• Asian-Australasian Journal of Animal Sciences
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• 제12권7호
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• pp.1085-1089
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• 1999

Energy requirement of Rhode Island Red (RIR) hens was studied by comparative slaughter technique. Seventeen hens above 72 weeks of age were slaughtered in batches. Batch I consisted of 5 hens which were slaughtered initially. Batch II comprised of six hens, which were fed ad libitum broken rice (BR)-based diet for 18 days. Record of feed intake, number of eggs laid and egg weight during the period was kept. These hens were slaughtered and body energy content was determined. Egg energy was consisted as energy deposited. Batch III consisting of six hens which were fed varying quantity of diet for 15 days, were slaughtered similarly as hens of batch II. Regression equation (body weight to body energy) developed on batch I was applied to batch II and developed on batch II was applied to batch III hens, to find out initial body energy content of hens. Egg energy (EE) was calculated according to formula: EE (kcal) = -19.7 + 1.81 egg weight (g). Regressing metabolisable energy (ME) intake on energy balance (body energy change + egg energy), maintenance ME requirement of hens was found to be $119.8kcal/kg\;W^{0.75}/d$. Multiple regression of ME required for production on energy retained as protein and fat (body plus egg energy) indicated that RIR hens synthesize proteins with an efficiency of 85.5 and fat with an efficiency exceeding 100 percent on BR based diet.

• Animal Bioscience
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• 제35권9호
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• pp.1426-1433
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• 2022

Objective: The present research was conducted to evaluate the interactive effect of dietary concentration of calcium (Ca) and 25-hydroxy vitamin D3 (25OHD3) on the performance, blood composition and digestibility of laying hens. Methods: A total of 540 Hy-line brown laying hens aged 61 to 70 weeks were randomly allotted in a 3×3 factorial arrangement, consisting of three levels of 25OHD3 (0, 25, and 50 ㎍/kg) and three levels of Ca (3.5%, 4.0%, and 4.5%). All diets had basal concentration of 3,000 IU/kg of vitamin D3 including the 2,800 kcal/kg of metabolic energy and 16% of crude protein. Results: The results showed that interactive effect (p<0.05) between Ca and 25OHD3 was such that dietary 25OHD3 linearly increased interleukin-6 at all levels of Ca inclusion. Interaction (p<0.05) occurred with the highest parathyroid hormone in laying hens that received dietary concentration of Ca (3.5%) with 25OHD3 (50 ㎍/kg), and Ca (4.0%) with 25OHD3 (50 ㎍/kg). Egg production and egg weight significantly (p<0.05) increased in the 4.5% Ca group compared to the 3.5% to 4.0% Ca groups. Egg shell thickness and tibia bone length also increased (p<0.05) in groups fed a high-Ca diet (4.0% to 4.5%). Phosphorus digestibility significantly (p<0.05) increased along with dietary Ca level. Among the tested 25OHD3 groups, higher (p<0.05) egg production and tibia thickness were present in hens fed 50 ㎍/kg of 25OHD3. Furthermore, Ca digestibility serum Ca and 25OHD3 were significantly increased in group offered 50 ㎍/kg of 25OHD3. Conclusion: The results gathered in this study indicate that dietary concentrations of 4.0% to 4.5% Ca and 50 ㎍/kg 25OHD3 improve the performance of hens from 61 to 70 weeks of age.

• Asian-Australasian Journal of Animal Sciences
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• 제9권6호
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• pp.727-735
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• 1996

The effects of four factors-two dietary protein levels (12 and 16%), feeding methods(ad libitum and restricted), strains (A and B), and age of hens-on egg quality and laying performance were examined. Use of the 12% dietary protein level resulted in significantly lower (p < 0.05) hen-day egg production, higher feed intake to about 85% of the ad libitum intake decreased mean hen-day production. Significant feeding method-by-age interactions ($F{\times}A$) were obtained for all parameters. Restricted feeding had favorable effects on shell strength and Haugh unit values after 28 and 16 weeks of egg production, respectively. There was significant difference in shell strength between the two strain. Examination of the three-factor interaction among protein levels, feeding method and strain ($P{\times}F{\times}S$) disclosed that the favorable effect of the A strain on shell strength was significant only with the 16% protein-restricted fed group. The other treatment group did show a trend for greater shell strength of the A strain. Mean values for all the parameters examined changed significantly (p < 0.01) with the age of hens. Feed intake per dozen eggs tended to increase, with some fluctuation, as the hens aged. There was a linear decrease in Haugh unit scores and shell strength. The effect of restricted feeding on either shell strength or Haugh unit scores were favorable for the aged chickens.

