• Asian-Australasian Journal of Animal Sciences
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• v.32 no.10
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• pp.1511-1520
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• 2019

Objective: The present study was conducted to select a plant oil without inhibitory effects on rumen fermentation and microbes, and to determine the optimal supplementation level of the selected oil in a series of in vitro studies for dietary application. Then, the selected oil was evaluated in a feeding study using Thai crossbred beef cattle by monitoring growth, carcass, blood and rumen characteristics. Methods: Rumen fluid was incubated with substrates containing one of three different types of plant oil (coconut oil, palm oil, and soybean oil) widely available in Thailand. The effects of each oil on rumen fermentation and microbes were monitored and the oil without a negative influence on rumen parameters was selected. Then, the dose-response of rumen parameters to various levels of the selected palm oil was monitored to determine a suitable supplementation level. Finally, an 8-month feeding experiment with the diet supplemented with palm oil was carried out using 12 Thai crossbred beef cattle to monitor growth, carcass, rumen and blood profiles. Results: Batch culture studies revealed that coconut and soybean oils inhibited the most potent rumen cellulolytic bacterium Fibrobacter succinogenes, while palm oil had no such negative effect on this and on rumen fermentation products at 5% or higher supplementation level. Cattle fed the diet supplemented with 2.5% palm oil showed improved feed conversion ratio (FCR) without any adverse effects on rumen fermentation. Palm oil-supplemented diet increased blood cholesterol levels, suggesting a higher energy status of the experimental cattle. Conclusion: Palm oil had no negative effects on rumen fermentation and microbes when supplemented at levels up to 5% in vitro. Thai crossbred cattle fed the palm oil-supplemented diet showed improved FCR without apparent changes of rumen and carcass characteristics, but with elevated blood cholesterol levels. Therefore, palm oil can be used as a beneficial energy source.

• Animal Bioscience
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• v.37 no.2_spc
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• pp.360-369
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• 2024

Ruminal methane production functions as the main sink for metabolic hydrogen generated through rumen fermentation and is recognized as a considerable source of greenhouse gas emissions. Methane production is a complex trait affected by dry matter intake, feed composition, rumen microbiota and their fermentation, lactation stage, host genetics, and environmental factors. Various mitigation approaches have been proposed. Because individual ruminants exhibit different methane conversion efficiencies, the microbial characteristics of low-methane-emitting animals can be essential for successful rumen manipulation and environment-friendly methane mitigation. Several bacterial species, including Sharpea, uncharacterized Succinivibrionaceae, and certain Prevotella phylotypes have been listed as key players in low-methane-emitting sheep and cows. The functional characteristics of the unclassified bacteria remain unclear, as they are yet to be cultured. Here, we review ruminal methane production and mitigation strategies, focusing on rumen fermentation and the functional role of rumen microbiota, and describe the phylogenetic and physiological characteristics of a novel Prevotella species recently isolated from low methane-emitting and high propionate-producing cows. This review may help to provide a better understanding of the ruminal digestion process and rumen function to identify holistic and environmentally friendly methane mitigation approaches for sustainable ruminant production.

• 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.23 no.6
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• pp.700-707
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• 2010

Effects of protease-resistant antimicrobial substances (PRA) produced by Lactobacillus plantarum and Leuconostoc citreum on rumen methanogenesis were examined using the in vitro continuous methane quantification system. Four different strains of lactic acid bacteria, i) Lactococcus lactis ATCC19435 (Control, non-antibacterial substances), ii) Lactococcus lactis NCIMB702054 (Nisin-Z), iii) Lactobacillus plantarum TUA1490L (PRA-1), and iv) Leuconostoc citreum JCM9698 (PRA-2) were individually cultured in GYEKP medium. An 80 ml aliquot of each supernatant was inoculated into phosphate-buffered rumen fluid. PRA-1 remarkably decreased cumulative methane production, though propionate, butyrate and ammonia N decreased. For PRA-2, there were no effects on $CH_4$ and $CO_2$ production and fermentation characteristics in mixed rumen cultures. The results suggested that PRA-1 reduced the number of methanogens or inhibited utilization of hydrogen in rumen fermentation.

