• Asian-Australasian Journal of Animal Sciences
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• v.26 no.4
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• pp.523-528
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• 2013

This study investigates the effects of three branched-chain amino acids (BCAA; valine, leucine, and isoleucine) on the in vitro ruminal fermentation of wheat straw using batch cultures of mixed ruminal microorganisms. BCAA were added to the buffered ruminal fluid at a concentration of 0, 2, 4, 7, or 10 mmol/L. After 72 h of anaerobic incubation, pH, volatile fatty acids (VFA), and ammonia nitrogen ($NH_3$-N) in the ruminal fluid were determined. Dry matter (DM) and neutral detergent fiber (NDF) degradability were calculated after determining the DM and NDF in the original material and in the residue after incubation. The addition of valine, leucine, or isoleucine increased the total VFA yields ($p{\leq}0.001$). However, the total VFA yields did not increase with the increase of BCAA supplement level. Total branched-chain VFA yields linearly increased as the supplemental amount of BCAA increased (p<0.001). The molar proportions of acetate and propionate decreased, whereas that of butyrate increased with the addition of valine and isoleucine (p<0.05). Moreover, the proportions of propionate and butyrate decreased (p<0.01) with the addition of leucine. Meanwhile, the molar proportions of isobutyrate were increased and linearly decreased (p<0.001) by valine and leucine, respectively. The addition of leucine or isoleucine resulted in a linear (p<0.001) increase in the molar proportions of isovalerate. The degradability of NDF achieved the maximum when valine or isoleucine was added at 2 mmol/L. The results suggest that low concentrations of BCAA (2 mmol/L) allow more efficient regulation of ruminal fermentation in vitro, as indicated by higher VFA yield and NDF degradability. Therefore, the optimum initial dose of BCAA for in vitro ruminal fermentation is 2 mmol/L.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.7
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• pp.1005-1015
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• 2009

Two experiments were carried out to determine the utility of sainfoin hay, a temperate tanniferous forage legume, as a dietary supplement for grass-fed cows. The condensed tannins (CT) of sainfoin might counteract the typical metabolic ammonia load of cows in intensive grazing systems. Furthermore, the physical fibrousness of sainfoin might improve ruminal pH stability. In the preliminary experiment, the eating rate of non-lactating Holstein cows of two tanniferous hays, sainfoin and birdsfoot trefoil, was compared to that of a grass-clover hay after specific periods of time (n = 4). The eating rate of sainfoin was superior to that of the other forages. In the main experiment, designed as a replicated 3${\times}$3 Latin square, six ruminally-cannulated, lactating Red Holstein cows received grass, concentrate and either no supplementation, 3 kg/d of grass hay or 3 kg/d of sainfoin hay (n = 6). Measured intakes of the grass hay and the sainfoin hay were 2.0 and 1.5 kg DM, and two cows entirely refused to eat the sainfoin hay and had to be excluded from data analysis. Grass DMI was similar for cows supplemented with sainfoin hay and cows fed only grass whereas intake of concentrate was higher (p<0.01) for the latter treatment. Continuous measurement of ruminal pH showed that the minimum pH at night tended to be lower (p<0.10) with grass-only feeding compared to sainfoin supplementation, but pH did not decline below the threshold of subacute acidosis for a longer period of time. The slightly higher intake of nitrogen (N) for cows supplemented with sainfoin hay (413 g/d) compared to cows fed only grass (399 g/d) was accompanied by an increased (p<0.05) fecal N excretion and a tendency for an increased (p<0.10) urinary N excretion. Ruminal ammonia concentration, as well as plasma and milk urea, were not affected by sainfoin supplementation. In conclusion, the lack of positive effects typical for CT might be explained either by the limited CT content of this plant species (55 g/kg DM) or the relatively low proportion of sainfoin in the total diet or both. Moreover, due to the unexpected low grass quality, the general ammonia load might have been too low for CT to have an impact.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1746-1751
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• 2005

