• Asian-Australasian Journal of Animal Sciences
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• v.19 no.3
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• pp.376-380
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• 2006

An experiment was conducted to study the effect of temperature and pH on in vitro nutrient degradability, volatile fatty acid profile and methane production. The fermenter used was the semi-continuous system, known as the rumen simulation technique (RUSITEC). Sixteen cylinders were used at one time with a volume of 800 ml, the dilution rate was set at 3.5%/hour, the infused buffer being McDougall's artificial saliva. Basal diet (9.6 g DM) used in RUSITEC consisted of (DM) 6.40 g Timothy hay, 1.86 g crushed corn and 1.34 g soybean meal. The food for the fermentation vessel was provided in nylon bags, which were gently agitated in the liquid phase. The experiment lasted for 17 d with all the samples taken during the last 5 d. Treatments were allocated at random to four vessels each and were (1) two temperature levels of $39^{\circ}C$ and $41^{\circ}C$ (2) two pH levels of 6.0 and 7.0. The total diet contained ($g\;kg^{-1}$ DM) 957 OM, 115 CP and $167MJ\;kg^{-1}$ (DM) GE. Although increase in temperature from $39^{\circ}C$ to $41^{\circ}C$ reduced degradation of major nutrients in vitro, it was non-significant. Interaction effect of temperature with pH also reflected a similar trend. However, pH showed a significant (p<0.05) negative effect on the degradability of all the nutrients in vitro. Altering the in vitro pH from 7 to 6 caused marked reduction in DMD from 60.2 to 41.8, CPD from 76.3 to 55.3 and GED from 55.3 to 35.1, respectively. Low pH (6) depressed total VFA production (61.9 vs. 34.9 mM) as well as acetate to propionate ratio in vitro (from 2.0 to 1.5) when compared to pH 7. Compared to pH 7, total gas production decreased from 1,841 ml to 1,148 ml at pH 6, $CO_2$ and $CH_4$ production also reduced from 639 to 260 ml and 138 to 45 ml, respectively. This study supported the premise that pH is one of the principal factors affecting the microbial production of volatile fatty acids and gas. Regulating the ruminal pH to increase bacterial activity may be one of the methods to optimize VFA production, reduce methane and, possibly, improve animal performance.

• Journal of Life Science
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• v.22 no.10
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• pp.1324-1329
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• 2012

The objective of this study was to evaluate the in vitro effects of organic acids on methane emission and ruminal fermentation characteristics. We expected our methodology to result in a decrease of methanogens attached to the surface of rumen ciliate protozoa by addition of organic acids and in particular a decrease in methane emission. A fistulated Holstein cow of 650 kg body weight was used as a donor of rumen fluid. Organic acids (aspartic acid, fumaric acid, lactic acid, malic acid, and succinic acid) known to be propionate enhancers were added to an in vitro fermentation system and incubated with rumen fluid. The microbial population, including bacteria, protozoa, and fungi, were enumerated, and gas production, including methane and fermentation characteristics, were observed in vitro. Organic acids appeared to affect the rumen protozoan community. The rumen protozoal popuation decreased with the addition of aspartic acid, fumaric acid, lactic acid, and malic acid. In particular, the methane emission was reduced by addition of lactic acid. The concentration of propionate with all organic acids that were added appeared to be higher than that of the control at 12 h incubation. Addition of organic acids significantly affected rumen bacteria and microbial growth. The bacteria in added fumaric acid and malic acid was significantly higher (p<0.05) and protozoa was significantly lower (p<0.05) than that of the control. Microbial growth with the addition of organic acids was greater than the control after 48 h incubation.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.11
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• pp.1601-1607
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• 2016

This study was conducted to determine the effect of lysozyme addition on in vitro rumen fermentation and to identify the lysozyme inclusion rate for abating methane ($CH_4$) production. An in vitro ruminal fermentation technique was done using a commercial concentrate to rice straw ratio of 8:2 as substrate. The following treatments were applied wherein lysozyme was added into 1 mg dry matter substrate at different levels of inclusion: Without lysozyme, 2,000, 4,000, and 8,000 U lysozyme. Results revealed that, lysozyme addition had a significant effect on pH after 24 h of incubation, with the highest pH (p<0.01) observed in 8,000 U lysozyme, followed by the 4,000 U, 2,000 U, and without lysozyme. The highest amounts of acetic acid, propionic acid (p<0.01) and total volatile fatty acid (TVFA) (p<0.05) were found in 8,000 U after 24 h of incubation. The $CH_4$ concentration was the lowest in the 8,000 U and the highest in the without lysozyme addition after 24 h of incubation. There was no significant differences in general bacteria, methanogen, or protozoan DNA copy number. So far, addition of lysozyme increased the acetate, propionate, TVFA, and decreased $CH_4$ concentration. These results suggest that lysozyme supplementation may improve in vitro rumen fermentation and reduce $CH_4$ emission.