• Journal of Animal Science and Technology
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• v.62 no.1
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• pp.52-57
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• 2020

In rumen in vitro experiments, although nitrogen gas (N₂) flushing has been widely used, its effects on rumen fermentation characteristics are not clearly determined. The present study is the first to evaluate the effects of N₂ flushing on rumen fermentation characteristics in in vitro batch culture system by comparing with new applicable non-metabolizable gas: argon (Ar). The rumen fluid was taken from two Korean native heifers followed by incubation for 3, 9, 12, and 24 h with N₂ or Ar flushing. As a result, in all incubation time, N₂ flushing resulted in higher total gas production than Ar flushing (p < 0.01). Additionally, in N₂ flushing group, ammonia nitrogen was increased (p < 0.01). However, volatile fatty acids profiles and pH were not affected by the flushing gases (p > 0.05). In conclusion, the present study demonstrated that N₂ flushing can influence the rumen nitrogen metabolism via increased ammonia nitrogen concentration and Ar flushing can be used as a new alternative flushing gas.

• Journal of Animal Science and Technology
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• v.64 no.6
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• pp.1077-1091
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• 2022

This study was conducted to determine the rumen fermentation dynamics of lupin flakes and elucidate the effects of lupin flake supplementation on the growth performance, blood metabolites, and carcass characteristics of Hanwoo steers. In vitro and in situ trials of lupin grains and lupin flakes were conducted using three Hanwoo cows with rumen fistulas. The feeding trial included 40 early-fattening Hanwoo steers randomly divided into four groups: control, T1, T2, and T3. Their formula feed contained 0%, 3%, 6%, and 9% lupin flakes, respectively. In vitro rumen pH and ammonia concentrations were lower in the lupin flake group than in the lupin grain group after 6 and 24 h of incubation, respectively (p < 0.05). Concentrations of propionate, butyrate, and total volatile fatty acids were higher in the lupin flake group than in the lupin grain group after 12 h of incubation (p < 0.05), as was the crude protein disappearance rate at 9 and 12 h of rumen fermentation (p < 0.05). Supplementation with lupin flakes did not affect the average daily gain. Compared to that in the control group, dry matter intake was lower in the lupin flake-supplemented groups (p < 0.05); the feed conversion ratio was lower in T2 and T3 (p < 0.05); and plasma total protein concentration in 29-month-old steers was lower in T1 and T3 (p < 0.05). Plasma triglyceride concentration was lower in the lupin flake-supplemented groups than in the control group (p < 0.05). The incidence rate of yield grade A was higher in T1 and T2 than in the control group; the incidence rate of meat quality 1⁺ grade or higher was highest in T2. The carcass auction price was higher in T2 than in the other groups. Overall, compared to whole lupin grains, lupin flakes seem to more substantially affect rumen ammonia concentrations and crude protein disappearance rate. Additionally, we suggest that supplementation with 6% lupin flake formula feed exerts positive effects on the feed conversion ratio, yield grade, and quality grade of Hanwoo steers.

• Journal of Practical Agriculture & Fisheries Research
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• v.19 no.1
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• pp.139-151
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• 2017

This study was conducted to confirm the rumen fermentation characteristics of large-scale CoenzymeQ10(CoQ10) producing bacteria R. spharoides in rumen. We conducted in vitro continuous culture test to investigate the characteristics of rumen fermentation with 5% R. spharoides as a direct fed microorganism. A rumen microbial fermentation characteristic has stability at after 12 days for 15 day of experimental period. pH value, NH₃-N, microbial protein synthesis, ADF digestibility and NDF digestibility were not shown significantly differences between control and treatment. However, UDP was significantly higher in treatment than control (p<0.05). CoQ10 concentration was 336.0mg/l with 5% R. spharoides. On the other hands, CoQ10 was not detected without R. spharoides. Our study was shown that R. spharoides can produce CoQ10 in rumen environment without harmful effects on rumen fermentation parameter. CoQ10 in rumen may transfer into cow milk through cow metabolism. This strategy might be helpful for producing functional dairy cow milk.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1625-1633
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• 2003

