• 한국자기학회지
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• 제17권3호
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• pp.120-123
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• 2007

이 연구에서는 Ta 45/Ru 9.5/IrMn 10/CoFe $3/AlO_x$/자유층/$AlO_x$/CoFe 7/IrMn 10/Ru 60(nm) 구조를 갖는 이중장벽 자기터널접합(double-barrier magnetic tunnel junction: DMTJ)를 다루었다. 자유층은 $Ni_{16}Fe_{62}Si_8B_{14}\;7nm$, $Co_{90}Fe_{10}(fcc)$ 7 nm 및 $CoFet_1$/NiFeSiB $t_2$/CoFe $t_1$으로 구성하였으며 두께 $t_1,\;t_2$는 변화시켰다. 즉 TMR비와 RA를 개선하기 위하여 부분적으로 CoFe층을 대체할 수 있는 비정질 NiFeSiB층이 혼합된 자유층 CoFe/NiFeSiB/CoFe을 갖는 DMTJ를 연구하였다. NiFeSiB($t_1=0,\;t_2=7$)만의 자유층을 갖는 DMTJ는 터널자기저항(TMR)비 28%, 면적-저항곱(RA) $86k{\Omega}{\mu}m^2$, 보자력($H_c$) 11 Oe 및 층간 결합장($H_i$) 20 Oe를 나타내었다. $t_1=1.5,\;t_2=4$인 경우의 하이브리드 DMTJ는 TMR비 30%, RA $68k{\Omega}{\mu}m^2$ 및 $H_c\;11\;Oe$를 가졌으나 $H_i$는 37 Oe로 증가하였다. 원자현미경(AFM)과 투과전자현미경(TEM)측정을 통하여 NiFeSiB층 두께가 감소하면 $H_i$가 증가하는 것을 확인하였다. 비정질 NiFeSiB층이 두꺼워지면 보통 계면의 기복을 유도하는 원주형성장(columnar growth)를 지연시키는데 유효하였다. 그러나 NiFeSiB층이 얇으면 표면거칠기는 증가하고 전자기적 Neel 결합 때문에 Hi는 커졌다.

• 농업과학연구
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• 제29권2호
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• pp.20-34
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• 2002

본 연구는 Aspergillus oryzae 배양물이 in vitro 건물, 섬유소 및 단백질 소화율과 pH에 미치는 영향을 구명하고자 실시하였다. 균종 Aspergillus oryzae는 한국 생명공학연구원에서 분양받았으며, 본 연구에 사용된 사료는 시중 유통중인 착유우용 배합사료와 TMR 사료로서, 일반성분 분석은 (주)우성사료 중앙실험실에서 실시하였고, 건물, 섬유소 및 단백질 소화율 실험은 충남대학교 실험실에서 실시하였다. 배합사료와 TMR에 Aspergillus oryzae 배양물 0, 1.0, 2.0 및 3.0%를 첨가한 후, Holstein종 착유우로부터 채취한 반추위액에 시료 2.0g 내외를 넣어 진탕배양기에서 24, 48 및 72시간 소화시켰다. 침전물에 0.2% pepsin이 들어있는 0.1N HCl 30ml를 넣고 $39^{\circ}C$ incubator에서 48시간 소화시키고 나서, 마지막으로 침전물을 $60^{\circ}C$의 건조기에서 48시간 건조시켰다. 실험은 3회 반복하여 실시하였다. 건물 소화율은 Aspergillus oryzae 발효물을 첨가하지 않은 대조구에 비해 24시간 배양시킨 배합사료의 경우 2.1%(63.1%), 9.7%(68.5%) 및 9.0%(68.0%) 개선되었고, TMR은 4.8%(60.0%), 6.4%(61.1%) 및 2.9%(58.8%)의 개선효과가 있었다. 이와 대조적으로, 48시간 및 72시간 배양시킨 시험구의 건물 소화율에 Aspergillus oryzae 배양물이 미치는 영향은 24시간 배양시보다 상대적으로 낮은 경향을 보였다. 섬유소 소화율에서 Aspergillus oryzae가 조섬유, ADF 및 NDF 소화율을 유의적으로 개선시킨다는 것을 알 수 있었다. 배합사료에서 3% 첨가구의 경우 24시간 배양시 13.3%(53.3%), 72시간 배양시 2.4%(54.6%)까지 증가되었다. 하지만, 첨가수준에 따라 소화율이 높아졌음에도 불구하고 첨가수준별 개선효과에는 유의적인 차이가 없었다. 단백질 소화율은 Aspergillus oryzae 배양물 첨가에 의해 배합사료에서 0.4%(79.7%)에서 9.4%(71.8%)의 유의적인 개선효과를 나타내었지만, 2.0%와 3.0% 첨가구간의 유의적인 차이는 인정되지 않았다. TMR의 경우에는 4.0%(70.4%)에서 6.3%(65.1%)의 유의적인 소화율 향상을 나타내었지만 2.0%와 3.0% 첨가구간의 유의적인 차이는 인정되지 않았다. 본 연구에서, pH 처리구간 유의적인 차이는 없었으나, Aspergillus oryzae 배양물 첨가에 따라 pH가 약간 감소하는 경향을 보였다. 그러므로 본 발효물은 pH에는 영향을 미치지 않으나 건물, 섬유소 및 단백질 소화율 향상에는 다소 효과가 있 는 것으로 결론을 내릴 수가 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권3호
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• pp.382-389
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• 2002

