• Asian-Australasian Journal of Animal Sciences
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• v.16 no.5
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• pp.748-763
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• 2003

Anaerobic rumen microorganisms mainly bacteria, protozoa and fungi degrade ligno-cellulosic feeds consumed by the ruminants. The ruminants in developing countries are predominantly maintained on low grade roughage and grazing on degraded range land resulting in their poor nutrient utilization and productivity. Hence, manipulation of rumen fermentation was tried during last two decades to optimize ruminal fermentation for improving nutrient utilization and productivity of the animals. Modification of rumen microbial composition and their activity was attempted by using chemical additives those selectively effect rumen microbes, introduction of naturally occurring or genetically modified foreign microbes into the rumen and genetically manipulation of existing microbes in the rumen ecosystem. Accordingly, rumen protozoa were eliminated by defaunation for reducing ruminal methane production and increasing protein outflow in the intestine, resulting in improve growth and feed conversion efficiency of the animals. Further, Interspecies trans-inoculation of rumen microbes was also successfully used for annulment of dietary toxic factor. Additionally, probiotics of bacterial and yeast origin have been used in animal feeding to stabilize rumen fermentation, reduced incidence of diarrhoea and thus improving growth and feed conversion efficiency of young stalk. It is envisaged that genetic manipulation of rumen microorganisms has enormous research potential in developing countries. In view of feed resource availability more emphasis has to be given for manipulating rumen fermentation to increase cellulolytic activity for efficient utilization of low grade roughage.

• Journal of Animal Science and Technology
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• v.60 no.6
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• pp.15.1-15.10
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• 2018

Methane emission from the enteric fermentation of ruminant livestock is a main source of greenhouse gas (GHG) emission and a major concern for global warming. Methane emission is also associated with dietary energy lose; hence, reduce feed efficiency. Due to the negative environmental impacts, methane mitigation has come forward in last few decades. To date numerous efforts were made in order to reduce methane emission from ruminants. No table mitigation approaches are rumen manipulation, alteration of rumen fermentation, modification of rumen microbial biodiversity by different means and rarely by animal manipulations. However, a comprehensive exploration for a sustainable methane mitigation approach is still lacking. Dietary modification is directly linked to changes in the rumen fermentation pattern and types of end products. Studies showed that changing fermentation pattern is one of the most effective ways of methane abatement. Desirable dietary changes provide two fold benefits i.e. improve production and reduce GHG emissions. Therefore, the aim of this review is to discuss biology of methane emission from ruminants and its mitigation through dietary manipulation.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.1
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• pp.96-114
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• 2000

Genetically selected beef cattle are fed high-energy diets in intensive production systems developed in industrial countries. This type of feeding can induce rumen dysfunctions that have to be corrected by farmers to optimise cost-effectiveness. The risk of rumen acidosis can be reduced by using slowly degradable starch, which partly escapes rumen fermentation and goes on to be digested in the small intestine. Additives are proposed to stabilise the rumen pH and restrict lactate accumulation, thus favouring the growth of cellulolytic bacteria and stimulating the digestion of the dietary plant cell wall fraction. This enhances the energy value of feeds when animals are fed maize silage for example. Supplementation of lipids to increase energy intake is known to influence the population of rumen protozoa and some associated rumen functions such as cellulolysis and proteolysis. The end products of rumen fermentation are also changed. Lipolysis and hydrogenation by rumen microbes alter the form of fatty acids supplied to animals. This effect is discussed in relation with the quality of lipids in beef and the implications for human health. Conditions for optimising the amount of amino acids from microbial proteins and dietary by-pass proteins flowing to the duodenum of ruminants, and their impact on beef production, are also examined.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.410-416
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• 2010

Methane emitted from ruminant livestock is regarded as a loss of feed energy and also a contributor to global warming. Methane is synthesized in the rumen as one of the hydrogen sink products that are unavoidable for efficient succession of anaerobic microbial fermentation. Various attempts have been made to reduce methane emission, mainly through rumen microbial manipulation, by the use of agents including chemicals, antibiotics and natural products such as oils, fatty acids and plant extracts. A newer approach is the development of vaccines against methanogenic bacteria. While ionophore antibiotics have been widely used due to their efficacy and affordable prices, the use of alternative natural materials is becoming more attractive due to health concerns regarding antibiotics. An important feature of a natural material that constitutes a possible alternative methane inhibitor is that the material does not reduce feed intake or digestibility but does enhance propionate that is the major hydrogen sink alternative to methane. Some implications of these approaches, as well as an introduction to antibiotic-alternative natural materials and novel approaches, are provided.

