• KOREAN POULTRY JOURNAL
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• v.22 no.2 s.244
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• pp.88-91
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• 1990

대한양계협회 닭경제능력검정소에서 실시한 산란계경제능력검정결과를 보면 최근의 산란계 능력은 72주까지 산란지수가 267개로 나타나고 있다. 10년전이 77년 산란계 72주까지의 산란지수 227개에 비하면 18$\%$가 향상되었음을 보여준다. 성계생존율 또한 88.2$\%$에서 92.0$\%$로 약 4$\%$가 향상되었다. 대체적으로 10여년간에 걸쳐 산란계의 능력이 눈에 띌 만큼 향상되었다고 보는데 최근에 산란계 관리가 미흡하여 계군의 산란피크가 80$\%$를 넘기기 어려운 농장이 나타나고 있어 90년도를 향한 봄병아리의 입추시에는 보다 철저한 사양관리를 위한 준비해야 한다.

• Korean Journal of Poultry Science
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• v.50 no.3
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• pp.133-141
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• 2023

We conducted a 5 × 5 diallel cross-combination test using 1,060 chickens from pure lines of Korean Rhode-C, -D, Korean Leghorn-F, -K, and Korean Native Yellowish-brown chicken (KNC-Y) to develop a new Korean native chicken layer breeder. The laying performance and combining ability, including livability, body weight, age of first egg-laying, hen-day egg production, and egg weight, were analyzed. The livability from birth to 48 weeks was 72.1±24.0%, with the highest observed in the YC and the lowest in the DK combination (P<0.01). The YC combination exhibited the highest general combining ability (GCA), while the YD combination showed the highest specific combining ability (SCA). Regarding body weight, combinations involving Leghorn showed lighter weights compared to combinations with Rhode and KNC-Y (P<0.01). Additionally, the offspring from the KNC-Y combination reached sexual maturity earlier than those from the Rhode combination. The hen-day egg production was 70.7±12.0%, with the highest seen in the CK combination at 86% (P<0.01). The effects of GCA and SCA on hen-day egg production were similar, with the SCA being highest in the YD combination and the GCA being highest in the Rhode-C. Significant differences in egg weight were observed among the combinations, with the eggs from Rhode and Leghorn combinations being heavier than those from combinations with KNC-Y (P<0.01). In conclusion, the YC and YD combinations, characterized by excellent livability, are highly desirable paternal strains, while the CF and CK combinations, with excellent laying performance and moderate egg weight, are preferred maternal strains for Korean native chicken layer breeders.

• KOREAN POULTRY JOURNAL
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• v.18 no.7 s.201
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• pp.91-96
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• 1986

닭의 산란능력에 영향을 미치는 요인들을 개괄하였으며 특히 바이러스성 질병에 대하여 논의하였다. 전염성질병은 예측할 수 없는 상황에서 발생하므로 질병의 발생을 방지할 수 있는 모든 방법들이 사전에 강구되어야만 한다. 최근들어 전염성기관염이 전국적으로 확산됨에 따라 채란계농가나 종계농가의 피해가 날로 높아가리라 사료되며, 우리 모두의 지혜를 모아 어려움을 슬기롭게 풀어가야 하리라 믿는다

• Korean Journal of Poultry Science
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• v.24 no.4
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• pp.199-206
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• 1997

In this experiment, three kinds of autoclaved poultry by-product meals, P1 (head+feet+viscera), P2(P1+blood), and P3(P2+feathers), mixed as to the yielding ratios, and three kinds of autoclaved hatchery by-products meals, H1 (male d-old chicks of egg strain), H2(dead embryos ＆ infertile eggs), and H3(H1+H2, 2:1) were formulated into the layer diets each at 5％ level, respectively, and compared with the control diets(C) containing fishmeal on laying performances and egg qualifies. The egg production, average egg weight, feed intake and feed conversion were not significantly affected by the poultry or hatchery by-product meals. The egg shell qualities, such as the egg specific gravity, egg breaking strength and shell thickness, were not different among treatments. The egg yolk colour was improved by the feeding of hatchery by-products meals (P<0.05). In conclusion, pultry and hatchery by-product meals could be used in layer diets without any adverse effects on laying performances to substitute for fishmeal at about 5％ level.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2002.11a
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• pp.140-142
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• 2002

