• Korean Journal of Poultry Science
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• v.27 no.2
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• pp.133-153
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• 2000

The egg's interior quality is one of the most important criteria for commercial producers and consumers. Internal quality is complex, including aesthetic factors such as taste, freshness, nutritional and processing values, and the genetic influences upon these upon these factors ranges from none to considerable. The rate of cholesterol synthesis in the hen is very high compared to other animals and humans. Genetic selection, diet drugs and other chemicals can alter cholesterol concentration in the plasma of laying hen, but attempts to manipulate the cholesterol concentration in the egg yolk are generally unsuccessful since the cholesterol can only be changed to a small extent. Factors which may affect the degree of pigmentation of the yolk include the type of xanthophyll and its concentration in the feed, the feed composition, and the health of the hen. Several feed ingredients interact with carotenoid pigment to improve or reduce their deposition rates in yolks. Egg weight is determined by genetics, body size prior to first egg housing density, environmental temperature, lighting program, total feed consumption, calcium, phosphorus, niacin, water, methionine, total sulfur amino acids, energy, linoleic acid, fat and protein levels. Eggs need to be promote levels. Eggs need to be promoted a versatile commodity and new processed egg items need to be developed. Organic eggs are laid by hens which were raised in chemical and drug frdd environments. There are still difficulties in producing these eggs due to the availability of organic poultry feeds and cost of organic grains.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.109-110
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• 2003

본 시험은 스테비아 부산물의 사료적 가치를 구명하기 위하여 산란계 사료에 첨가하여 산란계의 생산성, 난 품질, 계란의 지방산에 미치는 영향을 고찰하였다. 공시계는 78주령 하이라인 360수로 강제환우후 5％ 산란시기에 시행하여 총 20주 동안 사양시험을 시행하였다. 스테비아 부산물을 산란계 사료에 0, 2, 4, 8 ％를 첨가하여 동일한 에너지(2,800 kcal/kg)와 단백질(16 ％) 수준으로 급여하였으며, 처리구당 5반복, 반복당 18수씩 총 360수를 공시하였다. 시험기간 20주 동안, 총 산란율, 난중, 산란량, 사료요구율은 스테비아 부산물 급여구와 대조구 사이에 유의적인 차이는 없었다. 스테비아 부산물의 급여가 계란의 난 품질에 미치는 영향에서 난각강도, 난각두께, 난백고 및 Haugh Unit는 대조구와 차이가 없었지만, 난황색도는 스테비아 부산물의 급여수준이 증가할수록 높은 수치를 보여 스테비아 4 ％와 8 ％ 급여구는 대조구에 비하여 유의적으로 증가하였다. 계란의 당 전이도 시험에서는 스테비아 부산물을 급여하여 생산된 계란과 대조구 사이에 차이가 없었다. 계란의 지방산 함량은 스테비아 부산물 2 ％와 4 % 급여구가 포화지방산은 감소하였고, 단가 불포화지방산은 유의적으로 증가하였다. 이러한 결과 산란계 사료에서 스테비아 부산물은 원료사료로서 8 ％까지 가능하였다.

• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.197-208
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• 1991

