본 연구는 사료내 비테인, 글라이신, 그리고 콜린의 혼합 첨가가 고온 스트레스 환경에서 노령 산란계의 생산성, 난품질, 면역 반응 및 혈액성상에 미치는 영향을 조사하고자 수행되었다. 총 336마리의 86주령 로만 갈색종 노령 산란계를 6처리 7반복, 반복당 8수씩 임의 배치하였다. 대조구는 모든 영양소 및 에너지 요구량을 충족하거나 초과하도록 배합하였다. 대조구를 제외한 사료 처리구는 0.2% 비테인, 0.62% 글라이신, 그리고 0.32% 콜린을 단독, 두 가지 혼합, 혹은 세 가지 혼합으로 사료내 첨가하였다. 실험은 8주 동안 진행되었으며, 모든 산란계는 매일 8시간 동안 평균 온도 31.7±1.7℃, 습도 57%의 고온 스트레스 조건에서 사양되었고, 이외 시간에는 평균 온도 27±1.3℃, 습도 57%에서 사양하였다. 실험 결과, 비테인, 글라이신 및 콜린의 첨가는 생산성, 난품질, 그리고 면역 반응에 유의적인 영향을 미치지 않았다. 그러나, 0.2% 비테인과 0.62% 글라이신을 혼합 첨가한 처리구에서 혈청 알라닌 아미노전이효소 농도가 유의적으로 감소했다. 하지만, 다른 혈청 지표들은 처리간 유의적인 차이가 관찰되지 않았다. 결론적으로, 현재 수준에서 사료내 비테인, 글라이신, 그리고 콜린의 혼합 첨가는 고온 스트레스 환경에서 사양되는 노령 산란계의 생산성, 난품질, 면역 반응 및 혈액 성상에 긍정적인 영향을 미치지 않는다고 판단된다.

The objective of the present experiment was to investigate the effects of dietary vitamin C (VC), vitamin E (VE), and betaine (BT) supplementations on productive performance, egg quality, relative organ weights, liver visual characteristics, antioxidant status, immune response, and stress indicator in laying hens raised under heat stress conditions. A total of 280 47-wk-old Hy-Line Brown laying hens were allotted to 1 of 4 dietary treatments with 7 replicates in a completely randomized design. Each replicate had 10 birds per cage. The basal diet was formulated to meet or exceed the requirement estimates for Hy-Line Brown laying hens. Three additional diets were prepared by adding 250 mg/kg VC, 250 mg/kg VE, or 3,000 mg/kg BT to the basal diet. The experimental diets and water were provided to hens on an ad libitum basis for 8 wk. Average daily room temperature and relative humidity were 30.7±1.41℃ and 72.5±11.61%, respectively. Results indicated that hens fed diets containing 250 mg/kg VE had a less (p<0.05) egg production rate than other dietary treatments. For egg quality, hens fed diets containing 3,000 mg/kg BT had a less (p<0.05) eggshell thickness than those fed the diets containing 250 mg/kg VC or 250 mg/kg VE. For antioxidant status, there was a tendency (p=0.09) for the least malondialdehyde (MDA) concentrations in the liver for BT treatment. A tendency (p=0.05) was observed for less blood heterophil:lymphocyte ratio in BT treatment as compared to other treatments. In conclusion, dietary supplementation of 250 mg/kg VC, 250 mg/kg VE, and 3,000 mg/kg BT has no beneficial effects on productive performance, egg quality, relative organ weights, liver visual characteristics, and immune responses of laying hens raised under the current heat stress conditions. However, dietary supplementation of 3,000 mg/kg BT alleviates antioxidant status and stress response of laying hens exposed to heat stress.

