Animal Production Science Animal Production Science Society
Food, fibre and pharmaceuticals from animals
REVIEW

Ruminant enteric methane mitigation: a review

D. J. Cottle A C , J. V. Nolan A and S. G. Wiedemann B

A School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.

B FSA Consulting, 11 Clifford Street, Toowoomba, Qld 4350, Australia.

C Corresponding author. Email: dcottle@une.edu.au

Animal Production Science 51(6) 491-514 http://dx.doi.org/10.1071/AN10163
Submitted: 28 August 2010  Accepted: 4 March 2011   Published: 30 May 2011

Abstract

In Australia, agriculture is responsible for ~17% of total greenhouse gas emissions with ruminants being the largest single source. However, agriculture is likely to be shielded from the full impact of any future price on carbon. In this review, strategies for reducing ruminant methane output are considered in relation to rumen ecology and biochemistry, animal breeding and management options at an animal, farm, or national level. Nutritional management strategies have the greatest short-term impact. Methanogenic microorganisms remove H2 produced during fermentation of organic matter in the rumen and hind gut. Cost-effective ways to change the microbial ecology to reduce H2 production, to re-partition H2 into products other than methane, or to promote methanotrophic microbes with the ability to oxidise methane still need to be found. Methods of inhibiting methanogens include: use of antibiotics; promoting viruses/bacteriophages; use of feed additives such as fats and oils, or nitrate salts, or dicarboxylic acids; defaunation; and vaccination against methanogens. Methods of enhancing alternative H2 using microbial species include: inoculating with acetogenic species; feeding highly digestible feed components favouring ‘propionate fermentations’; and modifying rumen conditions. Conditions that sustain acetogen populations in kangaroos and termites, for example, are poorly understood but might be extended to ruminants. Mitigation strategies are not in common use in extensive grazing systems but dietary management or use of growth promotants can reduce methane output per unit of product. New, natural compounds that reduce rumen methane output may yet be found. Smaller but more permanent benefits are possible using genetic approaches. The indirect selection criterion, residual feed intake, when measured on ad libitum grain diets, has limited relevance for grazing cattle. There are few published estimates of genetic parameters for feed intake and methane production. Methane-related single nucleotide polymorphisms have yet to be used commercially. As a breeding objective, the use of methane/kg product rather than methane/head is recommended. Indirect selection via feed intake may be more cost-effective than via direct measurement of methane emissions. Life cycle analyses indicate that intensification is likely to reduce total greenhouse gas output but emissions and sequestration from vegetation and soil need to be addressed. Bio-economic modelling suggests most mitigation options are currently not cost-effective.

Additional keywords: Australian red meat industries, carbon price, greenhouse gas emissions.


References

Akunna J, Bizeau C, Moletta R, Bernet N, Heduit A (1994) Combined organic carbon and complete nitrogen removal using anaerobic and aerobic upflow filters. Water Science and Technology 30, 297–306.

Alcock D, Hegarty RS (2006) Effects of pasture improvement on productivity, gross margin and methane emissions of a grazing sheep enterprise. In ‘Proceedings of the 2nd international conference on greenhouse gases and animal agriculture’. (Eds CR Soliva, J Takahashi, MKreuzer) pp. 103–106. (Elsevier: Zurich)

Alcock D, Hegarty RS (2010) Impacts of animal management and genetic improvement on enteric methane output, emissions intensity and productivity of Australian sheep production systems. In ‘Proceedings of the 4th international conference on greenhouse gases and animal agriculture’. (Eds EJ McGeough, SM McGinn) p. 187.

Alford AR, Hegarty RS, Parnell PF, Cacho OJ, Herd RM, Griffith GR (2006) The impact of breeding to reduce residual feed intake on enteric methane emissions from the Australian beef industry. Australian Journal of Experimental Agriculture 46, 813–820.
The impact of breeding to reduce residual feed intake on enteric methane emissions from the Australian beef industry.CrossRef | open url image1

Allison MJ, Reddy CA (1984) Adaptations of gastrointestinal bacteria in response to changes in dietary oxalate and nitrate. In ‘Proceedings of the 3rd international symposium on microbial ecology’. (Eds MJ Klug, CA Reddy) pp. 248–256. (American Society for Microbiology: Washington, DC)

Allison MJ, Reddy CA, Cook HM (1981) The effects of nitrate and nitrite on VFA and methane production by rumen microbes. Journal of Animal Science 53, 391–399.

