• Asian-Australasian Journal of Animal Sciences
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• v.3 no.4
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• pp.337-341
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• 1990

An investigation was conducted to determine whether the rumen modifiers lasalocid and avoparcin, when included in molasses/urea based supplements, enhanced liveweight performance, in early weaned calves. As part of the study the broad-spectrum parasiticle Avermectin B1 was given to the calves to assess any undesirable side effects on animals of less than four months of age. There were no significant (p>0.05) liveweight responses to supplementation when the rumen modifiers lasalocid and avoparcin were included in supplement rations. Lasalocid reduced supplement intake, however, it had no adverse effect on liveweight gain. Avoparcin substantially improved growth when cottonseed meal was included in the ration. Weaners treated with Avermectin B1 tended to show a greater liveweight gain than untreated weaners during the experiment (p<0.10) and no adverse side effects were noted.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.4
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• pp.617-622
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• 1992

Four rumen-fistulated swamp buffaloes steers were used in a change-over experiment. This experiment was designed to provide a comparison of the effect of urea-ammonia treatment of rice straw with untreated rice straw. Nitrogen, mineral and trace elements were supplied at adequate levels to both diets in order to overcome deficiencies which may have otherwise confounded a direct comparison. There was a 46% increase in the intake of digestible organic matter (OM) with the urea-ammonia treated diet. This was contributed by a 17% increase in the digestibility of OM and a 25% increase in the voluntary intake of OM. Of the cell wall fraction, the digestibility of hemicellulose increased by the greatest amount (26%). There was an increased rate of passage of particulate matter out of the rumen for the treated straw, along with the increased rate of OM fermentation resulted in a 9% decrease in the amount of digesta dry matter (DM) contained in the rumen. The volatile fatty acid (VFA) pool in the rumen was 24% higher for the treated diet.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.11
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• pp.1694-1698
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• 2007

The objective of this study was to identify biohydrogenation pathways for linoleic, linolenic, oleic and stearic acids by Orpinomyces species of rumen fungus during in vitro culture. Biohydrogenation of linoleic acid produced conjugated linoleic acid (cis-9, trans-11 C18:2), which was then converted to vaccenic acid (trans-11 C18:1) as the end product of biohydrogenation. Biohydrogenation of linolenic acid produced cis-9, trans-11, cis-15 C18:3 and trans-11, cis-15 C18:2 as intermediates and vaccenic acid as the end product of biohydrogenation. Oleic acid and stearic acid were not converted to any other fatty acid. It is concluded that pathways for biohydrogenation of linoleic and linolenic acids by Orpinomyces are the same as those for group A rumen bacteria.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.1
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• pp.51-54
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• 1998

The present study investigated the use of cow faeces as a source of micro-organisms instead of sheep rumen liquor in in vitro digestibility assays of forages. Initially 40 forage samples comprising ryegrass, wheat, maize and barley were screened to select a wide range of digestibility (327-794 g/kg) of forages. Finally 8 forage samples were assessed using rumen liquor as well as faecal liquor. The absolute organic matter digestibility (OMD) values using faecal liquor were lower than those with rumen liquor. However, the relationship between OMD using rumen liquor and faecal liquor was highly significant (p < 0.001). The $R^2$ value exceed 0.90. The results suggest that micro-organisms from faecal liquor are capable of digesting forage samples.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.9
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• pp.1250-1260
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• 2010

Mycotoxins are secondary metabolites produced by fungi. These toxins pose serious health concerns to animals as well as human beings. Biodegradation of these mycotoxins has been considered as one of the best strategies to decontaminate food and feedstuffs. Biodegradation employs the application of microbes or enzymes to contaminated food and feedstuffs. Ruminants are considered to be resistant to the adverse effects of mycotoxins presumably due to the biodegrading ability of rumen microbes compared to mono-gastric animals. Therefore, rumen microbial source or microbial enzyme could be a great asset in biological detoxification of mycotoxins. Isolation and characterization of pure culture of rumen microorganisms or isolation and cloning of genes encoding mycotoxin-degrading potential would prove to have overall beneficial impact in the food and feed industry.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.2
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• pp.161-164
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• 1991

A rapid and accurate method is described for the determination of nucleo-bases in rumen micro-organisms. A procedure to satisfactorily hydrolyse the micro-organisms involving reaction with a mixture of readily volatile organic acids (acetic and formic acids) under high pressure, is proposed, and optimal conditions for an analytical procedure with reversed phase HPLC is described. The following nucleobases contents (mmol/kg DM) of rumen micro-organisms were found: Adenine (Ade), 82.62; Guanine (Gua), 61.34; Cytosine (Cyt), 84.61; Thymine (Thy), 35.74; Uracil (Ura), 68.62; Hypoxanthine (Hxn), 13.06; Xanthine (Xn), 8.35. Total purine-N content (g/kg N) of rumen micro-organisms were 99.60. The nucleic acid N content (g/kg N) of microbial isolates were: RNA-N, 109.9; DNA-N, 50.9.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.8
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• pp.1134-1138
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• 2002

Isopropyl alcohol (IPA), produced from acetone by rumen bacterial action, was infused into the rumen of three female goats kept in a climatically controlled experimental room during feeding to investigate the mechanism and roles of IPA in ruminating behavior (number of boli and ruminating time). The ruminating behavior measured by the number of boli, ruminating time, number of remastications, and remasticating time increased (p<0.05) with intraruminal IPA infusion. The concentrations of IPA and acetone in the rumen and the plasma significantly increased (p<0.05) during intraruminal IPA infusion. These data suggest that rumination receptors sensitive to IPA and acetone may be in an area such as the rumen epithelium and the brain stem where they can respond to metabolite levels.

• Asian-Australasian Journal of Animal Sciences
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• v.3 no.1
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• pp.27-31
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• 1990

Influences of plant phenolic acids and their possible metabolites(non-phenolic aromatic acids involved) in the rumen on the cellulolytic activity of mixed rumen populations were examined by a simple in vitro culture technique. Initial concentrations of aromatic acids were 1, 5, 10 and 20 mM/l. All the tested aromatic acids reduced microbial cellulose digestion especially at the higher initial concentration. P-Coumaric acid, ferulic acid and cinnamic acid, those having unhydrogenated propenoic side chain were more inhibitory than were 3-phenylpropinic acid and phloretic acid, those having hydrogenated propanoic side chain. Lag-time for cellulose digestion was prolonged by former three acids by 16 h. Apparent reduction in p-coumaric acid concentration was observed at 24 h when cellulose digestion began. Volatile fatty acid productions from cellulose fermentation were shifted by former three aromatic acids to produce more acetate and less propionate. This suggests that the selection of celluloytic organisms was induced by these aromatic acids.

• 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.