the several lines of Korean native chicken and cornish breed for the linkage analysis and many economic traits were collected for QTL(quantitative trait loci) detection. The experimental design were planed to detect QTLs of meat quality and laying performance from those two distinctive breeds.

• Steel and Composite Structures
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• v.33 no.2
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• pp.277-298
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• 2019

Concrete filled steel tubular (CFST) column joints with composite beams have been widely used as lateral loading resisting elements in civil infrastructure. To better utilize these innovative joints for the application of structural seismic design and analysis, it is of great importance to investigate the dynamic behavior of the joint under cyclic loading. With this aim in mind, a novel phenomenal model has been put forward in this paper, in which a Bouc-Wen hysteresis component is employed to portray the strength and stiffness deterioration phenomenon caused by increment of loading cycle. Then, a modified chicken swarm optimization algorithm was used to estimate the optimal model parameters via solving a global minimum optimization problem. Finally, the experimental data tested from five specimens subjected to cyclic loadings were used to validate the performance of the proposed model. The results effectively demonstrate that the proposed model is an easy and more realistic tool that can be used for the pre-design of CFST column joints with reduced beam section (RBS) composite beams.

• Korean Journal of Poultry Science
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• v.41 no.3
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• pp.191-196
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• 2014

The identification and utilization of potential candidate genes with significant effects on economically important traits have become increasingly important in poultry breeding programs. The ovocalyxin-32 (OCX-32) gene is located chromosome 9 in chicken, plays an important role in eggshell formation. This study was performed to assess the association between single nucleotide polymorphisms (SNPs) of OCX-32 gene and egg production traits in the Korean native chicken. Four Korean native chicken population (n = 181; including 46 females of Ogol, 46 females of white, 43 females of gray and 46 females of black) were used to analyze two SNPs (c.494A>C and c.267T>G) in the OCX-32 gene by PCR-RFLP (Polymerase Chain Reaction-Restricted Fragment Length Polymorphism). We measured egg production traits of age at first egg, first egg weight, egg production ratio and egg weight. The SNP c.494A>C was significantly associated with egg production ratio in Korean Ogol chickens (p<0.001) and egg weight in Korean white chickens (p<0.05). SNP c.267T>C was significantly associated with egg weight in Korean Ogol chickens (p<0.05). But there was no significant association in Korean gray and black chickens. Results suggest the possibility of using molecular markers in OCX-32 gene as a tool for performance and egg production traits in Korean native chicken breeding program.

• Journal of Animal Science and Technology
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• v.66 no.2
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• pp.398-411
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• 2024

Upregulation of the nutritional value of feed is the major target of various studies in the livestock industry, and dietary enzyme supplementation could aid in digesting the nondegrading nutrients of grains in feed ingredients. Dried distillers' grains with solubles (DDGS) is a byproduct of the fermentation process in the beverage industry and can be used as a large supply source of fiber in feed. Therefore, we conducted an experiment with male broiler chickens to investigate the effect of various types of enzymes on DDGS and compare the efficacy of single enzyme and multienzyme complexes on growth performance and gut environments in broiler chickens. We used 420 1-day-old broiler chickens (Ross 308), and they were allotted into 4 dietary treatments with seven replications (CON, corn-soybean meal [SBM] diet; NC, DDGS supplemented diet; SE, 0.05 % of mannanase supplemented DDGS-based diet; MC, 0.10% of multienzyme complex (mannanase and xylanase, glucanase) supplemented DDGS-based diet. The dietary exogenous enzyme in the DDGS-supplemented diet could improve growth performance as much as the growth of the control group, and digestibility of dry matter, crude protein, and gross energy were significantly increased by enzyme addition in groups of chicks fed DDGS-supplementation diet. Moreover, the populations of pathogenic bacteria, coliforms, and Bacteroidetes were significantly decreased by enzyme supplementation, which might lead to improved gut mucus-secreting cells and inflammatory cytokines in the jejunum. Collectively, dietary single enzyme and multienzyme complexes could improve gut environments, including intestinal immune responses and gut microbial population, and lead to improvement of growth performance in broiler chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1608-1614
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• 2014

