• Korean Journal of Poultry Science
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• v.29 no.4
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• pp.255-258
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• 2002

A study was conducted to investigate the correlation of cecal anaerobic bacterial counts with the cecal length in growing chicks. Half of 160 chicks of five weeks old were housed in cages and the remainings were kept with goats in free-range and allowed to have free access to goat's feed and faeces. All the experimental birds were fed ad libitum on a commercial chick formula diet during the period of 5 to 12 weeks of age. Body weight was larger in birds reared in the cage than in those reared on the field at 8 weeks of age (P<0.05), but vice versa at the end of experiment (P<0.05). The cecal length was longer in field-rearing than in cage-rearing at 6, 9, 10 and 11 weeks of age (P<0.05). The cecal length was correlated with body weight gain in both rearing groups (r=0.816 f3r cage-rearing, r=0.816 for field-rearing). The cecal anaerobic bacterial counts were significantly higher in field- rearing than in cage-rearing at 6, 9, 10 and 11 weeks of age (P<0.05). The cecal length was highly correlated with cecal anaerobic bacterial counts in cage- (r=0.9549) and field-(r=0.9866) rearing. It is concluded that the correlation of increase cecal length with increased cecal anaerobic bacterial counts ted a libelous of goat's faeces in growing chicks.

• Korean Journal of Poultry Science
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• v.29 no.4
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• pp.249-253
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• 2002

A 2 ${\times}$ 2 factorial experiment was conducted to determine the effect of cecectomy and urea supplementation on nitrogen utilization In growing chicks. Birds were either cecectomized or shamoperated and fed a 19% protein diet with or without 1% urea supplementation. All chicks were provided ad libitum access to feed and water throughout the six-day experimental period. In the cecectomized chicks, fred efficiency was significantly decreased when fed a 19% protein diet supplemented with 1% urea (P<0.05). When chicks were fed a 19% protein diet, cecectomy significantly shortened gastrointestinal passage time (GPT) of food (P<0.05). However, the GPT was significantly lengthened in chicks fed a 19% protein diet supplemented with urea (P<0.05). Regardless of diets, cecectomized chicks increased the moisture contents of the excreta (P<0.05) and feeding a 1% dietary urea also significantly increased (P<0.05). Cecectomy significantly decreased uric acid N excretion by about 30 mg per 100 g body weight per day (P<0.05) and uric acid N/ total N excretion when fed both diets (P<0.05). The present study suggests that cecectomy improves nitrogen utilization rate by decreasing uric acid excretion in growing chicks. These results are in good agreement with those obtained previously in a cecectomy study of adult chickens.

• Monthly Korean Chicken
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• s.133
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• pp.120-123
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• 2006

산업 동물에서 항상 문제가 되는 것 중 하나가 전체 동물들이 균일하게 성장하는 것이 어렵다는 것이다. 소든, 돼지든, 닭이든 산업동물에서 높은 생산성을 얻기 위해서는 전체 동물이 성장시 비슷한 속도로 비슷한 체중으로 커 주어야 한다. 그러나 현대 산업 동물은 농장별 사육수가 증가하고 각종 질병 및 스트레스 요인으로 인해 균일하게 키우는 것이 쉽지가 않다. 그 중에서도 육계는 우선 사육수가 타 동물에 비해 월등히 많고 사육기간이 짧아 보상 증체할 시간이 상대적으로 적어서 층아리 발생시 그 피해가 더욱 크다. 많은 전문가와 농장에서 층아리를 줄이기 위해 지금 이 순간에도 노력해 오고 있다. 하지만 현실적으로 층아리 없이 닭을 사육하는 것은 불가능해 보인다. 어떻게 하면 층아리를 효과적으로 줄일 수 있을까? 이 해답을 얻기 위해 우리가 알아야 하고, 조치해야 될 사항들을 간략히 정리해 보았다.