The aims of this study is to evaluate the effect of Aspergillus oryzae Fermentation Extract (AFE) on the performance of lactating cows in summer (May to July) and winter (December to February). The experiment was a completely randomized design (CRD) and dietary treatments were 1) basal diet without AFE, 2) basal plus 3 g/d AFE into the basal total mixed ration (TMR), 3) basal plus 45.4 mg AFE/kg the ensiling corn silage and 4) AFE inclusion in silage and TMR. Twenty-eight cows from each trial were selected and randomly allocated into the four treatment groups, confined in individual pens, and fed ad libitum for 8 weeks in both seasons of feeding trials. Results showed that AFE inclusion in corn silage significantly improved DM intake by 4.4% and milk yield by 3.1% (p<0.05) during summer. In the winter season, AFE inclusion in the diet significantly improved milk yield by 10%. Direct addition of AFE to the TMR even further significantly improved milk yield over the addition through corn silage by 7.4% in winter (p<0.05). An additive effect of AFE inclusion into TMR and through corn silage was also demonstrated in the winter-feeding. AFE inclusion however, did not improve DM intake during the winter trial. In the summer trial, inclusion of AFE showed an adverse effect on the percentage of milk fat, but did not impact on the milk fat yield. Adding AFE through corn silage showed a trend towards alleviating the negative effects of milk fat from direct AFE inclusion in TMR. The similar trend occurred in the winter trial. The inclusion of AFE through corn silage significantly lowered the milk protein content over direct AFE addition, but did not significantly impacted the milk protein yield in summer. AFE supplementation during the winter season significantly increased milk protein content. Adding AFE to the corn silage significantly increased milk protein content over direct AFE addition in winter although inclusion of AFE significantly decreased total milk solid content in the summer (p<0.005). During the winter season, inclusion of AFE required less DM to produce a unit of milk. Inclusion of AFE into corn silage required less DM, energy and protein to produce a unit of milk. But inclusion of AFE did not alleviate heat stress on the lactating cows.

• Animal Bioscience
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• 제35권4호
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• pp.556-566
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• 2022

Objective: This study aimed to determine the appropriate supplementation level of lactic acid bacteria (LAB; Lactobacillus plantarum and Bacillus clausii), yeast (Saccharomyces cariocanus and Wickerhamomyces anomalus) for degrading free gossypol and glucosinolate in the fermented total mixed ration (TMR) containing cottonseed meal (CSM) or rapeseed meal (RSM), to improve the utilization efficiency of these protein sources. Methods: For LAB, L. plantarum or B. clausii was inoculated at 1.0×10⁸, 1.0×10⁹, 1.0×10¹⁰, and 1.0×10¹¹ colony-forming unit (CFU)/kg dry matter (DM), respectively. For yeast, S. cariocanus or W. anomalus was inoculated at 5×10⁶, 5×10⁷, 5×10⁸, and 5×10⁹ CFU/kg DM, respectively. The TMR had 50% moisture and was incubated at 30℃ for 48 h. After fermentation, the chemical compositions, and the contents of free gossypol and glucosinolate were determined. Results: The results showed that the concentration of free gossypol content was reduced (p<0.05), while that of the crude protein content was increased (p<0.05) in the TMR containing CSM inoculated by B. clausii (1×10⁹ CFU/kg DM) or S. cariocanus (5×10⁹ CFU/kg DM). Similarly, the content of glucosinolate was lowered (p<0.05) and the crude protein content was increased (p<0.05) in TMR containing RSM inoculated with B. clausii (1×10¹⁰ CFU/kg DM) or S. cariocanus (5×10⁹ CFU/g DM). Conclusion: This study confirmed that inclusion of B. clausii with 1.0×10⁹ or 1.0×10¹⁰ CFU/kg DM, or S. cariocanus (5×10⁹ CFU/kg DM) to TMR containing CSM/RSM improved the nutritional value and decreased the contents of anti-nutritional factors.

