• Asian-Australasian Journal of Animal Sciences
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• 제29권2호
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• pp.211-218
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• 2016

This study evaluated the effect of Candida norvegensis (C. norvegensis) viable yeast culture on in vitro ruminal fermentation of oat straw. Ruminal fluid was mixed with buffer solution (1:2) and anaerobically incubated with or without yeast at $39^{\circ}C$ for 0, 4, 8, 16, and 24 h. A fully randomized design was used. There was a decrease in lactic acid (quadratic, p = 0.01), pH, (quadratic, p = 0.02), and yeasts counts (linear, p<0.01) across fermentation times. However, in vitro dry matter disappearance (IVDMD) and ammonia-N increased across fermentation times (quadratic; p<0.01 and p<0.02, respectively). Addition of yeast cells caused a decrease in pH values compared over all fermentation times (p<0.01), and lactic acid decreased at 12 h (p = 0.05). Meanwhile, yeast counts increased (p = 0.01) at 12 h. C. norvegensis increased ammonia-N at 4, 8, 12, and 24 h (p<0.01), and IVDMD of oat straw increased at 8, 12, and 24 h (p<0.01) of fermentation. Yeast cells increased acetate (p<0.01), propionate (p<0.03), and butyrate (p<0.03) at 8 h, while valeriate and isovaleriate increased at 8, 12, and 24 h (p<0.01). The yeast did not affect cellulolytic bacteria (p = 0.05), but cellulolytic fungi increased at 4 and 8 h (p<0.01), whereas production of methane decreased (p<0.01) at 8 h. It is concluded that addition of C. norvegensis to in vitro oat straw fermentation increased ruminal fermentation parameters as well as microbial growth with reduction of methane production. Additionally, yeast inoculum also improved IVDMD.

• Journal of Nutrition and Health
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• 제28권9호
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• pp.834-845
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• 1995

This study was conducted in order to establish an in vitro method simulating the physiological function of fibers along the large intestine of humans. Commercial fibers including guar gum, apple pectin, citrus pectin, CM-cellulose, alginic acid and $\alpha$-cellulose, and dietary fiber residues obtained from rice bran, barley, soybean, Korea cabbage, apple, tangerine and sea mustard were employed to determine the water-holding capacity, weight of hydrated residue and fiber content after anaerobic fermentation using human fecal inoculum for 24 hours, followed by dialysis under osmotic suction pressure. The weight of hydrated residue in commercial fibers was in the decreasing order of CM-cellulose > alginic acid, $\alpha$-cellulose > apple pectin, citrus pectin > guar gum and that in food fiber residues was in the decreasing order of rice bran, sea mustard > soybean > tangerine, Korean cabbage > barley > apple. It was demonstrated that the larger the weight of hydrated residue was, the more the weight of human stool increased. Consequently this in vitro method can be used as a preceeding test before undertaking animal or human experiment to predict the physiological effects of fiber residues from diverse food samples as well as commercially refined fibers.

• Asian-Australasian Journal of Animal Sciences
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• 제19권9호
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• pp.1314-1321
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• 2006

The objective of this work was to study the effect of mixed culture solid substrate fermentation of C. tropicalis ZD-3 with A. niger ZD-8 on detoxification of cottonseed meal (CSM), and to investigate the effect of fermentation period, proportion of CSM in substrate, sodium carbonate, minerals and heat treatment on the reduction of free gossypol levels during mixed culture solid substrate fermentation of CSM. Experiment 1: Three groups of disinfected CSM substrate were incubated for 48 h after inoculation with either of the fungi C. tropicalis ZD-3, A. niger ZD-8 or mixed culture (C. tropicalis ZD-3 with A. niger ZD-8). One non-inoculated group was used as the control. Levels of initial and final free gossypol (FG), CP and in vitro CP digestibility were assayed. The results indicated that mixed culture fermentation was far more effective than single strain fermentation, which not only had higher detoxification rate, but also had higher CP content and in vitro digestibility. Experiment 2: CSM substrates were treated according to experimental variables including fermentation period, proportion of CSM in substrate, sodium carbonate, minerals and heat treatment, Then, the treated CSM substrates were inoculated with mixed culture (C. tropicalis ZD-3 with A. niger ZD-8) and incubated at $30^{\circ}C$ for 36 h in a 95% relative humidity chamber. After fermentation ended, FG and CP content of fermented CSM substrate was assayed. The results showed that the appropriate fermentation period was 36 h, and the optimal proportion of CSM in substrate was 70%. Addition of sodium carbonate to CSM substrate was beneficial for fermentative detoxification. Heat treatment could facilitate fermentative detoxification, and supplementation with minerals was instrumental in reducing gossypol levels during mixed culture solid substrate fermentation of CSM.

