• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.651-658
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• 2009

Four multiparous lactating Holstein cows fitted with rumen cannulae were fed diets varying in the amount and source of rumen-degradable carbohydrates (starch vs. sucrose) to examine their effects on rumen fermentation, nitrogen metabolism and lactation performance. A $4{\times}4$ Latin square with four diets and four periods of 28 days each was employed. Corn starch and sucrose were added to diets and corn starch was replaced with sucrose at 0 (0 S), 2.5 (2.5 S), 5.0 (5.0 S) 7.5% (7.5 S) of diet dry matter in a total mixed ration (TMR) containing 60% concentrate and 40% forage (DM basis). Replacing corn starch with sucrose did not affect (p>0.05) ruminal pH which averaged 6.41, but the ruminal pH for 7.5 S decreased more rapidly at 2 h after morning feeding compared with other treatments. Sucrose reduced ($p{\leq}0.05$) ruminal $NH_3-N$ concentration (13.90 vs. 17.09 mg/dl) but did not affect peptide-N concentration. There was no dietary effect on total volatile fatty acids (110.53 mmol/L) or the acetate to propionate ratio (2.72). No differences (p>0.05) in molar proportion of most of the individual VFA were found among diets, except for the molar proportion of butyrate that was increased ($p{\leq}0.05$) with the inclusion of sucrose. Total branched chain volatile fatty acids tended to increase ($p{\geq}0.051$) for the control treatment (0 S) compared with the 7.5 S treatment. Dry matter intake, body weight changes and digestibility of DM, OM, CP, NDF and ADF were not affected by treatments. Sucrose inclusion in the total mixed ration did not affect milk yield, but increased milk fat and total solid percentage ($p{\leq}0.05$). Sucrose tended ($p{\geq}0.063$) to increase milk protein percentage (3.28 vs. 3.05) and reduced ($p{\leq}0.05$) milk urea nitrogen concentration (12.75 vs. 15.48 mg/dl), suggesting a more efficient utilization of the rapidly available nitrogen components in the diet and hence improving nitrogen metabolism in the rumen.

• Korean Journal of Organic Agriculture
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• v.20 no.2
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• pp.221-230
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• 2012

Rumen fermentative characteristic is useful indicators of the quality of ruminant feed stuffs and diets. An in vitro rumen fermentation experiment was therefore carried out to compare fermentation patterns among three forage sources. These were whole crop barley (WCBS), Italian ryegrass silage (IRGS) and rice straw silages (RSS). Rice straw (RS) was the control, making the treatments 4 in total. Forages were randomly allocated to serum bottles. The incubation times were arranged 0, 3, 6, 9, 12, 24, 48 and 72h at $39^{\circ}C$, respectively. Each forage source was replicated 3 times per incubation time. At each sampling time, total gas and pH were measured, whilst individual volatile fatty acids (VFAs), total volatile fatty acids (TVFAs) and ammonia nitrogen ($NH_3$-N) were determined later after storing samples at $-20^{\circ}C$. Acetate: Propionate ratio (A/P) was then calculated. Forage source had a significant effect (P<0.001) on pH and $NH_3$-N. RSS maintained higher pH values than the rest of the forage sources. A decreasing pH trend with increased time of incubation, in agreement with literature, was observed for all forage sources. WCBS recorded $NH_3$-N values higher than all the other treatments. Total gas, individual and total VFA and A/P ratio were not affected by forage source. However, there was a significant difference in all parameters (p<0.05) among forage sources at sampling periods at 3 to 72h. Therefore, the present results indicating that WCBS, IRGS, RS and RSS maintained in vitro rumen pH above the critical value. Also, WCBS produced the highest NH3-N and on this merit could be of better nutritive value, in vivo, in the ruminant.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.479-484
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• 2001