This study was conducted to estimated the genetic and phenotypic correlations between economic traits and certain other traits in Korean Native Ogol fowl The data analysis were the record of 450 pullets bred from 150 dams and 20 sires of Korean Native Ogol fowl at Chungnam National University from June 18, 1987 to April 6, 1989. The results obtained are summarized as follows ： 1 The genetic correlation coefficients of the economic traits and body shape components were as follows ： between body weight and shank length, breast width. breast girth, tibia length were 0.210~0.788, 0.231~0.826, 0.610~0.995 and 0.096~0.503 between age at first egg and shank length, breast width, breast girth, tibia length were 0.555~0.626, 0.149~0.270, 0.370~0.445 and 0.014-0.124. between number of egg production and shank length, breast girth, tibia length were -0.446~-0.167, -0.162~-0.320, 0.076~0.336 and 0.203~0.312 ： between egg weight and shank length, breast width, breast girth, tibia length were 0.132~0.498, 0.236~0.410, 0.148~0.775 and -0.019~0.593, respectively. 2. The genetic correlation coefficients of the economic traits and egg components were as follows ： between body weight and albumen weight, yolk weight, shell weight were 0.083~0.591, 0 110~0.541 and 0.336~0.782 between age at the first egg and albumen weight, yolk weight, shell weight were 0.476-0.692, 0.265~0.631 and 0.420~0.519 between number of egg Production and albumen weight, yolk weight, shell weight were -0.578~-0.240, -0.255~-0.060, -0.477~-0.313. between egg weight and albumen weight, yolk weight, shell weight were 0.825~0.939, 0.382~0.564, 0.374~0.337, respectively. 3. The genetic correlation coefficients of the economic traits and egg qualifies were as follows ： between body weight and egg shape index, shell thickness, albumen height, Haugh units were 0.215~0.367, 0.248~0.650, 0.161~0.624, 0.157~0.449. between number of egg production and egg shape index, shell thickness, albumen height, Haugh units were -0.384~-0.207, -0.557~-0.306, -0.555~-0.198, -0.582~-0.074 between egg weight and egg shape index, shell thickness, albumen height, Haugh units were 0.276~0.697, 0.290~0.627, 0.238~0.538, -0.207-0.020, respectively. 4. The genetic correlation coefficients of egg compositions and egg qualities were as follows ： between albumen weight and egg shape index, shell thickness, albumen height and Haugh units were 0.110~0.584, -0.380~-0.002, 0.239~0.887 and -0.195~0.279 ： between yolk weight and egg shape index, shell thickness, albumen height and Haugh units were -0.204~0.160, 0.294~0.133, -0.049~0.133 and -0.196~-0 136 ： between shell weight and egg shape index, shell thickness, albumen height and Haugh units were 0.127~0.503, 0.127~0.476, 0.140~0.273 and -0.172~0.233, respectively.

• Korean Journal of Poultry Science
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• v.35 no.2
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• pp.143-151
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• 2008

This study was conducted to identify the correlation of bacterial phytase ($Transphos^{(R)}$) to the calcium level in feed. Of all 21-week-old 720 HyLine brown laying hens, 2 birds of similar weight were placed on each individual cage. The experiment was conducted by $3{\times}2{\times}3$ factorial design with including 3 different levels of phytase (0, 300, and 1,000 DPU/kg), 2 different levels of calcium (3.5% and 4.0%), and 3 different levels of no NPP addition 0% (0.095 NPP), 0.5% (0.185% NPP), and 1.0% (0.275% NPP). The feeding trial maintained the ME level of 2,800 kcal/kg and 16% for crude protein. The diet was fed ad libitum and 17 hours of lighting was provided throughout the experimental period. Egg production seemed to increase, in the 300 DPU of bacterial phytase added group and the cracked egg tended to reduce in Transphos added group. The egg productivity between treatment groups did not show significant difference by dietary calcium level, whereas non NPP added group (0.095% NPP) was found to be low compared to NPP added groups (P<0.05). The highest mean egg weight and the highest daily egg mass were detected in 300 DPU phytase added group. Although the mean egg weight was significantly higher in treatment groups fed with 3.5% calcium containing feeds (P<0.05), daily egg mass was no among treatment groups. The mean egg weight and daily egg mass were the lowest in non NPP added group (0.095% NPP) compared to other treatment groups (P<0.05). The feed intake showed similar pattern regardless of the bacterial phytase and calcium levels in the diet. However, the treatment groups fed diets containing NPP level of 0.275% and 0.165% showed significantly higher feed intake than the group fed with 0.095% NPP (P<0.05). Although the feed conversion was not affected by calcium and NPP levels in the diet, the most improved result was obtained from 300 DPU phytase added group (P<0.05). The eggshell breaking strength and thickness increased as dietary calcium level increase the level of calcium increases in diet. The treatment groups fed diet containing 0.275% and 0.165% NPP revealed to show improvement in eggshell breaking strength and yolk color index compared to the NPP non added (0.095% NPP) treatment group. The result of the present study suggests that the appropriate level of microbial phytase is 300 DPU and at this level, tricalciumphosphate supplementation in feed can be reduced to 40% of NRC recommendation. Higher calcium level in feed fail to show synergistic effect by adding microbial phytase.

