• Korean Journal of Poultry Science
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• v.45 no.1
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• pp.1-15
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• 2018

Salmonella infections in livestock industry cause various problems such as worsening animal welfare and productivity, damaging consumer confidence in the food safety of animal products. Chicken meat and eggs are known as major source of pathogen causing human foodborne infections. Therefore food safety concerns have prompted the poultry producers and governments to introduce the strategy and regulation to control these pathogens. Salmonella can persist for long periods of time in a wide range of spaces including feed bin, feed processing facilities, poultry farm, slaughterhouse, processing plants, etc. For the effective and constant Salmonella control, combination of pre-harvest, harvest and post-harvest measures should be considered comprehensively. The control measures would be most effective at farm level where the contamination initiates. Transmission of pathogen from feed origin to the live poultry and finally to the products was proven already. To control bacteria in the feed ingredients and formula feed, thermal processing, irradiation or chemical treatment may be applied. Chemical treatments to inhibit Salmonella in the feed involve the use of products containing organic acids, formaldehyde, or a combination of such compounds. However, recontamination which might occur during storage and transport process and/or by other various factors should always be under control and eliminated. Feed additives used to control Salmonella in birds' gastrointestinal track can be of various types, including prebiotics, probiotics, organic acids and bacteriophages. Although their mode of action varies, they ultimately inhibit the colonization of Salmonella in the gut and improve the performance of birds. This review describes the strategies that could be adapted to the management of feedstuffs and the use of feed additives in pre-harvest stage to control Salmonella contamination in poultry farming.

• Korean Journal of Poultry Science
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• v.50 no.3
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• pp.187-191
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• 2023

Korean native ducks (KNDs) continue to have a high preference from consumers due to their excellent meat quality and taste characteristics. However, due to low productivity and fixed plumage color phenotype, it could not secure a large share in the domestic market compared to imported species. In order to improve the market share of KNDs, the genetic characteristics of the breed should be identified and used for improvement and selection. Therefore, this study was conducted to identify the genetic information of colored and white KNDs using next-generation resequencing data and screening for differences between the two groups. As a result of the analysis, the genetic variants that showed significant differences between the colored and white KND groups were mainly identified as mutations related to tyrosine activity. The variants were located in the genes that affect melanin synthesis and regulation, such as EGFR, PDGFRA, and DDR2, and these were reported as the candidate genes related to plumage pigmentation in poultry. Therefore, the results of this study are expected to be useful as a basis for understanding and utilizing the genetic characteristics of KNDs for genetic improvement and selection of white broiler KNDs.

• Korean Journal of Poultry Science
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• v.37 no.4
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• pp.347-354
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• 2010

The current work was carried out to investigate the effect of crossbred Korean native chickens (KNC) on performance and carcass ratio. Seven hundred twenty 1-d-old chicks were divided into groups by strain (A, B, C and D) and sex (male and female). Strains were A) (KNC egg-meat type C strains $\times$ KNC meat type S strains) $\times$ KNC meat type H strains, B) (KNC egg-meat type C strains $\times$ KNC meat type H strains) $\times$ KNC meat type S strains, C) (KNC native R strains $\times$ KNC meat type S strains) $\times$ KNC meat type H strains and D) (KNC native L strains $\times$ KNC meat type H strains $\times$ Ross broiler. Experimental diets consisted of 3 phases such as starter(0~5 weeks; CP 20.0%, ME 3,050 kcal/kg), earlier (5~8 weeks; CP 18.0%, ME 3,100 kcal/kg) and finisher (8~12 weeks; CP 16.0%, ME 3,150 kcal/kg). Body weight (BW) and feed intake (FI) was measured every week and carcass ratio(CR) was calculated at 5 and 10 week after starting experiment. There was no difference in BW among strains until 5 weeks (P>0.05), however D strain resulted in a higher BW after 5 weeks (P<0.05). Body weight gain (BWG) and FI in D strain were also significant higher compared to the other strains for all periods. However, D strains showed the lowest (P<0.05) fee conversion ratio (FCR). The other strains except D showed a similar BW, BWG, FI and FCR among strains. In addition, there were no differences in carcass weight (CW) and carcass ratio (CR) among strains at 5 weeks, however D strain showed higher CW and CR at 10 weeks. These results suggested the basic data that needed to develope the new strains.