The effect of dietary supplementation of sodium salt of isobutyric acid in low protein (10% CP) wheat straw based diet on nutrient utilization and rumen fermentation was studied in ruminally fistulated male crossbred cattle. The study included a 7 day metabolism and a 3 day rumen fermentation trials. The cattle were distributed into two equal groups of 4 each. The animals of control group were fed a basal diet consisting of wheat straw, concentrate mixture and green maize fodder in 40:40:20 proportion whereas branched chain volatile fatty acid (BCFA) supplemented group received a basal diet + isobutyric acid at 0.75 percent of basal diet. The duration of study was 36 days. The feed intake between experimental groups did not differ significantly and the average total DMI (% BW) was 2.01 and $2.28kg\;day^{-1}$ in control and BCFA supplemented diets. The dietary supplementation of BCFA improved (p<0.05) the DM, OM, NDF and cellulose digestibility by 4.46, 6.63, 10.57 and 11.31 per cent over those fed control diet. The total N retention on BCFA supplementation was improved (p<0.01) due to decreased (p<0.05) urinary N excretion. The concentrations of ruminal total N was 37.07 and $34.77mg\;100ml^{-1}$ in control and BCFA fed groups, respectively. Dietary supplementation BCFA significantly (p<0.01) reduced the ruminal ammonia N concentration as compared to control and the mean values ($mg\;100ml^{-1}$) were 13.18 and 9.42 in control and BCFA fed groups. The total VFA concentration was higher (p<0.01) in BCFA supplemented group (101.14 mM) than the control (93.05 mM). Among the VFAs, the molar proportion of acetate was higher (p<0.01) in BCFA supplemented group (71.07 mM) as compared to control (64.98 mM). However, the concentration of propionate and butyrate remained unchanged. Amino acids composition of bacterial hydrolysates was similar in both the groups. Ruminal outflow rate of liquid digesta was higher (p<0.01) in BCFA fed group ($67.56l\;day^{-1}$) than control ($52.73l\;day^{-1}$). It is concluded that the dietary supplementation of Na-salt of isobutyric acid in low protein diet improved the nutrient utilization and ruminal fermentation characteristics.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.6
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• pp.856-863
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• 2013

An in vitro gas production technique was used in this study to elucidate the effect of two strains of active live yeast on methane ($CH_4$) production in the large intestinal content of pigs to provide an insight to whether active live yeast could suppress $CH_4$ production in the hindgut of pigs. Treatments used in this study include blank (no substrate and no live yeast cells), control (no live yeast cells) and yeast (YST) supplementation groups (supplemented with live yeast cells, YST1 or YST2). The yeast cultures contained $1.8{\times}10^{10}$ cells per g, which were added at the rates of 0.2 mg and 0.4 mg per ml of the fermented inoculum. Large intestinal contents were collected from 2 Duroc${\times}$Landrace${\times}$Yorkshire pigs, mixed with a phosphate buffer (1:2), and incubated anaerobically at $39^{\circ}C$ for 24 h using 500 mg substrate (dry matter (DM) basis). Total gas and $CH_4$ production decreased (p<0.05) with supplementation of yeast. The methane production reduction potential (MRP) was calculated by assuming net methane concentration for the control as 100%. The MRP of yeast 2 was more than 25%. Compared with the control group, in vitro DM digestibility (IVDMD) and total volatile fatty acids (VFA) concentration increased (p<0.05) in 0.4 mg/ml YST1 and 0.2 mg/ml YST2 supplementation groups. Proportion of propionate, butyrate and valerate increased (p<0.05), but that of acetate decreased (p<0.05), which led to a decreased (p<0.05) acetate: propionate (A: P) ratio in the both YST2 treatments and the 0.4 mg/ml YST 1 supplementation groups. Hydrogen recovery decreased (p<0.05) with yeast supplementation. Quantity of methanogenic archaea per milliliter of inoculum decreased (p<0.05) with yeast supplementation after 24 h of incubation. Our results suggest that live yeast cells suppressed in vitro $CH_4$ production when inoculated into the large intestinal contents of pigs and shifted the fermentation pattern to favor propionate production together with an increased population of acetogenic bacteria, both of which serve as a competitive pathway for the available H2 resulting in the reduction of methanogenic archaea.