• Korean Journal of Poultry Science
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• v.19 no.4
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• pp.205-215
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• 1992

This study investigated the characteristics of Korean Native Fowl (KW) to standarize the feeding regime and compared with those of broiler. The characteristics of KNF studied were meat productivities and carcass traits. The data were collected for 14 weeks from March to June, 1992, by recording from 200 birds(50 birds per each sex and 2 breed) were as follows ： 1. Average body weight at 14 weeks of age of Korean Native Fowl(KW) and broiler were 868.7g and 3,526.6g, respectively and were 26.6 times and 72.9 times of day old chicks weight averages, respectively. 2. The carcass yields during 9∼14 wks were 74.1∼78.5％ for KNF male, 73.g∼77.5％ for KW female, 72.2∼76.9％ for broiler male and 71.7∼76.4％ for female. It was shown that carcass yields of KNF was 2％ higher than that of broiler. 3. In edible portion, the yields of wings weight to carcass weight were 11.5∼12.4％ for KNF male, 11.5∼13.1％ for KNF female, 10.7∼11.9％ for broiler male and 10.7∼12.2％ for broiler female, it was shown that wings weight of KW was higher than that of broiler and wings weight of KNF during 9∼14 wks. 4. The portions of back and breast weight were higher than those of KNF during 9∼14 wks. The back portions in carcass weight were 15.4∼17.0％ for KW male 15.4∼16.8％ for KNF female, 17.2∼19.0％ for broiler male, and 17.2∼19.0％ for broiler female. The breast portions in carcass weight were 19.6∼22.0％ for KNF male, 20.2∼22.7％ for KNF female 23.S∼24.5％ for broiler male, and 25.1∼27.7％ for broiler female. 5. The portion of thigh and drumsticks weight in carcass weight of KNF was similar to that of broiler. They were 26.8∼28.0％ for KNF male, 25.5∼27.1％ for KNF female, 27.7％ for broiler male, and 26.9％ for broiler female, respectively. 6. For the weight of inedible portion during 9∼14 wks, feather weight of KNF was 5.3∼6.8％ of live weight and 3.8 ∼4.4％ in those of broiler. This result indicated that KNF has more rooms for improvement than broiler. 7. Abdominal fat weight was 2.42∼3.88g for KNF male and 1.84∼3.08g for KNF female, which was 0.5％ of carcass weight. But broiler has more abdominal fat than KNF as 39.4∼56.3 g for male, 33.3∼67.8 g for female which was 2.5 ∼3.0％ of carcass weight.

• KOREAN POULTRY JOURNAL
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• v.11 no.3 s.113
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• pp.147-152
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• 1979

산란계에서는 성장중인 육계나 육성계에 비교하여 사료소비량과 단백질요구량의 결정에 더 많은인자가 영향을 주게된다. 이러한 여러가지 인자들중에서 가장 중요한 것은 닭의 크기나 품종, 환경온도, 주령 및 사료의 에너지 함량을 들수가 있다. 본소고에서는 산란계사료중의 단백질함량의 결정에 관계하는 이러한 인자들을 중심으로 설명해 보려고 한다.

• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.241-249
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• 2023

Following the Animal genetic resource for food and agriculture (AnGR) is considered as an independent resource for the possessing country, ensuring the sovereignty of AnGR is important. The present study investigated the growth and egg production performance of six breed enrolled in DAD-IS for the purpose of securing scientific data on AnGR in Korea. A total of 323 chickens (female 181, male 142) were used in this study, with the following six breeds: Korean Leghorn (LEG), Gyeongbuk Araucana (ARA), Korean native chicken (KNC), Korean Ogye (Ogye), Hyunindak (HIL), Heongseongyakdak (HYD). The body weight of male ARA from hatching to 32 weeks of age was the highest among the breeds, and LEG and Ogye were relatively lower (P<0.0001, excluded body weight data of HYD). The body weight of female ARA was the highest and HYD was significantly the lowest among the female chicken breeds (P<0.0001). The laying percentage was the highest in LEG and was the lowest in HYD among the breeds (P<0.0001). The average egg weight from 20 to 40 weeks of age was the highest in ARA, followed by LEG and was the lowest in Ogye (P<0.0001), and the adapted breed including LEG and ARA was higher than indigenous breed (P<0.05). Egg mass production was the highest in Korean Leghorn. Collectively, these results show that ARA has the best growth ability, and LEG has the best egg production performance among the used breeds. This suggests that the adapted breed with high commercial performance is important AnGR in Korea.

