• Korean Journal of Organic Agriculture
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• v.26 no.2
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• pp.281-296
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• 2018

This study was conducted to evaluate the effect of different processing of rice on rumen fermentation in in vitro and in situ experiments. Different processing treatments (extruding, roasting, and steaming) were used in this study and all treatments were ground through a cyclone mill (Foss, Hillerød, Denmark) fitted with a 1 mm screen. Non-treated rice was considered to a control substrate. Then, all treatments were used in in vitro and in situ experiments. Total gas production and dry matter digestibility in control were lower than any other treatment at all incubation times (P<0.01). The lowest ammonia nitrogen ($NH_3-N$) concentration was observed in control among treatments at 6, 12, and 24 h incubation (P<0.01). Extruding had a highest total volatile fatty acids (VFA) concentration at 6, 12 h incubation (P<0.01) and Steaming exhibited a highest total VFA at 24 h (P<0.01). The lowest total VFA concentration was observed in control at 6, 12, and 24 h (P<0.01). In an in situ, The highest value of soluble fraction, degradation rates, effective degradability was observed in extruding (P<0.01). It was considered that feed processing increased dry matter digestibility, total VFA concentration, and decreased pH as well as $NH_3-N$ concentration indicating that processing may increase nutrient degradation of rice in the rumen.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.628-636
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• 2008

Anaerobic denitrification in a two phase anaerobic digestion(TPAD) process combined with biological nutrients removal (BNR) system was studied for a piggery wastewater treatment. Denitrification efficiency and the effects of the nitrified effluent on acidification was investigated by recycling the nitrified effluent to the acidogenic reactor. Recycle of the nitrified effluent to the acidogenic reactor enhanced the conversion efficiency of the influent COD into volatile fatty acids(VFAs) in the TPAD-BNR system treating the piggery wastewater. Acidification rate of the acidogenic sludge acclimated with the nitrified effluent showed 6 times higher than that acclimated without it. VFA could be used for denitrification as carbon sources, however, nitrate could enhance acidification activity in the acidogenic reactor. VFA production rate was affected on the COD/Nitrate(COD/N) ratio, however, it depended much more whether the acidogenic sludge acclimated with nitrate or not. Denitrification with the acidogenic sludge acclimated without nitrified effluent followed zero-order reaction and the reaction rate constants were in the range of 1.31$\sim$1.90 mg/L$\cdot$h. Denitrification reaction rate constants of the acidogenic sludge acclimated with nitrified effluent were 3.30 mg/L$\cdot$h that showed almost twice of them evaluated from the previous tests. The stoichiometric ratios of utilized COD to removed nitrate showed similar in both tests which were in the range of 5.1$\sim$6.4 at COD/N ratio of 10.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.137-145
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• 1994

Amino acid (AA) substituted diets had no influence on rumen levels of total volatile fatty acids (VFA), ammonia and ${\alpha}$-amino-N, but tended to increase molar proportions of isovalerate and counts of total viable AA utilizing and celluloytic bacteria in the rumen as compared with the control urea diet. The AA diets did not affect daily flow to the duodenum of dry matter (DM), organic mater (OM) and acid detergent fibre (ADF), and rumen digestibility of these nutrients. However, the AA diets, in particular the 10 essential AA (EAA) diet improved total digestibility of DM, OM and ADF by decreasing faecal output of these fractions. Although N flow to the duodenum and N retention were not affected with the dietary treatments, duodenal bacterial flow appeared to increase by the AA diets when it was estimated by means of 2,6-diaminopimelic acid (DAP) and nucleic acid-purine bases (PB) as markers. The results suggest that AA supplements to a urea diet could improve feed utilization by stimulating microbial activity and proliferation in the rumen but and increased microbial activity per se is not necessarily associated with improvement of feed conversion.

• Journal of Biosystems Engineering
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• v.35 no.1
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• pp.53-63
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• 2010

The performance of two serial completely stirred tank reactors (CSTRs) for treatment of swine manure (SM) with Chinese cabbage silage (CCS) was studied. The two CSTRs of 41 liters each were connected in series and first reactor was fed swine manure with Chinese cabbage silage in 3:1 proportion by VS basis. The FOS/TAC, methane content (%) and pH were utilized as the parameters for the digester stability control. The FOS/TAC value was found to be effective indicator for instant digester condition. The stability of reactors can be obtained with the FOS/TAC value up to 1.0 with accumulation of FOS value below 10,000 mg/L. Material exchange method was effective in transferring the excess volatile fatty acids (VFA) from the first reactor to the second one and maintaining stability in both the reactors. The biogas yield and the methane yield was 0.55-0.61 and 0.41-0.42 L/g VS fed, respectively, at organic loading rate (OLR) of 2.2-2.6 g VS/L with total HRT of 32 days.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.371-377
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• 1997