• Journal of Animal Science and Technology
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• v.46 no.1
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• pp.61-68
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• 2004

An experiment was conducted to evaluate condensed molasses solubles(CMS, a by-product from monosodium glutamate production) as a source of nitrogen for ruminant with particular reference to its effects on microbial protein synthesis. Four non-lactating dairy cows fitted with rumen cannulas were used in a 4 ${\times}$ 4 Latin square with 14-day periods. The four treatments were (1) basal diet consisting of barley straw ad libitum and 3 kg/d of rolled barley, (2) basal diet plus 200 gld molasses and 300 g/d water, (3) basal diet plus 200 g/d molasses, 100 g/d CMS and 200 g/d water, (4) basal diet plus 200 g/d molasses, 200 g/d CMS and 100 g/d water. Ruminal pH remained at high levels and showed little variation during the day between treatments. The concentration of total and individual VFA in the rumen was similar between treatments. There was no difference in the concentration of ammonia in the rumen between treatments, although the intake of nitrogen in molassesl CMS mixture treatments was higher than that of control and molasses treatment. But there was a suggestion of an increased synthesis of microbial protein with the higher level of inclusion of CMS when the allantoin/creatinine ratio was used as an index of microbial protein production(P <0.10).

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.968-978
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• 2003

The effects of monensin, Tween 80 and exogenous fibrolytic enzymes on ruminal fermentation and animal performance were studied in vitro and in vivo. In Expt 1, the effects of the surfactant Tween 80 (0.2% wt/wt, DM basis) on ruminal fermentation of alfalfa, corn and orchardgrass silages were investigated using in vitro gas production techniques. Tween 80 did not affect (p>0.05) cumulative gas production at 24 h, but it reduced (p<0.05) the lag in fermentation of all three silages. With corn silage and orchardgrass silage, gas production rates and concentrations of total volatile fatty acids (VFA) were increased (p<0.05) by Tween 80; with alfalfa silage, they were reduced (p<0.05). Tween 80 increased (p<0.05) the proportion of propionate in total VFA, and reduced (p<0.05) acetate to propionate ratios (A:P) with all three silages. In Expt 2, exogenous fibrolytic enzymes (E; at 0, 37.5 or 75 g/tonne DM), monensin (M; at 0 or 25 ppm and Tween 80 (T; at 0 or 2 L/tonne DM) were added alone or in combination to backgrounding and finishing diets fed to 320 crossbred steers in a feeding trial with a $3{\times}2{\times}$2 factorial arrangement of treatments. The backgrounding and finishing diets contained barley grain and barley silage in ratios of 57.8:42.2 and 93.5:6.5 (DM basis), respectively. Added alone, none of the additives affected DM intake (p>0.1) in the backgrounding or in the finishing period, but interactive $M{\times}T$ effects were observed in the finishing period (p=0.02) and overall (p=0.04). In the finishing period, T without M tended to reduce DM intake (p=0.11), but T with M increased (p=0.05) DM intake. Monensin increased average daily gain (ADG) during backgrounding (p=0.07) and finishing (p=0.01), and this ionophore also improved overall feed efficiency (p=0.02). Warm carcass weight was increased (p<0.001) by M, but dressing percentage was reduced (p=0.07). In the backgrounding period, T increased ADG by 7% (p=0.06). Enzymes increased (p=0.07) ADG by 5 and 6% (low and high application rates, respectively) during backgrounding, but did not affect (p>0.10) ADG during finishing, or overall feed efficiency. Whereas T enhanced the positive effects of M on ADG during backgrounding (p=0.04) and overall (p=0.05), it had no impact (p>0.1) on the effects of E. Interactions between M and T suggest that the surfactant may have potential for enhancing the positive effects of monensin on beef production, but this requires further research.

