• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.207-207
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• 2018

본 연구는 난중일기의 기록 중 이순신 장군이 명량해전 이후 한반도 서남해안을 항해하면서 조선수군의 새로운 본영을 물색하고, 명량해전 이후의 조선수군의 전략을 구상하던 장소로서 전시 임시 전략지휘소로서 의미가 큰 안편도(발음도)의 현재의 지명으로 추정되는 섬들 중 팔금도를 대상으로 항해 과학적 관점에서 조명하고 분석한 내용이다. 분석 결과 이순신 장군과 그의 참모들이 올라가 주변을 조망한 위치로 추정되는 섬 중의 하나인 팔금도의 채일봉과 금당산에서 관측한 방향이 난중일기에 기록된 내용과 일치하지 않은 부분이 많음을 확인하였다.

• Korean Journal of Poultry Science
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• v.15 no.2
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• pp.115-145
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• 1988

우리나라 축산업이 과학적인 축산으로 변모하는 과정에서 선도적 역할을 해온 것이 양계분야인 만큼 생산성적에 있어서도 어느 타 선진국에 뒤지지 않을 만큼 높아지고 있다. 그러나 사료원료의 해외 의존도가 높고 개방경제시대에 접어들음으로서 외국의 양계산물과 경쟁을 벌리게 되는 이 시점에서 생산비중 가장 높은 비율을 차지하는 사료를 가장 경제적으로 이용함으로서 생산 효율을 극대화시킬 책임이 우리에게 있다. 우리나라의 년 중 기온차이가 심하고 대부분의 산란계가 유창계사에서 사육되고 있는 만큼 계절에 따른 온도 변화에 맞추어 계절 사양을 함으로서 하절기에는 영양소 결핍현상을 방지하고 동절기에는 영양소 과다 섭취로 인한 영양소 허실을 줄일 수 있다. 난중에 따른 난가 형성이 되는 시장 상황에서 난중을 조절함으로서 생산효율을 높일 수 있다. 비록 난중이 생리적인 현상에 의해서 결정되지만 닭이 섭취하는 아미노산과 지방의 함량을 증감함으로써 어느 정도의 난중조절이 가능하다. 산란율과 난중에 영향을 미치지 않는 범위에서는 산란계의 체중이 작을수록 경제성이 있다. 가급적 육성기간중의 사료비를 줄이고 성계 체중을 줄이는 방법으로 육성기간중의 사료비를 줄이고 성계 체중을 줄이는 방법으로 육성기간중 단백질 점증법이 시험되고 있다. 이러한 육성체계를 보급화 하기에 앞서서 좀 더 많은 비교 시험이 필요하리라 본다. 사료 원료의 영양가를 정확하게 평가하는 것은 닭이 필요로 하는 영양소 요구량을 충족시키기 위한 필수조건이 된다. 단지 영양성분의 화학분석만으로 사료배합에 임하지 말고 생물가를 측정함으로서 닭이 섭취하는 영양소의 이용률이 함께 고려하여야 한다.

• Korean Journal of Poultry Science
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• v.47 no.4
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• pp.267-274
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• 2020

This study was conducted to estimate genetic parameters for growth and egg production traits in Black Korean native chicken (L strain) and Korean White Leghorn (F, K strains) using a multi-traits animal model BLUP. Traits used for this study were body weight at 150 days (BW150) and 270 days (BW270), age at first egg (DAY1st), egg weight at first egg (EW1st) and 270 days (EW270), and number of eggs laid by 270 days (EP270), and included 68,688 pedigree and 123,905 performance records collected from 2001 to 2013. In L, F, K strains, heritability estimates of BW150 were high (0.48, 0.52 and 0.50, respectively); of BW270 were high (0.56, 0.57 and 0.56); of DAY1st were medium to high (0.45, 0.39 and 0.31); of EW1st were low (0.15, 0.16 and 0.15); of EW270 were high (0.58, 0.55 and 0.59) and of EP270 were moderate (0.22, 0.21 and 0.20). The genetic and phenotypic correlation of DAY1st with EP270 were highly negative (-0.73 to -0.63 and -0.48 to -0.42). The genetic and phenotypic correlation of EP270 with BW150 and BW270, respectively were low negative (-0.16 to 0.01 and -0.14 to -0.03) and low to moderate positive (-0.08 to 0.07 and -0.13 to 0.04). The genetic and phenotypic correlation of EW270 with BW150 and BW270, respectively were moderate to high positive (0.39 to 0.49 and 0.36 to 0.46) and (0.29 to 0.33 and 0.34 to 0.37). The study showed that there is a potential for genetic improvement of Korean Indigenous chicken through selection program.

