• Korean Journal of Crystallography
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• v.5 no.1
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• pp.33-38
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• 1994

'Heterogeneous' vapor diffusion experiments were carried out using hen egg white Iysozyme and equine serum albumin as model proteins: droplets were equilibrated against reservoir solutiorls containing an alternative precipitant which is different from results showed that the use of polyethylene glycol as an alternative precipitant instead of NaCl or ammonium sulfate reduces equilibration rate between droplet and reservoir solution. By using the heterogeneous vapor diffusion techniqlue it is possible to control the equilibration rate by adjusting the relative amounts of ionic salts and nonionic yecipitants in reservoir solutions.

• Korean journal of food and cookery science
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• v.12 no.1
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• pp.54-59
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• 1996

Immunoglobulins (IgY) were isolated from egg yolk of hens immunized with bovine serum albumin(BSA). The stability of anti-BSA IgY against heat and pH was investigated. Antibody activity was measured by enzyme linked immunosorbent assay. IgY was relatively heat-stable and most of the antibody activity remained after heating up 65$^{\circ}C$ for 30 minutes. IgY was stable at pH 5-11. However, inactivation of IgY was observed below pH 4, or above pH 12. Inactivation of IgY proceeded rapidly at low pHs(pH 2-3). Most of the antigen binding activity was lost at low pHs probably because of some conformational changes.

• Korean journal of food and cookery science
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• v.14 no.5
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• pp.492-497
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• 1998

The stabilizing effect of fructooligosanharide (FO) on hen＇s egg yolk immunoglobulin (yIgG) by heat and acid was investigated. The heat stability of yIgG at 70∼80$^{\circ}C$ was enhanced in a concentration-dependent manner by adding 0∼50% (w/v) FO to a yIgG solution. Acid-induced inactivation of yIgG was also suppressed in a concentration-dependent relationship by addition of FO. Addition of 50% FO almost completely stabilized yIgG at pH 3. The remarkable stablizing effect of FO on yIgG may enhance the use of yIgG as functional food ingredients.

• Preventive Nutrition and Food Science
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• v.5 no.2
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• pp.65-69
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• 2000

Hen egg-white lysozyme was conjugated with 7~9 mers xyloglucan hydrolysates(MW-1,400) at 6$0^{\circ}C$ and 79% relative humidity for 3 days. SDS-PAGE showed that the conjugation between lysozyme and the oligosaccharide began from 1-day incubation, and three molecules of carbohydrate chains were attached to a protein molecule after 30day incubation. The enzymatic activity of lysozyme was totally conserved in the neoglycoprotein, when measured by using glycol chitin as substrate. Besides, the emulsifying properties of lysozyme were vastly improved by the conjugation with the oligosaccharide, in which emulsifying activity of the neoglycoprotein was five times higher than that of native one.

• Korean Journal of Poultry Science
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• v.30 no.4
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• pp.281-287
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• 2003

This experiment was carried out to study the effect of dietary Monascus culture on the cholesterol contents of egg yolk, muscle and serum of layers with 180 Isa-Brown laying hens for 10 weeks. Control group(C) was fed the commercial laying hen diet and 2.67(T1), 5.33(T2) and 8.00(T3)% of Monascus culture which contained 0.6% monacolin-k added to control diet so as to supply the monacolin-k 20(T1), 40(T2) and 60(T3) mg respectively, per hen-day with 125g diet. Hen-day egg production and average egg weight were not affected by the dietary Monascus culture, but feed intake and feed conversion per kg egg were significantly decreased(P<0.05) as the dietary Monascus culture increased. Cholesterol contents of egg yolk measured 4~5 weeks after feeding the Monascus culture and those of thigh meat measured at the end of experiment were significantly decreased(P<0.05) as the dietary Monascus culture increased. Average cholesterol contents of serum showed a trend to decrease as the dietary Monascus culture increased without significant difference.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.991-997
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• 2019

This study was conducted to investigate the laying period performance of two crossbred Korean native chicken (KNC) grand parent stock (GPS) layer during 20 to 40 weeks. A total of 351 20-week-old KNC GPS were allocated in a completely randomized design to give 4 birds per each cage. The chickens were fed commercial diets [i.e., week 20 - 32, crude protein (CP) 18.0% and metabolizable energy (ME) 2,850 kcal/kg; week 32 - 40, CP 17.0% and ME 2,800 kcal/kg)] and fresh water during the whole experiment period ad libitum basis. Body weight, age of sexual maturity, egg weight, hen-day egg production (HDP) and feed conversion ratio (FCR) were measured during the experiment period (week 20 - 40). The results show no significant difference in the Body weight, age of sexual maturity, egg weight, and hen-day egg production (HDP) except for egg weight. 1B had a higher egg weight on week 36 only. We expect that the reason why most factors showed no significant difference is the lack of nutrients caused by limited feeding which follows the standard feeding system for the grand-parent stock. These results provide basic information for laying data in 2-way crossbred Korean native chickens.

