• 한국시스템다이내믹스연구
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• 제6권1호
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• pp.17-32
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• 2005

An agricultural commodity production cycle model consisting of corn, beef, and dairy sectors was constructed for the purpose of exploring the propagating effects of large-scale disruptive events. In an initial proof-of-concept exercise, we considered an agricultural disruption scenario in which foot-and-mouth disease (FMD) is introduced into the U.S., causing a large-scale outbreak of the disease in both beef and dairy cattle. The magnitude of disruption to the beef and dairy sectors are presented under the existing W response policy and then improvements under two alternative policies are shown.

• 한국축산식품학회지
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• 제34권4호
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• pp.482-495
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• 2014

The objectives of this study were to know the effect of repeated freeze-thaw cycles of beef on the sensory, physicochemical quality and microbiological assessment. The effects of three successive freeze-thaw cycles on beef forelimb were investigated comparing with unfrozen fresh beef for 75 d by keeping at $-20{\pm}1^{\circ}C$. The freeze-thaw cycles were subjected to three thawing methods and carried out to know the best one. As the number of freeze-thaw cycles increased color and odor declined significantly before cook within the cycles and tenderness, overall acceptability also declined among the cycles after cook by thawing methods. The thawing loss increased and dripping loss decreased significantly (p<0.05). Water holding capacity (WHC) increased (p<0.05) until two cycles and then decreased. Cooking loss increased in cycle 1 and 3, but decreased in cycle 2. pH decreased significantly (p<0.05) among the cycles. Moreover, drip loss, cooking loss and WHC were affected (p<0.05) by thawing methods within the cycles. 2-Thiobarbituric acid (TBARS) value increased (p<0.05) gradually within the cycles and among the cycles by thawing methods. Total viable bacteria, total coliform and total yeast-mould count decreased significantly (p<0.05) within and among the cycles in comparison to the initial count in repeated freeze-thaw cycles. As a result, repeated freeze-thaw cycles affected the sensory, physicochemical and microbiological quality of beef, causing the deterioration of beef quality, but improved the microbiological quality. Although repeated freeze-thaw cycles did not affect much on beef quality and safety but it may be concluded that repeated freeze and thaw should be minimized in terms of beef color for commercial value and WHC and tenderness/juiciness for eating quality.

• 농업생명과학연구
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• 제46권6호
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• pp.197-205
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• 2012

이 논문은 한육우 사육두수 주기를 분석하고 이 주기를 기초로 한육우 사육두수를 예측하였다. 이를 위해 일정한 주기를 가지고 정점과 저점을 반복하는 싸인함수를 활용하였다. 과거 한육우 사육두수의 주기는 짧게는 5년부터 길게는 12년까지의 패턴을 보여주었고, 이러한 주기는 시간이 흐름에 따라 점차 길어지는 양상을 보여주고 있다. 싸인함수를 활용하여 한육우 사육두수를 추정한 결과, 모형의 적합도가 0.95로 매우 높게 나타났다. 이 모형을 이용하여 한육우 사육두수를 예측한 결과, 사육주기에 따라 약간의 차이가 나지만 저점의 사육두수는 160~180만두 정도이고 정점의 사육두수는 320만두~370만두 수준으로 예측되었다. 이러한 예측결과는 사육두수 불안정성에 따른 농가 소득 불안정성을 내포하고 있어 그에 따르는 적절한 정책이 필요함을 시사한다.

• 한국축산식품학회지
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• 제35권6호
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• pp.772-782
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• 2015

This study was performed to explore the deterioration of physicochemical quality of beef hind limb during frozen storage at −20℃, affected by repeated freeze-thaw cycles. The effects of three successive freeze-thaw cycles on beef hind limb were investigated comparing with unfrozen beef muscle for 80 d by keeping at −20±1℃. The freeze-thaw cycles were subjected to three thawing methods and carried out to select the best one on the basis of deterioration of physicochemical properties of beef. As the number of repeated freeze-thaw cycles increased, drip loss decreased and water holding capacity (WHC) increased (p<0.05) till two cycles and then decreased. Cooking loss increased in cycle one and three but decreased in cycle two. Moreover, drip loss, WHC and cooking loss affected (p<0.05) by thawing methods within the cycles. However, pH value decreased (p<0.05), but peroxide value (p<0.05), free fatty acids value (p<0.05) and TBARS value increased (p<0.05) significantly as the number of repeated freeze-thaw cycles increased. Moreover, significant (p<0.05) interactive effects were found among the thawing methods and repeated cycles. As a result, freeze-thaw cycles affected the physicochemical quality of beef muscle, causing the degradation of its quality.