The objective of this study was to evaluate the effects of sarsaponin on methane production, ruminal fermentation, nutrient digestion and blood metabolites using three Holstein steers in a 3${\times}$3 Latin Square design. The steers were fed Sudangrass hay plus concentrate mixture at a ratio 1.5:1 twice daily, and sarsaponin (0, 0.5 and 1% of DM), which was given at 09:00 and 17:00 h daily by mixing with concentrate. Rumen samples were collected 0, 2, and 5 h after morning dosing. Ruminal pH was numerically decreased and numbers of protozoa were decreased linearly (p<0.01) by treatment. Ruminal ammonia-N was reduced (linear; p<0.05) and total VFA was increased (quadratic; p<0.05) at 2 and 5 h after sarsaponin dosing. The molar proportion of acetate was decreased (quadratic; p<0.05) and propionate was increased (linear; p<0.01) at all sampling times. Blood plasma glucose was increased and urea-N was decreased (linear; p<0.05) at 2 and 5 h after dosing. Methane was decreased by approximately 12.7% (linear; p<0.05). The apparent digestibility of DM and NDF were decreased (quadratic; p<0.05) and that of CP remained unchanged due to the sarsaponin. The numbers of cellulolytic bacteria were decreased (quadratic; p<0.05), while numbers of total viable bacteria remained unchanged due to the sarsaponin. These results show that sarsaponin can partially inhibit rumen methanogenesis in vivo and improve ruminal fermentation, which supports our previous in vitro results.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.391-397
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• 1997

Six medium-framed steers, fitted with ruminal cannulas, were utilized in a $6{\times}6$ Latin square design with a $3{\times}2$ arrangement of treatments to determine the effects of sorghum hybrid and grain supplementation on nutrient digestibilities and passage rates and ruminal metabolism of silage-based diets fed to growing steers. The diets consisted of three wholes-plant silages (a high grain-containing, grain sorghum and middle-season, moderate grain-containing, and late-season, low grain-containing forage sorghums), each fed with or without 25% rolled grain sorghum. No significant interactions occurred between sorghum hybrid and grain supplementation for the digestion or passage rate criteria measured. Ruminal butyrate concentration was the only fermentation characteristic affected by a hybrid ${\times}$ grain supplementation interaction. The grain sorghum silage diets had the highest DM, OM, and ADF digestibilities; the late-season silage diets, the lowest. Digestibility of NDF tended to be highest (p < 0.10) for the grain sorghum silage, whereas starch digestibility was not affected by sorghum hybrid. Ruminal ammonia, acetate, propionate, butyrate, and total VFA concentrations were highest for the grain sorghum silage diets. Grain supplementation increased DM and OM digestibilities, but had no effect on digestibilities of NDF, ADF, and starch. Ruminal pH was decreased, but total VFA concentration and acetate : propionate ratio were not affected by grain supplementation.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.1
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• pp.67-72
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• 1993

Three sheep fitted with cannulas in the rumen and the caecum were used in a $3{\times}3$ Latin square design to study the changes in ruminal and caecal microbial populations and their metabolite composition with ammoniated rice straw feeding. The 3 diets contained either 80% untreated rice straw (UTS) or ammoniated rice straw (ATS) and 20% formula feed. These were a control diet (C), a urea supplemented diet (U) containing urea at 1.1% and an ammoniated rice straw diet (AT). Data were analyzed by analysis of variance and means separated by the Student Neumann Kuel's multiple comparison. AT feeding increased ruminal bacterial counts, in particular cellulolytic bacterial counts (p < 0.05) which were 1.8, 2.4 and 7.0 (${\times}10^6/ml$ ruminal fluid) for C, U and AT, respectively. There was an increasing tendency (p < 0.10) in ruminal fungal population with U; values were 2.0, 5.2, 3.1 (${\times}10^3/ml$ ruminal fluid) for C, U and AT, respectively. Ruminal protozoa counts were not significantly (p > 0.05) altered with diets. Caecal total viable bacterial count with AT was about thrice the value with C. Total VFA concentration in the rumen was significantly increased (p < 0.025) (7.7 mmol/dl for C and 8.2 mmol/dl for AT) and correspondingly, pH lowered when AT was fed. Sheep on AT tended to produce less acetate and more butyrate in the rumen without significance (p > 0.05). Similar to the rumen, total VFA concentrations of 4.4, 3.8 and 5.2 mmol/dl were detected, respectively, for C, U and AT. Caecal ammonia-nitrogen concentrations were about six-fold of that in the rumen, though there were no differences (p > 0.05) among treatments.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.6
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• pp.776-782
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• 2019