• Korean Journal of Poultry Science
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• v.31 no.1
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• pp.37-44
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• 2004

It has been recognized that the hen, like its mammalian counterparts, provides young chicks with antibodies as protection against hostile invaders. This system facilitates the transfer of specific antibodies from serum to egg yolk, and provides a supply of antibodies called immunoglobulin Y(IgY) to the developing embryo and the hatched chick. The protection against pathogens that the relatively immune-incompetent newly hatched chick has, is through transmission of antibodies from the mother via the egg. Egg yolk, therefore, can be loaded with a large amount of IgY against pathogens which can immobilize the existing or invading pathogens during the embryo development or in day-old chicks. Thus, the immunization of laying hens to various pathogens results in production of different antigen-specific IgY in eggs. Egg yolk contains 8∼20 mg of jmmunoglobulins (IgY) per ml or 136∼340 mg per yolk suggesting that more than 30 g of IgY can be obtained from one immunized hen in a year. By immunizing laying hens with antigens and collecting IgY from egg yolk, low cost antibodies at less than $10 per g compared to more than $20,000 per g of mammalian IgG can be obtained. This IgY technology opens new potential market applications in medicine, public health, veterinary medicine and food safety. A broader use of IgY technology could be applied as biological or diagnostic tool, nutraceutical or functional food development, oral-supplementation for prophylaxis, and as pathogen-specific antimicrobial agents for infectious disease control. This paper has emphasized that when IgY-loaded chicken eggs are produced and consumed, the specific antibody binds, immobilizes and consequently reduces or inhibits the growth or colony forming abilities of microbial pathogens. This concept could serve as an alternative agent to replace the use of antibiotics, since today, more and more antibiotics are less effective in the treatment of infections, due to the emergence of drug-resistant bacteria.

• Korean Journal of Poultry Science
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• v.25 no.1
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• pp.21-30
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• 1998

The effects of dietary levels and feeding period of Korean hot pepper (Capsicum annum) seed on the performance and egg quality were investigated. Rhode Island Red layers of 84 wk of age were fed the experimental diets containing O.O(Control), 0.5, 1.0, 2.0, and 3.0% of HPS, respectively, in individual cages during 10 wk of the feeding period. The dietary hot pepper seed significantly(P<0.05) improved hen-day egg production and daily egg rnass, but reduced egg weight(P<0.05). During the 10 wk of the feeding period, the egg production and daily egg mass improved after 6 or 7 wk of feeding 0.5, 1.0 or 2.0% hot pepper seed diets. When the layers were fed the 3.0% HPS diet, it only took 1 wk to improve the egg production and daily egg mass. In addition, the birds fed 3.0% hot pepper seed diet showed relatively constant egg weight while those of the Control increased gradually as the feeding period passed. The dietary hot pepper seed significantly improved the eggshell thickness, and redness and whole color of egg yolk. The results indicate that dietary hot pepper seed( $\geq$2.0%) may improve the egg production and egg shell thickness, and increase the redness of egg yolk in layers.

• Korean Journal of Veterinary Service
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• v.23 no.3
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• pp.263-269
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• 2000

This study was carried out to set a standard of damage compensation by researching state of damage due to noises in laying and prelaying hens. Recently, there are many damage cases in chicken farms near construction site that were caused by noises of construction. Therefore disputes and complaints about economical loss have increased ceaselessly. But we have few research and report such a thing. The result have shown that the weight loss rate was ranged from 9.48% to 23.2% and mortality of laying period of hens was higher than prelaying period. Pathological findings were fatty liver, congestion and hemorrhage of intestine, erosion of proventriculus and gizzard in order of case frequency. And these signs in hens of laying period was more serious than prelaying period. Half-life rate of antibody titers against Newcastle disease and infectious bronchitis in sound stressed hens was no different compared with non-stressed hens. Egg production rate dropped from 38% to 45% according to strength of noises. Before being stressed, hens produced special, large, middle, small-size eggs in the order. But after being stressed, their egg Production rate of middle, small-size Increased while egg production rate of special, large-size decreased. Production rate of soft and broken shell eggs was 0.015% in the stressed flocks higher than 0.005% in the non-stressed flocks.

• Korean Journal of Poultry Science
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• v.44 no.2
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• pp.123-134
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• 2017

This study was conducted to establish new synthetic lines of Korean Native Chicken. We performed $5{\times}5$ diallel crossings with GPS lines of Korean Native Chicken for the selection of parent stock. The production traits including viability, body weight, age at first egg laying, egg weight, hen-day egg production, and hen-housed egg production were measured and analyzed for 25 crosses with 1,157 hens. The heterosis effects of these traits were also estimated. The results showed that the average survival rate during laying periods was 67.7% in the pure lines and 77.1% in the crosses. The 25 cross combinations were shown to be distinctly divided into three groups according to body weight; nine crosses in the high-weight group, 12 crosses in the medium-weight group and four crosses in the light-weight group. The average body weight at 12 weeks of age was $1,873.8{\pm}43.0g$ in the high group, $1,595.4{\pm}56.6g$ in the medium group and $1,152.7{\pm}24.7g$ in the light group, and $1,560.2{\pm}339.3g$ in the pure lines and $1,640.9{\pm}213.7g$ in the crosses. In terms of egg production performance, the age at first egg laying was $139.7{\pm}4.9$ days in the pure lines and $135.8{\pm}5.1$ days in the crosses. The average egg weight was $52.3{\pm}1.6g$ in the pure line and $53.0{\pm}1.6g$ in the crosses. The average hen-housed egg production from 20 to 40 weeks was $58.3{\pm}12.9$ eggs in the pure line and $69.2{\pm}10.4$ eggs in the crosses. The average heterosis effect was 16.9% for survival rate, 5.4% for body weight at 12 weeks, -2.7% for age at first egg laying, 1.3% for egg weight, and 14.3% for hen-day egg production. Generally, the heterosis effect for viability and egg production traits was higher than that for growth trait. On the basis of these results, it is expected that the selection of the HF combination, which had excellent growth performance, is the most desirable as the paternal strain, and the selection of GW and FW combinations, which had excellent laying performance, are preferable as the maternal strain.