The objective of this study was to investigate the different dietary ratios of n-6 to n-3 (n-6/n-3) fatty acid (FA) on performance and n-6/n-3 FA in muscles of broiler chickens. A total of 300 one-day-old Cobb chicks were randomly assigned to 3 treatments of 10 replicates in each (10 birds/replicate). Birds were fed on a corn-soybean meal-based diet containing 1% oil during starter (day 1 to 21) and 2% oil during finisher (day 22 to 39) phases, respectively. Treatments of high, medium and low dietary n-6/n-3 FA were formulated by replacing rice bran oil with linseed oil to achieve n-6/n-3 FA close to >20:1, 10:1 and 5:1, respectively. Average daily gain, average daily feed intake, and feed conversion ratio were similar (p>0.05) among the treatments. Serum glucose, cholesterol and triglycerides concentrations were not affected (p>0.05) by dietary treatments. In breast, concentration of C18:3n-3 was significantly greater (p = 0.001) for medium and low vs high n-6/n-3 FA, while concentrations of C20:5n-3, C22:6n-3, total n-3 FA, and n-6/n-3 FA were significantly higher for low vs medium, and medium vs high dietary n-6/n-3 FA. In contrast, concentrations of C18:2 and mono-unsaturated FA (MUFA) were lower for low vs high dietary n-6/n-3 FA. In thigh muscles, concentrations of C20:5n-3 were higher (p<0.05) for medium and low vs high dietary n-6/n-3 FA, and concentrations of C18:3n-3, C22:6, and n-3 FA were greater (p<0.05) for medium vs high, low vs medium dietary n-6/n-3 FA. However, concentrations of C18:1, MUFA, n-6/n-3 were lower (p<0.05) for low and medium vs high dietary n-6/n-3 FA. In conclusion, lowering the dietary n-6/n-3 FA did not affect the performance of chickens, but enhanced beneficial long-chain n-3 FA and decreased n-6/n-3 FA in chicken breast and thigh, which could be advantageous for obtaining healthy chicken products.

• Korean Journal of Poultry Science
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• v.37 no.3
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• pp.207-213
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• 2010

The current study was conducted to estimate the effect of dietary pyroligneous acid (PA) on performance, noxious gas emission in excreta, blood parameter and fatty acid composition of breast meat in Korean native chicken. A total of 240 one-day-old chicks were allocated to three treatments (PA; 0, 0.1, 0.2%) with five replicate of 16 each per treatment for 10 weeks. Although there was no effect on the performance, ammonia gas concentration was significantly decreased in the PA treatments compared to the control (p<0.05). Birds fed PA had higher serum total protein and high density lipoprotein-cholesterol (HDL-cholesterol) concentration but lower triglyceride content in the PA 0.2% treatment than control (p<0.05). In fatty acids composition of breast meat, myristic and stearic acid were significantly decreased, whereas oleic and linolenic acid were significantly increased in the group fed PA compared to those of the control group (p<0.05). The result of the current study indicates that dietary PA may reduce the noxious gas emission and improve lipid levels as well as increase of monounsaturated fatty acids composition of breast meat in Korean native chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.2
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• pp.266-273
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• 2002

A total of 225 day-old broiler chicks (43.08 g initial body weight) were allotted to three dietary treatments for a 6-week feeding trial. The treatments were 1) Control (defatted rice bran; DFRB), 2) fresh rice bran (FRB) and 3) rancid rice bran (RRB). Rice brans were intentionally spoiled by two degrees of rancidity by the values of free fatty acids (FFA): 7.6% (FRB) and 16.3% (RRB). Diets were prepared on an isonutrient basis, and defatted or rancid rice brans were included 5 and 10% for starter (0-3 week) and finisher (3-6 week), respectively. At the end of the feeding trial, six chicks per treatment were sacrificed, and thigh meats were ground and stored at $1^{\circ}C$ for thiobarbituric acid reactive substances (TBARS) and peroxide value (POV) analyses. For a digestibility, 48 growing chicks (4 weeks old) were employed in cages (3 replicates/treatment, 2 birds/cage) according to the experimental design: FRB, RRB, pelleted and extruded rice bran. Some of the FRB were pelleted ($70^{\circ}C$) or extruded ($110^{\circ}C$). There was no significant difference in growth performance during the starter period, but chicks fed a diet containing DFRB grew faster (p<0.05) with increased feed intake (p<0.05) than those fed diets containing rice brans, FRB or RRB, during the finisher period. Feed conversion ratio in the RRB was inferior (p<0.05) to the DFRB. Between rice bran groups, weight gain was higher (pco.os) in FRB than in RRB during finisher period. There was a similar trend in growth performance of chicks for the overall period (0-6 week) as the finisher period. Dry matter and energy digestibilities were higher (p<0.05) in extruded than in RRB group. Protein digestibility was improved (p<0.05) when rice bran was extruded, but not pelleted. The chicken meats from RRB showed higher (p<0.05) TBARS than those from FRB during storage for 4 weeks at $1^{\circ}C$. In conclusion, it would appear that feeding rancid rice bran gave negative effects on growth performance and lipid stability of meat in broiler chicks.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.938-945
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• 2010

