• Korean Journal of Organic Agriculture
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• v.9 no.4
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• pp.135-148
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• 2001

Antibiotics supplementation in animal feeds results in bacterial resistance to the antibiotics and residue of the antibiotics in animal products, which can cause serious problems in human health. Therefore, the finding of new substances replacing antibiotics are needed. New substances are egg york antibody, probiotics, organic acid, mannanoligosaccharide(MOS), fructooligosaccharide(FOS), and chitosan etc. Egg york antibody is antibody to obtain from egg york of the chicken injected the specific antigen. Probiotics can prevent the problems of residue of the antibiotics and resistance to the antibiotics. Organic acids ctrl preservation of colostrum inhibit the rottenness and increase the beneficial bacteria. MOS and FOS increase the beneficial bacteria, too. Chitosan is used the immune material to active the anti-bacteria.

• Korean Journal of Poultry Science
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• v.41 no.4
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• pp.287-296
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• 2014

Chicken eggs undergo various physiological changes during egg maturation. To study genes associated with the egg maturation in pre-ovulation (immature) and post-ovulation (mature), we compared gene expression patterns between in the immature egg and mature egg using RNA sequencing data. Mature and immature eggs were obtained from a Heuksaek Jaerae-jong of Korean native chicken. Total RNAs obtained from the eggs were sequenced by Illumina HiSeq 2000 platform, and the generated sequence reads were mapped to Galgal4 reference sequence assembly using Tuxedo Protocol. From the comparison of the RNA sequencing data, 315 genes were differentially expressed between mature and immature eggs, and 46 genes were only detected in immature egg. Further gene ontology (GO) analysis was performed for the differentially expressed genes using DAVID, showing that 29 and 28 GO terms were independently clustered from mature and immature, respectively. From those clustered GO terms, genes related to germ cell development, sex differentiation and defense response to bacterium were mainly expressed in the immature egg, while genes related to regulation of apoptosis, steroid metabolic process and lipid homeostasis were mainly detected in the mature egg. Our results could contribute to understand egg maturation before and after ovulation, and develop genetic markers for improving egg quality and productivity.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.391-398
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• 2010

This study was conducted to investigate the effects of feeding probiotics(gene modified yeast) on the egg quality in laying hens. The laboratory method of this study is as follow: In hens, 300, 36 weeks old ISA brown commercial layer, were employed in 13weeks feeding trial with a 7 days adjustment period. Dietary treatments are 1) control (basal diet) 2) Y0.3 (basal diet+0.3% probiotics), 3) Y0.5% (basal diet+0.5% probiotics), 4) PY0.3% (basal diet+0.3% plasmid modified probiotics), 5) PY0.5% (basal diet+0.5% plasmid modified probiotics). For overall period, hen-day egg production, egg weight (p<0.05) by dietary probiotic supplementation were recorded. Eggs were collected and weighed every day. Egg production number and egg production rate, egg weight, failure egg ratio and trouble egg ratio were recorded for 13weeks days. Diets PY0.3 and PY0.5 improved Egg production rate, egg production number and egg weight, compared to control diet (linear effect. p<0.05). And, diets PY0.3 and PY0.5 improved Egg production rate, egg production number, compared to Y0.3 and Y0.5 (linear effect. p<0.05). But, in Inferior egg and cracked egg, diets PY0.3 and PY0.5 did not tended to increase by dietary probiotic supplementation compared to control diet and Y group (0.3, 0.5) (linear effect. p<0.05). The productivity enhance on the egg quality in laying hens is considered from the effects of feeding probiotics(gene modified yeast).

• Korean Journal of Poultry Science
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• v.31 no.1
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• pp.55-59
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• 2004

1975년의 통계를 100으로 하여 각 연차별 증감비율을 나타내었다. 1975년도 사양농가수는 507,300호, 총 사양수수는 154,504천 수, 성계 암탉수수는 116,420천 수 및 계란 생산량은 1,787,845톤이었다. 다만 1995년도와 1998년도의 통계에는 사양수수가 300수 미만인 농가는 제외하였다.(중략)

• Korean Journal of Veterinary Research
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• v.42 no.3
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• pp.371-376
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• 2002

Swine respiratory diseases have induced severe economic lasses in swine industry worldwide. Therefore, several methods have been made and applied to prevent and control the diseases. However, these methods still have a problem and also induce side effects. Recently, the use of egg yolk antibody was introduced to control and prevent the diseases as one of new trials. As a study of using egg yolk antibody, antibody titers against several different antigens of major pathogens in swine respiratory diseases were compared in egg yolk and serum of hens immunized with those antigens. The titers were measured by ELISA using the antigens as coating antigens. The relationship in antibody titers between egg yolk and serum were identified by analysis of variance for linear regression. Almost of antigens used in this study showed the high relationship in antibody titers between egg yolk and serum (r = 0.87 ~ 0.93) even though the relationship in antibody titers against P. multocida A:3 IROMP was slightly low (r = 0.74)(P<0.01). These results indicated that antibody titer in egg yolk could be useful to predict the titer in serum of chicken.