• Journal of Microbiology and Biotechnology
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• v.29 no.7
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• pp.1083-1095
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• 2019

Butyrate is known to play a significant role in energy metabolism and regulating genomic activities that influence rumen nutrition utilization and function. Thus, this study investigated the effects of an isolated butyrate-producing bacteria, Clostridium saccharobutylicum, in rumen butyrate production, fermentation parameters and microbial population in Holstein-Friesian cow. An isolated butyrate-producing bacterium from the ruminal fluid of a Holstein-Friesian cow was identified and characterized as Clostridium saccharobutylicum RNAL841125 using 16S rRNA gene sequencing and phylogenetic analyses. The bacterium was evaluated on its effects as supplement on in vitro rumen fermentation and microbial population. Supplementation with $10^6CFU/ml$ Clostridium saccharobutylicum increased (p < 0.05) microbial crude protein, butyrate and total volatile fatty acids concentration but had no significant effect on $NH_3-N$ at 24 h incubation. Butyrate and total VFA concentrations were higher (p < 0.05) in supplementation with $10^6CFU/ml$ Clostridium saccharobutylicum compared with control, with no differences observed for total gas production, $NH_3-N$ and propionate concentration. However, as the inclusion rate (CFU/ml) of C. saccharobutylicum was increased, reduction of rumen fermentation values was observed. Furthermore, butyrate-producing bacteria and Fibrobacter succinogenes population in the rumen increased in response with supplementation of C. saccharobutylicum, while no differences in the population in total bacteria, protozoa and fungi were observed among treatments. Overall, our study suggests that supplementation with $10^6CFU/ml$ C. saccharobutylicum has the potential to improve ruminal fermentation through increased concentrations of butyrate and total volatile fatty acid, and enhanced population of butyrate-producing bacteria and cellulolytic bacteria F. succinogenes.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.674-680
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• 2009

The objective of this study was to investigate antimicrobial activity, during the storage period, of animal feed and any effects on in vitro rumen digestion by supplementing different levels (5.55, 11.1, and 22.2 g/kg) of freeze dried citrus peel (FDCP) to the feed compared to untreated feed and feed treated with an antifungal agent (AA) at 0.05 g/kg. In a preservation test, feed supplemented with FDCP showed no deterioration over 21 days. Untreated feed and AA-treated feed, however, showed signs of deterioration after 16 days storage. Yellow colour and red colour, measured by spectro chromameter, decreased in the untreated and AA-treated feeds, but not in feed supplemented with FDCP. Aflatoxin was detected in untreated and AA-treated feeds at 16 days (8 ppb and 2 ppb) and 21 days (8 ppb and 4 ppb), but aflatoxin was not detected in the feed supplemented with FDCP. In a second experiment, fermentation by rumen microorganisms of FDCP (22.2 g/kg) and AA (0.05 g/kg) supplemented feeds was studied in vitro. Feeds were incubated with buffered rumen fluid for 3, 6, 9, 12, 24, and 48 h. Dry matter digestibility (DMD) and organic matter digestibility (OMD) were affected by treatment, but ammonia-N, total, and individual volatile fatty acids (VFA) were not adversely affected by treatment. In conclusion, the results indicated that FDCP might be useful for inhibiting microbial growth of animal feed during storage without disrupting rumen fermentation.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.75-81
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• 2007

The object of this study was to determine the influence of supplementation of concentrate containing high levels of cassava chip on rumen ecology, microbial protein and digestibility of nutrients. Four, rumen fistulated crossbred beef steers with initial body weight of 400${\pm}$10 kg were randomly assigned according to a 4${\times}$4 Latin square design. The dietary treatments were concentrate cassava chip based offering at 0, 1, 2 and 3% BW with urea-treated rice straw fed ad libitum. It was found that ruminal pH was significantly decreased with increase of concentrate. Volatile fatty acids (VFA) concentration in the rumen was significantly different among treatments. In addition, a molar proportion of propionate was higher in supplemented groups at 2 and 3% BW (p<0.05), leading to significantly decreased acetate:propionate ratio. Furthermore, microbial N supply was significantly improved and was highest at 2% BW supplementation. The efficiency of rumen microbial-N synthesis based on organic matter (OM) truly digested in the rumen was highest in level of concentrate supplementation at 2% BW (80% of cassava chip in diets). Moreover, bacterial populations such as amylolytic bacteria was linearly increased, while cellulolytic bacteria was linearly decreased (p<0.01) when cattle received concentrate supplementation in all levels. The total protozoal counts were significantly increased, while fungal zoospores were dramatically decreased in cattle receiving increased levels of concentrate. In conclusion, cassava chip can be use as energy source at 80% in concentrate and supplementation of concentrate at 2% BW with urea-treated rice straw as roughage could improve rumen fermentation efficiency in beef cattle.

