• The Korean Journal of Zoology
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• v.30 no.4
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• pp.432-444
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• 1987

Very early stage of chick embryo cultivated in the medium containing DLtryptophan by beaker method has been investigated in vitro morphologically using electron microscopy at cellular level and found that the development of tryptophan treated chick embryos corresponding to 18∼66 hrs incubation was impaired and york granule degradation was significantly delayed. It was also found that DNA, RNA and protein biosynthesis of tryptophan treated chick embryo was greatly lowered than those of control group. Conversion of L-tryptophan into serotonin was traced using 14C-L-tryptophan and found that 13.8cA of added radioactivity was recovered from serotonin formed during 18 hrs incubation and the amounts of serotonin formed were depend upon added amount of tryptophan in e99 yolk. It seemed that the serotonin formed from external tryptophan might inhibit the degradation of yolk granule by feedback mechanism, resulting in malformation of chick embryogenesis.

• Korean Journal of Poultry Science
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• v.12 no.2
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• pp.59-64
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• 1985

The study was carried out to determine if a difference in initial chick weight was still evident in market body weight(6 or 8 week body weight) of broilers. The data of a total of 800 broiler commercial chick raised at Poultry Breeding Farm, Seoul National University from Aug. 6, 1981 to Oct. 1, 1981 were analysed. The results were summarized as follows: 1. Although the initial chick weight was about the same, male chick grew more rapidly than female and sex difference was the most striking factor in growth rate of broiler in this analysis. 2. The relationship between initial chick weight and body weight after hatching was decreased to the increase of weeks of age in both sexes. Though the correlation coefficients of the 6 week and 8 week body weight to the initial chick weight were 0.15 & 0.15 in female and 0.18 & 0.17 in male, the relationship was highly significant in both sexes. 3. Regressions of 6 and 8 week body weight on the initial chick weight in both sexes indicate that, for each increase of one gram in weight of chick at hatching, the average increase in body weight was 8.33 gram ＆ 10.07 gram in female and 7.85 gram ＆ 11.28 gram in male. Results show that the initial chick weight (1 day of age) influence average body weight of commercial broiler at 6 and 8 weeks of age.

• Journal of Food Hygiene and Safety
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• v.2 no.1
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• pp.41-49
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• 1987

• Food Science of Animal Resources
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• v.30 no.4
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• pp.568-574
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• 2010

This study introduced a chick embryos’ infection model to elucidate the pathogenesis mechanism of Pseudomonas aeruginosa, which causes serious diseases in human after ingestion of P. aeruginosa-contaminated animal originated foods. The embryonic chick model is able to give a rapid and relatively inexpensive method to assess bacterial pathogenicity compared to embryos of other vertebrates. Embryos were infected with P. aeruginosa and elastase-deficient P. aeruginosa. After infection with P. aeruginosa cells, total bacterial cell numbers and gelatinase activities in the embryos were compared. Thereafter, precartilage condensation and chondrogenesis were assessed by peanut agglutinin (PNA) binding on day 3 and by Alcian blue staining for sulfated proteoglycans on day 5, respectively. P. aeruginosa significantly increased in embryos, resulting in abnormal limb development, whereas P. aeruginosa defective in elastase activity partly impaired proliferation. In addition, P. aeruginosa-infected chick embryos significantly stimulated the production of matrix metalloproteinases. Several analyses showed that elevated proteases suppressed the proliferation and survival of chondrogenic cells. The results show that this infection model was a useful assay to determine the virulence mechanism of P. aeruginosa in human after intake of microbiologically contaminated foods.

• Journal of Animal Environmental Science
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• v.19 no.2
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• pp.133-140
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• 2013

The aim of this study was to investigate the behavioral changes of laying hens in an aviary system. In this study, 500 laying hens (Hyline brown) were held in an aviary system in a open-type poultry house. The behaviors of laying hens were recorded using CCD cameras and a digital video recorder. The data were scanned every 2 min to obtain an instantaneous behavioral sample. In the behaviors of laying hens, 'Feeding' and 'Drinking' increased from 3 d placing chick and stabilized after 5 d placing chick. 'Perching' increased from 19:00 to 05:00, while 'Nest visiting' increased from 06:00 to 18:00. 'Aggressive behavior' decreased gradually after 5 d placing chick. These results suggest that the behaviors of laying hens are changed rapidly for about 5 days after placing chick and the behaviors of the laying hens are almost stabilized at 5 d placing chick.

• Korean Journal of Veterinary Research
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• v.34 no.2
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• pp.375-379
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• 1994

A teratogenicity test of 'folpet' was carried out in the developing chick embryos to investigate and validate the safety of rural environmental hazardous materials. Folpet was administered to chick embryos' yolk sac at a rate of 0.1mg and 0.01mg per SPF eggs at 96 hours of incubation. The morphological changes were examined. Fertility ratio of SPF eggs used was 94.9%. Hatching rate of untreated control group was 74.4% and the group dosed with 100ul of corn oil into the yolk sac was 70.0%. The $LD_{50}$ of folpet was 0.663mg/100ul/egg. After hatching, mean body weight, body length, claw length and beak length of high and low dose administered groups were not significantly different from untreated and vehicle control group. There was no abnormal appearence in all the groups. Therefore it seems that, within the doses applied, folpet dose not induce potential teratogenicity in the developing chick embryos.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.585-589
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• 1994

The effects of T-2 toxin on mitogen-induced blastogenesis of chick splenic cells were investigated. The [$^3H$] thymidine incorporation in splenic cells stimulated by lipopolysaccharide and concanavalin A were equally inhibited as the concentration of T-2 toxin was increased. The effective dose of T-2 toxin causing a 50% reduction of [$^3H$] thymidine incorporation was inbetween 1.0 and 5.0 ng/ml for both mitogens. Mitogen-induced blastogenesis in chick splenic cells showed differences among experimental groups with different exposure time of T-2 toxin, exhibiting the most inhibition in the experimental group exposed to T-2 toxin at both embryonic and chick periods.

• Journal of the korean veterinary medical association
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• v.5 no.1
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• pp.6-7
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• 1961

A 50 days old chick was examined for a diagnosis of tumor occured on the back. Chick was abnormal as early as days old, by having a small tumor, with symptom of anorexja and general depression. A the time of death, tumor had growned as large as avoid ches

• Journal of the korean veterinary medical association
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• v.16 no.4_5
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• pp.189-192
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• 1980

The studies were undertaken with the objective to observe water distribution and its content in egg during the incubation periods by dry method. The resalts obtained were sammarized as follows: 1. Chick embryo was not recogenizable on second and third day

• Toxicological Research
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• v.5 no.2
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• pp.167-171
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• 1989

Potential teratogenicity of sodium glycyrrizinate in developing chick embryo was investigated. Body length was shortened significantly by dosage related when compared to untreated and vehicle control, but there was no significant difference on body weight, hind-limb length, claw length in all of the groups.