• Animal Bioscience
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• 제35권2호
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• pp.184-195
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• 2022

Objective: In this study we aimed to evaluate the effect of dietary live yeast supplementation on ruminal pH pattern, fermentation characteristics and associated bacteria in beef cattle. Methods: This work comprised of in vitro and in vivo experiments. In vitro fermentation was conducted by incubating 0%, 0.05%, 0.075%, 0.1%, 0.125%, and 0.15% active dried yeast (Saccharomyces cerevisiae, ADY) with total mixed ration substrate to determine its dose effect. According to in vitro results, 0.1% ADY inclusion level was assigned in in vivo study for continuously monitoring ruminal fermentation characteristics and microbes. Six ruminally cannulated steers were randomly assigned to 2 treatments (Control and ADY supplementation) as two-period crossover design (30-day). Blood samples were harvested before-feeding and rumen fluid was sampled at 0, 3, 6, 9, and 12 h post-feeding on 30 d. Results: After 24 h in vitro fermentation, pH and gas production were increased at 0.1% ADY where ammonia nitrogen and microbial crude protein also displayed lowest and peak values, respectively. Acetate, butyrate and total volatile fatty acids concentrations heightened with increasing ADY doses and plateaued at high levels, while acetate to propionate ratio was decreased accordingly. In in vivo study, ruminal pH was increased with ADY supplementation that also elevated acetate and propionate. Conversely, ADY reduced lactate level by dampening Streptococcus bovis and inducing greater Selenomonas ruminantium and Megasphaera elsdenii populations involved in lactate utilization. The serum urea nitrogen decreased, whereas glucose, albumin and total protein concentrations were increased with ADY supplementation. Conclusion: The results demonstrated dietary ADY improved ruminal fermentation dose-dependently. The ruminal lactate reduction through modification of lactate metabolic bacteria could be an important reason for rumen pH stabilization induced by ADY. ADY supplementation offered a complementary probiotics strategy in improving gluconeogenesis and nitrogen metabolism of beef cattle, potentially resulted from optimized rumen pH and fermentation.

• 한국유기농업학회지
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• 제22권4호
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• pp.801-813
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• 2014

본 연구는 반추위 메탄저감용 약용식물 첨가제 개발을 위해 유산균을 이용하여 발효한 두충 및 감초 추출물의 항균활성, 항산화활성 및 in vitro 반추위 발효시험을 실시하였다. 발효 약용식물 추출물 제조를 위해 접종된 종균의 성장효율을 조사하기 위해 실시한 생균수 측정 결과 L. curvatus NJ40, L. brevis NJ42 및 L. plantarum NJ45가 두충과 감초 모두에서 유의적으로 높은 균주 성장을 나타냈다(p<0.05). 항균활성측정 결과는 두충과 감초 추출물에서 공통적으로 L. curvatus NJ40 및 L. plantarum NJ45 로 발효한 추출물이 일부 병원균에 대한 항균효과를 나타내는 것으로 조사되었다. In vitro 반추위 발효시험에서 두충 및 감초발효 추출물을 적용한 결과, 감초 추출물에서 메탄 저감효과가 나타났다. 특히 반추위내 미생물 발효 특성을 대표할 수 있는 휘발성지방산 생성효율을 향상 시키면서, 전반적 반추위 발효에 부정적 영향이 없는 것으로 나타났다.