본 연구는 고온 환경에서 사료내 트립토판과 나이아신의 첨가가 산란계의 생산성, 난품질, 지방간 지표 및 혈액성상에 미치는 상호작용 효과를 조사하고자 수행되었다. 총 384수의 25주령 로만 갈색종 산란계를 4처리 8반복으로 반복당 12수씩 무작위 임의 배치하였다. 기본 사료는 트립토판과 나이아신의 추가적인 첨가는 없으며 모든 영양소 및 에너지는 로만갈색종 산란계의 요구량에 충족하거나 초과하도록 배합되었다. 사료 처리구는 2 × 2 요인 실험 설계법으로 두 가지 수준의 트립토판(0 및 0.16%)과 두 가지 수준의 나이아신(0 및 0.03%)이 포함되었다. 모든 산란계의 사양환경은 일반 농가에서 낮시간에 온도가 올라가는 점을 고려하여 일일 중 8시간은 온도 31.4 ± 1.17℃, 습도 86.0 ± 4.28%으로 설정하였으며, 나머지 16시간은 온도 26.7 ± 1.10℃, 습도 61.7 ± 6.34%로 유지하여 주기적인 고온 환경을 조성하였다. 실험은 10주간 진행되었다. 실험 결과 사료내 트립토판과 나이아신의 주요 효과와 상호작용은 나타나지 않았다. 이와 유사하게, 난각 강도, 난각 두께, 난각색, 난황색 및 호우유닛에 대한 상호작용 도 나타나지 않았다. 주요 효과로 0.03%의 나이아신 첨가는 난황색을 유의적으로 감소시켰으나 호우유닛은 유의적으로 증가시켰다. 하지만, 0.16%의 트립토판 첨가는 난품질에 영향을 끼치지 않았다. 지방간 지표와 혈액성상에서 사료내 트립토판과 나이아신의 주요 효과 및 상호작용은 나타나지 않았다. 결론적으로, 본 연구에서 설정한 농도의 사료내 트립토판과 나이아신의 첨가는 고온 환경에서 사양되는 산란계의 생산성, 난품질, 지방간 지표 및 혈액성상에 긍정적인 영향을 미치지 않았다.

계란의 비린내 강도는 가금류의 종류와 개인의 인식에 따라 다르지만 여러 요인에 의해 발생할 수 있다. 특히 트 리메틸아민(TMA)이 원인으로 밝혀졌다. 주목할만한 점은 리보플라빈이 TMA를 무취의 트리메틸아민-N-옥사이드로 전환시키는 역할을 하는 효소인 플라빈 함유 모노옥시게 나제 3의 활성을 증가시킬 수 있다는 점이다. 본 연구는 난황의 TMA 함량을 분석하여 비린내에 대한 기여도를 평 가하고, 비린내를 방지하는 방법을 개발하는 것을 목적으 로 하였다. 고체상 미세추출-기체 크로마토그래피/질량 분 석법을 사용하여 리보플라빈이 강화, 보충된 사료를 먹인 암탉의 난황에 있는 휘발성 화합물을 감지하고 정량화했다. 또한 샘플 간 휘발성 물질의 상대적 함량을 비교하기 위해 전자코를 이용하여 상관관계 연구를 수행하였다. TMA는 콜린이 함유된사료를 섭취한 가금류의 난황에서 고농도로 검출되었지만 리보플라빈이 보충된 사료를 섭취한 가금류 에서는 검출되지 않았다. 전반적으로, 이 연구는 리보플라 빈이 TMA를 포함하여 계란에 존재하는 휘발성 물질의 양 과 품질에 영향을 미친다는 것을 시사한다. 이러한 발견 이 계란의 비린내를 줄이는 것은 물론 품질 향상에 기여 하기를 기대한다.

The present study evaluated the repellent activity and the improvements in egg production and mortality rate on laying hens infested with poultry red mites (PRM) administered with a mixture of Korean traditional herbal methanolic extracts (CHE, Foeniculum vulgare : Sophora flavescens : Cinnamomum cassia : Glycyrrhiza glabra = 1:1:1:1, w/w/w/w). PRM numbers per laying hens in CHE-0.5 administered with CHE 0.5 kg/ton feed were significantly decreased compared to those in Non-CHE (control) during overall experimental periods (1st week post-treatment, p<0.05; 2nd week post-treatment, p<0.01; 3rd-4th week post-treatment, p<0.001). In CHE-1.0 administered with CHE 1.0 kg/ton feed, PRM numbers were significantly decreased compared to those in Non-CHE during the whole experimental periods (1st week post-treatment, p<0.01; 2nd-4th week post-treatment, p<0.001). After administration of CHE for 4 weeks, egg production and mortality rate in CHE-0.5 and CHE-1.0 were significantly improved compared to those in Non-CHE (p<0.05). In addition, hematological and blood biochemical parameters in all CHE-treated groups were insignificantly different compared to those in Non-CHE. This study showed that CHE (0.5 and 1.0 kg/ton feed) had a repellent activity on PRM in laying hens and effects on the improvement in egg production and mortality rate of laying hen. CHE could be an effective and safe candidate for the control of PRM and the improvement in egg production and mortality rate of laying hens.