Objective of the present study were to investigate effects of different levels of concentrate in complete rations on nutrient digestibilities and ruminal fermentation in sheep and growth performance in Korean native bulls. Increasing levels of concentrate (35, 50, 65, and 80% of complete rations) improved digestibilities of dry matter (DM), crude protein (CP) and ether extract (EE) without affecting digestibility of neutral detergent (NDF) and acid detergent fiber (ADF). Increasing levels of concentrate decreased ruminal fluid pH but increased concentrations of $NH_3-N$, propionic acid, and total volatile fatty acids (VFA). Both the disappearance rates of DM and nitrogen (N) in an in sacco study were linearly increased as the levels of concentrate in complete rations increased. Meanwhile, increasing levels of concentrate in complete rations improved growth rate and feed conversion ratio in Korean native bulls. In conclusion, the complete rations containing 80% concentrate showed better digestibility and energy supply than those of the lower levels (35, 50 and 65%) of concentrate of the rations, resulting in improved growth performance of Korean native bulls.

• Korean Journal of Agricultural Science
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• v.45 no.3
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• pp.419-427
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• 2018

The present study was conducted to investigate the effect of different levels of Korean corn grain on in vitro ruminal fermentation with total mixed ration (TMR) as a basal feed. Three ruminal cannulated Holstein steers (Body Weight $479{\pm}33.0kg$) were used as rumen fluid donors. Treatments for in vitro fermentation were TMR only (control, 3.0 g), TMR substituted partially with high level (HC, TMR 1.5 and corn 1.5 g), and with low level of Korean corn grain (LC, TMR 2.25 and corn 0.75 g), respectively. To measure in vitro ruminal pH, gas production, ammonia N and volatile fatty acids (VFA), the in vitro fermentation incubation was triplicated at $39^{\circ}C$, 120 rpm for 0, 1, 3, 6, 12, 24 and 48 h, respectively. Mean ruminal pH was significantly lower (p < 0.05) for HC than control. Changes in rumen pH was rather similar between the groups till 6 h after incubation, but the lowest pH for HC (pH 5.10) appeared at 48 h compared with control and LC. Total gas production was tended (p < 0.09) to be higher and ammonia N was significantly lower (p < 0.05) for HC than control and LC. Total VFA was higher (p < 0.05) for HC and LC than control but no differences appeared between HC and LC. Overall, the present data indicate that feeding different levels of Korean domestic corn grain may lead to high and sustainable starch degradation in the rumen.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.5
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• pp.672-676
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• 2003

Effect of a surfactant Tween 80 on the bacterial growth in the rumen was examined on the in vitro pure cultures of Streptococcus bovis, Selenomonas ruminantium, Butyrivibrio fibrisolvens, Prevotella ruminicola, Megasphaera elsidenni, Fibrobacta succinogenes, Ruminanococcus albus and Ruminococcus flavefaciens. Dry matter degradability (DMD), concentrations and compositions of volatile fatty acids (VFA), and the most probable number (MPN) of cellulolytic bacteria and total number of bacteria in the presence of Tween 80 were also examined on the in vitro rumen mixed culture either with barley grain or orchardgrass hay. The growth of S. bovis, S. ruminantium, B. fibrisolvens, P. ruminicola, M. elsidenni and F. succinogenes were significantly higher (p<0.05) at over 0.05% concentrations of Tween 80 than those of the control cultures, while was not changed with R. albus and R. flavefaciens. With rumen mixed culture the DMD of barley grain and orchardgrass hay was significantly higher (p<0.05) at a 0.2% concentration of Tween 80 than the control, being reflected in the significantly higher (p<0.05) VFA production (mmol $g^{-1}$DDM) with orchardgrass hay. The higher (p<0.05) ratio of propionate to acetate at a 0.2% concentration of Tween 80 was also observed with orchardgrass hay, showing a similar trend with barley grain. No changes in the total bacterial number and MPN of cellulolytic bacteria were observed.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1425-1434
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• 2008