• Korean Journal of Poultry Science
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• v.35 no.2
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• pp.177-182
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• 2008

This studies were conducted to investigate the effect of holding time of broiler at slaughter house on chicken meat quality. Short holding time ($1{\sim}2hrs $) increased chicken meat quality compared to long holding time ($14{\sim}15 hrs$), which resulted in 14% higher grade $1^+$ chicken. In portioned meat, short holding time ($1{\sim}2 hrs$) resulted in 15% higher incidence of grade $1^+$ chicken breast. Also, long holding time occurred higher PSE incidence of chicken breast. pH value of the chicken meat with short holding time was similar to that with long holding time, and that with medium holding time showed the lowest. $L^*$ (lightness) value of the chicken meat was lower with medium holding time than with short holding time, but that in muscle and skin showed increasing tendency with long holding time. Holding time showed no effect on $a^*$ (redness) of the chicken meat, but longer holding time decreased $b^*$ (yellowness) value. This indicated that long holding time adversely affected chicken meat quality.

• Korean Journal of Poultry Science
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• v.41 no.3
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• pp.151-157
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• 2014

Korean native chicken (KNC) is classified as five lines (grey, black, red, white, brown) based on the plumage colors. The KNC has superior meat quality and flavor compared with those of the commercial broilers, which can be explained by the high arachidonic acid contents. The current study was conducted to investigate arachidonic acid contents in five lines of KNC and used for the development of commercial KNC. Breast and thigh muscles from 597 F1 KNC birds were used in this study and linoleic (precursor of the arachidonic acid) and arachidonic acid contents were measured by the standard protocol. In addition, heritabilities and genetic correlations were estimated. As the results, arachidonic acid contents were significantly different among the KNC lines. Also, relatively high heritabilities (0.414~0.570) for arachidonic acid contents were estimated in both breast and thigh muscles. The estimated genetic correlation was negative between linoleic and arachidonic acids. This study indicated that selection of KNC is possible for improving meat flavor in relation to the arachidonic acid. Also, this study can be used for making breeding plans for commercial KNC in the future.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.393-405
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• 1983

The demand for livestock and poultry products including beef, pork, chicken, egg and milk whose income elasticities are relatively higher than other staple foods, has been increased significantly during the past two decades in response to the remarkable increase in per capita GNP. This trend will be continued during the fifth and the sixth five year economic development plan period beginning with 1982. The annual GNP growth rate will be 7.5% on the average during the next 10 years. It is greatly needed to estimate the demand for beef, pork, chicken egg and milk and to study the feasibilities of domestic production of livestock products for the formulation of adequate policies in order to equate the consumption and the production during the 1980s. So this study reviewed the possible changes in the food consumption patterns during the 1980s, estimated the demand for beef, pork, chicken, egg and milk by using empirical demand functions and finally made suggestions for the formulation of long term price stabilization policies for each livestock, poultry and dairy products through the equilibrium of the quantity of demand for and supply of the products. There are many factors affecting the demand for meats, but this study considered own price, prices of supplements and substitutes and per capita income as the independent variables in the demand equations. It was found that it's own price and income were most significantly affecting factors among others and the degree of substitution effects were remarkably different among the products. According to the meat demand derived in this study, per capita consumption of beef, pork and chicken in the base year 1982 was 11.2kg for total meat, 2.5kg beef, 6.0kg pork and 2.5kg chicken, 106 pieces egg, 15.1kg milk respectively, while those in 1991 were 19.3kg for total meat, 4.8kg beef, 9.6kg pork, 4.9kg chicken, 133pieces egg and 44.1kg milk. It is also predicted through this study that, when the level of production costs be maintained, the domestic production of pork and chicken will meet the demand for them during the fifth and sixth five year economic plan period. However, there will be chronic shortage of beef supply during the coming years. The annual import requirement will be 30,000tons to 40,000tons during the period. In order to stabilize the domestic livestock and poultry and dairy products market, the government should introduce measures to curb the increase in beef consumption by encouraging the consumption of pork and chicken. For this, the livestock production policy measures should be concentrated on : 1) the improvement of infrastructures of beef production by introducing advanced feeding and management technology, subsidies for the establishment of facilities and price support programs for farmers : 2) the development of dairy beef : 3) the reinforcement of the forecast systems for pork and chicken production and consumption.