• Journal of Animal Science and Technology
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• v.62 no.4
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• pp.475-484
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• 2020

This study was conducted to evaluate the effect of the thickness of corn flakes produced by pressurized steam chamber (PSC) on rumen fermentation characteristics and nutrient degradability in Hanwoo and Holstein cows. Corn flakes were treated by PSC, in three groups based on corn flake thickness: < 2.5 mm (T1), 2.5-3.0 mm (T2), and > 3.0 mm (T3). Corn flake thickness significantly influenced pH (p < 0.01) and propionate concentration (p < 0.05) and slightly but not significantly influenced acetate, butyrate, and total-volatile fatty acids (T-VFA) concentrations. The dry matter (DM) degradability increased significantly with a reduction in corn flake thickness (p < 0.01), being significantly greater in T1 and T2 than T3 groups (p < 0.01) and similar between T1 and T2 groups throughout whole incubation time. Also, starch degradability was the lowest in T3 groups than others (p < 0.01). Thus, the present results showed that considering the production efficiency and economic feasibility, the optimal thickness of corn flakes produced in a PSC is recommended to be 2.5-3.0 mm.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.6
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• pp.823-829
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• 2003

Four different types of silage from new cultivars of Napier grass (Pennisetum purpureum), cv. NG 1 and NG 2, were fed to eight wethers in order to evaluate their preference and intake by sheep. The silages were prepared from direct-cut NG 1 herbage; pre-wilted NG 1 herbage; NG 1 herbage with maize meal (5% inclusion) and NG 2 herbage with maize meal (5% inclusion). All silages were palatable to sheep. Maize-treated silage had high quality fermentation, characterized by high Fleig scores and low pH, volatile fatty acids (VFA) and ammoniacal nitrogen contents. The pH, Fleig score, in vitro digestible organic matter (IVDOMD) and ammoniacal-N contents for maize-treated cv. NG 1 silage were 3.7, 78, $540g\;kg^{-1}$ dry matter (DM ) and $0.18g\;kg^{-1}$ DM whereas, in maize-treated cv. NG 2 they were 3.6, 59, $^458g\;kg{-1}$ DM and $0.18g\;kg^-1$ DM, respectively. The superior quality of maize-treated silages made them more preferable to sheep. Among the maize-fortified silages, palatability and intake were significantly (p<0.001) greater with cv. NG 1. Although direct-cut silage had better fermentation quality compared to wilted silage, wilted silage was significantly (p<0.001) more preferable to sheep. However, there were no significant differences (p<0.05) in the levels of preference and intake of wilted silage compared to maize-treated cv. NG 2 silage, even though the latter tended to be more palatable. There were indications that high pH (4.6 vs 3.5) and IVDOMD content (476 vs $457g\;kg^{-1}%$ DM) of wilted silage contributed to higher intake, compared to direct-cut silage. It was generally concluded that pre-wilting and treatment of Napier grass with maize meal at ensiling enhances intake and palatability.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1444-1452
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• 2007

An in vitro experiment was conducted to evaluate the differences in microbial activity of five faecal inocula from weaned pigs and one faecal inoculum from unweaned pigs in combination with 6 substrates. The substrates tested were negative control diet, corn, soybean meal, oligofructose (OF), ground chicory roots and a mixture (60% chicory pulp and 40% OF). The inocula used were derived from pigs fed either a corn-soy based diet without antibiotics (NCON), the NCON diet supplemented with oligofructose (OF), a mixture of chicory pulp (40%) and OF (60%) (MIX), ground chicory roots (CHR) or the NCON diet supplemented with antibiotics (PCON). The cumulative gas production measured fermentation kinetics and end products, such as total gas production, ammonia and volatile fatty acids, were also determined. Both the substrate and the inoculum significantly affected the fermentation characteristics. The cumulative gas production curve showed that different substrates caused more differences in traits of fermentation kinetics than the different inocula. Inocula of weaned pigs gave a significantly higher VFA production compared to the inoculum from unweaned animals, whilst the rate of fermentation and the total gas produced did not differ. OF showed the highest fermentation kinetics and the lowest $NH_3$, pH and OM loss compared to other substrates. It was concluded that the microbial activity was significantly affected by substrate and inoculum. Inoculum from weaned pigs had more potential for microbial fermentation of the carbohydrate ingredients and oligofructose than that of unweaned pigs. A combination of high and low polymer inulin may be more beneficial to the gut ecosystem than using high- or low-polymer inulin alone.