• 한국생활과학회지
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• 제14권1호
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• pp.217-221
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• 2005

마이크로웨이브 처리가 소고기 및 돼지고기의 이화학적 특성 및 미생물 총 균수 변화에 미치는 영향을 검토하였다. 시료는 발전 주파수 2450MHz, 출력 500Watt인 마이크로웨이브를 사용하여 50% duty cycle로 10초 및 20초간 처리하였다. 마이크로웨이브 처리는 소고기 및 돼지고기의 육즙손실과 TBA가를 증가시켰으며 육즙 손실은 소고기에 비해 돼지고기가 더 많았다. 마이크로웨이브 처리한 소고기 및 돼지고기는 마이크로웨이브로 처리하지 않은 대조군에 비해 L값과 b값이 증가하였으며 a값은 변화하지 않았다. 한편 전단력은 20초간 마이크로웨이브 처리한 소고기와 돼지고기가 대조군에 비해 높게 나타났다. 마이크로웨이브 처리는 소고기 및 돼지고기의 미생물 총 균수를 감소시켰다. 미생물 총 균수는 20초간 처리에 의해 미생물 총 균수가 2 log cycle 감소하였다. 따라서 20초 정도의 마이크로웨이브 처리는 돼지고기의 미생물 총 균수를 상당히 감소시킬 수 있어 미생물학적 안전성 확보에 매우 효과적 방법으로 생각된다.

• 한국가축번식학회지
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• 제12권2호
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• pp.91-96
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• 1988

A study was conducted to improve breeding efficiency of dairy and beef cows on Cheju Island. Milk progesterone and plasma progesterone profiles were determined by using radioimmunoassay techniques during the oestrus cycle, onset on oestrus and during the gestation period. Progesterone connections in milk were very low during the oestrus with a means value of 2.4ng/ml and 4.6ng/ml at the onset of oestrus but gradually declined at 4 to 9 hr after oestrus. In the cyclic cow, milk progesterone concentraitons in the early part of the cycle, ranged from 3 to 5ng/ml and increased from 6.0 to 11.6ng/ml on day 13 to 21 of cycle. Milk progesterone concentrations of pregnancy cows ranged from 5.0 to 40ng/ml during the gestation and grom basal line to 3.5ng/ml for nonpregnant cows. Plasma progesterone concentrations of beef during pregnancy period ranged form 3.0 to 33ng/ml and basal levels ranged from 0 to less than 2.5ng/ml for non-pregnant beef cows.

• 한국유기농업학회지
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• 제17권4호
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• pp.463-481
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• 2009

Regional Agricultural Cluster(RAC) at Asan area has been formed with Purundeul farming union corporation(Purundeul) as the center from the year 2005. Originally, RAC has been proceeded by Ministry for Food, Agriculture, Forestry and Fisheries (MFAFF) all over the nation from 2005. This RAC has helped Asan area to establish the foundation of environmentally friendly agriculture(EFA) searching for nutritional cycle. This also made jumping age turn developing age in EFA at Asan area. The number of Purundeul producer members was 386 farmers in 2008. Purundeul introduced organic livestock farming(Korean beef cattle; Hanwoo) for proceeding EFA searching for nutritional cycle in 2007, and had 719 cattle at the end of March 2009. Feedstuff materials for organic livestock is mostly produced from seeding farming by-products within Asan or the country. Asan RAC had built factories for feedstuff producing and beef processing with producers' investment.

• 한국식품영양과학회지
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• 제29권6호
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• pp.1016-1024
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• 2000