• Korean Journal of Poultry Science
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• v.50 no.3
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• pp.143-159
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• 2023

The study aimed to evaluate the antioxidative effects of rosemary (Rosmarinus officinalis L.) and clove (Syzgyium aromaticum L.) essential oils on fried Korean native thigh meat, including their impact on processed characteristics and flavor compounds. Clove essential oil showed higher DPPH scavenging activity, FRAP and total phenol content compared to rosemary essential oil (P<0.05). The treatments with the addition of 0.005% and 0.01% rosemary (0.005RB and 0.01RB) and clove (0.005CB and 0.01CB) essential oils to the batter weight compared to control that did not include essential oils in batter. The addition of rosemary and clove essential oils to fried Korean native chicken thigh meat did not significant affect proximate composition, pH, TBARS, sensory characteristics. Except for 0.005CB, treatments adding essential oils decreased cooking loss (P<0.05) and 0.005CB showed significantly higher pick-up value than control. Addition of clove essential oil in fried Korean native chicken thigh meat resulted in higher levels of arachidonic acid compared to control (P<0.05). Volatile organic compounds (VOCs) analysis showed that addition of rosemary essential oil might mask its own VOCs, while clove essential oil addition reduced some pyrazine compounds. Although addition of rosemary and clove essential oil did not have significant sensory characteristics on fried Korean native chicken thigh meat, instrumental analysis revealed changes in the compounds that influenced flavor. Further studies are required to evaluate the stability of flavor and sensory characteristics of fried Korean native chicken thigh meat with added essential oils during storage.

• Korean Journal of Poultry Science
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• v.45 no.3
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• pp.175-182
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• 2018

The carcass and meat quality of new native chicken strains (A, C, and D) being developed in the Golden Seed Project for Samgyetang were compared with a commercial native chicken (Hanhyup No. 3, H) and Baeksemi (white semi broiler, W) strains. In total, 250 male chicks were raised under the same feeding and raising conditions for 5 weeks. After slaughter, the carcass weight and percentage yield of parts from each strain were measured and the physicochemical quality traits (general composition, color values, fatty acid composition, and sensory evaluation) of breast muscles were comparatively analyzed. The carcass weight (875.10 g) of the W strain was significantly heavier than that of the other native chicken strains, while that of A strain (537.54 g) was the lowest. The percentage yield of breast meat was also higher in the W strain than in the other strains. The fat content of W strain was higher than that of the other native chicken strains. The new native chicken strains (A, C, D) had higher contents of linoleic acid (C18:2) than the H strain. The A and D strains especially showed relatively high content of arachidonic acid (C20:4), a characteristic fatty acid in native chicken meats. On the other hand, the fatty acid composition of C strain was similar to that of the W strain. This study provides important information on specific quality characteristics than can be used to select new native chicken lines for breeding program.

• Korean Journal of Poultry Science
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• v.37 no.4
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• pp.313-321
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• 2010

This study was conducted to investigate the effects of dietary supplementation of mulberry leaves and dandelion extracts on pH, meat color, TBARS (thiobarbituric acid reactive substance), and VBN (volatile basic nitrogen). Two hundred broiler chickens were fed diets for five weeks containing 1% mulberry leaves extracts (T1), 2% mulberry leaves extracts (T2), 1% dandelion extracts (T3), and 2% dandelion extracts (T4). At the end of five weeks feeding experiment, broilers were slaughtered, and stored at $4^{\circ}C$ for five weeks. As storage time increased, the presence of mulberry leaves and dandelion extracts resulted in decreased pH, and $L^*$ and increased TBARS, VBN, and $a^*$ value in all treatment groups (P<0.05). The pH value, TBARS, and VBN were significantly decreased by the supplementation of mulberry leaves and dandelion extracts relative to the control (P<0.05). Therefore, mulberry leaves and dandelion extracts had the possibility to improve shelf life of chicken meat. Especially, T4 was significantly more effective in delay lipid oxidation compared to the control group. However, no significantly difference was found in pH, TBARS, and VBN among mulberry leaves and dandelion extracts treatment groups. In conclusion, this study demonstrates that compared to control group, supplementation of mulberry leaves and dandelion extracts were effective in decreasing pH, TBARS, and VBN and increasing $a^*$ value.

• 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.