• Journal of the korean veterinary medical association
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• v.22 no.12
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• pp.792-793
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• 1986

• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.101-102
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• 2004

The observed means and standard divisions of the egg texture per generation in korean native chickens were as follow. The egg shell strength, the egg shell thickness and the egg shell colour were 3.8$\pm$0.2~4.2$\pm$0.1 kg/$\textrm{cm}^2$, 356.4$\pm$4.9~368.8$\pm$6.5${\mu}{\textrm}{m}$ and 47.0$\pm$1.7~50.0$\pm$3.3％. The regression coefficients were -0.03~0.03 kg/$\textrm{cm}^2$, -0.84~4.40${\mu}{\textrm}{m}$ and -0.88~-0.36％ respectively.

• Korean Journal of Poultry Science
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• v.49 no.2
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• pp.53-60
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• 2022

This study investigated correlations between egg quality indicators to identify external egg quality traits to predict internal egg quality using non-destructive and convenient measurements. Thirteen indicators, including Haugh unit, albumen height, eggshell breaking strength, eggshell thickness, eggshell color (CIE L^*, CIE a^*, CIE b^*), and reflectivity value, egg weight, egg length, egg width, shape index, and yolk color, were investigated. A total of 180 brown eggs were obtained from one 27-week-old flock of Hy-line brown-laying hens raised in a cage system. Correlations were evaluated using Pearson's correlation coefficient (r). The results showed strong correlations between Haugh unit and albumen height, eggshell color CIE L^* and reflectivity, egg weight and width, egg weight and length, eggshell color CIE L^* and CIE a^*, eggshell color CIE a^* and reflectivity, and shape index and egg length (P<0.001). Moderate correlations were observed between eggshell breaking strength and eggshell thickness, eggshell color CIE a^* and CIE b^*, and shape index and egg width (P<0.001). Eggshell color CIE L^* was correlated with eggshell breaking strength (P<0.01), and eggshell color CIE a^* was correlated with Haugh unit, albumen height (P<0.01), and eggshell breaking strength (P<0.001). The present study showed significant correlations between eggshell color and other quality indicators. Thus, this study suggests that eggshell colors based on reflectiveness and the CIE L^*a^*b^* value can be used to estimate the Haugh unit, albumen height, eggshell breaking strength, and thickness.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.05a
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• pp.49-59
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• 2003

Heat stress환경의 육용종계에서 사료에 첨가한 비타민 C(200 mg/kg)와 비타민 E(250 mg/kg)가 난각 품질 및 경골 강도에 미치는 영향을 확인하고자 실험을 실시하였다. 강제 환우에서 회복된 83주령의 Ross품종 육용종계 160수를 4처리 4반복 10수씩 개별 케이지에 수용 한 뒤, 10일간의 적응 기간을 둔 뒤, 3주간에 걸쳐 32$^{\circ}C$에서 지속적으로 온도를 유지하면서 사료 섭취량, 산란율, 폐사율, 난중, Haugh unit, 난각의 품질, 경골 파괴강도 그리고 혈액 중의 혈구 세포 등을 조사하였다. Heat stress는 폐사율, 산란율, 난중, 그리고 Haugh unit를 감소시키는 경향이 있었으나 통계적으로 유의하지는 않았다. 난각의 SWUSA와 압축 파괴강도는 비타민 C/E 첨가구에서 2, 3주차에 무첨가구보다 유의하게 높았으나 (P<0.05), 비타 C 또는 E 첨가구 사이에서는 유의차가 없었다. Heterophil과 lymphocyte의 숫자는 heat stress 동안에 각각 증가 또는 감소하였다. 처리구간에는 비타민 C/E 첨가구가 H/L/ratio 수준이 가장 낮았으며, 무첨가구가 가장 높은 경향을 나타내었다. 경골의 파괴강도는 비타민 C 첨가구에서 가장 높았다(P<0.05). 혈액 중의 비타민 C 농도는 비타민 C첨가구와 비타민 C/E 첨가구에서 각각 12.73 g/ml과 8.23 g/ml으로 높았다(P<0.05). 비타민 E 첨가구와 비타민 C/E 첨가구에서 혈액 중 비타민 E 농도가 유의하게 높았다 (P<0.05). Corticosterone 농도는 무첨가구에서 5.97g/ml으로 통계적으로 유의하게 높았다.(P<0.05).

• KOREAN POULTRY JOURNAL
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• v.40 no.6 s.464
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• pp.152-153
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• 2008

갈색난의 색이 옅으면 상품가치를 저하시켜 난가에 영향을 주게 된다. 닭은 빛에 의해 비타민 D를 체내 합성을 할 수 있으므로, 고농도의 비타민 D3수준을 유지하면서 자외선에 노출 될 경우 독성으로 난각 색이 옅은 알을 산란하게 된다. 기존의 비타민 D3양을 공급하더라도 자외선에 노출 되지 않을 경우 난각 색은 정상으로 돌아온다. 산란 계의 간에서 비타민 D3독성은 난각 색 저하의 주된 원인으로 꼽히므로 사료 내 비타민 D 함량은 항상 일조량을 염두에 두고 결정 해야 한다.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.815-823
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• 2014