This study was conducted to observe effects of dietary acidogenicity value (AV) on rumen fermentation characteristics and nutrients digestibility. The AV of feedstuffs was based on the dissolution of Ca from $CaCO_3$ powder added at the end of a 24 h in vitro fermentation. Three diets were formulated to be iso-energetic and iso-nitrogenous with different AV. Two experiments were involved in this study. In experiment 1, it appears that pH, $NH_3-N$ concentration and A:P ratio tended to decrease, but gas production, VFA production and DM disappearance tended to increase with increasing dietary AV. In experiment 2, the rumen pH tended to decrease in order of high AV>medium AV>low AV treatment, respectively. There were no significant effects of dietary AV on $NH_3-N$ concentration, enzyme activity and nutrient digestibility. In addition, total VFA and individual VFA concentrations tended to increase with increasing dietary AV without significance. In fact, we hypothesized that different dietary AV would affect rumen fermentation and nutrients digestibility because dietary AV was adjusted with fermentable carbohydrate sources. The present results indicate that differences in dietary AV between treatments were too small to affect rumen fermentation and its effects were minimal.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.6
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• pp.807-813
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• 2016

Two experiments were conducted assessing the effects of presence or absence of rumen protozoa and dietary nitrate addition on rumen fermentation characteristics and in vitro methane production in Brahman heifers. The first experiment assessed changes in rumen fermentation pattern and in vitro methane production post-refaunation and the second experiment investigated whether addition of nitrate to the incubation would give rise to methane mitigation additional to that contributed by defaunation. Ten Brahman heifers were progressively adapted to a diet containing 4.5% coconut oil distillate for 18 d and then all heifers were defaunated using sodium 1-(2-sulfonatooxyethoxy) dodecane (Empicol). After 15 d, the heifers were given a second dose of Empicol. Fifteen days after the second dosing, all heifers were allocated to defaunated or refaunated groups by stratified randomisation, and the experiment commenced (d 0). On d 0, an oral dose of rumen fluid collected from unrelated faunated cattle was used to inoculate 5 heifers and form a refaunated group so that the effects of re-establishment of protozoa on fermentation characteristics could be investigated. Samples of rumen fluid collected from each animal using oesophageal intubation before feeding on d 0, 7, 14, and 21 were incubated for in vitro methane production. On d 35, 2% nitrate (as $NaNO_3$) was included in in vitro incubations to test for additivity of nitrate and absence of protozoa effects on fermentation and methane production. It was concluded that increasing protozoal numbers were associated with increased methane production in refaunated heifers 7, 14, and 21 d after refaunation. Methane production rate was significantly higher from refaunated heifers than from defaunated heifers 35 d after refaunation. Concentration and proportions of major volatile fatty acids, however, were not affected by protozoal treatments. There is scope for further reducing methane output through combining defaunation and dietary nitrate as the addition of nitrate in the defaunated heifers resulted in 86% reduction in methane production in vitro.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.1
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• pp.1-9
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• 2017

This research was conducted to investigate the effects of feeding high and low forage diets with different forage sources on rumen fermentation characteristics and blood parameters of Holstein cows during the dry period. Eight Holstein cows were completely randomized assigned to two groups and repeated measurement was utilized in the analysis. Cows in two treatments were fed with diets with high (F:C = 70:30, 70F; forage source: mixed-sowing whole crop barley and Italian ryegrass silage, BIRG) and low (F:C = 55:45, 55F; forage source: tall fescue hay, TF) forage level. Rumen fluid pH was higher in 70F group. Levels of acetic acid, propionic acid, and butyric acid showed a similar pattern: from the lowest value at 07:30 h to the highest at 10:30 h and then decreased in both groups. The ratio of acetic acid to propionic acid was significantly higher (p < 0.05) in 55F group at 09:30 and 10:30 h. Rumen fluid $NH_3-N$ concentrations were significantly higher (p < 0.05) in 70F group at 09:30 and 10:30 h. Blood urea nitrogen was significantly higher (p < 0.05) in 70F group. It was concluded that BIRG based diet with a high forage level had no adverse effects on rumen fermentation, some blood chemical parameters, and immune system in dry Holstein cows and could be used as a forage source instead of imported TF.