• Korean Journal of Poultry Science
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• v.28 no.3
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• pp.187-192
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• 2001

The repeatabilities on Yolk percentage and yolk to albumen (Y:A) ratio of the eggs produced consecutively were investigated. The differences between two yolk lines in major egg characteristics were also evaluated. The investigations using one hundred ISA-Brown layers were conducted at 29 wk, 33 wk, 38 wk, and 43 wk of age. At the initiated age (29 wk of age) of the experiments, the birds producing eggs with lower or higher Y:A ratio than the overall mean Y:A ratio were classified as Low Yolk Line (LYL) or High Yolk Line (HYL), respectively. Overall, the eggs of LYL were significantly (P<0.05) lighter in yolk weight and lower in yolk percentage for the whole egg weight and Y:A ratio, but heavier in egg weight, albumen weight, and shell weight than those of HYL. The overall mean correlations among the three consecutive laying days in Y:A ratio showed highly significant (P<0.001) in both lines. At four different ages, the mean phenotypic correlation coefficients (r$_{p}$) among the three consecutive laying days in Y:A ratio also had very high significant(P<0.01 ~ 0.001) positive values. The egg weight was more closely associated with albumen weight than with yolk weight in both yolk lines.s.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.151-156
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• 2002

The objective of this study was to compare the two different eggshell lines of commercial layers on egg traits and egg production rate. Hy-line W-98 (white shell line; WSL) and Hy-line Brown (brown shell line; BSL) were used as experimental stocks. The birds in each line were allocated to three floor pens each containing 25-birds. They were fed a ration containing 15.5% CP and 2,700 ㎉/kg ME, and were supplied 16 h of light per day throughout the experimental Periods. The egg traits and egg Production rate were measured from 53 to 56-wk-old and 20 to 56-wk-old, respectively. The mean egg weight and the mean percentage albumen were significantly heavier and higher (P<0.05) in the BSL than in the WSL, respectively. The mean eggshell thickness and the mean percentage shell were also significantly thicker and higher (P<0.05) in the BSL than those in the WSL, respectively. However, the mean percentage yolk and the yolk to albumen ratio showed a reverse trend as shown in the mean percentage albumen or percentage eggshell. Although the WSL birds started laying 4 d earlier than the BSL ones, the overall mean egg Production rate for BSL during 20 to 56 wk of age was significantly higher (P<0.05) by 6.6% than the WSL. It was concluded that the eggs of brown eggshell line had heavier egg weight and thicker shell, and they had more percentage of albumen, but less percentage of yolk than those of the white eggshell line. These results suggest that the brown eggshell line raised on the floor might be more beneficial than the white eggshell line not only for the preference of the table egg consumers, but also for the efficient production of the eggs.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.127-128
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• 2003

This study was conducted to obtain for genetic information with 11, 538 progenies of 5 strains in Korean native chicken. The heritability estimates of the body weights at 150 and 270days of age were 0.25~0.61 and 0.32~0.59 in 5 strains, the heritabilities of the body weight at 270 days were relatively higher than that of the body weight at 150 days. The medium or low heritability estimates were observed in the ages at first egg as 0.15 ~0.31, and heritability estimates of the egg weights at the first egg and 270 days of age were 0.06~0.09 and 0.24~0.41. Medium or low heritability estimates were observed for the number of egg production as 0.09 ~0.26, respectively.