본 연구는 계란 생산성, 계란품질 및 악취저감에 관한 Bacillus subtillus, Streptomyces galilaeus 및 Sphingobacteriaceae로 구성된 복합생균제(PM, probiotic mixture)의 효과를 조사하였다. 산란계 Hy-Line Brown 240수를 4처리구로 구분하여 6주 동안 사육하였다. 처리구는 복합생균제를 함유하지 않은 대조구(CON, control), 일반생균제(CP3, commercial probiotics 0.3%), 복합생균제 3(PM3, 복합생균제 0.3%), 복합생균제 5(PM5, 복합생균제 0.5%)로 구분하였다. 산란율, 계란 호우유니트, 난각두께, 난각강도, 난황색 및 농후난백 높이는 PM3, PM5가 CON 및 CP3에 비해서 높았다. 계분으로부터 암모니아, E. coli, 총호기성균, Coliform, Salmonella 균수는 CON>CP3>PM3>PM5 순서로 증가하였다. 본 결과는 B. subtillus, S. galilaeus 및 Sphingobacteriaceae로 구성된 복합생균제 0.3%가 산란율, 계란품질 개선 및 분에서 암모니아 발생을 낮추어 양계장 악취저감 효과를 갖는다는 점을 보여 준다.

본 연구는 산란후기 사료에 뽕잎의 수준별 첨가 급여가 산란계의 생산성, 계란품질 및 혈액성상에 미치는 영향을 구명하고자 시행하였다. 74주령 하이라인 브라운 산란계 360수를 4개처리 5반복 반복당 18수씩 배치하여 12주간 사양실험을 실시하였다. 처리구는 ME 2750kcal/kg, CP 15%인 기초사료에 뽕 잎분말을 0, 0.2, 0.4 및 0.8% 수준으로 첨가 급여하였다. 산란율과 난중은 매일, 사료섭취량과 계란품 질은 4주 단위로 조사하였고, 혈액성상과 난황지방산은 사양실험종료 후 채취하여 측정하였다. 전체 사양실험기간에서 산란율과 1일 산란량은 뽕잎 첨가구에서 증가하는 경향을 보였지만 처리구간에 통계적 차이는 없었고, 난중, 사료섭취량 및 1일산란량도 유의적 차이는 없었다. 사료요구율은 실험 전기간 뽕 잎첨가구에서 개선되는 경향이 있었으며, 특히 82~85주령에서는 통계적 차이를 확인하였다(p<0.05). 난백높이, 호유닛, 난각강도 및 두께는 처리구간 차이가 없었다. 불포화지방산은 뽕잎의 첨가수준에 따 라 현저하게 증가하였지만(p<0.05), 포화지방산은 감소되었다(p<0.05). 혈청 HDL 콜레스테롤은 0.4% 첨가수준에서 현저하게 증가하였고(p<0.05), 중성지방은 뽕잎 급여수준에 따라 매우 감소하는 경향을 보였다. 그러므로 본 연구결과는 뽕잎의 첨가급여가 산란후기 산란계의 생산성, 계란품질 및 강건성을 개선하는데 효과적인 것을 시사한다.

