• Asian-Australasian Journal of Animal Sciences
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• v.12 no.1
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• pp.84-92
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• 1999

The rumen microbial ecosystem is coming to be recognized as a rich alternative source of genes for industrially useful enzymes. Recent advances in biotechnology are enabling development of novel strategies for effective delivery and enhancement of these gene products. One particularly promising avenue for industrial application of rumen enzymes is as feed supplements for nonruminant and ruminant animal diets. Increasing competition in the livestock industry has forced producers to cut costs by adopting new technologies aimed at increasing production efficiency. Cellulases, xylanases, ${\beta}$-glucanases, pectinases, and phytases have been shown to increase the efficiency of feedstuff utilization (e.g., degradation of cellulose, xylan and ${\beta}$-glucan) and to decrease pollutants (e.g., phytic acid). These enzymes enhance the availability of feed components to the animal and eliminate some of their naturally occurring antinutritional effects. In the past, the cost and inconvenience of enzyme production and delivery has hampered widespread application of this promising technology. Over the last decade, however, advances in recombinant DNA technology have significantly improved microbial production systems. Novel strategies for delivery and enhancement of genes and gene products from the rumen include expression of seed proteins, oleosin proteins in canola and transgenic animals secreting digestive enzymes from the pancreas. Thus, the biotechnological framework is in place to achieve substantial improvements in animal production through enzyme supplementation. On the other hand, the rumen ecosystem provides ongoing enrichment and natural selection of microbes adapted to specific conditions, and represents a virtually untapped resource of novel products such as enzymes, detoxificants and antibiotics.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.6
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• pp.571-574
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• 1997

Attempts were made in the laboratory to produce bypass fat using acid oil by precipitation and fusion methods. The degree of saponification by both of these methods was above 80 percent. Where heating facilities are not available, precipitation method could be used, otherwise, fusion method of bypass fat production is found to be more convenient, especially for commercial scale operations as handling of large volume of solutions is eliminated. Bypass fat thus produced was tested in vitro for rumen fermentation. Incorporation of acid oil in the incubation medium reduced TVFA conc. from 127.06 to 124.09 mM/l SRL and increased ammonia-N levels from 210.50 to 223 mg/l SRL indicating that the microbial activity was affected on incorporation of acid oil in the incubation medium. However, incorporation of bypass fat in the incubation medium did not significantly affect TVFA conc. as well as ammonia-N levels. In another experiment, nine rumen fistulated sheep in three groups of three each were fed bypass fat at two different levels. Dry matter disappearance in 24 h from the nylon bags suspended in the rumen of animals under different groups was found to be $47.74{\pm}1.10$, $47.55{\pm}0.21$ and $50.74{\pm}1.11$ in group I (control), group II (fed bypass fat 50 g/day) and group III (fed bypass fat 100 g/day), respectively. These studies indicated that it is possible to produce bypass fat from acid oils, a by-product of oil refining process, and its feeding did not affect rumen fermentation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.2
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• pp.74-83
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• 2018

The objectives of this study was to evaluate the degradability and digestibility of crude protein (CP), rumen undegradable protein (RUP), and individual amino acids (AA) on six by-product feedstuffs (BPF) (rice bran, RB; wheat bran, WB; corn gluten feed, CGF; tofu residue, TR; spent mushroom substrate from Pleurotus ostreatus, SMSP; brewers grain, BG) as ruminants feed. Three Hanwoo steers (40 months old, $520{\pm}20.20kg$ of body weight) fitted with a permanent rumen cannula and T-shaped duodenal cannula were used to examine of the BPF using in situ nylon bag and mobile bag technique. The bran CGF (19.2%) and food-processing residue BG (19.7%) had the highest CP contents than other feeds. The RUP value of bran RB (39.7%) and food-processing residues SMSP (81.1%) were higher than other feeds. The intestinal digestion of CP was higher in bran RB (44.2%) and food-processing residues BG (40.5%) than other feeds. In addition, intestinal digestion of Met was higher in bran RB (55.7%) and food-processing residues BG (44.0%) than other feeds. Overall, these results suggest that RB and BG might be useful as main raw ingredients in feed for ruminants. Our results can be used as baseline data for ruminant ration formulation.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.5
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• pp.659-665
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• 2016

