• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.35-36
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• 2004

A total of 1.200 eggs obtained from 312-day-old Hy-line Brown layer breeder hens and 319-day-old Hy-line Brown commercial layer hens (600 eggs obtained from each ones) were used to investigate the effects of storage period, storage temperature, and insemination of hens on the change of albumen height, Haugh unit (HU), albumen pH, shell strength, and yolk color. Eggs were stored up to 14 days after lay at $3\;^{\circ}C\;or\;10\;^{\circ}C$ and sampled one day after stored and then 24 hours interval. Longer periods of storage resulted in lower albumen height and HU at both storage temperatures, but in higher albumen pH. The eggs stored at $3\;^{\circ}C$ were generally higher in HU and lower in albumen pH than the ones stored at $10\;^{\circ}C$. There was no statistically difference although the eggs obtained from the non-inseminated-hens were slightly higher in albumen height and HU than the eggs obtained from the inseminated-hens. Whereas, the eggs obtained from the non-inseminated-hens in the albumen pH of eggs stored at $3\;^{\circ}C$ was significantly (P<0.05) higher than the ones obtained from the inseminated-hens, but the albumen pH of eggs stored at $10\;^{\circ}C$ did not differ each other. The mean shell strength of the eggs obtained from the inseminated-hens was significantly (P<0.05) stronger than that of the eggs obtained from the non-inseminated-hens at both storage temperatures. Albumen height and albumen pH were negatively correlated(P<0.01~0.001) in both inseminated and non-inseminated-hen's egg groups. The degree of yolk colors were not significantly changed overall of the experimental periods in both storage temperatures. The study suggests that the change of egg freshness such as albumen height and HU are relatively more associated with storage period and storage temperature than insemination or non-insemination of hens.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.1
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• pp.102-112
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• 2003

The objective of this study was to investigate the effects of food waste and probiotics supplementation on productive performance and egg composition of laying hens. Total 120 layers (Brown Tetran) 22 weeks old were divided into five groups with 4 replicates for each treatments and raised in battery cage. The experimental design was completely randomized. The egg Production rate was significantly increased in layer supplemented with 0%, 0.5%, 1.0% and 1.5% of probiotic supplemented diets compared to control (P<0.05). At feeding with food waste and probiotic supplementation had no effect on the egg shell strength (P>0.05). Haugh unit of the eggs was significantly increased in layers fed with 1.5% of probiotic supplemented diet (P<0.05). The different levels of inclusion of the food waste and probiotic supplementation had not effect on egg shell color, blood spot and albumen index of the eggs (P<0.05). There were not significant differences in over all acceptability, juiciness, texture and color of the eggs from layer fed with different levels of wood waste and probiotic supplementation. The appearance and flavor significantly deteriorated in eggs from layers fed with probiotic diets compared to control (P<0.05).

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.119-128
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• 2007

The effects of microbial phytase on laying performance, egg quality, and ileal digestibility of nutrients and amino acids were examined at three levels of phytase (0, 300, 600 unit/kg) in 55-wk-old White Leghorn for 4 weeks. Egg productivity tended to increase with supplemental phytase compared to that of control. Daily feed intake of hens fed phytase also increased. Egg shell thickness was not significantly different among the treatments. Haugh unit and yolk color were not statistically different. However, egg shell breaking strength was high at phytase treatment. Excretion and absorption of nitrogen were no difference among all treatments, but those of phosphorus was higher in the phytase treatment than control. The digestibility was high at crude fiber, crude ash, calcium and phosphorus in nutrients, at lysine, methionine and phenylalanine in essential amino acids, and alanine, cystine, glutamic acid, glycine and tyrosine in non-essential amino acids. In conclusion, supplemental microbial phytase in laying hens diet may help to improve egg production and to decrease P of feces. But, further studies were needed to investigate on the digestibility.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.203-212
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• 2004

A total of 1,200 eggs obtained from 312-day-old Hy-line Brown laying breeder hens and 319-day-old Hy-line Brown commercial laying hens (600 eggs obtained from each one) at same day were used to investigate the effects of egg storage, storage temperature, and insemination of hens on the change of albumen height, Haugh unit(HU), albumen pH, shell strength, and yolk color. Eggs were stored up to 14 days after lay at $3^{\circ}C$ or $10^{\circ}C$ and sampled one day after stored and then 24 hours interval. Longer periods of storage resulted in lower albumen height and HU at both storage temperatures, but in higher albumen pH. The eggs stored at $3^{\circ}C$ were significantly (P<0.05) higher in HU and lower in albumen pH than the ones stored at $10^{\circ}C$. The eggs obtained from the non-inseminated-hens were significantly (P<0.05) higher in albumen height, HU, and albumen pH than the eggs obtained from the inseminated-hens. Whereas, the eggs obtained from the non-inseminated-hens in the mean albumen pH of eggs stored at $3^{\circ}C$ were significantly (P<0.05) higher than the ones obtained from the inseminated-hens, but the mean albumen pH of eggs stored at 10^{\circ}C did not differ each other. The mean shell strength of the eggs obtained from the inseminated-hens was significantly (P<0.05) stronger than that of the eggs obtained from the non-inseminated-hens at both storage temperatures. Albumen height and albumen pH were negatively correlated $(P<0.01\~0.001)$ in both inseminated and non-inseminated-hen's egg groups. The degree of yolk colors was not significantly changed overall of the experimental periods in both storage temperatures. The study suggests that the change of egg freshness such as albumen height and HU is relatively more associated with storage period and storage temperature than insemination or non-insemination of hens.

