• Journal of Animal Environmental Science
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• v.2 no.2
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• pp.103-110
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• 1996

This survey was conducted to investigate the situation of three types of laying hen houses and farmers' awareness of farm automation. Six windowless, three high-rising windowless and four open-sided laying hen houses were surveyed to compare their characteristics, and sixty farmers answered questionnaires. 1. Population density of laying hen was 13.9 birds/m^2$ in open-sided, 28.9 birds/m^2$ in high-rising windowless, and 44.9 birds/m^2$ in windowless laying hen houses. 2. Feeder space was $12{\sim}13.5cm$ in open-sided laying hen houses, but feeder space of windowless and high-rising hen houses was narrower than that of open-sided laying hen houses. 3. Thermal resistance values were $14.6{\sim}18.7\;m^2\;{\circ}C/W$ in wall, #22.0{\sim}23.7\;m^2\;{\circ}C/W$ in roof of windowless and high-rising windowless laying hen houses but the wall of open-sided laying hen houses was only $1.9\;m^2\;{\circ}C/W$. 4. Maximum ventilation capacity was 0.161{\sim}0.326$ cmm/bird in summer. Minimum rate of tunnel Ventilation laying hen houses in winter was $0.013{\sim}0.040$ cmm/bird, but minimum rate of crossflow and high-rising windowless laying hen houses was larger than that of tunnel ventilation houses. 5. One person managed about 8,100 birds in open-sided, and about 23,500 birds in windowless and high-rising windowless laying hen houses. 7. 90.7% of farmers responsed that they want to construct automatized laying hen houses in the future.

• Korean Journal of Poultry Science
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• v.13 no.1
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• pp.31-40
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• 1986

The energy metabolism with the normal laying hen and progesterone injected non-laying hen are compared. 1. The FHP of 109.7Kcal for laying hen was 25.5 percent higher than the 87.4 Kcal found for non-laying hen. 2. The MEm's of laying hen and non-laying hen were 149, and 135Kcal/Kg$\^$0.75/day and NAME's of the diets were 77 and 83 percent, respectively. For the laying hen shown negative retention in body energy during the experiment, the 77 percent NAME was the value of supporting egg production. For the non-laying hen shown the positive retention in body energy and zero egg production, the 83 percent NAME was of growth. 3. A change in body weight of 1g was comparable to 3.54 Kcal for laying hen, and 5.0 Kcal for non-laying hen, when calculated on regression equations between body weight change and body energy retention(BE). The figures indicate that the tissue energy is used with an efficiency of 70 percent for egg production. 4. Plasma level of triiodothyronine(T3) for the laying hen is appeared to be higher than that of non-laying hen, although the levels of thyroxine (T4) are equal both in laying and non-laying hen. 5. Activities of four hepatic enzymes(ATP citrate lyase, fructose diphosphate aldolase, isocitrate dehydrogenase and glutamte pyruvic transaminase) were significantly greater in the laying hen than in the non-laying hen.

• Korean Journal of Veterinary Service
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• v.20 no.2
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• pp.183-189
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• 1997

This article reports a spontaneous thoracic teratoma in a laying hen (Deklb brown warren). In this case, a 40 days old hen was submitted for necropsy as part of an investigation into a flock problem suspected Marek's disease to Chonbuk Veterinary Service Laboratory in 1983. On the gross finding, mass was In the cranial subpulmonary cavity and attached to the vertebral column. It contained fully developed contour feathers. Histologically, feathers were arised from feather follicles complete with arrector plumi muscle, nerve, vessel and mucous gland composed with simple tall columnar epithelium. The outer surface of mass was lined by keratinized or nonkeratinized stratified squamous epithelium. It converted to pseudostratified ciliated columnar epithelium in some area. There were lymphocyte infiltration around gland tissue and eosinophilic intranuclear inclusion bodies in nonkeratinized epithelium. This thoracic teratoma was composed of ectodermal origin, squamous epithelium and nerve, and endodermal origin, mucous gland. This case in laying hen has never been reported in the literature in the world.

• Food Science of Animal Resources
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• v.34 no.1
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• pp.127-132
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• 2014

Optimization of carnosine and anserine extraction from chicken breast was performed using response surface methodology (RSM) to obtain the maximized physiological activities for anti-glycation and anti-oxidation. The optimum extraction conditions were water extraction for 1.6 h in the case of the 20-wk laying hen muscle and water extraction for 2.12 h in the case of 90-wk laying hen muscle. Higher carnosine and anserine contents were measured in the 20-wk laying hen muscle, along with higher physiological activities, which increased in direct proportion with the dipeptide contents. The extracts prepared from the 20-wk laying hen under optimum conditions showed 57% inhibition of advanced glycated end-product formation, 64% inhibition of lipid peroxidation, and 61% of DPPH radical scavenging effects. On the other hand, 52% inhibition of AGE formation, 62% inhibition of lipid peroxidation, and 53% of DPPH radical scavenging effect were demonstrated within the 90-wk laying hen. In addition, the ratio of carnosine was a key indicator for the physiological activities of the extracts.