The effects of three different feeding systems on beef cattle production performance, rumen fermentation, and rumen digesta particle structure were investigated by using 18 Limousin (steers) with a similar body weight ($575{\pm}10kg$) in a 80-d experiment. The animals were equally and randomly divided into three treatment groups, namely, total mixed ration group (cattle fed TMR), SI1 group (cattle fed concentrate firstly then roughage), and SI2 group (cattle fed roughage firstly then concentrate). The results showed that the average daily gain was significantly higher in cattle receiving TMR than in those receiving SI1 and SI2 (p<0.05). Consumption per kg weight gain of concentrate, silage, and combined net energy (NEmf) were significantly decreased when cattle received TMR, unlike when they received SI1 and SI2 (p<0.05), indicating that the feed efficiency of TMR was the highest. Blood urea nitrogen (BUN) was significantly decreased when cattle received TMR compared with that in cattle receiving SI1 (p<0.05), whereas there was no difference compared with that in cattle receiving SI2. Ammonia nitrogen concentration was significantly lower in cattle receiving TMR than in those receiving SI1 and SI2 (p<0.05). The rumen area of cattle that received TMR was significantly larger than that of cattle receiving SI1 (p<0.05), but there was no difference compared with that of cattle receiving SI2. Although there was no significant difference among the three feeding systems in rumen digesta particle distribution, the TMR group trended to have fewer large- and medium-sized particles and more small-sized particles than those in the SI1 and SI2 groups. In conclusion, cattle with dietary TMR showed increased weight gain and ruminal development and decreased BUN. This indicated that TMR feeding was more conducive toward improving the production performance and rumen fermentation of beef cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.1
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• pp.93-103
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• 1999

Recent advances in the biotechnology of ruminal bacteria have been made in the characterization of enzymes involved in plant cell wall digestion, the exploration of mechanisms of gene transfer in ruminal bacteria, and the development of vectors. These studies have culminated in the introduction and expression of heterologous glucanase and xylanase genes and a fluoroacetate dehalogenase gene in ruminal bacteria. These recent studies show the strategy of gene and vector construction necessary for the production of genetically engineered bacteria for introduction into ruminants. Molecular research on proteolytic turnover of protein in the rumen is in its infancy, but a novel protein high in essential amino acids designed for intracellular expression in ruminal organisms provides an interesting approach for improving the amino acid profile of ruminal organisms.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.8
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• pp.1136-1144
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• 2016

Leucaena silage was supplemented with different levels of molasses and urea to study its nutritive value and in vitro rumen fermentation efficiency. The ensiling study was randomly assigned according to a $3{\times}3$ factorial arrangement in which the first factor was molasses (M) supplement at 0%, 1%, and 2% of crop dry matter (DM) and the second was urea (U) supplement as 0%, 0.5%, and 1% of the crop DM, respectively. After 28 days of ensiling, the silage samples were collected and analyzed for chemical composition. All the nine Leucaena silages were kept for study of rumen fermentation efficiency using in vitro gas production techniques. The present result shows that supplementation of U or M did not affect DM, organic matter, neutral detergent fiber, and acid detergent fiber content in the silage. However, increasing level of U supplementation increased crude protein content while M level did not show any effect. Moreover, the combination of U and M supplement decreased the content of mimosine concentration especially with M2U1 (molasses 2% and urea 1%) silage. The result of the in vitro study shows that gas production kinetics, cumulation gas at 96 h and in vitro true digestibility increased with the increasing level of U and M supplementation especially in the combination treatments. Supplementation of M and U resulted in increasing propionic acid and total volatile fatty acid whereas, acetic acid, butyric acid concentrations and methane production were not changed. In addition, increasing U level supplementation increased $NH_3$-N concentration. Result from real-time polymerase chain reaction revealed a significant effect on total bacteria, whereas F. succinogenes and R. flavefaciens population while R. albus was not affected by the M and U supplementation. Based on this study, it could be concluded that M and urea U supplementation could improve the nutritive value of Leucaena silage and enhance in vitro rumen fermentation efficiency. This study also suggested that the combination use of M and U supplementation level was at 2% and 1%, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.12
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• pp.1890-1896
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• 2018