Objective: Fasting may lead to changes in the microbiota and activity in the rumen. In the present study, the effects of fasting on rumen microbiota and the impact of fasting on in vitro rumen fermentation were evaluated using molecular culture-independent methods. Methods: Three ruminally cannulated Holstein steers were fed rice straw and concentrates. The ruminal fluids were obtained from the same steers 2 h after the morning feeding (control) and 24 h after fasting (fasting). The ruminal fluid was filtrated through four layers of muslin, collected for a culture-independent microbial analysis, and used to determine the in vitro rumen fermentation characteristics. Total DNA was extracted from both control and fasting ruminal fluids. The rumen microbiota was assessed using denaturing gradient gel electrophoresis (DGGE) and quantitative polymerase chain reaction. Microbial activity was evaluated in control and fasting steers at various intervals using in vitro batch culture with rice straw and concentrate at a ratio of 60:40. Results: Fasting for 24 h slightly affected the microbiota structure in the rumen as determined by DGGE. Additionally, several microorganisms, including Anaerovibrio lipolytica, Eubacterium ruminantium, Prevotella albensis, Prevotella ruminicola, and Ruminobacter amylophilus, decreased in number after fasting. In addition, using the ruminal fluid as the inoculum after 24 h of fasting, the fermentation characteristics differed from those obtained using non-fasted ruminal fluid. Compared with the control, the fasting showed higher total gas production, ammonia, and microbial protein production (p<0.05). No significant differences, however, was observed in pH and dry matter digestibility. Conclusion: When in vitro techniques are used to evaluate feed, the use of the ruminal fluid from fasted animals should be used with caution.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.8
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• pp.1215-1221
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• 2007

Three Holstein steers fitted with ruminal and duodenal cannulae were fed grass silage-based diets supplemented with potato pulp silage as a substitute for rolled corn at levels of 0%, 50% and 100% on a DM basis in a $3{\times}3$ Latin square design to investigate the effect of potato pulp silage on nitrogen (N) utilization in ruminants. Organic matter (OM) intake, and rumen and total tract digestibilities did not differ among treatment diets. Rumen and post-rumen starch digestibilities were similar among treatments, although starch intake decreased (p<0.01) with potato pulp supplementation. There were no significant differences (p>0.05) in ruminal N utilization and non-ammonia N supply to the duodenum of steers fed grass silage supplemented with potato pulp silage as a substitute for rolled corn. There were no treatment differences (p>0.05) in rumen pH, volatile fatty acid (VFA) concentration or the molar percentages of acetate and propionate. The ammonia-N concentration in rumen fluid tended to decrease (p<0.1) when rolled corn was substituted with potato pulp silage. Ether extract intake and post-ruminal digestibility significantly (p<0.01) decreased in steers fed diets containing potato pulp silage. Concentrations of total cholesterol and phospholipids in serum markedly decreased (p<0.01) with potato pulp silage supplementation without adversely affecting liver function. These data suggested that potato pulp silage has a similar value as rolled corn as an energy source for rumen microorganisms.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.861-870
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• 2006

This study was conducted to examine the effects of supplementing coated vitamin C+E with cottonseed on rumen fermentation and body weight gain, blood metabolites and hormone concentrations in Hanwoo steers fed fermented feedstuff. Experiments were done with two treatment groups, T1 without any supplements and T2 supplemented with coated vitamin C+E and cottonseed. Ruminal pH was lower in T2 than in T1 at 3h after morning feeding (p<0.05), but was higher in T2 than in T1 at 6 and 9h after morning feeding (p<0.05). Ruminal ammonia concentration was higher in T2 than in T1 for 12h after morning feeding (p<0.05). Concentrations of acetate, propionate, butyrate and total-VFA were higher in T2 than in T1 at 3h after morning feeding (p<0.05), but were lower in T2 than in T1 at 9 and 12h after morning feeding (p<0.05). Average daily gain and concentrations of blood metabolites and hormones between T1 and T2 were similar. Results indicate that supplementation of coated vitamin C+E and cottonseed to fermented feedstuff affects on ruminal pH, ammonia and VFA. But it has no influences on body weight gain and concentrations of blood metabolites and hormones in Hanwoo steers.