• 농업생명과학연구
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• 제51권4호
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• pp.97-109
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• 2017

본 시험은 항염에 효과가 있다고 알려진 식물 추출물의 첨가가 반추위 발효와 메탄 생성에 미치는 영향을 알아보기 위해 in vitro 실험을 수행하였다. 항염과 항산화 효과가 있는 산뽕나무, 뽕나무, 예덕나무, 오동나무, 방아풀과 은행나무 6종을 선발하였다. 반추위액과 McDougall buffer 혼합액 15mL과 티모시 0.3g, 각각의 추출물을 기질의 5%로 넣고 $39^{\circ}C$에서 3, 9, 12, 24, 48 그리고 72시간 배양하였다. 항염 효과가 있는 식물 추출물의 첨가는 반추위 발효 성상(pH, 건물소화율, Glucose 농도, 암모니아 농도, 단백질 농도, 미생물 성장량, 휘발성지방산)에는 영향을 미치지 않았다. 총 가스 발생량은 각기 다른 양상을 보였으며, 이산화탄소 발생량은 48시간대에서 예덕나무와 방아풀에서 대조구에 비해 유의적(p<0.05)으로 높았다. 또한 메탄 발생량은 배양 초기에는 대조구보다 첨가구에서 유의적(p<0.05)으로 감소하였으나, 발효가 진행될수록 대조구에 비해 첨가구에서 더 많은 메탄이 발생하였다. Polyphenol과 flavonoid는 은행나무 추출물구에서 가장 높았다. 본 시험의 결과에서 항염에 효과가 있는 식물 추출물을 in vitro 반추위 배양액에 첨가하였을 때, 반추위 발효에는 영향을 미치지 않았고, 메탄은 초기 발효에 저감 효과가 있는 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권4호
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• pp.491-500
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• 2010

Three experiments were conducted to investigate the effects of polyurethane coated urea on in vitro ruminal fermentation, ammonia release dynamics and lactating performance of Holstein dairy cows fed a steam-flaked corn-based diet. In Exp. 1, a dual-flow continuous culture was run to investigate the effect of polyurethane coated urea on nutrient digestibility, rumen fermentation parameters and microbial efficiency. Three treatment diets with isonitrogenous contents (13.0% CP) were prepared: i) feedgrade urea (FGU) diet; ii) polyurethane coated urea (PCU) diet; and iii) isolated soy protein (ISP) diet. Each of the diets consisted of 40% steam-flaked corn meal, 58.5% forages and 1.5% different sources of nitrogen. PCU and FGU diets had significantly lower digestibility of NDF and ADF (p<0.01) than the ISP diet. Nitrogen source had no significant effect (p = 0.62) on CP digestibility. The microbial efficiency (expressed as grams of microbial N/kg organic matter truly digested (OMTD)) in vitro of the PCU diet (13.0 g N/kg OMTD) was significantly higher than the FGU diet (11.3 g N/kg OMTD), but comparable with the ISP diet (14.7 g N/kg OMTD). Exp. 2, an in vitro ruminal fermentation experiment, was conducted to determine the ammonia release dynamics during an 8 h ruminal fermentation. Three treatment diets were based on steam-flaked corn diets commonly fed to lactating cows in China, in which FGU, PCU or soybean meal (SBM) was added to provide 10% of total dietary N. In vitro $NH_3-N$ concentrations were lower (p<0.05) for the PCU diet than the FGU diet, but similar to that for the SBM diet at all time points. In Exp. 3, a lactation trial was performed using 24 lactating Holstein cows to compare the lactating performance and blood urea nitrogen (BUN) concentrations when cows were fed PCU, FGU and SBM diets. Cows consuming the PCU diet had approximately 12.8% more (p = 0.02) dietary dry matter intake than those consuming the FGU diet. Cows fed the PCU diet had higher milk protein content (3.16% vs. 2.94%) and lower milk urea nitrogen (MUN) concentration (13.0 mg/dl vs. 14.4 mg/dl) than those fed the FGU diet. Blood urea nitrogen (BUN) concentration was significantly lower for cows fed the PCU (16.7 mg/dl) and SBM (16.4 mg/dl) diets than the FGU (18.7 mg/dl) diet. Cows fed the PCU diet had less surplus ruminal N than those fed the FGU diet and produced a comparable lactation performance to the SBM diet, suggesting that polyurethane coated urea can partially substitute soybean meal in the dairy cow diet without impairing lactation performance.