The present study was conducted to determine the optimal supplementation level of beta-mannanase in the diet of laying hens. A total of 320 Hy-Line Brown layers (80 weeks of age) were assigned randomly into four groups on the basis of laying performance. Each treatment had eight replicates with 10 birds each (80 birds per treatment). Two hens were caged individually. Treatments were basal diet supplemented with 0 (control), 0.04, 0.08, and 0.16% beta-mannanase during the nine-week feeding period. Laying hens fed diets supplemented with increasing levels of beta-mannanase had increased (linear, p<0.05) overall egg production and egg mass. In addition, these hens had greater retention of dry matter, crude protein, gross energy, calcium, and mannan (linear, p<0.05). Dietary beta-mannanase treatments had no effect on blood metabolites such as total carbohydrate, triglycerides, glucose, total protein, and blood urea nitrogen, or excreted ammonia nitrogen and volatile fatty acids. The results obtained in present study indicate that dietary supplementation of beta-mannanase has the potential for improving the performance of laying hens. The optimal supplementation level is 0.04% beta-mannanase in the diet.

본 연구는 마늘껍질 생균제 급여가 산란계의 생산성 및 계란 품질에 미치는 영향을 구명하고자 실시하였다. 60주령의 산란계(Hy-line Brown)를 4개 처리구(control, T1, T2 및 T3)로서 처리당 6반복, 반복 당 6수씩 총 144수를 공시하였다. 시험구인 T1, T2 및 T3는 마늘껍질 생균제를 각각 0.5%, 1.0%, 2%를 첨가하여 4주간 급여하였으며, 산란계의 생산성 및 계란 품질을 분석하였다. 난중은 처리구들간 유의차가 없었으나, 사료섭취량은 대조구에 비해 마늘껍질 생균제 0.5%와 2% 급여구인 T1 및 T3에서 높게 나타났다(P<0.05). 계란생산량은 모든 마늘껍질 생균제 급여구에서 대조구에 비해 높게 나타났으며, 마늘껍질 생균제 급여량이 증가할수록 계란 생산량 또한 증가하였다(P<0.05). 계란품질을 평가하는 난각강도, 난각두께, 난황높이 및 haugh unit 값에선 유의차가 없었으나(P>0.05), 마늘껍질 생균제 급여시 증가됨을 확인하였다. 난황 내 아미노산 조성 결과, T2에서 높은 황함유아미노산 값을 나타내었으며, T3에서 가장 높은 불포화지방산 함량을 나타내었다. 또한 마늘껍질 생균제 급여량이 증가할수록 불포화지방산 함량이 높게 나타났다(P<0.05). 따라서 마늘껍질 생균제 급여는 산란계의 사료섭취량 및 계란생산성 증가뿐만 아니라 계란 품질을 개선시키는 것으로 사료된다.

발효 새송이버섯 균사체(FPEM)의 사료 내 첨가급여 효과를 검토하기 위하여 산란계(ISA Brown) 16수를 4개 그룹으로 나누어 대조구는 기초사료(C)만 급여하였고, 시험구는 기초사료에 FPEM 1%(T1), 3%(T2) 및 5%(T3)로 하여 8주 동안 사료 내 첨가하였다. FPEM을 산란계의 사료 내 첨가한 결과 1%에서 산란율이 감소한 것을 확인할 수 있었으나(p<0.05), 계란 무게는 FPEM 모든 첨가구에서 대조구와 비교하여 유의하게 증가하였다(p<0.05). 결과적으로 계란 생산량과 사료섭취량에서 대조구와의 차이가 나타나지 않아서 사료요구율 또한 대조구와 유의한 영향을 주지 않았다. 하지만 대체적으로 FPEM 5% 수준인 T3에서 계란 생산량 증가와 사료요구율 감소의 경향을 나타내었다. 계란의 품질의 경우 FPEM 1%에서 난백고와 난각중이 대조구에 비해 유의하게 증가하였으며(p<0.05), FPEM 5%에서는 계란의 외부 품질인 난각중과 난각두께 모두 대조구에 비해 유의하게 증가하였다(p<0.05). 하지만 난황색, 육반과 혈반 그리고 계란의 저장성의 경우에는 처리간 차이를 보이지 않았다. 난황 내 지방산 조성의 경우 FPEM 첨가에 의해 불포화지방산과 다가 불포화지방산 중 n-3지방산의 비율이 높아졌으며(p<0.05), FPEM 5%는 다른 처리구보다 초기 계분의 가스 발생량을 유의하게 감소시키는 것으로 나타났다(p<0.05). 결과적으로 산란계 사료 내 FPEM 5%첨가는 계란 생산과 품질뿐만 아니라, 환경 개선 효과도 있는 것으로 밝혀져 항생제를 대체할 수 있는 산란계 사료 첨가제로 기대된다.