• Animal Bioscience
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• v.37 no.2_spc
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• pp.370-384
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• 2024

Rumen microbiota play a central role in the digestive process of ruminants. Their remarkable ability to break down complex plant fibers and proteins, converting them into essential organic compounds that provide animals with energy and nutrition. Research on rumen microbiota not only contributes to improving animal production performance and enhancing feed utilization efficiency but also holds the potential to reduce methane emissions and environmental impact. Nevertheless, studies on rumen microbiota face numerous challenges, including complexity, difficulties in cultivation, and obstacles in functional analysis. This review provides an overview of microbial species involved in the degradation of macromolecules, the fermentation processes, and methane production in the rumen, all based on cultivation methods. Additionally, the review introduces the applications, advantages, and limitations of emerging omics technologies such as metagenomics, meta-transcriptomics, metaproteomics, and metabolomics, in investigating the functionality of rumen microbiota. Finally, the article offers a forward-looking perspective on the new horizons and technologies in the field of rumen microbiota functional research. These emerging technologies, with continuous refinement and mutual complementation, have deepened our understanding of rumen microbiota functionality, thereby enabling effective manipulation of the rumen microbial community.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.499-500
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.504-510
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• 2003

Rumen ecology plays an important role in the fermentation process and in providing end-products for ruminants. These studies were carried out to investigate variations in rumen factors namely pH, $NH_3-N$ and microorganisms in cattle and swamp buffaloes. Furthermore, studies on diurnal patterns of rumen fermentation and the effect of rumen digesta transfer from buffalo to cattle was conducted. Based on these studies, diurnal fermentation patterns in both cattle and buffaloes were revealed. It was found that rumen NH3-N was a major limiting factor. Rumen digesta transfer from buffalo to cattle from buffalo to cattle was achievable. Monitoring rumen digesta for 14d after transfer showed an improved rumen ecology in cattle as compared to that of original cattle and buffalo. It is probable that buffalo rumen digesta could be transferred. However, further research should be undertaken in these regards in order to improve rumen ecology especially for buffalo-based rumen.

• 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.16 no.2
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• pp.306-314
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• 2003

Bio-hydrogenation of $C_{18}$-unsaturated fatty acids released from the hydrolysis of dietary lipids in the rumen, in general, occurs rapidly but the range of hydrogenation is quite large, depending on the degree of unsaturation of fatty acids, the configuration of unsaturated fatty acids, microbial type and the experimental condition. Conjugated linoleic acid (CLA) is incompletely hydrogenated products by rumen microorganisms in ruminant animals. It has been shown to have numerous potential benefits for human health and the richest dietary sources of CLA are bovine milk and milk products. The cis-9, trans-11 is the predominant CLA isomer in bovine products and other isomers can be formed with double bonds in positions 8/10, 10/12, or 11/13. The term CLA refers to this whole group of 18 carbon conjugated fatty acids. Alpha-linolenic acid goes through a similar bio-hydrogenation process producing trans-11 $C_{18:1}$ and $C_{18:0}$, but may not appear to produce CLA as an intermediate. Although the CLA has been mostly derived from the dietary $C_{18:2}$ alternative pathway may be existed due to the extreme microbial diversity in the reticulo-rumen. Regardless of the origin of CLA, manipulation of the bio-hydrogenation process remains the key to increasing CLA in milk and beef by dietary means, by increasing rumen production of CLA. Although the effect of oil supplementation on changes in fatty acid composition in milk seems to be clear its effect on beef is still controversial. Thus further studies are required to enrich the CLA in beef under various dietary and feeding conditions.

• Journal of Veterinary Clinics
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• v.30 no.1
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• pp.80-85
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• 2013

Twenty one cows in Goyang and Paju cities were referred due to displacement of the abomasum and foreign body in the rumen. Omentopexy and rumenotomy through a right flank celiotomy were performed for treatment of abomasal displacement and the foreign body removal in the rumen. The right paralumbar fossa is clipped and prepared surgically. Local anesthesia is instituted by performing inverted L block. The abdomen was entered through 25 to 30 cm vertical incision in the right paralumbar fossa starting 4 to 5 cm ventral to the transverse processes of the lumbar vertebrae. A 14-gauge needle with rubber tubing attached is inserted to relieve the gaseous pressure and to facilitate further exploration and manipulation. The rumen was gently pulled out of the abdominal cavity and incision was made at the omentum. Rumenotomy was done and retrieved the foreign body. After the rumen was rinsed with sterile saline, the rumen wall was closed by a Lembert suture technique. The omentum was closed by a simple continuous suture. Right flank omentopexy was performed for the surgical correction of abomasal displacement. Recovery results among 21 cows included 9 excellent, 5 good, 2 fair and 5 bad. It was considered that operation of abomasal displacement and foreign body removal in the rumen through right flank celiotomy was a good surgical technique to reduce expenses, surgical pain, and surgery time.