본 연구는 식품에 존재하는 L. monocytogenes균의 신속한 검출방법을 조사하기 위하여 hlyA 유전자 primer 를 사용하여 PCR 기법으로 행하였으며 primer의 특이성과 PCR의 민감성, L. monocytogenes균의 검출을 위한 최적조건 및 우유 및 소고기의 적용시험을 각각 조사하였다 PCR 특이성 실험에서는 L. monocytogenes 20주에 대한 PCR 분석 결과 모두 713 bp 크기의 PCR products를 확인할 수 있었고, Listeria spp. 및 다른 세균에서는 동일한 Poducts가 증폭되지 않으므로써 hiyA based primer의 L. monocytogenes에 대한 PCR 특이성이 관찰되었다. PCR 분석법의 민감도는 L. monocytogenes ATCC 19111의 1 pg DNA와 2.4$\times$$10^4$cell 수준에서 target DNA가 증폭되었다. Tailing의 제거와 민감도를 높이기 위하여 PCR cycle 수에 따른 최적조건을 조사한 결과 20~30 cycle 정도의 PCR clcyle 수가 좋은 것으로 나타났으며 민감도는 20 cycle PCR amplification을 행한 후 한번 더 10~15 cycle로 처리했을 때 훨씬 증가하였다. 한편, 우유(10 mL)와 쇠고기 절편(10g)에 0~$10^{7}$ CFU/mL 또는 g 수준으로 L. monocytogenes를 신속하게 검출하기 위하여 PCR을 적용한 결과, 우유시료에서는 2번 PCR을 반복함으로써 2 cells까지 검출할 수 있었고, 쇠고기 절편은 LEB로 35$^{\circ}C$에서 24시간 증균하여 PCR합으로써 2.6$\times$$10^2$cell가지 검출할 수 있었다.

• 한국시스템다이내믹스연구
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• 제14권3호
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• pp.135-163
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• 2013

This study aims to analyze the feedback loops and policy simulation of price fluctuation of Korean Cattle. The Korean Cattle market shows the 'Cycle of Beef' since 1970. In general, the market for agricultural commodities exhibit repeated cycles of prices and production. Why Beef products market in Korea shows the fluctuation of cattle and beef price repeatedly for forty years? To find an answer, this paper explores the feedback structure of the dynamics of the beef market by the systems thinking and build a stock-flow diagram model for the simulation of future behavior of the market sector of the Cattle. The dynamic simulation model was developed to identify and analyze the cyclical behavior among many variables, which is the number of cattle (calves, cow, etc.), the price of cattle, the demand for beef, the desirable number of cattle, slaughter, etc. The results of this study demonstrate that dominant feedback loops between the number of cattle and livestock prices. The demand for Beef and slaughter with time delay, also the results of the simulation to explain the persistence of future price fluctuations and actions meat market until 2025.

• Animal Bioscience
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• 제36권3호
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• pp.506-520
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• 2023

Objective: Japanese Brown (JBR) cattle, especially the Kochi (Tosa) pedigree (JBRT), is a local breed of moderately marbled beef. Despite the increasing demand, the interbreed differences in muscle metabolites from the highly marbled Japanese Black (JBL) beef remain poorly understood. We aimed to determine flavor-related metabolites and postmortem metabolisms characteristic to JBRT beef in comparison with JBL beef. Methods: Lean portions of the longissimus thoracis (loin) muscle from four JBRT cattle were collected at 0, 1, and 14 d postmortem. The muscle metabolomic profiles were analyzed using capillary electrophoresis time-of-flight mass spectrometry. The difference in post-mortem metabolisms and aged muscle metabolites were analyzed by statistical and bioinformatic analyses between JBRT (n = 12) and JBL cattle (n = 6). Results: A total of 240 metabolite annotations were obtained from the detected signals of the JBRT muscle samples. Principal component analysis separated the beef samples into three different aging point groups. According to metabolite set enrichment analysis, post-mortem metabolic changes were associated with the metabolism of pyrimidine, nicotinate and nicotinamide, purine, pyruvate, thiamine, amino sugar, and fatty acid; citric acid cycle; and pentose phosphate pathway as well as various amino acids and mitochondrial fatty acid metabolism. The aged JBRT beef showed higher ultimate pH and lower lactate content than aged JBL beef, suggesting the lower glycolytic activity in postmortem JBRT muscle. JBRT beef was distinguished from JBL beef by significantly different compounds, including choline, amino acids, uridine monophosphate, inosine 5'-monophosphate, fructose 1,6-diphosphate, and betaine, suggesting interbreed differences in the accumulation of nucleotide monophosphate, glutathione metabolism, and phospholipid metabolism. Conclusion: Glycolysis, purine metabolism, fatty acid catabolism, and protein degradation were the most common pathways in beef during postmortem aging. The differentially expressed metabolites and the relevant metabolisms in JBRT beef may contribute to the development of a characteristic flavor.