• KOREAN POULTRY JOURNAL
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• v.40 no.7
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• pp.129-131
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• 2008

국내에서 발생하고 있는 닭 질병 중에서 심각하게 경제적인 피해를 일으키는 질병들은 주로 온도가 낮은 시기에 집중되어 있다. 하절기에는 몇몇 세균성 질병을 포함하여 고온다습한 환경 조건에 닭이 노출됨으로써 오는 일사와 열사병, 곰팡이 독소 중독증 그리고 가금티푸스를 포함한 몇몇 세균성 질병 등이 주를 이룬다. 그러나 간과해서는 안 될 것은 여름철이라고 해서 환절기와 동절기에 바이러스성 질병의 발생이 없는 것이 아니라 사육환경이 좋아짐으로써 질병의 증상이 잘 드러나지 않고 피해가 나타나지 않을 뿐 각종 질병의 발생이 계속되고 있다는 사실이다. 더위는 털이 많은 닭에게 있어서 분명 견디기 힘든 환경일 것이다. 더위로 인해 겪는 계군의 피해는 사료섭취 감소, 산란저하, 난중감소, 난각질 저하, 부화율 저하, 사료효율의 저하와 스트레스 호르몬의 분비에 의해 성장저하 및 면역시스템에 좋지 않은 영향을 주어서 질병에 대한 감수성이 높아지게 만든다. 계군이 더위를 잘 이기게 해주는 일련의 관리방법들은 계군에 대한 스트레스를 감소 시켜주어 결국은 닭의 면역시스템을 보호해 주는 넓은 의미의 질병 예방 관리라 할 수 있을 것이다. 7월의 폭염을 계군이 효과적으로 이길 수 있게 해 주는 일반적인 관리방법들을 나열해 본다.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.85-90
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• 2007

The chicken liver has been involved in various biological functions including detoxification, glycogen storage and plasma protein synthesis. The aim of this study was to investigate differentially expressed genes in chicken liver in four different growing stages. Using 10 arbitrary Annealing Control Primers (ACPs), five differentially expressed genes have been identified. Based on the Basic Local Alignment Search Tool (BLAST) search results, three of them were matched with previously known genes, and the other two were matched with unknown EST sequence and a hypothetical protein, respectively. In order to confirm the expression results, quantitative real-time PCR was also performed. The high similarities between the expression data using arbitrary ACPs and quantitative real-time PCR indicate that the identified genes are the real differentially expressed genes in different growing stages. The genes identified in this study can be used as valuable biomarkers in chicken with further investigation of the functions.

• Korean Journal of Poultry Science
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• v.16 no.1
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• pp.1-8
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• 1989

This experiment was conducted to improve the performance of chickens by the precise separation and analysis of chromosomes which are integrated genetic materials, and by the use of gene manipulation techniques. Following are the main results obtained. 1. When the chromosomes were separated through the leucocyte culture and analyzed by Giemsa banding techniques (especially by the method in which 20 layers of banding patterns could be found in chromosome ＃1), the normal Patterns of chromosomes ＃l-9 and sex chromosomes, and the location of constitutive heterochromatin without any gene activities in all chromosomes were discovered. 2. To utilize the primodial germ cells (PGC) as the genetic vector which is one of the most important gene manipulation techniques, PGC's from triploid were transplanted to normal host embryos. Since the donor PGC's(3n) were found in the gonads of growing host embryos gene manipulation in poultry using PGC's, seemed to be possible.

• Korean Journal of Poultry Science
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• v.46 no.4
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• pp.255-262
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• 2019

The micronutrients and flavor compounds of three new native chicken strains (A, C, and D) being developed in a breeding program (Golden Seed Project) were compared with a commercial native chicken strain (H) and the Baeksemi (W, white semi broiler). After 100 male chicks in each strains were reared for 5 weeks, the breast muscles from randomly selected 40 birds were analyzed at 8 replications. Native chicken strain A had greater amounts of α-tocopherol and α-tocotrienol compared with strain W. Native chicken strains showed higher contents of vitamin B₁₂ than Stain W. Stain H strain had the highest values of cholesterol content and strain D did the lowest. There was no different content of most minerals between native chickens (A, C, D, and H) and W, but Cu were more contained in native chicken strains compared with W. In terms of nucleotide-related flavor compounds, Stain A had the lowest content of hypoxanthine and strain D had highest inosine monophosphate. Native chicken strains had higher contents of umami-related free amino acids (glutamate and aspartate) than W. Among native chickens, strain A had more amounts in the contents of taurine, tasty flavor compounds, and certain vitamins, despite of the relatively low growth productivity. This result will provide information to select a strain with characteristic meat quality in a chicken breeding program.