• Korean Journal of Poultry Science
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• v.46 no.4
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• pp.279-286
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• 2019

Currently, feather-sexing, which is based on differences in feather development at hatching, is a widely used chick sexing method in the poultry industry. For effective chicken feather-sexing, paternal early-feathering (EF) chickens and maternal late-feathering (LF) chickens must be bred. Therefore, it is critical to identify the effect of EF and LF patterns on production traits in chickens. Thus, the purpose of this study is to analyze and compare the production performances between 522 EF and 232 LF chickens in order to establish the Korean native chicken feather-sexing lines. The results showed that the survival rate of the LF group was significantly higher than that of the EF group from hatching to 52 weeks of age (P<0.05). Body weight, however, was not significantly different between the two groups at all ages. LF and EF groups did not significantly differ in age at first egg laying. However, the hen-day and hen-housed egg production of the LF group were significantly higher than those of EF group (P<0.01). No significant differences were found between the EF and LF groups in all egg quality indicators such as egg weight, eggshell color, albumin height and Haugh unit. Because the breeding target of Korean native commercial chicken is meat-type chicken, feather-sexing strains of Korean native chicken should be established using weighing-based paternal EF lines and laying-based maternal LF lines. Therefore, these results are critical for establishing desirable and effective feather-sexing strains.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.263-270
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• 2013

The vent sexing and the auto-sexing by using sex-linked traits are general sexing methods of day-old chicks. Currently, the feather sexing which is based on the differences in the feather characteristics at hatching is the representative sexing method of chicken, because the late-feathering is sex-linked trait. The feather sexing can be used if the breed has dominant feathering gene (K) in maternal and recessive gene ($k^+$) in paternal. Therefore it is necessary to identify the association of feathering genes and quantitative traits in chickens. In this study, we investigated the influence of the rate of feathering on productive traits in Korean Native Chicken. In results, there was no significant difference between early-feathering chickens and late-feathering chickens in reproductive performance such as fertility and hatchability. Livability, body weights, egg production, egg weight and egg quality also did not significantly differ between early- and late-feathering chickens. Age at first egg was the only trait of those tested in which significant difference was observed. The early-feathering chickens laid eggs 3 days earlier than late-feathering chicken. As a result, there is no influence of feathering phenotypes on productive performance in Korean Native Chickens. Consequentially, establishing the feather sexing strain is available using the Korean Native Chicken breed without considering of the effect of feathering genes on productive traits.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2005.11a
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• pp.74-75
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• 2005

In order to evaluate dietary brown seaweed and vancomycin on the performance, layers(Isa brown) were fed on basal diet and diets containing 2.0% of brown seaweed or 10ppm vancomycin. Brown seaweed diet significantly increased(p<0.01) nitrogen balance in layer, while excretion of uric acid nitrogen and metabolizable energy utilization were not different among diets. Layer consumed more the brown seaweed diet(p<0.05). Egg production were significantly different by diets but reduced(p<0.0001) with the experimental period passed. Layer fed brown seaweed diet gave thicker shell eggs, higher Haugh unit and higher egg white CuZnSOD activity compared with those in basal diet. Also, Brown seaweed diet increased MnSOD activity in erythrocyte cytosol and peroxidase in plasma, but decreased peroxide level in plasma, and increased proliferation of PBMC stimulated with PHA-P The result indicated that brown seaweed 2.0% diet in layer improved egg quality and performance due to increased protein synthesis which were related to regulation of antioxidant system and immune cell function in blood.

• Korean Journal of Poultry Science
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• v.32 no.3
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• pp.219-224
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• 2005

This study was carried out to investigate the effect of feldspar on laying Performance and e99 qualify in hens. A total of 96 'Tetra Brown' layers were assigned to 4 treatments in a completely randomized design. Each treatment consisted 4 replicates accommodating 6 layers per replication. Experiment diets were a control diet without feldspar and supplemented 0.5, 1.0 and $1.5\%$ feldspar. The egg Production rate was significantly increased in layers 134 diets supplemented 0.5 and $1.0\%$ feldspar compared to that of control (P<0.05). Egg weight, egg mass, feed intake, feed conversion ratio, egg shell strength and egg yolk color were not significantly different among the treatments (P>0.05). The haugh unit and blood spot of the eggs were significantly increased in $1.5\%$ feldspa. diets compared to that of control (p<0.05). However, the albumen index and meat spot in the eggs were not statistically different among treatments (P>0.05). Sensory evaluation traits were not significantly differed in terms of appearance, color, texture flavor and overall acceptability of eggs (P>0.05). The juiciness of boiled eggs was significantly increased in eggs of birds fed $1.0\%$ feldspar diets(P>0.05).

• Korean Journal of Poultry Science
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• v.34 no.3
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• pp.197-205
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• 2007

This study was conducted to compare the effect of feeding molting and fasting molting on the performance, egg quality, and visceral organs in laying hens for animal welfare. Eighty one 62-wk-old White Leghorn hens that egg production was over 80% and average weight was $1.6{\pm}0.3\;kg$ were used in this study. Treatments were control (non-molt treatment), feeding molt treatment, and fasting molt treatment. The three treatments were administered to three replicate group of nine hens wherein each group. All treatment groups were fed the basal diet (CP 15%, ME 2,700 kal/kg) for two weeks as the adaptation period. Induced molt diets contains low CP (6.7%) and low energy (2,200 kal/kg). Test periods were 14 days for feeding molting and 10 days for fasting molting. Egg production decreased to be 0% at 10 days of feeding molting treatment, but at 2 or 3 days of fasting molting treatment. Egg production restarted after 19 days ending molt at feeding molting treatment, while after 24 days at fasting molting treatment. On the egg quality was improved at molting treatments (p<0.05) except egg yolk. Egg shell tissue was crowded at molting treatment to compare to control. Liver weights, heart weight, and oviduct weight of laying hens decreased at molting treatments (p<0.05). Finally, feeding molting might could be replaced fasting molting on the welfare and further studies were needed about molting program.