Antibodies are used for preventing several infectious diseases in food animals. Though, antibiotics can deal with infection however, their widespread usage may cause developments of resistance and can also get transferred to humans through animal products. Therefore, production of antibodies against infectious agents in the egg yolk could be an interesting alternative. The present study was conducted with a focus on producing the antibody against Escherichia coli E68 and H28 in egg yolk of laying hens, which are believed to be a cause for diarrhea and beriberi in piglets. The result received from the experiment were promising and have shown efficiency of antibody production in the range of 2-7.3% in the groups which are infected with E68 only and the one which was infected with both strains. The outcome of present research has revealed the potentiality of egg yolk in production of antibody for laying hens, could open a new approach for production of antibodies to manage diarrhea and beriberi

This study was conducted to evaluate the feeding value of black soldier fly pupa (BSFP) on fecal microorganism, immunoglobulinm egg quality and egg production laying hens. One hundred twenty laying hens were assigned to 4 treatments (0, 5, 7 and 10% BSFP) with 3 replicates for 8 weeks. The formulae of 4 experimental diets were modified to contain 18% CP and 2,900 kcal/kg. All the treated groups differed in feed intake, egg production, egg weight and egg mass compared to those of a control group. The egg weight and production were increased (p < 0.05) in BSFP groups compared to the control. The HDL-C was increased (p < 0.05) in BSFP groups compared to the control. The level of immunoglobulin IgG and Haugh unit were increased (p < 0.05) in BSFP groups compared to the control. These result suggested that the addition of BSFP to the layer diet could improve the egg quality and the laying performance.

We investigated the duration of laying worker oviposition and egg-laying behavior in three queenless colonies of A. cerana by in situ video recording. Egg load was determined by dissecting laying workers in September 2012. Egg size, length and breadth, shape index and egg elongation were calculated. To determine the number of eggs laid by laying workers per cell at 24, 53, 74, 120 and 171 hours was also monitored. To estimate the number of eggs per cell per week, a small comb was squeezed between two frames. The combs were collected at given hours and weekly to count the number of eggs, respectively. The results showed that the duration of oviposition of laying workers on average was 109.2 ± 67.5 seconds per cell. During oviposition, egg-laying workers showed two types of behaviors, viz; a still phase, where the egg-laying workers did not move, and a recovery phase, where the egg-laying workers vigorously wagged their abdomens after oviposition. The results showed that on average, 4.0 ± 5.1 of worker eggs per cell per week was recorded. The highest number of eggs was recorded at 120 hours compare to at 24, 53, 74 and 171 hours. Three different shapes of the eggs namely oval, elongated long and elongated curve shaped was laid by workers. The results showed that the laying worker carried 1 to 4 mature eggs in her ovaries and may lay from one to four per oviposition. In conclusion, the laying worker shows a still and a recovery phase during and after laying the eggs. The laying workers retain 1 to 4 eggs in their ovaries. The breadth of eggs is strong positive relationships with length. One worker cell can accumulate up to 33 eggs in queenless colonies.

본 연구는 산란계 사료 내 돼지감자(Helianthus tuberosus L.)로부터 제조한 미세캡술화 이눌린(microcapsulated inulin, MI)의 고수준 첨가가 혈액지질, 계란콜레스테롤 및 지방산조성에 미치는 영향을 조사하기 위해 실시하였다. 25주령 갈색산란계를 이용하여 4주 동안 실험사료를 급여하였으며, 실험처리구는 MI 무첨가 대조군, 800 ppm, 900 ppm 및 1,000 ppm로 구분하였다. 혈액 중성지방, 총콜레스테롤 및 계란 콜레스테롤은 MI 무첨가군과 비교할 때 첨가군에서 유의하게 감소하였다. 계란 포화지방산 조성은 MI무첨가군과 비교할 때 첨가군에서 낮았으나 불포화지방산은 그 반대로 유의하게 높았다. 본 연구결과는 미세캡슐화 이눌린을 산란계 사료 내 첨가해주면 혈액지질 감소에 의해 계란품질을 향상시킬 수 있음을 시사해준다.