• 한국가금학회지
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• 제44권2호
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• pp.67-73
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• 2017

The purpose of our study was to determine the effects of varying levels of energy, protein, and amino acids on the performances of laying hens. A total of 240 Hy-Line Brown laying hens at 36 weeks of age were used in this 4-week feeding trial. The hens were randomly allocated to five treatment diets, with eight replications of six hens in each replicate cage. The treatment diets were as follows: A- basal diet + 18% crude protein, metabolizable energy 2,800 kcal, total (methionine + cysteine) 0.65%; B- basal diet + 17% crude protein, metabolizable energy 2,700 kcal, total (methionine + cysteine) 0.59%; C- basal diet + 16.5% crude protein, metabolizable energy 2,700 kcal, total (methionine + cysteine) 0.59%; D- basal diet + 16.5% crude protein, metabolizable energy 2,700 kcal, total (methionine + cysteine) 0.54%; and E- basal diet + 16% crude protein, metabolizable energy 2,680 kcal, total (methionine + cysteine) 0.54%. The study results revealed that the hen-day egg production of hens that were fed with low-energy diets (B, C, and D) was comparable with that of hens fed with high-energy diet A, whereas average daily feed intake in hens fed treatment diet D and E was significantly higher (P<0.05) than that in hens fed treatment diet A. Overall, the eggshell thickness was unaffected by any of the treatment diets. Egg weight was comparable among the treatment diets, except for treatment diet E. Haugh unit improved with decreasing levels of dietary energy, protein, and methionine + cysteine in the diet. We can summarize that laying hens fed with low dietary energy and low crude protein treatment diets B, C, and D had satisfactory performance compared with those fed with high-energy treatment diet A. This indicates that there is the potential to reduce feed costs by formulating diets with lower energy and low protein levels.

• Journal of Animal Science and Technology
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• 제54권1호
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• pp.43-49
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• 2012

본 연구는 산란계의 주령 및 난각의 형태이상 및 이상 정도가 내부품질에 미치는 영향을 조사하기 위해 실시되었다. 동일 주령의 산란계 2계군에서 56주령부터 62주령 사이에 산란한 계란 21,000개 중 각 주별 1,000개를 무작위 추출하여 축산물품질평가사가 정상란과 형태 이상란을 구분하였다. 각각의 출현율과 할란검사를 실시하여 내부품질을 조사한 결과 전체적으로 정상란은 81.22%, 이상란은 18.78%의 출현율을 보였다. 주령의 증가에 따른 이상란의 출현율은 유의적인 차이를 보이지 않았으며(p>0.05), Haugh unit은 60주령이 56주령에 비해 높게 나타났으며 그 외에는 차이가 없었다. 동일 주령대를 비교했을 경우 난백고와 Haugh unit은 형태 이상란이 낮고 또한 이상의 정도가 심한 경우 더 낮게 측정되는 결과를 보였다(p<0.05). 특히 이상란 중 기형란의 난고와 Haugh unit이 현저하게 낮은 결과를 보여 이상란 중에서도 기형란이 내부 품질이 가장 낮게 판명되었다. 결과를 종합해 보면 56~62주령 산란계로부터 생산된 계란의 외형적 이상은 내부품질의 저하와 밀접하게 상관한다고 볼 수 있으며, 현 계란 등급판정 체계에서 외관판정은 신선도 평가에 근거가 될 수 있을 것으로 보인다.

• 한국환경과학회지
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• 제29권10호
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• pp.1011-1014
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• 2020

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.

• 한국가금학회지
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• 제40권1호
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• pp.49-55
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• 2013

본 연구는 산란 주령과 중량에 따른 계란의 주요 성분과 내부 품질의 변화를 확인하기 위하여 수행되었다. Hy-Line Brown 품종의 18주령에서 63주령으로부터 계란을 주령별로 약 50개씩 총 2,140개를 수거하여 난각, 난황 및 난백의 중량과 난백 높이 그리고 Haugh unit을 측정하였다. 중량 규격이 높아짐에 따라 난각, 난황 및 난백의 중량은 증가하였으나, 난백 높이와 Haugh unit은 낮아짐을 나타내었다. 또한, 산란 주령이 경과함에 따라 난황은 증가하고, 난백 비율은 감소하는 경향을 나타내었으며, 산란 주령은 난각, 난황, 난백 및 전체 계란 중량과 정의 상관관계를 보였으나, 난백 높이와 Haugh unit과는 부의 상관관계를 나타내었다. 또한 계란 중량이나 주요 구성 성분의 중량이 증가함에 따라 난백 높이 및 Haugh unit은 감소하는 것으로 나타났다.