• Food Science of Animal Resources
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• v.32 no.6
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• pp.740-748
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• 2012

This research was conducted to develop a new approach to Chuncheon Dakgalbi processing by various chicken materials, seasoning (conventional sauce/CS and new approach of seasoning by adding the curing mixture/CSA), and cooking methods. Three chicken breeds (broiler, old broiler and spent laying hen) were divided into five experimental groups: broiler-CS, old broiler-CS, old broiler-CSA, spent laying hen-CS, and spent laying hen-CSA. All samples were stored at $5^{\circ}C$ for 12 d. For sensory evaluation, all samples were cooked with conventional cooking (pan grilling) or high temperature and pressure cooking (at $121^{\circ}C$ with pressure 1.5 $Kg_f/cm^2$ for 30 min). The chicken material analysis showed that the moisture and crude protein content, cooking loss and shear-force of the old broiler and spent laying hen were higher (p<0.05) than those of the current broiler, but the crude ash, crude lipid and WHC were lower (p<0.05). The addition of CSA increased the pH value and reduced the lipid oxidation at the end of storage regardless of chicken breeds (p<0.05). The high temperature and pressure cooking method seemed to increase the taste, smell and overall-acceptability scores of the old broiler and spent laying hen Chuncheon Dakgalbi regardless of the implementation of new approach of seasoning (CSA). In conclusion, an old broiler and spent laying hen can be used as material of Chuncheon Dakgalbi by the application of a new approach of seasoning and cooking method.

• Korean Journal of Poultry Science
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• v.13 no.1
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• pp.1-14
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• 1986

The subject of this study was to obtain some genetic information for developing superior layer chickens. Heterosis and combining ability effects were estimated with 5,759 progenies of full diallel crosses of 6 strains in White Leghorn. Fertility, hatchability, brooder-house viability, rearing- house viability, laying-house viability, age at 1st egg laying, body weight at 1st egg laying, average egg weight, hen-day egg production, hen-housed egg production, and feed conversion were investigated and analyzed into heterosis effect, general combining ability, specific combining ability and reciprocal effect by Grilling's model I. The results obtained were summarized as follows; 1. The general performance of each traits was 94.76% in fertility, 74.05% in hatchability, 97.47% in brooder-house viability, 99.72% in rearing-house viability, 93.81% in laying-house viability, 150 day in the age at 1st egg laying, 1,505g in the body weight at 1st egg laying, 60.08g in average egg weight, 77.11% in hen-day egg production, 269.8 eggs in hen-housed egg Production, and 2.44 in feed conversion. 2. The heterosis effects were estimated to -0.66%, 9.58%, 0.26%, 1.83%, -3.87%, 3.63%, 0.96%, 4.23%, 6.4%, and -0.8%, in fertility, hatchability, brooder-house viability, laying-house viability, the age at 1st egg laying, the body weight at 1st egg laying, average egg weight, hen-day egg Production, hen-housed egg production and feed conversion, respectively. 3. The results obtained from analysis of combining ability were as follows ; 1) Estimates of general combining ability, specific combining ability and reciprocal effects were not high in fertility. It was considered that fertility was mainly affected by environmental factors. In the hatchability, the general combining ability was more important than specific combining ability and reciprocal effects, and the superior strains were K and V which the additive genetic effects were very high. 2) In the brooder-house viability and laying-house viability, specific combining ability and reciprocal effects appeared to be important and the combinations of K${\times}$A and A${\times}$K were very superior. 3) In the feed conversion and average egg weight, general combining ability was more important compared with specific combining ability and reciprocal effects. On the basis of combining ability the superior strains were F, K and B in feed conversion, F and B in the average egg weight. 4) General combining ability, specific combining ability and reciprocal effects were important in the age at 1st egg laying and the combination of V ${\times}$F, F${\times}$K and B${\times}$F were very useful on the basis of these effects. In the body weight at 1st egg laying, general combining ability was more important than specific combining ability and reciprocal effects, relatively. The K, F and E strains were recommended to develop the light strain in the body weight at 1st egg laying. 5) General combining ability, specific combining ability and reciprocal effects were important in the hen-day egg production and hen-housed egg production. The combinations of F${\times}$K, A${\times}$K, and K${\times}$A were proper for developing these traits. 4. In general, high general combining ability effects were estimated for hatchability, body weight at 1st egg laying, average egg weight, hen-day egg production, hen-housed egg production, and feed conversion and high specific combining ability effects for brooder-house viability, laying house viability, age at 1st egg laying, hen-day egg production and hen-housed egg production, and high reciprocal effects for the age at 1st egg laying.

