In this work, ultra-fine calcium oxide (CaO) powder derived from eggshells is used as the starting material to synthesize mineral trioxide aggregate (MTA). The prepared CaO powder is confirmed to have an average particle size of 500 nm. MTAs are synthesized with three types of fine CaO-based powders, namely, tricalcium silicate (C3S), dicalcium silicate (C2S), and tricalcium aluminate (C3A). The synthesis behavior of C3S, C2S and C3A with ultra-fine CaO powder and the effects of C3A content and curing time on the properties of MTA are investigated. The characteristics of the synthesized MTA powders are examined by X-ray diffraction (XRD), field emission-scanning electron microscope (FE-SEM), and a universal testing machine (UTM). The microstructure and compressive strength characteristics of the synthesized MTA powders are strongly dependent on the C3A wt.% and curing time. Furthermore, MTA with 5 wt.% C3A is found to increase the compressive strength and shorten the curing time.

To elucidate the effect of feeding differently prepared CaCO3 (industrially purified limestone) on laying performance, egg shell quality and serum calcium and phosphorus concentration, totally 288 layers (52 wks old), with 16 birds per replicate, 3 replicates per treatment for six treatments were employed into the series of CaCO3 treatments followed by feeding study. Six CaCO3 treatment and diet preparation includes mash diet with naturally sized CaCO3 (MNaC), mash diet with coarsely particled CaCO3 (MCoC), mash diet with finely particled CaCO3 (MFiC), pelleted diet with naturally sized CaCO3 (PNaC), pelleted diet with casein coated CaCO3 (PCnC) and pelleted diet with agar coated CaCO3 (PAgC). Hen day egg production of the bird fed both fine CaCO3 and pelleted CaCO3 were lower (p<0.05) than those fed other CaCO3 diets. Although there is no difference in average egg weight among treatments, the weight tended to be heavier once the egg production rate was low. There is no difference in feed conversion ratio (intake/egg) among treatments. Egg shell thickness was the highest (p<0.05) with feeding of MCoC whereas the value was the lowest with feeding of pelleted CaCO3 diet. Although there is some difference in egg shell thickness, the shell breaking forces were not significantly different among treatments. Calcium content of the shell was the lowest (p<0.05) in the egg from the layer fed finely particled CaCO3. Serum Ca content tended to decrease up to 8 hrs after feeding, then tended to increase afterwards. Although both agar and casein coating of CaCO3 tended to retard the recovering increase of blood Ca, the difference needed to be clarified with individual ovulation cycle. Serum P level was generally decreased as time passed after feeding. Crude protein utilizability was the highest with feeding of agar coated CaCO3 and that of fat was higher with hens fed pelleted diets. Both ash and P utilizabilities of diet with finely particled CaCO3 were the highest among treatment although there were no differences in both energy and Ca utilizabilities. Conclusively, both the particle size of CaCO3 and pelleting of CaCO3 diet could affect shell quality of the egg. The effect was more evident by the differentiation of CaCO3 particle size than any other processing such as pelleting and coating.

난각칼슘을 식초에 침지하여 제조한 양조칼슘, 현미칼슘과 난각칼슘분 및 침 강성탄산칼슘을 횐쥐에 식이 후 칼슘의 혈청 중 보유량(흡수율)에 관하여 비교시험 결과는 다음과 같다. 1. 이온화율이 높은 양조칼슘낀폐,통기 현미칼슘의 흡수는 경구투여 2시간 후에 최고치에 이른 것으로 나타났으며 이온화율이 낮은 난각칼슘분이나 침감성탄산칼슘은 이보다 늦은 5시간 후에 최고치에 이른 것으로 나타났다. 이는 이온화율이 높은 칼슘일 수록 흡수가 빠르게 진행되는 것으로 사료된다. 2. 횐쥐에 식이한 칼슘시료의 칼슘의 혈청 중 보유량은 현미칼슘>양조칼슘(밀폐))양조칼슘(통기))침강성탄산칼슘>난각칼슘분 순으로 낮게 나타났다. 이는 이온화율의 순과 같았다 3. 현미칼슘의 혈청중 칼슘농도가 난각칼슘분에 비하여 약 4배 높은 것으로 나타난 것으로 보아 칼슘의 혈청 중 보유량은 칼슘 섭취수준에 의한 영향보다 칼슘 이온화율과 밀접한 관련이 있는 것으로 사료된다. 4. 제조 조건에 따른 양조칼슘의 칼슘의 혈청 중 보유량은 밀폐조건이 통기조건에 비해 약 1.4배 높은 것으로 나타난 이유를 규명하기 위해서는 연구가 계속 진행되야 할 것으로 본다

멧누에나방(Bombyx mandarina) 난각유전자의 형질발현기구를 규명하기 위한 연구의 일환으로 각형성과정에 있어서 난각단백질의 합성과정을 분석하였다. 난각단백질의 합성과정을 여포세포의 기난관배양에 의한 in vitro합성계에 의하여 분석한 결과, 합성과정은 8단계로 나눌 수 있었으며 SDS-PAGE 분석에 의해 17개 이상의 단백질 band로 분리되었다. 멧누에 난각단백질은 합성시기에 따라 3단계로 구분되며 초기에는 비교적 고분자 성분이, 합성의 중후기에는 비교적 저분자성분이 합성되는 등 난각단백질의 합성은 시기특이적으로 조절되었다.