• Asian-Australasian Journal of Animal Sciences
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• 제28권5호
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• pp.632-638
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• 2015

Two experiments were conducted to evaluate the nutrient composition, in vitro dry matter disappearance (IVDMD) and organic matter disappearance (IVOMD) of three kinds of distillers grains (DG); i) wet distillers grains (WDG, KRW 25/kg), ii) dried distillers grains (DDG, KRW 280/kg), iii) dried distillers grains with solubles (DDGS, KRW 270/kg) produced from tapioca 70% and rice 30%, and to evaluate dietary effects of WDG on the performance of Hanwoo steers. In Exp. 1, twelve-WDG, four-DDG and one-DDGS were collected from seven ethanol plants. Average crude protein, crude fiber, neutral detergent fiber, and acid detergent fiber of WDG, DDG, and DDGS were: 32.6%, 17.8%, 57.5%, and 30.2% for WDG, 36.7%, 13.9%, 51.4%, and 30.5% for DDG, and 31.0%, 11.9%, 40.3%, and 21.2% for DDGS (DM basis), respectively. The DDGS had a higher quantity of water-soluble fraction than WDG and DDG and showed the highest IVDMD (p<0.05) in comparison to others during the whole experimental time. The IVDMD at 0 to 12 h incubation were higher (p<0.05) in DDG than WDG, but did not show significant differences from 24 to 72 h. The same tendency was observed in IVOMD, showing that DG made from tapioca and rice (7:3) can be used as a feed ingredient for ruminants. Considering the price, WDG is a more useful feed ingredient than DDG and DDGS. In Exp. 2, 36 Hanwoo steers of 21 months ($495.1{\pm}91kg$) were randomly assigned to one of three dietary treatments for 85 days; i) Control (total mixed ration, TMR), ii) WDG 10% (TMR containing 10% of WDG, as fed basis), and iii) WDG 20% (TMR containing 20% of WDG, as fed basis). With respect to body weight and average daily gain, there were no differences between control and WDG treatments during the whole experimental period. Dry matter intake of control (9.34 kg), WDG 10% (9.21 kg) and 20% (8.86 kg) and feed conversion ratio of control (13.0), WDG 10% (13.2) and 20% (12.1) did not show differences between control and WDG treatments. Thus, the use of WDG up to 20% in TMR did not show any negative effect on the performance of Hanwoo steers.

• Asian-Australasian Journal of Animal Sciences
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• 제27권7호
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• pp.960-964
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• 2014

An experiment was conducted to determine the effects of diets containing coarse-texture rice straw and small particle size alfalfa pellets as a part of total mixed ration (TMR) on milk productivity and chewing activity in lactating dairy cows. Sixteen multiparous Holstein dairy cows ($670{\pm}21kg$ body weight) in mid-lactation ($194.1{\pm}13.6$ days in milk) were randomly assigned to TMR containing 50% of timothy hay (TH) or TMR containing 20% of rice straw and 30% of alfalfa pellet mixture (RSAP). Geometric mean lengths of TH and RSAP were found to be 5.8 and 3.6, respectively. Dry matter intake, milk yield and milk composition were measured. Moreover, eating and ruminating times were recorded continuously using infrared digital camcorders. Milk yield and milk composition were not detected to have significant differences between TH and RSAP. Dry matter intake (DMI) did not significantly differ for cows fed with TH or RSAP. Although particle size of TH was larger than RSAP, eating, ruminating and total chewing time (min/d or min/kg of DMI) on TH and RSAP were similar. Taken together, our results suggest that using a proper amount of coarse-texture rice straw with high value nutritive alfalfa pellets may stimulate chewing activity in dairy cows without decreasing milk yield and composition even though the quantity of rice straw was 40% of TH.

• 농업과학연구
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• 제44권3호
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• pp.375-383
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• 2017

This study was conducted to investigate the effects of sex, environmental factors, and feeding system on the carcass traits of Hanwoo (Korean Native Cattle). Data were collected from 7,866 heads slaughtered in Chungnam province during one-year period. Using the collected carcass traits data which greatly influence a Hanwoo's carcass grade, the effects of sex class, slaughter season, and feeding system were estimated. Backfat thickness of steers was significantly higher than that of bulls (p < 0.05). Marbling score was also the highest in steers when compared with cows and bulls (p < 0.05). Live weight and carcass weight were significantly higher in winter than in summer (p < 0.05). However, backfat thickness was significantly lower in summer than in other seasons (p < 0.05). Marbling score was higher in spring and fall than in summer and winter (p < 0.05). In terms of feeding systems, TMR (Total mixed ration) and TMF (Total mixed fermentation feed) fed groups showed the highest carcass grade (p < 0.05). However, the group fed TMR and formula feed at the final fattening period showed the lowest performance (p < 0.05) and it is assumed that some stress was associated to the feed change. The results reconfirm that castration may be recommended in order to improve meat quality and marbling scores in bulls. There was no consistent trend of seasonal effects of slaughter on carcass traits although some traits were significantly affected. Regarding the feeding system, either TMR or TMF can be supplied to achieve high feed efficiency and good carcass characteristics in Hanwoo.