• Korean Journal of Poultry Science
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• v.26 no.4
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• pp.247-252
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• 1999

This experiment was carried out to investigate the effects of the laying hens on the immune response against bovine serum albumin(BSA) in egg yolk. Total 45 laying hens were divided into three groups according to breeds (White Leghorn, ISA Brown, Native hen). They were fed the experimental diet for 12 weeks. Immune response were examind in egg yolk from three groups of hens injected with BSA. The results obtained from this work were summaried as follows : 1. The weight of egg yolk and the percentage of hen-day production in the ISA Brown hens are greater than those in the Native hens and the White Leghons. 2. IgY concentrations in eggs from hens immunized with BSA were not different among the breeds laying hens. 3. The anti-BSA antibody activities determined by enzyme linked immunosorbent assay (ELISA) in the egg yolk were similar between the White-Leghorn and ISA Brown hens, but Native hens tended to decrease in 20∼50 days respectively. Therefore, the weight of egg yolk and the percentage of hen-day production in the ISA Brown hens are greater than those in the Native hens and the White Leghons will be as important factors for an efficient production of IgY.

• Korean Journal of Poultry Science
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• v.41 no.4
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• pp.271-277
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• 2014

The objective of this study was to determine the effect of the meat from spent laying hen on the shelf-life and physicochemical properties of emulsified sausage. Four types of sausage were made: 0% (Control), 10% (T1), 20% (T2) and 30% (T3) of spent hen meat added. Each sausage type was tested in triplicate. The addition of spent hen meat resulted in decreased crude fat and cooking loss, and increased WHC (water holding capacity), CIE $a^*$ and hardness. Values for crude fat and cooking loss were significantly decreased by the addition of spent laying hen meat relative to the control (P<0.05). Especially, T3 was significantly (P<0.05) decreased compare to other treatment groups. Spent laying hen meat addition had no significantly effects on moisture, crude protein, crude ash, pH, WHC, TBARS (thiobarbituric acid reactive substance) values, shear force, total plate counts (TPC), CIE $L^*$ and $b^*$ values. In conclusion, this study demonstrates that the addition of spent laying hen meat to emulsified sausages tended to improve sausage quality.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.7
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• pp.994-998
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• 2017

Objective: An experiment was conducted to determine the effect of superdosing phytase on productive performance and egg quality in laying hens. Methods: A total of 200 42-wk-old Hy-Line Brown laying hens were allotted into 1 of 5 dietary treatments with 5 replicates consisting of 8 hens per replicate. The positive control (PC) and negative control diets (NC) were prepared based on the recommended P levels in layer diets. Supplemental phytase was added to the negative control diet at 10,000 (SD10), 20,000 (SD20), or 30,000 (SD30) fytase units (FTU)/kg. Productive performance was summarized for 6 weeks from 42 weeks to 47 weeks of age. Egg quality was assessed from 4 eggs per replicate randomly collected at the conclusion of the experiment. Results: The SD20 treatment had greater (p<0.05) hen-day egg production than PC, NC, and SD10 treatment groups. There was no difference in hen-day egg production between SD20 and SD30 treatment groups. However, SD30 treatment had greater (p<0.05) hen-day egg production than PC treatment, but showed no difference in hen-day egg production as compared to NC and SD10 treatment groups. However, egg weight, egg mass, feed intake, and feed conversion ratio were not affected by dietary treatments. Egg quality including eggshell strength, eggshell color, egg yolk color, and haugh unit was not influenced by dietary treatments. Conclusion: Superdosing level of 20,000 FTU/kg phytase in diets has a positive effect on egg production rate, but no beneficial effect on egg quality in laying hens.

• Reproductive and Developmental Biology
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• v.37 no.1
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• pp.41-49
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• 2013

Ovarian cancer is the most lethal world-wide gynecological disease among women due to the lack of molecular biomarkers to diagnose the disease at an early stage. In addition, there are few well established relevant animal models for research on human ovarian cancer. For instance, rodent models have been established through highly specialized genetic manipulations, but they are not an excellent model for human ovarian cancer because histological features are not comparable to those of women, mice have a low incidence of tumorigenesis, and they experience a protracted period of tumor development. However, the laying hen is a unique and highly relevant animal model for research on human ovarian cancer because they spontaneously develop epithelial cell-derived ovarian cancer (EOC) as occurs in women. Our research group has identified common histological and physiological aspects of ovarian tumors from women and laying hens, and we have provided evidence for several potential biomarkers to detect, monitor and target for treatment of human ovarian cancers based on the use of both genetic and epigenetic factors. Therefore, this review focuses on ovarian cancer of laying hens and relevant regulatory mechanisms, based on genetic and epigenetic aspects of the disease in order to provide new information and to highlight the advantages of the laying hen model for research in ovarian carcinogenesis.