This study was conducted to evaluate the feeding value of the spent mushroom (Pleurotus eryngii) substrates (SMS) in laying hens (Hy-Line Brown). The fresh spent mushroom (Pleurotus eryngii) substrates collected from the DOJUN farm were fermented with Bacillus subtilis EJ3 for 2 weeks. A total of twenty-four laying hens were fed corn-soy based experimental diets containing 0% (control), 5% (T1), 10% (T2) and 15%(T3) fermented SMS for 7 weeks. There were no significant differences among the treatments in egg production, egg weight, egg mass, feed conversion and viability during the experimental period. Feed intake was significantly lowered in control (118.3 g) than T1 (121.9 g), T2 (120.3 g) and T3 (122.4 g). There were no significant differences among the treatments eggshell breaking strength, thickness and haugh unit, whereas the yolk color of T1, T2 and T3 were significantly heavy than T0. The palatability of boiled meat was significantly better in the T3 laying hens than in the T0 laying hens. In conclusion, fermented SMS can be used as resource of feed in laying hen feed at 5.0-15% level without effect on performance and egg qualify.

This study was conducted to investigate the effect of dietary sericite(SC) on laying performance, feed conversion ratio, egg quality and fecal ammonium nitrogen. Three hundreds and sixty 92-wk-old, Lohman Lite layers were randomly divided into 20 groups of 18 birds each and assigned to five experiment for 4 weeks (72 birds per treatment). Dietary treatments were Control (control diet), SC 0.5 (control diet +0.5% sericite), SC 1.0 (control diet +1.0% sericite), SC 1.5 (control diet +1.5% sericite), and SC 2.0 (control diet +2.0% sericite). Hen-day egg production tended to increase by the SC 1.0%, SC 1.5% and SC 2.0% supplementation in the diets. Egg weight also tended to increase by the SC 1.0% addition in the diets. Feed intake was increased (p<0.05) in SC 1.5 and SC 2.0 but feed conversion was improved (p<0.05) only in SC 1.0 (p<0.05). Digestibility of nutrients were not linearly affected by dietary supplementation of sericite although there was an inconsistent difference. Egg shell strength, albumin height, yolk color, and egg shell thickness were not affected (p<0.05) by treatments. Fecal NH3-N concentration was decreased (p<0.05) by dietary sericite supplementation compared to control. This study showed that dietary 1.0% sericite supplementation can be beneficial to improve egg production, egg weight and feed conversion and to decrease fecal NH3-N concentration.

We investigated the effect of different kinds of dietary added fat on the fatty acid composition, cholesterol content and quality of hens‘ eggs. The Haugh units, breaking strength, shell thickness and yolk color were not significant difference among the groups. Dietary fat notably altered the polyunsaturated fatty acid composition and cholesterol content in the egg yolk. The n-6 fatty acid of egg yolk was highest in the corn oil fed group with 31.61%, and this tended to decrease in the order of the tallow, linseed oil and fish oil fed groups(p<0.05). The n-3 fatty acid of egg yolk tended to increase in the linseed oil and fish oil fed groups as 9.74% and 5.16%, respectively(p<0.05). Theses alterations in the yolk fatty acid composition resulted in a reduced cholesterol content of the eggs. The ranges of cholesterol content showed values of 15.98-18.37 mg/g of yolk or 227-261 mg/60g of egg, respectively(p<0.05). The cholesterol content of egg yolk was highest in the tallow fed group, and this tended to be reduced in the order of the fish oil, linseed oil and corn oil fed groups(p<0.05). The reduction of the egg yolk cholesterol content in the other groups compared to the tallow group was significantly different, i.e., 13.01% in the fish oil group, 11.49% in the linseed oil group and 6.91% in the corn oil group, respectively(p<0.05). This result suggests that it is possible to reduce the cholesterol content or to increase the n-6 and n-3 polyunsaturated fatty acids in eggs by manipulation of the dietary added fats.

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.