• Korean Journal of Poultry Science
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• v.29 no.1
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• pp.19-23
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• 2002

This studs was conducted to investigate the effects of dietary carbohydrase (multi-enzyme: $\alpha$-galactosidase and mannanase) on egg quality and nutrient digestibility in laying hens. One hundred forty four, 47-wk-old, ISA Brown commercial layers were used in a 28-d feeding trial after a 7-d adjustment period. Dietary treatments were 1) CON(basal diet), 2) ME 0.1 (basal diet +0.1% multi -enzyme), 3) ME 0.2 (basal diet + 0.2% multi-enzyme). Fer overall Period, hen-day egg Production, egg weight, egg shell breaking strength and egg shell thickness were not influenced by the multi-enzyme. As the adding levels of multi-enzyme increased in the diet, egg Yolk color and egg Yolk index tended to increase with significant differences. Digestibility of DM was not affected by multi-enzyme. However, digestibility of N increased significantly as the concentration of multi-enzyme in the diet was increased. In conclusion, supplemental carbohydrase in laying hen diets nay have some roles in improving the egg Yolk color and N digestibility.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.13-15
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• 2004

Telomeres are the end of chromosomes and consist of a tandem repeat sequence of (TTAGGG)n and associated proteins. Telomeres are essential for chromosome stability and are related with cell senescence and apoptosis. This study was carried out to analyze the amount of telomeric DNA of chicken lymphocytes, which is to considered as bio-marker. The amount of telomeric DNA of lymphocytes in Korean Native Chicken and White Leghorn was analyzed by quantitative-fluorescence in situ hybridization (Q-FISH) technique using the chicken telomeric DNA probe. Telomere quantifies were compared among breeds, ages and sex, and the relationship between the amount of telomeres and their productive trait was also analyzed. Comparing the amount of telomeric DNA on lymphocytes during growing period, the amount of telomeres was gradually decreased as growing older. The telomere quantity was also significantly different in breeds and sex. Estimating correlation coefficient, the amount of telomeres was positively correlated to sexual maturity and body weight but negatively correlated to hen day egg production and egg weight. These results implicate the telomere quantity is considered as an individual bio-marker.

• 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.113-115
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• 2002

Two experiments were conducted to compare the effects of the natural and the synthetic commercial pigments on the laying performance, pigmentation and fatty acid contents in egg Yolk of laying hens. Feed intake, egg production, egg weight and feed efficiency did not have significant difference(p〈0.05) in experiments I and II. White height and haugh unit did not have significant difference(p〈0.05) in two experiments. In order to approach the yolk pigmentation to 12∼13 of Roche color fan, addition level of natural red pigment was 25∼30 ppm. In the case of synthetic red pigment, the level was 15∼20 ppm. In this experimental condition, the pigmenting effect of the synthetic pigment had better than that of the natural pigment. In the experiment 2, the Pigmenting effect of mixing Pigments were inveatigated between TM2 mixed with natural red pigment, and TM6 mixed with synthesis red pigment. The fatty acid content in yolk was not affected by pigment addition.

• Korean Journal of Agricultural Science
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• v.9 no.1
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• pp.314-356
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• 1982

In order to improve the efficiency of the main economic traits in layers the present selection index is based on body weight, age at first egg, egg production and egg weight. But as the edible parts of the egg, the yolk and the albumin, are very important economic traits, this study was conducted to estimate the selection indices combining the latter traits with the former traits, and to examine the accuracy of the indices. The experiment were 351 Single Comb White Leghorns(S. C. W. Leghorn) and 326 Rhode Island Reds (R. I. Red), improved by the closed flock breeding system at the Daejeon Branch Station of the National Livestock Breeding Station. The egg compositions were checked a total of 6097 eggs. The data for each traits were collected and analysed until 500 days of age from March 1, 1979.

• Korean Journal of Poultry Science
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• v.15 no.4
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• pp.281-286
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• 1988

This experiment was conducted to determine the optimum level of Red Pepper (including seeds) for laying-hen'diet in summer. A total 240 birds of 37 week-old Manina Brown Hen was alloted to 4 treatments, 3 replications per treatment, according to complecately randomized design to find out the effects of adding levels (0, 0.03, 0.05, 0.08%) of Red Pepper on laying Performance and e99 Quality of experimental birds for 10 weeks. The results obtained from this study were summaried as follows : 1) I班 shell thickness was different significantly among treatments, (P＜0.05). Especially, Ta was highest one. 2) Egg shell breaking strength was highly significant difference between C and $T_1$, $T_2$, $T_3$ (p＜0.01). 3) Yolk color of $T_1$, $T_2$, $T_3$ was higher than C (p＜0.01), but there was no significant difference between treatments. 4) Egg Production was slightly higher with adding Red Pepper, but the differences were no significant. 5) No significant differences were found in average egg weight among treatments.