Twenty macropods from five locations in Queensland, Australia, grazing on a variety of native pas... more Twenty macropods from five locations in Queensland, Australia, grazing on a variety of native pastures were surveyed and the bacterial community of the foregut was examined using 454-amplicon pyrosequencing. Specifically, the V3/V4 region of 16S rRNA gene was examined. A total of 5040 OTUs were identified in the data set (post filtering). Thirty-two OTUs were identified as 'shared' OTUS (i.e. present in all samples) belonging to either Firmicutes or Bacteroidetes (Clostridiales/ Bacteroidales). These phyla predominated the general microbial community in all macropods. Genera represented within the shared OTUs included: unclassified Ruminococcaceae, unclassified Lachnospiraceae, unclassified Clostridiales, Peptococcus sp. Coprococcus spp., Streptococcus spp., Blautia sp., Ruminoccocus sp., Eubacterium sp., Dorea sp., Oscillospira sp. and Butyrivibrio sp. The composition of the bacterial community of the foregut samples of each the host species (Macropus rufus, Macropus giganteus and Macropus robustus) was significantly different allowing differentiation between the host species based on alpha and beta diversity measures. Specifically, eleven dominant OTUs that separated the three host species were identified and classified as: unclassified Ruminococcaceae, unclassified Bacteroidales, Prevotella spp. and a Syntrophococcus sucromutans. Putative reductive acetogens and fibrolytic bacteria were also identified in samples. Future work will investigate the presence and role of fibrolytics and acetogens in these ecosystems. Ideally, the isolation and characterization of these organisms will be used for enhanced feed efficiency in cattle, methane mitigation and potentially for other industries such as the biofuel industry. Citation: Gulino L-M, Ouwerkerk D, Kang AYH, Maguire AJ, Kienzle M, et al. (2013) Shedding Light on the Microbial Community of the Macropod Foregut Using 454-Amplicon Pyrosequencing.
Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed ... more Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed degradation and methane formation by ruminants rely on metabolic interactions between rumen microbes and affect ruminant productivity. Rumen and camelid foregut microbial community composition was determined in 742 samples from 32 animal species and 35 countries, to estimate if this was influenced by diet, host species, or geography. Similar bacteria and archaea dominated in nearly all samples, while protozoal communities were more variable. The dominant bacteria are poorly characterised, but the methanogenic archaea are better known and highly conserved across the world. This universality and limited diversity could make it possible to mitigate methane emissions by developing strategies that target the few dominant methanogens. Differences in microbial community compositions were predominantly attributable to diet, with the host being less influential. There were few strong co-occurrenc...
Meeting the Kyoto Target. Implications for the …, 1999
... Rodgers, PB. Potential of biopesticides in agriculture. Pesticide Science39, 1993, 117-129. S... more ... Rodgers, PB. Potential of biopesticides in agriculture. Pesticide Science39, 1993, 117-129. Sahl, HG. Gene-encoded antibiotics made in bacteria. In Antimicrobial peptides. ... New York. 1995, 329-349. Williams, AG, and Coleman, SG. The rumen protozoa. Springer Verlag. ...
Until recently, knowledge of ruminant gut microbiology was primarily obtained using classical cul... more Until recently, knowledge of ruminant gut microbiology was primarily obtained using classical culture based techniques, which probably only account for 10 to 20% of the rumen microbial population. New gene-based technologies can now be employed to examine microbial diversity through the use of small sub-unit ribosomal DNA analysis (e.g. 16S rDNA) and to understand the function of complex microbial ecosystems in the rumen through metagenomic analysis. These technologies have the potential to revolutionize the understanding of rumen function and will overcome the limitations of classical based techniques, including isolation and taxonomic identification of strains important to efficient rumen function and better understanding of the roles of microorganisms in relation to achieving high productivity and decreasing environmental pollutants. This book presents a comprehensive up-to-date account of the methodologies and protocols for conventional and modern molecular techniques that are c...