• 한국초지조사료학회지
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• 제37권3호
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• pp.216-222
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• 2017

This study was conducted to examine the effect of corn (Zea mays L.) - soybean (Glycine max L.) silage prepared by intercropping method on the nutritive value of the silage, in vitro rumen fermentation characteristics, dry matter degradability, as well as milk yield and milk composition of dairy cows. In a couple of experiments intercropped corn-soybean silage (CSBS) was compared with corn silage (CS) and/or Italian ryegrass hay (IRG). Numerically, CSBS had higher crude protein, ether extract, and lactic acid contents compared to CS. In vitro rumen fermentation analysis demonstrated that up to a 24-h incubation period, both CS and CSBS showed higher total gas production, ammonia N concentration, and dry matter degradability compared to IRG (p<0.05). The investigation on animals was conducted in a commercial dairy farm located in Gyeongju, South Korea, employing 42 Holstein cows that were divided into 2 group treatments: CS and CSBS in a completely randomized design. Although no significant difference was observed in milk yield, animals fed on CSBS showed significantly higher milk protein (p<0.05) and milk fat content (p<0.01), compared to animals fed on CS. Taken together, our findings indicate that corn-soybean silage that is cultivated, harvested, and prepared through intercropping can improve the protein content of the silage, and can also enhance in vitro rumen fermentation, dry matter degradability, and performance of dairy cattle.

• Asian-Australasian Journal of Animal Sciences
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• 제33권2호
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• pp.230-235
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• 2020

Objective: This study was realized to evaluate the nutritional value of rice grains as a replacement for corn grains in the diet of growing Hanwoo steers. Methods: Two experimental diets were prepared: i) Corn total mixed ration (TMR) consisting of 20% corn grains and ii) Rice TMR consisting of 20% rice grains, in a dry matter (DM) basis. These treatments were used for in vitro rumen fermentation and in vivo growth trials. In the rumen fermentation experiment, the in vitro DM digestibility (IVDMD), in vitro crude protein digestibility (IVCPD), in vitro neutral detergent fiber digestibility, pH, ammonia nitrogen, and volatile fatty acids (VFA) were estimated at 48 h, and the gas production was measured at 3, 6, 12, 24, and 48 h. Twenty four growing Hanwoo steers (9 months old; body weight [BW]: 259±13 kg) were randomly divided into two treatment groups and the BW, dry matter intake (DMI), average daily gain (ADG), and feed conversion ratio (FCR) were measured. Results: The in vitro experiment showed that the IVDMD, IVCPD, and VFA production of the Rice TMR were higher than those of the Corn TMR (p<0.05). The growth trial showed no differences (p>0.05) in the final BW, ADG, DMI, and FCR between the two TMRs. Conclusion: The use of rice grains instead of corn grains did not exhibit any negative effects on the rumen fermentation or growth performance, thereby rice grains with a DM of less than 20% could be used as a starch source in the diet of growing steers.

• 농업과학연구
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• 제44권4호
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• pp.541-548
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• 2017

This study was conducted to compare in vitro rumen fermentation characteristics among corn grains imported from America, Brazil, Argentina and Ukraine A and Ukraine B. Two Holstein steers, each surgically fitted with a ruminal cannula, consuming total mixed ration were used as rumen fluid donors. In vitro rumen fermentation experiments were performed in a completely random design which included a control (no corn) and treatments with 3.0 g of corn from different geographical origins, i.e., America, Brazil, Argentina, and Ukraine A and Ukraine B, respectively. Ruminal pH, ammonia-N, volatile fatty acid (VFA) and total gas production were measured at 0, 1, 3, 6, 12, 24 and 48 h post-incubation, respectively. No differences (p > 0.05) in mean ruminal pH appeared among the treated groups, however, ruminal pH patterns differed; i.e. corn treated groups had dramatically lower pH compared with control during the entire incubation period. Similarly, no different patterns between the groups in ammonia-N (p > 0.05) appeared until 6 h post-incubation. Unexpectedly, higher ammonia-N concentration for control than that for the corn treated groups appeared after 12 h post-incubation despite that for all groups increased. Total VFA was similar between the groups until 6 h post-incubation, but VFA after 12 h post-incubation was different (p < 0.05), i.e. VFA for corn from Argentina, Ukraine A, Ukraine B, and Brazil were comparatively higher than for America. Overall, data in this study showed that the corns of different origins may have different feed values to ruminants despite having similar chemical compositions.