• Korean Journal of Poultry Science
• /
• v.35 no.4
• /
• pp.391-398
• /
• 2009

The objective of the present study was to compare of the effects of four molting methods on performance of laying hens. In total, 120 White Leghorn layers (62 weeks of age) were used. The four molting methods consisted of 10 days of feeding and the first 3 days of water withdrawal (FW1, 2) followed by ad libitum access to a layer diet 1 and 2 from day 11; 28 days of restricted feeding (NFW1); 28 days without withdrawing their feed (NFW2). Egg production of postmolt decreased until $3{\sim}4$ days at FW1 and FW2 treatments and until $16{\sim}18$ days at NFW1 and NFW2. 50% recovery of egg production were 7, 6, 7 and 5 week at FW1, FW2, NFW1, and NFW2 treatments, respectively. At day 14 of postmolt, the weight of livers, hearts, and oviducts decreased at molting treatments (P<0.05). Egg quality was improved on egg weight, eggshell thickness, eggshell break strength, and Haugh unit except egg yolk color (P<0.05).

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2003.11a
• /
• pp.117-118
• /
• 2003

This experiment was conducted to investigate the effect of feed restriction in early stage of growth on the compensatory growth in male and female broiler chickens. Day-old 480 male and 480 female commercial broiler chickens(Ross strain) were randomly allotted to 32 pens(replicates), 30 birds per pen, to compare the sex difference in growth performance and carcass characteristics. Birds in control group(C) were full fed throughout the study. T1, T2 and T3 were restricted at 4∼11d, 4∼14d and 4∼18d, respectively. Chickens were weighed every week, and one bird was selected from each pen to measure carcass characteristics at the end of experiment. In female chickens, all restricted-fed groups except for T3 weighed same as or heavier than the control group at 7 weeks of age. In male chickens, both T2 and T3 that had longer feed restriction period were significantly different from the control group. Viability was not different significantly. Feed intake in both male and female chickens of T3 group statistically differed from the control group. The female chicks showed larger abdominal fat pad sizes than did male birds up to market age.

• Monthly Korean Chicken
• /
• v.2 no.7 s.13
• /
• pp.2-8
• /
• 1996

육류중 유해물질 검사 강화 - 육계 초기 사료제한 연구 - 잔류 항생제 정성검사 키트 개발 - 일본인 육류섭취량 증가추세 - 축산폐수 단속기중 강화 - 축산물 소비촉진 홍보대책 필요 - 사료용 부연료 할당관세 $2.5{\%}$적용 - 가금티푸스 예방약 개발 - 가금인플루엔자 방역대책 시급 - 종계 ND 발생지역 백신 프로그램 - 수입종란 외래질병 매개 가능성 - 안전축산물 생산운동연합회 발족 - 중국, 닭고기 산업 잠재력 무한 - 삼계탕 수출 급속 성장중 - 소비자 단체 임원 닭 생산현장 방문 - 산란노계 처리 계속 어려워 - 인도, 육계수입 규제완화 재검토 - 축산기자재 구입 외화자금 사용가능 - 미국, 도계전 급이중단 실험 - 러시아, 수입쿼터제 부과 - 호주, 브로일러 산업 지속적 성장 - 배합사료업체 사료원료 선물구매 기피

• Journal of the KSME
• /
• v.26 no.2
• /
• pp.138-144
• /
• 1986

지금까지 몇가지의 차등법들을 계산의 정확도 및 안정성에 관하여 검토하였다. 상류 차등법과 왜도 차등법은 좋은 안정성을 가지고 있으나 그 정확도가 미흡한게 결점이고 중앙 차등법은 비 교적 좋은 정확드를 가지고 있으나 불안정한게 큰 결점이다. QUICK 차등법의 경우에는 보다 정확한 수치해를 얻기위해 종속 변수를 보다 고차의 근사치로 표시하였는데 정확도가 증가함에 따라 몇가지의 불이익이 생기게 된다. 그 불이익으로는 제일 먼저 계산 비용의 증가를 들 수 있으며 수치 계산이 불안정하게 되고 경계 조건의 표시가 어려워 진다. 또한 난류 에너지 방 정식과 같이 종속 변수가 반드시 양수값을 갖는 방정식에서 그 차등방정식의 종속 변수도 양수 치를 가져야 한다는 제한 조건을 만족시키는데 일반적으로 어려움이 많다. 그 이유는 QUICK 차등법을 이용한 차등방정식은 흔히 음수치의 원천항을 갖기 때문에 차등방정식을 푼 후 그 종속 변수가 음수치를 갖기 때문이다. 아직도 고차의 정확도를 갖는 차등법이 연구 개발중이며 종속 변수가 반드시 양수치인 유동방정식을 푸는 좋은 차등법은 아직까지도 없는 실정이어서 2차 이 상의 정확도와 절대 안정성 (absolute stability)을 갖는 새로운 차등법의 개급이 시발하다 하겠다.