• 한국유기농업학회지
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• 제28권4호
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• pp.605-614
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• 2020

This study was conducted to investigate the effects of TMR on in vitro rumen fermentation and methane production of goat with different forage sources. The experiment was arranged 4×2 factorial design. The different forage sources were rice straw (RS), Italian rye grass (IR), timothy (TI) and alfalfa (AL), respectively. There were two different forage : concentrate ratios such as 20:80 (20) and 50:50 (50), respectively. Therefore, totally 8 treatments were used: 1) RS20, 2) RS50, 3) IR20, 4) IR50, 5) TI20, 6) TI50, 7) AL20, and 8) AL50, respectively. The rumen fluid of goat was collected from the slaughterhouse. For fermentation parameters, ruminal pH, total gas, methane, hydrogen, ammonia nitrogen, and volatile fatty acid were determined. The pH values were within an optimal range across all treatments. Total gas productions at TI20 and AL50 were significantly greater than others (p<0.05). Methane production was significantly lower in TI and AL compared with other treatments (p<0.05). The relatively high dietary NDF content in treatments showed significantly lower methane production (p<0.05). Significant alterations treatments were detected at ammonia nitrogen concentration according to the ratio of forage : concentrate (p<0.05). AL treatment showed greater total volatile fatty acid production compared with other treatments (p<0.05). Therefore, the present study suggests that both Timothy and Alfalfa could be recommendable forage sources for goat based on results with volatile fatty acid as an energy source and methane as an index for energy loss and environmental issues. Also, the 50:50 (forage : concentrate) ratio would prefer to 20:80.

• Journal of Dairy Science and Biotechnology
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• 제36권4호
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• pp.196-207
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• 2018

This study was carried out to investigate the rheological properties and composition of unsaturated fatty acid of farm butter made from the milk of cows grazing at high mountain pasture in Pyronogchang SKY ranch (above sea level, 935 m). From two groups containing 7 cows each, a group was fed in-door with TMR (total mixed ration) feed and whereas the other group was grazed pastures for 12 h. The daily intake of feed on basis of dry matter (DMI), milk yields, concentration of milk constituents, and fatty acid profile of pasture milk were compared with control TMR milk. In addition, the physiochemical properties and composition of unsaturated fatty acids of the butter were also compared with those of the butter made from control TMR milk. Upon comparison, the health-promoting index (HPI) of fatty acids; the ratio of omega-6 fatty acids to omega-3 fatty acids (n-6 to n-3 UFA), the atherogenicity index (AI), and the ratio of linoleic acid to ${\alpha}$-linolenic acid (LA to ALA) was apparently improved in farm butter than those of control butter. Thus, it could make the dairy farm visitors to consume the farm butter containing the health-promoting fatty acids from the milk of cows grazing on mountain pasture.

• 한국축산식품학회지
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• 제41권1호
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• pp.45-58
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• 2021

This study investigated the dietary effect of total mixed ration (TMR) based on high roughage content on the growth performance, carcass characteristics, and meat quality of Hanwoo steers. Twenty-four Hanwoo steers (average body weight, 195.3±4.7 kg; age, 8.5 mon) were randomly allocated to three experimental groups according to forage and concentrate ratio (DM basis): 25:75 (control), 50:50 (T50), and 70:30 (T70). Productivity in the fattening period and final body weight were significantly higher in the control. Average daily gain and feed conversion ratio were the same among treatments. Serum parameters, cholesterol, blood urea nitrogen, and total protein were higher in the control. Carcass weight was comparable in the control and T50 but feeding more roughage was significantly correlated with a higher intramuscular fat. Shear strength and drip loss were higher while n-6/n-3 was lower in T70 compared to the other groups. However, meat color was not significantly different among treatments. In terms of free amino acid contents, glutamic acid and glycine were higher in the control than T50 and T70. Overall, feeding Hanwoo steers with high forage content TMR had the lowest n-6/n-3 ratio of fatty acid content but highest intramuscular fat, shear strength, and drip loss. High forage content TMR is the best feed for Hanwoo steers that gives more benefits for human health and consumption but also provides the best meat grade and quality, which is important in the beef market in Korea.