Amer P, Ludemann C, Young M, McEwan J (2009) Spin-off benefits from current genetic improvement in the New Zealand sheep industry and potential for enhancement. In ‘Livestock breeding for GHG outcomes. MAFF, PGGRC and Learn workshop, 3–5 March 2009’. (Ed. R Hegarty) (MAFF: Wellington, NZ). Available at http://www.livestockemissions.net/Publications/tabid/63/Default.aspx [Verified 8 April 2011]

Anderson RC, Callawaya TR, Van Kesselb JS, Junga YS, Edringtona TS, Nisbet DJ (2003) Effect of select nitrocompounds on ruminal fermentation; an initial look at their potential to reduce economic and environmental costs associated with ruminal methanogenesis. Bioresource Technology 90, 59–63.
Effect of select nitrocompounds on ruminal fermentation; an initial look at their potential to reduce economic and environmental costs associated with ruminal methanogenesis.CrossRef | 1:CAS:528:DC%2BD3sXkvFGlsrY%3D&md5=04cf6ec2a85cd645e790212c314085c6CAS | 12835058PubMed | open url image1

Anderson RC, Carstens GE, Miller RK, Callaway TR, Schultz CL, Edrington TS, Harvey RB, Nisbet DJ (2006) Effect of oral nitroethane and 2-nitropropanol administration on methane-producing activity and volatile fatty acid production in the ovine rumen. Bioresource Technology 97, 2421–2426.

Archer JA, Bergh L (2000) Duration of performance tests for growth rate, feed intake and feed efficiency in four biological types of beef cattle. Livestock Production Science 65, 47–55.
Duration of performance tests for growth rate, feed intake and feed efficiency in four biological types of beef cattle.CrossRef | open url image1

Archer JA, Arthur PF, Herd RM, Parnell PF, Pitchford WS (1997) Optimum post weaning test for measurement of growth rate, feed intake and feed efficiency in British breed cattle. Journal of Animal Science 75, 2024–2032.

Archer JA, Arthur PF, Herd RM, Richardson EC (1998) Genetic variation in feed efficiency and its component traits. In ‘Proceedings of the 6th world congress on genetics and applied livestock production’. pp. 81–84. (University of New England: Armidale, NSW)

Archer JA, Richardson EC, Herd RM, Arthur PR (1999) Potential for selection to improve efficiency of feed use in beef cattle: a review. Australian Journal of Agricultural Research 50, 147–161.
Potential for selection to improve efficiency of feed use in beef cattle: a review.CrossRef | open url image1

Archer JA, Barwick SA, Graser H-U (2004) Economic evaluation of beef cattle breeding schemes incorporating performance testing of young bulls for feed intake. Australian Journal of Experimental Agriculture 44, 393–404.
Economic evaluation of beef cattle breeding schemes incorporating performance testing of young bulls for feed intake.CrossRef | open url image1

Arthur PF, Herd RM, Wright J, Xu G, Dibley K, Richardson EC (1996) Net feed conversion efficiency and its relationship with other traits in beef cattle. Proceedings of the Australian Society of Animal Production 21, 107–110.

Arthur PF, Archer JA, Herd RM, Richardson EC, Wright JH, Dibley KCP, Burton DA (1997) Genotypic and phenotypic variation in feed intake, feed efficiency and growth rate in beef cattle. Proceedings of the Association for Advancement of Animal Breeding Genetics 12, 234–237.

Arthur PF, Archer JA, Johnston DJ, Herd RM, Richardson EC, Parnell P (2001) Genetic and phenotypic variance and covariance components for feed intake, feed efficiency and other post weaning traits in Angus cattle. Journal of Animal Science 79, 2805–2811.

Asanuma N, Iwamoto M, Hino T (1999) Effect of the addition of fumarate on methane production by ruminal microorganisms in vitro. Journal of Dairy Science 82, 780–787.
Effect of the addition of fumarate on methane production by ruminal microorganisms in vitro.CrossRef | 1:CAS:528:DyaK1MXitlGitLs%3D&md5=7146d0ecc5c656921b3530302d4e4af6CAS | 10212465PubMed | open url image1

Attwood G, McSweeney C (2008) Methanogen genomics to discover targets for methane mitigation technologies and options for alternative H2 utilisation in the rumen. Australian Journal of Experimental Agriculture 48, 28–37.
Methanogen genomics to discover targets for methane mitigation technologies and options for alternative H2 utilisation in the rumen.CrossRef | 1:CAS:528:DC%2BD1cXovVGl&md5=cd1b04d1c9c64128a14c73b9634a45d5CAS | open url image1

Australian Farm Institute (2009) ‘FarmGAS calculator user guide April, 2009.’ (AFI: Sydney)

Australian Greenhouse Office (2007) ‘National inventory report, 2005 – volume 1.’ (Commonwealth of Australia: Canberra)

Barendse W, Reverter-Gomez A (2006) A method for assessing traits selected from longissimus dorsi peak force, intramuscular fat, retail beef yield and net feed intake in bovine animals. PCT/AU2006/001044. Available at http://www.wipo.int/pctdb/en/wo.jsp?WO=20070121199 [Verified 4 April 2010]

Barendse W, Reverter A, Bunch RJ, Harrison BE, Barris W, Thomas MB (2007) A validated whole-genome association study of efficient food conversion in cattle. Genetics 176, 1893–1905.
A validated whole-genome association study of efficient food conversion in cattle.CrossRef | 1:CAS:528:DC%2BD2sXhtVeiur3K&md5=2d5bd567d53b458eecccd420c0e37f9fCAS | 17507676PubMed | open url image1

Bath C (2008) Investigating rumen genomics for emission reductions Victorian DPI Newsletter No. 11 October, 2008. Available at http://www.livestockemissions.net/Portals/0/Publications/GIA_Newsletter_Oct08.pdf [Verified 4 April 2010]

Bauchop T (1967) Inhibition of rumen methanogenesis by methane analogues. Journal of Bacteriology 94, 171–175.