Green tea has been known to show beneficial effects on alleviating stress. The present study was conducted to determine the effects of dietary green tea on quality of eggs, during storage, laid by laying hens treated with corticosterone in order to mimic the current practice of the egg market. Hens were fed for 2 weeks one of three diets containing green tea at 0.0, 0.4 or 1.0%. Each dietary group was divided into two subgroups receiving corticosterone at 0 or 30 mg/kg for 1 week. Eggs, laid at 5-7 days following the initiation of corticosterone treatment, were stored at $10^{\circ}C$ for 1 or 5 weeks and then analyzed for egg quality. After 1 week of storage, egg weight was significantly increased by green tea (p<0.025) but decreased by corticosterone (p<0.0001), but no interaction was observed between both. Corticosterone decreased shell color (p<0.0001) but green tea significantly decreased shell strength (p<0.006). Yolk color, albumen height and Haugh unit were not affected by both treatments. After 5 weeks of storage, corticosterone resulted in reduced egg weight (p<0.01) and eggshell color (p<0.001) and increased shell strength, which were not attenuated by green tea. Taken together, the results of the current study show that dietary corticosterone reduces egg quality during storage, which are attenuated in part by dietary green tea.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.560-567
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• 2023

This study is part of the research on fire-resistant materials to prepare for changing fire behavior, oyster shell and egg shell, which are natural calcium carbonate materials, were substituted as fine aggregates. The purpose of this study was to evaluate the strength and fire resistance performance according to the substitution rate, and to provide data for use as fire resistance material. Oyster shells and egg shells were substituted with 10~50 % of the fine aggregate, respectively, and tested for strength and Simplified heating according to the KS test method. Although the strength of OS was measured to be higher than that of ES, the backside temperature was also measured to be higher. As a result, it is recommended to use fireproof boards with OS where strength performance is required, such as explosive fires, Where high fire resistance performance is required, such as high-temperature fires over 1000 ℃, fireproof boards with ES can be selected according to the application.

• Korean Journal of Poultry Science
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• v.50 no.2
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• pp.73-80
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• 2023

Vitamin D3 is an essential nutrient which plays an important role in calcium metabolism for eggshell formation, in calcium and phosphorus metabolism for bone mineralization, and in maintaining host immunity. Although there have been a great deal of studies investigating the role of vitamin D3 in eggshell quality and vitamin D3 contents in eggs, no attempts have been made to monitor the eggshell quality and vitamin D3 contents in eggs at farm level. Thus, this survey was conducted to measure eggshell quality and vitamin D3 contents in eggs laid from laying hens fed diets containing different levels of vitamin D3. Eggs from four commercial laying hen farms were sampled before and 1, 2, 3 and 5 weeks after provision of the vitamin D3-enriched diets added with the level of 16,500 IU and 29,000 IU. Dietary vitamin D3 did not affect the eggshell color and breaking strength, but increase the eggshell thickness. In addition, vitamin D3 contents in eggs were elevated as vitamin D3 in diets was increased. It is concluded that addition of dietary vitamin D3 into the diets of laying hens at the commercial laying hen farms could improve eggshell quality and vitamin D3 contents in eggs. It is expected that the prediction equation for egg vitamin D3 contents might be produced if more data on vitamin D3 contents in diets and eggs at the farms are to be analyzed.

• Korean Journal of Poultry Science
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• v.23 no.1
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• pp.39-46
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• 1996

An experiment was conducted to investigate the effect of feeding split diets for a.m. and p.m. in laying hens on egg shell qualities, and to study the relationship among the methods of measuring shell quality with 480 ISA Brown layers during 32∼36, 52∼56 and 72∼76 wk of age, respectively. A total of 1,080 eggs were collected from 6 treatment groups in every laying period and weighed individually. Egg specific gravity, egg breaking strength, shell thickness and shell percentage of eggs were measured, and then correlation coefficients (r) and regression equations were calculated. By feeding the split diets for a.m. and p.m. differing in ME, CP, and Ca levels, and as the Ca level of the p. m. diet increased, eggshell qualities were improved(P<0.05). The correlation coefficient values indicate that shell percentage, shell thickness and egg specific gravity are highly correlated with the egg breaking strength(P<0.01).

• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.107-108
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• 2004

산란계 육성기 제한시기 및 제한강도가 육성기 발육형태 및 산란생산성 반응을 구명하고자 1일령 갈색 산란 실용계 Isa-brown 1,000수를 공시하여 70주간 사양시험을 실시하였다. 사료급여 방법은 자유채식구와 제한급이구 9처리를 두었는데, 제한시기는 4, 6 및 8주령으로 하였고 제한강도는 각 시기별 70 %, 85 % 및 12주령 기준으로 70 %에서 85 %로 하는 처리를 두었다. 육성기 사료섭취량은 제한급이시기가 빠를수록 제한강도가 강할수록 자유채식구에 비하여 유의적으로 낮게 나타났다(P<0.05). 산란생산성은 4주령, 85 %구와 6주령 70 % 및 6주령 70 $\longrightarrow$ 85 % 전환구가 가장 우수한 것으로 나타났다. 계란 난각의 품질은 제한급이구가 산란후기에 자유채식구 대비 양호한 것으로 나타났다. 이상의 결과에서 육성기 제한급이는 육성기 사료섭취량을 절감할 수 있으며 생산성과 난각질 향상에 기여할 것으로 판단된다.