• Journal of Animal Science and Technology
• /
• v.51 no.1
• /
• pp.53-60
• /
• 2009

Thirty one Hanwoo steers were used in a completely randomized design experiment to see the effects of concentrate feeding method (group vs. individual feeding) and age at slaughter (26 vs. 28 months of age) on growth performance, feed intake and carcass characteristics. Steers were randomly assigned to one of four groups, G26 (group feeding slaughtered at 26 months of age), G28 (group feeding slaughtered at 28 months of age), I26 (individual feeding slaughtered at 26 months of age) or I28 (individual feeding slaughtered at 28 months of age). Amount of concentrate were restricted to 1.5% of BW for the growing period and 1.8% of BW for the early fattening period in both groups. For the late fattening period, concentrate were given ad libitum for G26 and G28, but were given up to 1.7% of BW for I26 and I28. Average daily gains were higher in individual feeding groups (I26 and I28) than those in group feeding groups (G26 and G28) for the early fattening period (p<0.05). ADGs were higher in group feeding groups than those in individual feeding groups (p<0.05). Concentrate intake in individual feeding groups tended to be higher compared to that in group feeding groups for the early fattening period, but tended to be higher in group feeding groups compared to that in individual feeding groups for the late fattening period. Feeding method or slaughter age had no significant effects on carcass characteristics, yield grade and quality grade. Shear force and tenderness of longissmus muscle were higher in groups slaughtered at 28 months of age than in groups slaughtered at 26 months of age (p<0.05). Feeding method or slaughter age had no effects on cooking loss, water holding capacity, juiciness, flavor, moisture, protein and fat of longissmus muscle.

• Journal of Energy Engineering
• /
• v.9 no.1
• /
• pp.54-59
• /
• 2000

전자부품 및 시스템의 고속/고밀도화 추세에 따라 발열밀도가 계속증가하고 있다. 최근 팬티엄 II 급이상의 노트북 컴퓨터의 CPU에서는 칩당 발열량이 10W 이상으로 증가하고 있고 패키징 공간의 제한 때문에 소형히트파이프를 이용한 냉각이 많이 적용되고 있다. 본 연구에서는 모세압구동력이 크고 생산성등이 고려된 편조 형태의 새로운 윅을 개발하였으며 , 노트북 컴퓨터의 CPU 등 소형 전자부품냉ㄱ가에 적용가능한 직경 3, 4 mm 히트파이프를 설계 및 제작하였다. 직경 3, 4 mm Miniature Heat Pipe (이하 MHP) 의 작동특성은 일반적인 중형히트파이프와 다르므로 MHP 의 열전달 특성 및 작동성능에 미치는 각종 인자들의 영향을 파악하고자 성능시험을 수행하였다. 고려된 작동인자로는 작동유체 충전률, 전체 파이프길이 및 증발부, 응축부길이, 설치 경사각, 윅의 가닥수, 열부하 등이다. 작동인자의 영향과 관련된 연구결과는 향후 패키징을 위한 응용연구의 기초자료로 활용할 수 있을 것이다.

• Journal of fish pathology
• /
• v.31 no.2
• /
• pp.115-122
• /
• 2018

The Houttuynia cordata has been utilized for various beneficial purposes in humans mainly because of its potent antioxidant principle quercitrin present in this plant. This study examines the possibility of producing a functional sea food commodity containing active principle quercitrin by feeding H. cordata for a extended period. Spotted sea bass (Lateolabrax maculatus) were fed a diet containing H. cordata at 0.1-1.0% levels for 1 month and tissue concentrations of quercitrin were analyzed in serum, hepatopancreas and muscle. It was observed that quercitrin was found in the ranking order of hepatopancreas>muscle>serum. After a bolus administration of quercitrin (20 mg/kg, oral) to spotted sea bass and Nile tilapia (Oreochromis niloticus), idential rank order was observed after 48 hr. In contrast, the order was liver>serum>muscle in rat and mice, indicating that higher quercitrin distribution occurs to the muscle in fishes compared with in mammals tested. High residue concentration of qeurcitrin in the edible tissue can be an advantageous property in terms of functional food production. High level H. cordata extract inclusion of 1.0% seems to have detrimental effects in spotted sea bass leading to growth retardation and hepatic damage. It was concluded that incorporation of H. cordata extract into diet can be a way of producing healthy foods. However the level of active extract needs fine tuning to avoid toxicity to fishes.