The study was conducted to evaluate and compare the effects of feed additives on ruminal fermentation, nutrient digestibility and performance of lambs fed diets containing 60% wet brewers grains (WBG). In Experiment 1, two simultaneous trials were conducted. Fifty intact ($20.2{\pm}0.8kg\;BW$) lambs were used in a feedlot trial and 10 (rumen cannulated; $32{\pm}1kg\;BW$) in a digestion trial. The pH, volatile fatty acids (VFA) and ammonia-N in lambs were also estimated. Lambs were randomly assigned to one of five diets: i) without additives (Con), ii) with 1% bicarbonate (Bic), iii) with 1% bentonite (Ben), iv) with 33 mg/kg monensin (Mon) and v) with 200 mg/kg fibrolityc enzymes (Enz). In Experiment 2, 120 RambouilletPelibuey intact male lambs ($19.5{\pm}1.5kg\;BW$) were used in a feedlot trial and randomly assigned to four diets: i) without additives (control), ii) with 1% Bic, iii) with 33 mg/kg Mon and iv) with 1% Bic and 33 mg/kg Mon. In Experiment 1, lambs fed diets containing Bic or Mon had significantly higher final weight, DMI, ADG than other lambs. However, apparent DM, OM, CP, NDF and ADF digestibilities and ruminal individual VFA content were similar (p>0.05) among treatments. Conversely, treatmentcollection period interaction was significant for ruminal pH and NH3. In Experiment 2, lambs fed diets containing a Bic and Mon combination had significantly higher final weight, DMI and ADG. It is concluded lambs fed Bic or Mon or Bic and Mon combination had better performance characteristics than lambs on Ben or Enz.

• Korean Journal of Agricultural Science
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• v.42 no.3
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• pp.237-244
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• 2015

Four ruminally cannulated Holstein steers (BW $401.0{\pm}2.22kg$) fed TMR containing low protein (CP 9.63 %) as a basal diet were used to investigate the effects of cornell net carbohydrates and protein system (CNCPS) fraction enriched protein feeds on rumen fermentation and blood metabolites. The steers used in a $4{\times}4$ Latin square design consumed TMR only (control), TMR with rapeseed meal (AB1), TMR with soybean meal (B2) and TMR with perilla meal (B3C), respectively. The protein feeds were substituted for 30 % crude protein of TMR intake. For measuring ruminal pH, ammonia-N and volatile fatty acids (VFA), ruminal digesta was sampled through ruminal cannula at 1 h-interval after the afternoon feeding. Blood was sampled via the jugular vein after the ruminal digesta sampling. Different CNCPS fraction-enriched proteins did not affect (p>0.05) ruminal pH except B3C being numerically low compared with the other groups. Ammonia-N and VFA were not significantly different among the experimental groups. Numerically low ammonia-N appeared in the steers fed rapeseed meal even though it contained high soluble N composition (A and B1 fractions). The discrepancy is unclear; however this may be related to low protein level in the diet and/or low DM intake. Blood metabolites were not significantly affected by the protein substitution except for blood urea nitrogen that was significantly (p<0.05) increased.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.6
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• pp.661-672
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• 1998

Two experiments were conducted to examine the effects of a range of concentrations of ruminal fluid ammonia ($NH_3$-N) on forage digestibility, microbial growth efficiency and the mix of microbial species. Urea was either continuously infused directly into the rumen of sheep fed 33.3 glh of oaten chaff (Exp. I) or sprayed onto the oaten chaff (750 g/d) given once daily (Exp. 2). Concentrations of $NH_3$-N increased with incremental addition of urea (p < 0.01). Volatile fatty acids (VFA) concentrations and 24 h in sacco organic matter digestibility in the rumen were higher when supplemental urea was given (p < 0.01). The (C2 + C4) : C3 VFA ratio was lower (p < 0.05) when $NH_3$-N was above 200 mgN/I. The fungal sporangia appearing on oat leaf blades were significantly higher when urea was supplemented, indicating that $NH_3$-N was a growthlimiting nutrient for fungi at levels of $NH_3$-N below 30 mgN/l. The density of protozoa was highest when $NH_3$-N concentrations were adjusted to 30 mgN/I for continuously fed ($4.4{\times}10^5/ml$) and to 168 mgN/1 for once daily feeding ($2.9{\times}10^5/ml$). Thereafter increasing concentrations of $NH_3$-N, were associated with a concomitant decline in protozoal densities. At the concentration of $NH_3$-N above 200 mgN/l, the density of protozoa was similar to the density of protozoa in ruminal fluid of the control sheep ($1.8{\times}10^5/ml$). The efficiency of net microbial protein synthesis in the rumen calculated from purine excretion was 17-47% higher when the level of $NH_3$-N was above 200 mgN/1. The possibilities are that 1) there is less bacterial cell lysis in the rumen because of the concomitant decrease in the protozoal pool and/or 2) microbial growth per se in the rumen is more efficient with increasing $NH_3$-N concentrations.