Introduction: Large variation in live weight gain (LWG) occurs in weaners. One aspect that may di... more Introduction: Large variation in live weight gain (LWG) occurs in weaners. One aspect that may differ is the association of the microbial population with the LWG. The aim of this experiment was to evaluate the relationship between the ruminal bacterial population and post-weaning LWG by examining (using denaturing gradient gel electrophoresis (DGGE)) rumen bacterial profiles of steers grazing low crude protein (CP) pasture. Methods: Two hundred and three male calves from Lakefield Station, Mataranka, NT, were weighed, marked and weaned in April 2010 and then grazed native pastures as a single mob and were offered a loose lick supplement (10% urea, 26% salt, 15% kynofos, 10% gran-am, 15% copra meal, 20% limestone and 4% trace mineral mix) at approximately 120 g/head/day. Ninety days after weaning the steers were weighed and post-weaning ADG was determined. Thirty six pairs of steers divergent in post-weaning ADG were selected for the pen study by pairing steers with the same weaning ...
ABSTRACT Methane is a potent greenhouse gas with a global warming potential similar to 28 times t... more ABSTRACT Methane is a potent greenhouse gas with a global warming potential similar to 28 times that of carbon dioxide. Consequently, sources and sinks that influence the concentration of methane in the atmosphere are of great interest. In Australia, agriculture is the primary source of anthropogenic methane emissions (60.4% of national emissions, or 3 260 kt(-1) methane year(-1), between 1990 and 2011), and cropping and grazing soils represent Australia's largest potential terrestrial methane sink. As of 2011, the expansion of agricultural soils, which are similar to 70% less efficient at consuming methane than undisturbed soils, to 59% of Australia's land mass (456 Mha) and increasing livestock densities in northern Australia suggest negative implications for national methane flux. Plant biomass burning does not appear to have long-term negative effects on methane flux unless soils are converted for agricultural purposes. Rice cultivation contributes marginally to national methane emissions and this fluctuates depending on water availability. Significant available research into biological, geochemical and agronomic factors has been pertinent for developing effective methane mitigation strategies. We discuss methane-flux feedback mechanisms in relation to climate change drivers such as temperature, atmospheric carbon dioxide and methane concentrations, precipitation and extreme weather events. Future research should focus on quantifying the role of Australian cropping and grazing soils as methane sinks in the national methane budget, linking biodiversity and activity of methane-cycling microbes to environmental factors, and quantifying how a combination of climate change drivers will affect total methane flux in these systems.
Methods in Gut Microbial Ecology for Ruminants, 2005
Bacteriophages are ubiquitous to the rumen ecosystem; they have a role in nitrogen metabolism thr... more Bacteriophages are ubiquitous to the rumen ecosystem; they have a role in nitrogen metabolism through bacterial lysis in the rumen, they may help to regulate bacterial population densities, be an agent for genetic exchange and be of use in biocontrol of bacterial populations ...
The effect of Leucaena leucocephala inclusion in sheep diets upon rumen function was evaluated. N... more The effect of Leucaena leucocephala inclusion in sheep diets upon rumen function was evaluated. Nine Pelibuey sheep, 32.6 ± 5.33 kg live weight (LW), fitted with rumen cannula were used. A complete randomized block design was employed. Two experimental periods of 60 days each, with 60-day intervals between them, were used. Experimental treatments were as follows (n = 6): T1 (control), 100 % Pennisetum purpureum grass; T2, 20 % L. leucocephala + 80 % P. purpureum; T3, 40 % L. leucocephala + 60 % P. purpureum. In situ rumen neutral detergent fiber (aNDF) and crude protein (CP) degradation, dry matter intake (DMI), volatile fatty acids (VFA) production, estimated methane (CH4) yield, rumen pH, ammonia nitrogen (N-NH3), and protozoa counts were measured. The aNDF in situ rumen degradation of P. purpureum and leucaena was higher (P < 0.05) in T2 and T3. Leucaena CP degradation was higher in T2 and T3 but for P. purpureum it was only significantly higher in T3. Leucaena aNDF and CP degradation rate (c) was 50 % higher (P < 0.05) in T2 and T3, but only higher in T3 for P. purpureum. Voluntary intake and rumen (N-NH3) was higher in T2 and T3 (P = 0.0001, P = 0.005, respectively). Molar VFA proportions were similar for all treatments (P > 0.05). Protozoa counts and in vitro gas production (48 h) were lower in T2 and T3 (P < 0.05, P < 0.0001). Estimated methane yield (mol CH4/day) was higher in sheep fed leucaena (P < 0.0001). However, CH4 yield relative to animal performance (mol CH4/g LW gain) was lower in T2 and T3 (P < 0.0001). In summary, these results indicate that including L. leucocephala in sheep diets did not modify rumen fermentation pattern (same VFA ratios) nor reduce the amount of CH4 per unit of DMI (mol CH4/g DMI). However, leucaena inclusion does increase rumen N-NH3, aNDF and CP digestibility, and voluntary intake.