• Journal of the Korea Society for Simulation
• /
• v.17 no.3
• /
• pp.63-73
• /
• 2008

The aim of study is to analyze the berth occupancy rate according to the ship size. P Iron and steel company operate exclusive bulk terminal at P port and G port and the depth of water at berth are not so equal each other. And to reduce the sea transport cost between loading port and unloading port P and G, P company increases the number of large ship while ship scheduling. But it causes to increase the berth congestion at the specific water depth berth owing to the draught of large ship. At this point, usually ship waiting time starts to rise even at low levels of berth occupancy rate, and will rise more and more sharply at the level of full utilization. But it is not common at exclusive terminal like P port and G port. Bulk ships arrive at port according to the early planned arrival time and the coefficient of variation of ship arrival time is not so big. So queueing time at exclusive terminal does not rise sharply near 80-90 berth occupancy rate.

• Korean Journal of Agricultural Science
• /
• v.13 no.1
• /
• pp.68-81
• /
• 1986

This experiment was conducted to find out the effects of the six different feeding methods on the development of body weight, testis, comb and pituitary gland, and the sexual maturity of White Plymouth Rock cockerels. From hatching to 22 weeks of age, the weights of whole body, testis, comb and pituitary gland, and the histological changes of testis and the semen characteristics were checked every other week. The results obtained in this expeniment were as follows: 1. The growth rates of the self-feeding groups were faster than those of the limited feeding groups (70 percent of the self-feeding) by about 2 weeks. The weights of testis and comb showed the most marked increase at 20 weeks of age in the self-feeding groups and at 22 weeks of age in the limited feeding groups, respectively. 2. The weights of pituitary gland from hatching to 22 weeks of age at all observation weeks were not recognized significantly among the compared groups except 4, 14 and 16 weeks of age. 3. Correlations between week of age, body weight, testis, comb and pituitary gland, in the course of 22 weeks, were highly significant. 4. The diameters of lumina and tubules in the seminiferous tubules increased very slowly until 10 weeks of age. They showed the most marked increase at 12 weeks of age in the self-feeding groups and at 14 weeks of age in the limited feeding groups, and then continueously increased until 22 weeks of age. 5. Primary spermatocytes appeared at first at 8 weeks in the all treatment groups. Secondary spermatocytes appeared at first at 10 weeks in the self-feeding groups and at 12 weeks in the limited feeding groups. At 14 weeks of age spermatids and spermatozoa were found at first in the self-feeding groups but spermatids were found in the limited feeding groups. 6. Age of the first ejaculation was between 14 and 16 weeks of age in the all treatment groups. The average semen volume and sperm concentration ranged from $0.1{\sim}0.2m{\ell}/ejaculate$ and $5.6{\sim}9.8{\times}10^8sperm/m{\ell}$ at the age of the first ejaculation but $0.30{\sim}0.35m{\ell}/ejaculate$ and $22.4{\sim}42.7{\times}10^8sperm/m{\ell}$ at the 20 weeks of age in the all treatment groups.

• Journal of Environmental Impact Assessment
• /
• v.27 no.6
• /
• pp.695-703
• /
• 2018

This study was conducted to suggest a sustainable farming practice forresource recycling in vegetable gardens of North Korea. In North Korea, farmers are allowed to own private vegetable gardens less than $100m^2$. However, usage of fertilizers in private vegetable gardens is very limited due to economic sanctions by UN security council. If North and South Korea initiated the cooperative action in the near future, agricultural sector would be the highest priority cooperation area. Considering the current North Korean situation in agriculture, we would like to suggest a method for producing organic fertilizer manure. For raw materials for producing manure, we selected corn byproduct, which is the most abundant material, and rabbits' feces, which are easily obtained from individual private farms in North Korea. As we cannot get corn byproducts and rabbits' feces from North Korea, we prepared samples of corn byproducts and rabbits; feces from many places in South Korea. After statistical analysis of variance, there was no significant difference in the T-N contents of corn byproducts from Gyeonggi, Gangwon, Chungnam, Chungbuk, Jeollabuk and Gyeongsangnam-dos, which indicates that the fertilizing quality of corn byproducts does not vary significantly in the spatial scale of South. Korea. In this sense, if we use corn samples from Gyeonggi province, they would not be very different from those of North Korean regions. Physicochemical properties of rabbits' feces were different between those eating feed grains and those eating plants only. Hence, we used rabbits' feces of the rabbits from Yeonchun area, which were fed by plants only. Using three different mixing ratios of corn byproducts and rabbits' feces, composting was conducted for 60 days. The mixing ratio of 1:1 produced the manure with % T-N of 1.98% and OM/N ratio of 31.7 after 30 days of composting, which is comparable to the quality of commercial manure.