• Korean Journal of Poultry Science
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• v.23 no.1
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• pp.19-26
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• 1996

The present study was conducted to estimate average weights, and corrlation and regression coefficients among various traits of eggs obtained from Korean native and imported chicken. Data were obtained from 360 layers (180 of Korean native origin, and 180 of imported Decalb Brown) between November 8, 1994 to February 8, 1995. The results obtained are summerized as follows : 1. The mean weights of whole egg, yolk, dense white, thin white, and egg shell of native chicken were lighter (P<0.01) than those of Decalb Brown. 2. The coefficients of variability in each egg trait were lower in native chicken than in Decalb Brown, indicating the higher ability of native chicken to adapt to the local environment. 3. The phenotypic correlation coeffcients between whole egg and weights of yolk, dense white, thin white, and eggshell were 0.842∼0.992(P<0.01) in native chicken, and 0.865∼0.985(P<0.01) in Decalb Brown. 4. The average eggshell thicknesses of native and imported Decalb Brown were 362.5 $\mu\textrm{m}$ and 407.9 $\mu\textrm{m}$, respectively. 5. The regression coefficients of most of the traits of eggs from native chicken were lower than those from Decalb Brown layers, suggesting that Korean native chicken should be improved further in various egg traits measured in this study.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.299-306
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• 2004

The objective of this study was to investigate the influence of egg storage, broiler breeder age, and the change of egg weight during incubation on growth rate of chicks and 43-day-old dressing percentage. The trials involved hatching eggs obtained from 27-wk-old hens and stored for 6 d for the Young-EXP group, from 28-wk-old hens and stored for 0 d for the Young-CON group, from 51-wk-old hens and stored for 6 d for the Old-EXP group, and from 52-wk-old hens and stored for 0 d for the Old-CON group, The hens were two commercial broiler breeder flocks of the same strain (Cobb) but of different egg producing stages(early and middle stages of egg production). The chicks were grown on floor pens for 6 wks, The differences of setting egg weights between Old-CON and Old-EXP groups were 1 g, but those between Young-CON and Young-EXP groups were 2.9 g(P<0,05). The loss of egg weight during 18 d incubation did not greatly differ among four groups, but the loss of egg weight during 21 d incubation was significantly (P<0.05) more in the middle stage of egg production groups than in the early stage of egg production groups. The mean birth weights of the middle stage of egg production groups were significantly(P<0,05) heavier by 8,7 g than those of the early stage of egg production groups; however, the differences of 6-wk-old body weight were not significant between egg producing stages. The differences of body weights in both egg producing stages were not significantly influenced by egg storage period in overall wks of ages. Egg storage and hen age did not greatly influence to the 43 d dressing percentages, either, The correlations of the setting egg weight with 18 d egg weight during incubation, growth rate of chicks, or 43 d dressing percentage were not significant.

• KOREAN POULTRY JOURNAL
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• v.26 no.8 s.298
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• pp.108-111
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• 1994

• Korean Journal of Agricultural Science
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• v.27 no.1
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• pp.48-53
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• 2000

The various errors existing in a weight measurement system in most automatic egg sorting system available in Korean poultry farms have caused a large amount of economic losses to the egg producers. The object of this study was an importance of egg measurement system by changing both the number and the arrangements of load cells to reduce measuring errors. The results obtained were summarized as follow : 1. Four arrangements of load cells were selected as follows : layout I : Conventional one load cell method layout II : One load cell located as egg moving direction layout III : Two load cells located facing each other layout IV : Two load cells located as parallel with egg moving direction 2. The results of egg weight measurement according to four arrangements (Layout I, II, III, IV) showed that the average errors were 1.1218g, 0.5953g, 0.7786g, 0.2793g respectively. This indicated that the Layout IV (measuring by 2 load cells located parallel with the egg moving direction) caused the lowest average error and the best in precision. 3. The average vibration of axis X, y, Z were resulted as $5.1937{\times}10^{-3}G$, $9.3604{\times}10^{-3}G$, and $16.8657{\times}10^{-3}G$ respectively when sorting large sized egg. This indicated that the vibration of axis-Z was relatively higher than those of axis-X, and axis-Y.