• 한국가금학회지
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• 제15권2호
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• pp.73-79
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• 1988

본 시험은 육용종계의 사료급여시간 및 급여누수가 산란율. 난중 사료요구율, 1일 중 산란분포와 종란의 수정율 및 부화율과 난각질 등에 미치는 영향을 조사하기 위하여, 마니커 육용종계 1,248수를 공시하여, 사료의 급여시간 (08：00시와 14：00시)과 급여구수(1일 1회, 1일 2회, 2일 1회)의 효과를 36주간 비교시험 하였는바 얻어진 결과는 다음과 같이 요약된다. 1 육용종계의 산란율과 사료요구율은 사료의 급여시간이나 급여회수에 영향을 받지 않았고, 난중은 42주령이전에는 사료를 오후에 급여함으로서 증가하였으나 (p＜0.01) 42주령 이후에는 사료급여시간이나 급여회수에 따라 차이가 없었다. 2. 1일 중 산란분포는 격일급여구 (시험2)를 제외하고 오후사료급여구는 오전사료급여구에 비해 오전 산란수는 적고 오후산난수는 많은 경향이었다 (p＜0.01). 3 36주령과 60주령에 각각 조사한 종란의 수정률과 부화율은 처리간에 차이가 없었고, 종란의 난각질은 36주령시에는 차이가 없었으나 60주령시에는 사료를 오후에 급여함으로서 난각강도가 증가하였다. (p＜0.05).

• Asian-Australasian Journal of Animal Sciences
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• 제2권2호
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• pp.67-75
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• 1989

Studies were conducted to compare the utilization of dietary calcium between brown laying Tsaiya duck and Leghorn hen. Birds were fed corn-soybean diets containing 1.0, 2.0, 3.0, 4.0 and 5.0% calcium, respectively, with five birds per treatment. The metabolizability of calcium was determined by the indicator method. Experiments were conducted three times each at the age of 27, 31 and 36 weeks. Results appeared that duck eggs were heavier with better shell quality in comparison with hen eggs. Ducks fed 1% calcium diet resulted in severely depressed egg production (19%), but not for hens which still had 56% egg production. The metabolizability of calcium for hens was significantly higher than that for ducks (P<0.05) when both were fed diets containing 1 or 2% calcium. As the dietary calcium level was increased to 3 to 5%, there was no significant difference in calcium metabolizability between ducks and hens. When the dietary calcium was between 2 to 5%, the ducks retained more calcium than did the hens. Plasma calcium content for both hens and ducks fed 1% calcium diet was about the same. When the amount of the dietary calcium was increased to 2-5%, the plasma calcium level of ducks was approximately 7-10 mg/dl higher than that of hens. The calcium content in the egg shell of duck was significantly higher than that of hens, too. As the dietary calcium level was increased, there was a decreased magnesium content in the eggshell of hens, but not for ducks. The magnesium level in the eggshell was higher in hens than that in ducks. It is concluded that ducks could retain significantly more calcium and maintain higher plasma calcium level which might be the reason for larger eggs with better shell quality by ducks.

• 한국가금학회지
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• 제50권3호
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• pp.119-124
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• 2023

본 연구는 산란후기 '우리맛닭' 종계의 사료 내 ME 수준이 체중, 산란율, 종란품질 및 부화율에 미치는 영향을 조사하기 위해 수행되었다. 48주령 '우리맛닭' 종계 암탉 80수를 개별 케이지에 분배한 후 16주간 사양실험을 실시하였다. 처리구는 두 가지 수준의 ME(2,500 kcal/kg, 2,700 kcal/kg)사료를 4반복과 반복 당 10수씩 배치하여 급여하였다. 본 연구결과, 종계의 체중과 사료섭취량은 ME의 수준에 따른 통계적 차이가 없었다. 48~52주령의 종계는 2,500 kcal/kg 처리구에서 2,700 kcal/kg 처리구보다 개선된 산란율을 나타냈다(P<0.05). 그러나 52~64주령의 종계에서는 처리구 간 유의적 차이가 없었다. 종란의 난중, 난각두께 및 난각강도는 처리구 간에 차이가 나타나지 않았다. 종란의 수정률과 부화율은 ME 수준에 따른 차이를 보이지 않았다. 결론적으로 산란후기 '우리맛닭' 종계의 ME 수준을 2,500 kcal/kg으로 낮추어도 생산성 측면에서 에너지 요구량을 충족시킬 것으로 판단된다.