Probiotic supplements are single or mixed strain cultures of live microorganisms that benefit the... more Probiotic supplements are single or mixed strain cultures of live microorganisms that benefit the host by improving the properties of the indigenous microflora (Seo et al 2010). In a pilot study at the University of Queensland, Norton et al (2008) found that Bacillus amyloliquefaciens Strain H57 (H57), primarily investigated as an inoculum to make high-quality hay, improved feed intake and nitrogen utilisation over several weeks in pregnant ewes. The purpose of the following study was to further challenge the potential of H57 -to show it survives the steam-pelleting process, and that it improves the performance of ewes fed pellets based on an agro-industrial by-product with a reputation for poor palatability, palm kernel meal (PKM), (McNeill 2013). Thirty-two first-parity White Dorper ewes (day 37 of pregnancy, mean liveweight = 47.3 kg, mean age = 15 months) were inducted into individual pens in the animal house at the University of Queensland, Gatton. They were adjusted onto PKM-b...
Twenty macropods from five locations in Queensland, Australia, grazing on a variety of native pas... more Twenty macropods from five locations in Queensland, Australia, grazing on a variety of native pastures were surveyed and the bacterial community of the foregut was examined using 454-amplicon pyrosequencing. Specifically, the V3/V4 region of 16S rRNA gene was examined. A total of 5040 OTUs were identified in the data set (post filtering). Thirty-two OTUs were identified as 'shared' OTUS (i.e. present in all samples) belonging to either Firmicutes or Bacteroidetes (Clostridiales/ Bacteroidales). These phyla predominated the general microbial community in all macropods. Genera represented within the shared OTUs included: unclassified Ruminococcaceae, unclassified Lachnospiraceae, unclassified Clostridiales, Peptococcus sp. Coprococcus spp., Streptococcus spp., Blautia sp., Ruminoccocus sp., Eubacterium sp., Dorea sp., Oscillospira sp. and Butyrivibrio sp. The composition of the bacterial community of the foregut samples of each the host species (Macropus rufus, Macropus giganteus and Macropus robustus) was significantly different allowing differentiation between the host species based on alpha and beta diversity measures. Specifically, eleven dominant OTUs that separated the three host species were identified and classified as: unclassified Ruminococcaceae, unclassified Bacteroidales, Prevotella spp. and a Syntrophococcus sucromutans. Putative reductive acetogens and fibrolytic bacteria were also identified in samples. Future work will investigate the presence and role of fibrolytics and acetogens in these ecosystems. Ideally, the isolation and characterization of these organisms will be used for enhanced feed efficiency in cattle, methane mitigation and potentially for other industries such as the biofuel industry. Citation: Gulino L-M, Ouwerkerk D, Kang AYH, Maguire AJ, Kienzle M, et al. (2013) Shedding Light on the Microbial Community of the Macropod Foregut Using 454-Amplicon Pyrosequencing.
Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed ... more Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed degradation and methane formation by ruminants rely on metabolic interactions between rumen microbes and affect ruminant productivity. Rumen and camelid foregut microbial community composition was determined in 742 samples from 32 animal species and 35 countries, to estimate if this was influenced by diet, host species, or geography. Similar bacteria and archaea dominated in nearly all samples, while protozoal communities were more variable. The dominant bacteria are poorly characterised, but the methanogenic archaea are better known and highly conserved across the world. This universality and limited diversity could make it possible to mitigate methane emissions by developing strategies that target the few dominant methanogens. Differences in microbial community compositions were predominantly attributable to diet, with the host being less influential. There were few strong co-occurrenc...
Meeting the Kyoto Target. Implications for the …, 1999
... Rodgers, PB. Potential of biopesticides in agriculture. Pesticide Science39, 1993, 117-129. S... more ... Rodgers, PB. Potential of biopesticides in agriculture. Pesticide Science39, 1993, 117-129. Sahl, HG. Gene-encoded antibiotics made in bacteria. In Antimicrobial peptides. ... New York. 1995, 329-349. Williams, AG, and Coleman, SG. The rumen protozoa. Springer Verlag. ...
Until recently, knowledge of ruminant gut microbiology was primarily obtained using classical cul... more Until recently, knowledge of ruminant gut microbiology was primarily obtained using classical culture based techniques, which probably only account for 10 to 20% of the rumen microbial population. New gene-based technologies can now be employed to examine microbial diversity through the use of small sub-unit ribosomal DNA analysis (e.g. 16S rDNA) and to understand the function of complex microbial ecosystems in the rumen through metagenomic analysis. These technologies have the potential to revolutionize the understanding of rumen function and will overcome the limitations of classical based techniques, including isolation and taxonomic identification of strains important to efficient rumen function and better understanding of the roles of microorganisms in relation to achieving high productivity and decreasing environmental pollutants. This book presents a comprehensive up-to-date account of the methodologies and protocols for conventional and modern molecular techniques that are c...
Introduction: Large variation in live weight gain (LWG) occurs in weaners. One aspect that may di... more Introduction: Large variation in live weight gain (LWG) occurs in weaners. One aspect that may differ is the association of the microbial population with the LWG. The aim of this experiment was to evaluate the relationship between the ruminal bacterial population and post-weaning LWG by examining (using denaturing gradient gel electrophoresis (DGGE)) rumen bacterial profiles of steers grazing low crude protein (CP) pasture. Methods: Two hundred and three male calves from Lakefield Station, Mataranka, NT, were weighed, marked and weaned in April 2010 and then grazed native pastures as a single mob and were offered a loose lick supplement (10% urea, 26% salt, 15% kynofos, 10% gran-am, 15% copra meal, 20% limestone and 4% trace mineral mix) at approximately 120 g/head/day. Ninety days after weaning the steers were weighed and post-weaning ADG was determined. Thirty six pairs of steers divergent in post-weaning ADG were selected for the pen study by pairing steers with the same weaning ...
ABSTRACT Methane is a potent greenhouse gas with a global warming potential similar to 28 times t... more ABSTRACT Methane is a potent greenhouse gas with a global warming potential similar to 28 times that of carbon dioxide. Consequently, sources and sinks that influence the concentration of methane in the atmosphere are of great interest. In Australia, agriculture is the primary source of anthropogenic methane emissions (60.4% of national emissions, or 3 260 kt(-1) methane year(-1), between 1990 and 2011), and cropping and grazing soils represent Australia's largest potential terrestrial methane sink. As of 2011, the expansion of agricultural soils, which are similar to 70% less efficient at consuming methane than undisturbed soils, to 59% of Australia's land mass (456 Mha) and increasing livestock densities in northern Australia suggest negative implications for national methane flux. Plant biomass burning does not appear to have long-term negative effects on methane flux unless soils are converted for agricultural purposes. Rice cultivation contributes marginally to national methane emissions and this fluctuates depending on water availability. Significant available research into biological, geochemical and agronomic factors has been pertinent for developing effective methane mitigation strategies. We discuss methane-flux feedback mechanisms in relation to climate change drivers such as temperature, atmospheric carbon dioxide and methane concentrations, precipitation and extreme weather events. Future research should focus on quantifying the role of Australian cropping and grazing soils as methane sinks in the national methane budget, linking biodiversity and activity of methane-cycling microbes to environmental factors, and quantifying how a combination of climate change drivers will affect total methane flux in these systems.