• Journal of Animal Science and Technology
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• v.50 no.3
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• pp.381-390
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• 2008

Two experiments were conducted to investigate effects of molasses addition to silage materials in ensiling Socheongryongtang meal on the nutritive quality of silage, palatability and various ruminal parameters in Korean native goats. In Experiment 1, Socheongryongtang meal silage was produced by the addition of 0, 0.5, or 1.0% molasses and stored for 40 days at room temperature. There were three replicates per treatment. Lactic acid contents of Socheongryongtang meal silage containing molasses(0.5 and 1.0%) were significantly(p<0.05) higher than that of the control(0%). However, the pH and butyric acid contents of Socheongryongtang meal silage containing molasses(0.5 and 1.0%) were lower than those of the control(0%). In addition, molasses(0.5 and 1.0%) increased the number of lactobacillus, but decreased the number of fungi in Socheongryongtang meal silage. In vitro dry matter disappearance tended to increase by molasses addition. In Experiment 2, three 1.5-yr-old Korean native female goats were employed in cross-over design to measure the palatability and various ruminal parameters of Socheongryongtang meal silage. Feed intake of Socheongryongtang meal silage containing molasses(0.5 and 1.0%) for 30 min significantly higher than that of control(0%). Silmilar trend was found when the feed intake was measured for 6 hr. In various ruminal parameters, molasses addition to silage materials increased propionic acid(P) and total volatile fatty acid contents, but decreased pH, acetic acid (A), and butyric acid. The A/P ratio was the lowest in 1.0% molasses treatment group. It is concluded that molasses addition in ensiling Socheongryongtang meal could enhance its nutritional quality and lengthen storage period. Also the palatability of silage was improved by the addition of molasses.

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.917-930
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• 2017

This study was conducted to evaluate Raphanus sativus extracts to methane reduction in rumen. Five different levels of R. sativus extracts were used to investigate the most effective dosing level for the decrease of methane production in the rumen. The rumen fluid was collected from a cannulated one Hanwoo cow ($BW=450{\pm}30kg$) consuming 600 g/kg timothy and 400 g/kg concentrate. On fermentation day, rumen fluid was collected at 2 hr postfeeding R. sativus extracts was dosed to achieve final concentration of 0, 1, 3, 5, 7, and 9% respectively, to fermentation bottles containing the mixture of rumen fluid and McDougall's buffer and 300 mg of timothy was added as a substrate. The fermentation was conducted for 3, 6, 9, 12, 24, 48 and 72 hr incubation time at $39^{\circ}C$ with shaking. In vitro ruminal pH values were measured normal range for ruminal fermentation. Dry matter disappearance was significantly higher (p<0.05) at 3 hr incubation time 1, 3 and 5% doses than that of control. The highest methane reduction was observed in 12 hr incubation time 5, 7 and 9%. The carbon dioxide emission was also significantly (p<0.05) lower than that of control at 12 hr incubation time 5, 7 and 9%. The total volatile fatty acid was no significant difference between control and all doses level at 12 and 24 hr incubation time. At 24 hr incubation time, the result of real-time PCR were indicated that M. archea was significantly lower (p<0.05) at all doses level comparing to that of control. In conclusion, R. sativus extracts were significantly decreased methane emission. R. sativus extracts were significantly lower (p<0.05) than that of control at 12 hr incubation time 5, 7 and 9% and no adversely effect in rumen pH, dry matter disappearance and total VFA.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.131-142
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• 2003