This study was conducted to obtain some genetic information for developing superior Korean native chickens. Heterosis and combining ability effects were estimated with 1,080 progenies of full diallel crosses of 3 strains in Korean Native Chicken. The traits of egg productivity were Investigated, and heterosis effect, general combining ability, specific combining ability and reciprocal effect were analyzed model I of the Griffing's method 1. The general performance were 147.0 days in age at first egg laying, 71.8 eggs in egg numbers to 270 days, 50.1g in egg weight at 270 days, 75.6 in egg shape index, 356$\mu\textrm{m}$ in egg shell thickness, and 4.27kg/$\textrm{cm}^2$ in egg shell strength, respectively. According to result, heterosis effect revealed comparatively high in age at first egg laying, egg numbers, egg weight, and egg shell strength. The effects estimated highly in general combining ability for age at first egg laying, egg numbers, egg weight, egg shape Index and egg shell thickness, and in specific combining ability were egg numbers, egg weight and egg shell thickness, and in reciprocal effects for egg numbers, egg shape index, and egg shell thickness. This result could be used for developing Korean native chicken.

• KOREAN POULTRY JOURNAL
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• v.22 no.8 s.250
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• pp.126-131
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• 1990

• KOREAN POULTRY JOURNAL
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• v.17 no.9 s.191
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• pp.38-41
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• 1985

• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.203-212
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• 2023

This study conducted a diallel-crossbreeding test using four Korean native chicken parent stock lines (YC, YD, CK, and CF) to develop a native commercial layer with high egg-laying performance. A total of 312 chickens in six combinations were examined for various traits, including livability, body weight, age at first egg-laying, hen-day, and hen-housed egg production, egg weight, and egg quality, from hatching to 60 weeks of age. The results showed that the average survival rate was 77.1±18.8% with the YDYC combination having the highest survival rate along with excellent specific combining ability. The YDYC combination exhibited significantly higher body weight compared to the other combinations (P<0.01). The average age at first egg-laying was 121.3±2.5 days, with no significant difference between the combinations. The average hen-day egg production was 74.0±6.4%, and the hen-housed egg production was 181.4±33.8 eggs with the YDCF and YCCK combinations demonstrating the highest laying performance, while the YDYC and CKCF combinations had the lowest (P<0.05). Laying performance was more influenced by specific combining ability than general combining ability. The eggs from the YDYC combination were significantly lighter and had the darkest shell color (P<0.01), whereas the YDCF combination exhibited the thickest eggshells. There was no difference in internal egg quality among combinations, except the YDCF combination had the darkest yolk color. Overall, we concluded that the YCCK combination, characterized by high laying performance and livability, and the YDCF combination with high laying performance and good egg quality are the most desirable combinations for Korean native commercial layers.

• KOREAN POULTRY JOURNAL
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• v.7 no.10 s.72
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• pp.63-66
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• 1975

양계업의 성공 여부는 산란계 한 마리가 년간 몇 개의 알을 낳느냐에 의하여 결정된다. 일반적으로 산란지수가 많은 계군이 산란피크도 높으므로 더 많은 알을 얻기 위한 방법으로는 산란피크를 향상시켜야 할 것이다. 그러나 아직도 많은 농장에서 보다 빠른수입을 목적으로 또는 관리 부주의로 조산을 시키는 경향이 있다. 조산하게 되면 산란율이 정상적으로 오르지 못하므로 30$\~$33주령이 되어도 산란피크가 보잘 것 없게 되며 이때야 비로소 여러 가지 방법을 강구하지만 이미 닭의 산란능력이 결정되었으므로 보다 좋은 성적은 기대하기 어렵다. 닭의 산란생리는 일단 산란피크에 도달한 다음 산란율이 일정한 비율로 서서히 떨어지게 되어 있다. 그러므로 산란피크가 얼마나 올라가느냐는 장차 계군이 몇 개의 알을 생산할 수 있는가를 예측하는 기준이 될 수 있다.

• KOREAN POULTRY JOURNAL
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• v.24 no.2 s.268
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• pp.155-159
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• 1992