한국산 멧누에(Bomdyx mandarina)chorion 유전자의 형질 발현기구를 규명하기 위한 연구의 일환으로 본 실험을 실시했다. 멧누에의 난각구조를 주사형 전자현마경에 의해 관찰한 결과 매우 특이적인 구조가 인정되었다. 즉 원추상의 불규칙 돌기에 의한 돌기구조층과 이 돌기 구조층을 덮고 있는 한 층의 얇은 덮개 구조층이 그것이다. 2차원 전기영동법에 의해 chorion 단백질을 분석한 결과, 난각을 구성하는 주요 단백질 성분은 등전점 4~6, 분자량 6~30 kd로 밝혀졌다. 특히 특이난각구조와 관련된 특이단백질 성분을 검출하였으며 이들의 대부분은 고cysteine 단백질인 것으로 추정했다. 이상의 연구결과에 의해 멧누에 난각의 특이 구조 형성에 따른 유전자발현기구 규명을 위한 기초자료가 얻어졌다.

The purpose of this study was to investigate the egg freshness and eggshell characteristics of old laying hens by adding sea urchin shell powder to the feed of such hens to achieve the objectives continuously pursued by environmental management, such as business profitability and waste resource utilization. A total of 90 Hy-Line Brown layers (66 weeks of age) were randomly divided into 2 treatments with 3 replicates, each of which consisted of 15 older layers, for 4 weeks. These treatments included a control (i.e., 0%) and 2% sea urchin shell powder. The 2% supplementation of sea urchin shell powder increased the Haugh unit (HU) at 2 and 4 weeks and eggshell strength at 4 wks compared to the controls (p<0.05). The HU at 0 weeks, eggshell thickness from 0 through 3 weeks, and eggshell strength at 0 and 2 weeks were not different between treatments (p>0.05). These results suggest that the addition of 2% sea urchin powder to the feed of laying hens improves egg freshness and eggshell strength in old laying hens.

This study was conducted to investigate the effects of dietary supplementation of various types of fermented red ginseng marc with red koji to laying hens on eggshell and egg yolk quality characteristics. A total of 240 Hy-line Brown laying hens (40 wk of age) were randomly allotted to 24 pens (6 replicates per treatment and 10 laying hens per replicate). Experimental diets consisted of 4 treatments containing basal diet (control), 1% fermented red ginseng marc powder with red koji, 1% fermented red ginseng marc pelleted with red koji and 1% fermented red ginseng marc coated with red koji. During the 8-wk feeding trial, there were no significant differences in eggshell strength, eggshell thickness and eggshell color among the treatments, except for eggshell strength at 4 and 8 wk and eggshell thickness at 0 wk. In addition, no differences in egg yolk color and egg yolk index were found for all treatments throughout the 8-wk feeding period, except for egg yolk color at 0 wk. Thus, using various types of fermented red ginseng marc with red koji to laying hens did not improve eggshell and egg yolk quality characteristics.

폐기되고 있는 난각을 건조(80℃) 및 회화(1,000℃) 처리하여 칼슘 소재화하고 이의 농도(0.5, 1.0, 2.0%)를 달리하여 절단배추에 처리하여 polyethylene(PE) 지퍼백에 넣어 5℃에서 6주 동안 저장하면서 선도유지 효과를 조사하였다. 난각 칼슘 소재의 칼슘 함량은 회화처리(ESP-2)가 건조처리(ESP-1)보다 2배 가량 높은 값(51.86%)을 나타내었다. 난각 칼슘 소재는 citric acid 수용액에서 높은 용해도를 나타내었으며, ESP-2가 ESP-1보다 용해도가 높았다. 절단배추의 이화학적 품질특성의 측정 결과, ESP-2 0.5% 처리구에서 중량감소율, 적정산도, 가용성 고형분 및 색차의 변화가 가장 적게 나타났다(p<0.05). 저장기간에 따른 관능평가결과 각 처리구의 유의적인 차이는 나타나지 않았다(p<0.05). ESP-2 0.5% 처리는 절단배추의 단기 저장 시 선도유지에 효과적인 것으로 사료된다.