We evaluated the effects of adding fibrolytic enzyme into ruminant diets on ruminal fermentation (in vitro) and lactational performances of dairy cows (in vivo). Through the in vitro experiment that was carried out with different contents of NDF (34, 38, 43%) in diets, digestibilities of NDF in the rumen appeared not significantly different by the addition of enzyme but were different by NDF content in diets showing higher digestibility in NDF 43% diet. It could be attributed by the relatively higher amount of hemicellulose in the current experimental diets than in conventional diets that might have been digested easily by the addition of fibrolytic enzyme in the rumen. The addition of fibrolytic enzyme tended to increase NDF digestibilities to a little extent both in 0.05 and 0.1% enzyme levels. Ruminal pH, NH3-N concentrations and VFA production in the rumen were not affected by the addition of fibrolytic enzyme. Activities of CMCase and xylanase were higher in enzyme treated diets of both NDF 34 and 38%. In particular, the activities of xylanase that slowly decreased from 0 to 12 hr but rapidly after 24 hr indicates that the major action of the enzyme in the rumen occurs in early period of incubation. Through an in vivo experiment, fibrolytic enzyme addition into the diets of dairy cows indeed affected lactational performance of milk yield. The cows fed enzyme treated diets produced 8% (1.9kg/d) more amounts of milk than with no enzyme addition. Milk composition of milk fat and protein was not affected by enzyme addition. Overall, the results of this in vivo study indicates that fibrolytic enzyme can be used to improve milk production in lactating cows. In respect that animals in different treatments of this study had the same amounts of intake, the increased milk yield with enzyme addition may be attributed to the improved utilization of nutrients in the digestive tract.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.2
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• pp.119-127
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• 2021

The objective of this study was to evaluate effects of feeding methods on in vitro ruminal fermentation, total gas and methane production in Hanwoo steers. Six Hanwoo steers fitted with rumen cannula (430 ± 21 kg of body weight) were randomly assigned to one of three feeding systems: 1) feeding forage 1 hour after concentrate, 2) feeding concentrate 1 hour after forage, 3) feeding mixed ration. Rumen fluid sampled from each animals was incubated 24 hours with maize or timothy substrates in in vitro. Ruminal pH was increased in feeding method 2 or maize substrate than that of other methods or timothy substrate (P < 0.001). The production of total volatile fatty acid, acetate, propionate, butyrate, and valerate were increased when steers fed diets using feeding method 1 or rumen fluid was incubated with maize substrate (P < 0.001). Increased production of total gas and methane was observed in feeding method 1 and maize substrate compared to those of other methods or timothy substrate (P < 0.001). Due to the inconsistent results between ruminal fermentation and gas production in this study, further research is required to estimate effects of feeding method on enteric fermentation and gas production in in vivo.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.7
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• pp.957-965
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• 2005

The effect of ammoniation with urea and with soybean meal (SBM) as a source of urease on the nutritive value of wheat straw was evaluated in sheep. Twenty-four male Najdi lambs were used in a 3${\times}$2 factorial design, in which the animals were allocated to three straw treatments: 0% urea-treated (NT), 6% urea-treated (UT) and 2.2% urea-supplemented (US) straws. Each straw treatment was either supplemented or non-supplemented with 70 g SBM $kg^{-1}$ straw during the treatment time with urea, giving a total of six straw treatments. Each of these treatments was individually fed ad libitum to 4 lambs, together with 300 g of barley grain/head/day. Total N content of UT and US straws increased significantly (p<0.001) as compared to NT straw. The degree of urea hydrolysis, either with or without SBM addition, was nearly similar. Lambs fed either UT or US straw based diets had significantly (p<0.01) and numerically (p>0.05) higher straw DM intake (g $d^{-1}$ $kg^{-1}$ $BW^{0.75}$), compared to those fed NT straw based diet. Apparent DM or OM digestibilities increased significantly (p = 0.014) in lambs fed UT diet, and numerically (p>0.05) in lambs fed US diet as compared to those fed NT diet. Fiber (CF, NDF, ADF, cellulose and hemicellulose) digestibility increased to a similar magnitude, averaging 20.2 (p<0.001) and 7.8% (p<0.07); this corresponds to 35 (p<0.001) and 51% (p<0.001) in N digestibility and approximately 78 (p<0.017) and 105% (p<0.002) in N retention, for UT and US diets, respectively, as compared to NT diet. However, the UT diet had higher (p<0.01) fiber digestibility over the US diet. Addition of SBM tended to improve (p = 0.09) straw DM and digestible OM intakes, while significantly increasing (p<0.001) total and digestible CP intakes across all diets. Lambs fed on US diet had higher ruminal ammonia N than those fed on UT (p<0.05) or NT (p<0.001) diets. However, ruminal pH and molar proportion of the volatile fatty acids did not differ (p>0.05) among the treatment diets. This study suggests that US and UT treatments, particularly the latter, improved straw intake, digestibility and N utilization by lambs compared to NT treatment. On the other hand, addition of SBM as a source of urease had a negligible effect on urea hydrolysis.