• Korean Journal of Agricultural Science
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• v.45 no.2
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• pp.229-237
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• 2018

This study was conducted to investigate the effect of natural mineral complex fed to laying hens during the summer in terms of the egg quality. A total of 480 laying hens (160 leghorns, 160 Korean native chickens and 160 silkies, all 62 weeks old), were used for 4 weeks. The four dietary treatments were as follows: CON) basal diet; MC1) CON + 0.1% natural mineral complex (NMC); NMC3) CON + 0.3% NMC, and NMC5) CON + 0.5% NMC. In terms of egg weight, the NMC3 and NMC5 treatments had significantly higher egg weights than that of the CON (p < 0.001) in all species. Eggshell strength in the NMC3 and NMC5 treatments was significantly higher than that of the CON in the leghorns on 2 week (p < 0.01). In the Korean native chickens, the eggshell strength for the NMC1, NMC3 and NMC5 treatments was significantly higher than that of the CON during all periods. In 4 week, the eggshell strength for the CON and NMC1 treatment was significantly higher in the leghorns (p < 0.001), but the MC treatments had a significantly higher eggshell strength than that of the CON in Korean native chickens. Egg production was significantly improved in all the treatments compared to the NMC3 treatment (p < 0.05), and hatchability was also improved compared to the CON (p < 0.05). In conclusion, supplementation of natural mineral complex in chicken diets influenced the egg quality during the summer season.

• Korean Journal of Poultry Science
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• v.50 no.3
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• pp.133-141
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• 2023

We conducted a 5 × 5 diallel cross-combination test using 1,060 chickens from pure lines of Korean Rhode-C, -D, Korean Leghorn-F, -K, and Korean Native Yellowish-brown chicken (KNC-Y) to develop a new Korean native chicken layer breeder. The laying performance and combining ability, including livability, body weight, age of first egg-laying, hen-day egg production, and egg weight, were analyzed. The livability from birth to 48 weeks was 72.1±24.0%, with the highest observed in the YC and the lowest in the DK combination (P<0.01). The YC combination exhibited the highest general combining ability (GCA), while the YD combination showed the highest specific combining ability (SCA). Regarding body weight, combinations involving Leghorn showed lighter weights compared to combinations with Rhode and KNC-Y (P<0.01). Additionally, the offspring from the KNC-Y combination reached sexual maturity earlier than those from the Rhode combination. The hen-day egg production was 70.7±12.0%, with the highest seen in the CK combination at 86% (P<0.01). The effects of GCA and SCA on hen-day egg production were similar, with the SCA being highest in the YD combination and the GCA being highest in the Rhode-C. Significant differences in egg weight were observed among the combinations, with the eggs from Rhode and Leghorn combinations being heavier than those from combinations with KNC-Y (P<0.01). In conclusion, the YC and YD combinations, characterized by excellent livability, are highly desirable paternal strains, while the CF and CK combinations, with excellent laying performance and moderate egg weight, are preferred maternal strains for Korean native chicken layer breeders.

• Journal of Applied Biological Chemistry
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• v.55 no.4
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• pp.247-252
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• 2012

This study examined the control effects of amino acid biochemical agent extracted from chicken feathers on Meloidogyne incognita for the purpose of developing an environmentally friendly nematicidal agent that can replace chemical control of root-knot nematodes (RKN). We investigated the lethal effects of J2 juveniles for 19 types of commercial amino acids. As a result, five kinds of amino acids (L-asparagine, L-aspartic acid, L-methionine, L-tyrosine, L-cysteine) showed mortality rate of more than 50% at a concentration of 50 mM. L-asparagine showed the highest mortality rate at 94%. We also investigated the lethal effect of J2 juveniles and suppressive effects of egg hatching by feather amino acids (FAA) biochemical agent. It showed that the mortality rate of J2 juveniles was more than 80% and suppression rate of egg hatching was 74% at 1/50 concentrations of FAA. As a result of conducting a tomato pot culture experiment for 60 days after treating 1/50 concentrations of FAA biochemical agent in rhizosphere soil, it showed that the control effects were 63% of juveniles density in the soil, 59% of egg mass and 61% of root gall index, respectively. Based on the above results, it is considered that the FAA biochemical agent extracted from chicken feathers can be used as an environmentally friendly nematicidal agent of RKN.

• Research in Plant Disease
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• v.12 no.2
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• pp.144-147
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• 2006

Egg yolk immunoglobulin (IgY) is much widely used in medical fields, but its use in serology of plant viruses is much limited. We produced an IgY against pepper mild mottle virus (PMMoV) and applied it to several serological tests. Polyclonal antibodies were obtained from the egg yolk of chicken immunized with a total of 2mg of purified PMMoV over 2 months. The titers of antibodies were measured with the ring-test over six months after the first injection. The highest.titers of IgY was 1/2,560 at 2 months after the first injection. Approximately 60-80 mg of IgY were obtained from one egg yolk. Using the IgY, 1ng/ml of purified PMMoV was detected with the indirect ELISA. Gelrite gel double diffusion test, ELISA and tissue immuno-binding assay employing IgY gave similar sensitivity and specificity to those of IgG developed in rabbit. Therefore, the IgY which can be obtained in large quantities from a chicken, might be useful for the antibody production and the serology of plant viruses.

• Korean Journal of Poultry Science
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• v.47 no.4
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• pp.237-245
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• 2020

This study investigated the effects of breed, laying age, and egg storage period on hatching performance. Eggs were collected from early laying period (27 to 29 weeks old) and late laying period (50 to 52 weeks old) in Hwanggalsaek Jaeraejong, Korean Rhode Island Red, and Korean White Leghorn chicken breeds. Eggs laid for each period were stored for 3, 7 and 14 days and then hatched. Fertility, hatchability, and embryonic mortality were observed to determine the hatching performance. The results showed that hatching performance was affected by breed, laying age, and egg storage period with independently or interactively. The Korean Rhode Island Red breed had the lowest hatching performance. Hatchability and early embryonic mortality rate increased in early laying period eggs compared to the late laying period, but the late embryonic mortality rate increased in late laying period eggs. Additionally, hatching performance decreased as the egg storage period increased. Using breed-specific hatching management techniques, avoiding late laying period eggs, and shortening the egg storage period to seven days after laying may improve the hatching performance.