Objective: As the climate changes, it influences ruminant's feed intake, nutrient digestibility, rumen methane production and emission. This experiment aimed to evaluate the effect of feeding Sweet grass (Pennisetum purpureum cv. Mahasarakham; SG) as a new source of good quality forage to improve feed utilization efficiency and to mitigate rumen methane production and emission. Methods: Four, growing crossbred of Holstein Friesian heifers, 14 months old, were arranged in a $4{\times}4$ Latin square design to receive four dietary treatments. Treatment 1 (T1) was rice straw (RS) fed on ad libitum with 1.0% body weight (BW) of concentrate (C) supplementation (RS/1.0C). Treatment 2 (T2) and treatment 3 (T3) were SG, fed on ad libitum with 1.0% and 0.5% BW of concentrate supplementation, respectively (SG/1.0C and SG/0.5C, respectively). Treatment 4 (T4) was total Sweet grass fed on ad libitum basis with non-concentrate supplementation (TSG). Results: The results revealed that roughage and total feed intake were increased with SG when compared to RS (p<0.01) while TSG was like RS/1.0C treatment. Digestibility of nutrients, nutrients intake, total volatile fatty acids (VFAs), rumen microorganisms were the highest and CH4 was the lowest in the heifers that received SG/1.0C (p<0.01). Total dry matter (DM) feed intake, digestibility and intake of nutrients, total VFAs, $NH_3-N$, bacterial and fungal population of animals receiving SG/0.5C were higher than those fed on RS/1.0C. Reducing of concentrate supplementation with SG as a roughage source increased $NH_3-N$, acetic acid, and fungal populations, but it decreased propionic acid and protozoal populations (p<0.05). However, ruminal pH and blood urea nitrogen were not affected by the dietary treatments (p>0.05). Conclusion: As the results, SG could be a good forage to improve rumen fermentation, decrease methane production and reduced the level of concentrate supplementation for growing ruminants in the tropics especially under global climate change.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.2
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• pp.106-111
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• 2018

This study was conducted to investigate the relationship between changes of rumen microflora and bloat in Jersey cow. Jersey cows (control age: 42 months, control weight: 558kg; treatment age: 29 months, treatment weight 507kg) were fed on the basis of dairy feeding management at dairy science division in National Institute of Animal Science. The change of microbial population in rumen was analyzed by using next generation sequencing (NGS) technologies due to metabolic disease. The diversity of Ruminococcus bromii, Bifidobacterium pseudolongum, Bifidobacterium merycicum and Butyrivibrio fibrisolvens known as major starch fermenting bacteria was increased more than 36-fold in bloated Jersey, while cellulolytic bacteria community such as Fibrobacter succinogenes, Ruminococcus albus and Ruminococcus flavefaciens was increased more than 12-fold in non-bloated Jersey. The proportion of bacteroidetes and firmicutes was 33.4% and 39.6% in non-bloated Jersey's rumen, while bacteroidetes and firmicutes were 24.9% and 55.1% in bloated Jersey's. In conclusion, the change of rumen microbial community, in particular the increase in starch fermenting bacteria, might have an effect to occur the bloat in Jersey cow.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.9
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• pp.1273-1279
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• 2016

The objectives of this study were to determine an optimal cultivation time for populations of yeast and lactic acid bacteria (LAB) co-cultured in fermented milk and effects of soybean meal fermented milk (SBMFM) supplementation on rumen degradability in beef cattle using nylon bag technique. The study on an optimal cultivation time for yeast and LAB growth in fermented milk was determined at 0, 4, 8, 24, 48, 72, and 96 h post-cultivation. After fermenting for 4 days, an optimal cultivation time of yeast and LAB in fermented milk was selected and used for making the SBMFM product to study nylon bag technique. Two ruminal fistulated beef cattle ($410{\pm}10kg$) were used to study on the effect of SBMFM supplementation (0%, 3%, and 5% of total concentrate substrate) on rumen degradability using in situ method at incubation times of 0, 2, 4, 6, 12, 24, 48, and 72 h according to a Completely randomized design. The results revealed that the highest yeast and LAB population culture in fermented milk was found at 72 h-post cultivation. From in situ study, the soluble fractions at time zero (a), potential degradability (a+b) and effective degradability of dry matter (EDDM) linearly (p<0.01) increased with the increasing supplemental levels and the highest was in the 5% SBMFM supplemented group. However, there was no effect of SBMFM supplement on insoluble degradability fractions (b) and rate of degradation (c). In conclusion, the optimal fermented time for fermented milk with yeast and LAB was at 72 h-post cultivation and supplementation of SBMFM at 5% of total concentrate substrate could improve rumen degradability of beef cattle. However, further research on effect of SBMFM on rumen ecology and production performance in meat and milk should be conducted using in vivo both digestion and feeding trials.

• 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.