Methods in Gut Microbial Ecology for Ruminants, 2005
Bacteriophages are ubiquitous to the rumen ecosystem; they have a role in nitrogen metabolism thr... more Bacteriophages are ubiquitous to the rumen ecosystem; they have a role in nitrogen metabolism through bacterial lysis in the rumen, they may help to regulate bacterial population densities, be an agent for genetic exchange and be of use in biocontrol of bacterial populations ...
The effect of Leucaena leucocephala inclusion in sheep diets upon rumen function was evaluated. N... more The effect of Leucaena leucocephala inclusion in sheep diets upon rumen function was evaluated. Nine Pelibuey sheep, 32.6 ± 5.33 kg live weight (LW), fitted with rumen cannula were used. A complete randomized block design was employed. Two experimental periods of 60 days each, with 60-day intervals between them, were used. Experimental treatments were as follows (n = 6): T1 (control), 100 % Pennisetum purpureum grass; T2, 20 % L. leucocephala + 80 % P. purpureum; T3, 40 % L. leucocephala + 60 % P. purpureum. In situ rumen neutral detergent fiber (aNDF) and crude protein (CP) degradation, dry matter intake (DMI), volatile fatty acids (VFA) production, estimated methane (CH4) yield, rumen pH, ammonia nitrogen (N-NH3), and protozoa counts were measured. The aNDF in situ rumen degradation of P. purpureum and leucaena was higher (P < 0.05) in T2 and T3. Leucaena CP degradation was higher in T2 and T3 but for P. purpureum it was only significantly higher in T3. Leucaena aNDF and CP degradation rate (c) was 50 % higher (P < 0.05) in T2 and T3, but only higher in T3 for P. purpureum. Voluntary intake and rumen (N-NH3) was higher in T2 and T3 (P = 0.0001, P = 0.005, respectively). Molar VFA proportions were similar for all treatments (P > 0.05). Protozoa counts and in vitro gas production (48 h) were lower in T2 and T3 (P < 0.05, P < 0.0001). Estimated methane yield (mol CH4/day) was higher in sheep fed leucaena (P < 0.0001). However, CH4 yield relative to animal performance (mol CH4/g LW gain) was lower in T2 and T3 (P < 0.0001). In summary, these results indicate that including L. leucocephala in sheep diets did not modify rumen fermentation pattern (same VFA ratios) nor reduce the amount of CH4 per unit of DMI (mol CH4/g DMI). However, leucaena inclusion does increase rumen N-NH3, aNDF and CP digestibility, and voluntary intake.
Probiotic supplements are single or mixed strain cultures of live microorganisms that benefit the... more Probiotic supplements are single or mixed strain cultures of live microorganisms that benefit the host by improving the properties of the indigenous microflora (Seo et al 2010). In a pilot study at the University of Queensland, Norton et al (2008) found that Bacillus amyloliquefaciens Strain H57 (H57), primarily investigated as an inoculum to make high-quality hay, improved feed intake and nitrogen utilisation over several weeks in pregnant ewes. The purpose of the following study was to further challenge the potential of H57 -to show it survives the steam-pelleting process, and that it improves the performance of ewes fed pellets based on an agro-industrial by-product with a reputation for poor palatability, palm kernel meal (PKM), (McNeill 2013). Thirty-two first-parity White Dorper ewes (day 37 of pregnancy, mean liveweight = 47.3 kg, mean age = 15 months) were inducted into individual pens in the animal house at the University of Queensland, Gatton. They were adjusted onto PKM-b...
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