• Journal of Animal Science and Technology
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• v.48 no.1
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• pp.101-106
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• 2006

In this study, changes of ammonia, alcohol and volatile fatty acid(VFA) concentrations or pH in in vitro ruminal fluid were studied to determine the effects of alcoholic feeds on in vitro ruminal fermentation characteristics. To formulate the alcoholic feeds, alcohol was added to commercial formulated feed at the levels of 1, 3, and 5 %. Experiments were done with four treatment groups, control(commercial feed), AF-1(commercial feed+1% alcohol), AF-3(commercial feed+3% alcohol), and AF-5(commercial feed+5% alcohol). Ammonia concentrations of AF-1 and AF-5 were significantly lower than that of control for the 12h incubation(p<0.05). Ruminal alcohol concentration was increased with the addition level of alcohol increased(p<0.05). TVFA concentrations of AF-1, AF-3 and AF-5 were significantly higher than those of control at 12h(p<0.05). Significant decrease of molar percentage of acetate was observed in control from 8 to 12h incubation, but molar percentage of acetate for AF-1, AF-3 and AF-5 was constant. Molar percentage of propionate was increased in control compared with AF-1, AF-3 and AF-5 from 8 to 12h incubation(p<0.05). Molar percentages of butyrate and valerate were higher in AF-1, AF-3 and AF-5 than in control(p<0.05). Molar percentage of caproate for AF-1, AF-3 and AF-5 was 0.05, 0.58 and 0.47M% at 8h, respectively, but that was not detected for control. Present results may indicate that the alcoholic feeds show positive effects on in vitro ruminal ammonia, alcohol and VFA concentrations or pH. Furthermore, the results of this study implies that the addition level of 5% could be more effective to ruminal fermentation than other addition levels.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.2
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• pp.191-200
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• 2011

Four ruminally cannulated Hanwoo steers (BW 600 ${\pm}$ 48.4 kg) fed whole crop rice silage (WRS) as forage were used to investigate the effects of its dietary on rumen fermentation and blood metabolites at different harvesting time such as milk, dough, yellow ripe and mature stages of WRS, respectively. Mean ruminal pH sampled at 0, 1, 2, 4, 6 and 8 h after the morning feeding was not significantly (p>0.05) different between the WRS by the harvesting time. In diurnal pattern in ruminal pH, the lowest pH for the mature stage treatment (Mature) appeared at 6 h after the feeding while it appeared at 2-4 h for the other treatments. This may indicate that retention time in the rumen of Hanwoo fed WRS harvested at the Mature increased. Although feeding WRS harvested at different stages did not significantly (p>0.05) affect ruminal ammonia N concentration, the ammonia N for WRS harvested at the milk stage (Milk) tended (p=0.11) to decrease compared with that for the yellow stage treatment (Yellow). In the blood metabolites analysis, BUN concentration for Yellow numerically decreased compared with that for Milk. This, taking lower concentration of ruminal ammonia N for Milk than the other treatments into account, clearly indicates that the BUN concentrations may not increase in proportion to ruminal ammonia N concentration according to ammonia N concentration entering into the lower gastric tracts. Lower (p=0.03) concentration of blood albumin for the dough stage treatment than that for Mature may indicate high protein synthesis in Hanwoo fed WRS at the dough stage, but further studies in terms of mechanism of nutrients distribution should be required. Present results indicate that different harvesting time did not affect rumen fermentation and blood metabolites in Hanwoo. Thus, based on the results of the present and the previous studies, utilizing WRS harvested at yellow stage could be recommendable for Hanwoo steers.