This study was conducted to investigate the dietary effects of germinated and fermented (with Monascus pupureus) soybean screenings (GFS) on growth performance and meat quality in broiler chicken. A total of 750 1-day-old Ross ${\times}$ Ross male broiler chicks were randomly allocated into five groups (five replications with 30 birds each) and fed experimental diets for 5 wks as follows: Group 1, negative-control (antibiotics-free diet); Group 2, positive-control (negative-control with 10 ppm of Avilamycin); Group 3, negative-control with 0.3% GFS; Group 4, negative-control with 0.5% GFS; Group 5, negative-control with 1% GFS. The final body weight of each group fed a diet containing 1% GFS was significantly higher than that of the negative-control group. The feed conversion ratios of all groups fed diets containing GFS and the positivecontrol group were significantly improved compared to the negative-control group during the whole period (p<0.05). The relative weights of various organs along with the activities of serum glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) were not influenced by the dietary treatments. The levels of total serum cholesterol in groups fed diets containing 0.5% and 1% GFS were more significantly lowered compared to those of the control groups without GFS (p<0.05). There were no significant differences in the cecal microflora profiles among the groups. Further, the dietary treatments did not influence the physico-chemical properties of the edible meat, including the shear force, pH, meat color (CIE $L^*$, $a^*$ and $b^*$), and content of malondialdehyde (MDA). Cooking loss of breast muscle in the groups fed GFS was significantly lowered compared to that of the negative control group (p<0.05). These results indicate that dietary GFS could improve growth performance in broiler chicken and may affect meat quality in some instances.

• Journal of Food Hygiene and Safety
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• v.35 no.2
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• pp.118-124
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• 2020

We investigated the content of sugar and sodium in 4 types of chicken (fried, seasoned, soy sauce-flavored, cheese powder-flavored). A total of 123 samples were collected from franchise stores and markets in Seoul. The sugar content of chicken samples was analyzed by HPLC-ELSD (High Performance Liquid Chromatography-Evaporative Light Scattering Detector). The average sugar content of seasoned chicken was highest at 8.7±2.3 g/100 g while that of fried chicken was lowest at 0.6±0.3 g/100 g. The average content of sugar sorted by place of sale showed a significant difference (P<0.05). The sodium content in chicken samples was analysed using the ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry). The sodium content of seasoned chicken with cheese powder was the highest at 627.0±109.2 mg/100 g and that of fried chicken was the lowest at 448.0±65.3 mg/100 g. The sugar content of seasoned chicken sold in both franchise stores and markets was found to exceed the 50 g daily level as recommended by the WHO. In addition, the average sodium content in seasoned chicken (franchise stores and markets) and cheese-powdered chicken was more than twice as high as the daily 2,000 mg recommended by the WHO.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.4
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• pp.569-576
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• 2012

Two experiments were conducted to investigate the potential for Forsythia suspensa extract (FSE) to substitute for antibiotic in broiler chicken. First, a well-diffusion assay procedure and a 2-fold dilution method were used to determine the bacteriostatic activity of FSE on Escherichia coli K88, staphylococcus aureus, and salmonella was assayed. An inhibitory effect of FSE was observed on the growth of these bacteria. This effect seems to be dose depended, which disappeared after 25.00, 12.50, 1.56 mg/ml. Second, a 42-d trial with 252 broiler chickens (d 1, $38.7{\pm}1.1$ g BW) was conducted to evaluate the effect of dietary supplementation of FSE in broiler chicken. The feeding program consisted of a starter diet from d 1 to 21 and a finisher diet from d 22 to 42. Dietary treatments included were: i) NC: negative control fed a corn-soybean meal based diet; ii) PC: positive control group fed based diet with chlortetracycline; and iii) FC: a test group fed with 100 mg FSE/kg diet. In this study growth performance did not differ among treatments during the starter period. However, dietary supplemental chlortetracycline and FSE increased (p<0.05) average daily gain (ADG), average daily feed intake (ADFI) compared with NC during the finisher and overall phase. Apparent digestibility of calcium on d 21, digestibility of energy and calcium on d 42 of FC was greater (p<0.05) than NC. Moreover, cecal Escherichia coli counts for birds from FC were lower (p<0.05) than NC. Dietary FSE supplementation also improved (p<0.05) villus height and villus height to crypt depth ratios in both duodenum and ileum and decreased (p<0.05) crypt depth in the duodenum. Duodenum villus height and villus height to crypt depth ratio in both duodenum and ileum from the FC group were also greater (p<0.05). Serum growth hormone and IGF-1 were not influenced by different treatments. Apparently, FSE has the potential to substitute for antibiotic in broiler chicken.