Bayaru E, Kanda S, Kamada T, Itabashi H, Andoh S, Nishida T, Ishida M, Itoh T, Nagara K, Isobe Y (2001) Effect of fumaric acid on methane production, rumen fermentation and digestibility of cattle fed roughage alone. Animal Science Journal 72, 139–146.

Beauchemin KA, McGinn SM (2005) Methane emissions from feedlot cattle fed barley or corn diets. Journal of Animal Science 83, 653–661.

Beauchemin KA, Kreuzer M, O’Mara F, McAllister TA (2008) Nutritional management for enteric methane abatement: a review. Australian Journal of Experimental Agriculture 48, 21–27.
Nutritional management for enteric methane abatement: a review.CrossRef | 1:CAS:528:DC%2BD1cXovVGn&md5=36eb7e54a2aa53d5c5e72e40049f37d7CAS | open url image1

Benchaar C, Pomar C, Chiquette J (2001) Evaluation of dietary strategies to reduce methane production in ruminants: a modelling approach. Canadian Journal of Animal Science 81, 563–574.

Bentley D, Hegarty RS, Alford AR (2008) Managing livestock enterprises in Australia’s extensive rangelands for greenhouse gas and environmental outcomes: a pastoral company perspective. Australian Journal of Experimental Agriculture 48, 60–64.
Managing livestock enterprises in Australia’s extensive rangelands for greenhouse gas and environmental outcomes: a pastoral company perspective.CrossRef | 1:CAS:528:DC%2BD1cXovVGq&md5=a3ce9a9b6f891c3b39cbb12bf8e0b85aCAS | open url image1

Blaxter KL, Clapperton JL (1965) Prediction of the amount of methane produced by ruminants. The British Journal of Nutrition 19, 511–522.
Prediction of the amount of methane produced by ruminants.CrossRef | 1:CAS:528:DyaF28XitFKktg%3D%3D&md5=5fe13fb5b73d762bff30e3e1ffd3e95aCAS | 5852118PubMed | open url image1

Blaxter KL, Czerkawski J (1966) Modifications of the methane production of the sheep by supplementation of its diet. Journal of the Science of Food and Agriculture 17, 417–421.
Modifications of the methane production of the sheep by supplementation of its diet.CrossRef | 1:CAS:528:DyaF28XltVWrur4%3D&md5=a31f96b24a74deb9e4eaf9b28c32452fCAS | 5913171PubMed | open url image1

Bozic A, Anderson R, Carstens G, Ricke S, Callaway T, Yokoyama M, Wang J, Nisbet D (2009) Effects of the methane-inhibitors nitrate, nitroethane, lauric acid, Lauricidin (R) and the Hawaiian marine algae Chaetoceros on ruminal fermentation in vitro. Bioresearch and Technology 100, 4017–4025.
Effects of the methane-inhibitors nitrate, nitroethane, lauric acid, Lauricidin (R) and the Hawaiian marine algae Chaetoceros on ruminal fermentation in vitro.CrossRef | 1:CAS:528:DC%2BD1MXmtVelsbY%3D&md5=ad22fdbe76be3b9ec2bf30e9757ac993CAS | open url image1

Breznak JA, Kane MD (1990) Microbial H2/CO2 acetogenesis in animal guts: nature and nutritional significance. FEMS Microbiology Reviews 87, 309–314.
Microbial H2/CO2 acetogenesis in animal guts: nature and nutritional significance.CrossRef | 1:CAS:528:DyaK3MXnvVaktg%3D%3D&md5=6d2e5b370e736df5b9d22950d09c1723CAS | open url image1

Breznak JA, Switzer JM (1986) Acetate synthesis from H2 plus CO2 by termite gut microbes. Applied and Environmental Microbiology 52, 623–630.

Brosh A (2007) Heart rate measurements as an index of energy expenditure and energy balance in ruminants: a review. Journal of Animal Science 85, 1213–1227.
Heart rate measurements as an index of energy expenditure and energy balance in ruminants: a review.CrossRef | 1:CAS:528:DC%2BD2sXksF2htb0%3D&md5=02420bba516c27b30a88907c84f12b3aCAS | 17224466PubMed | open url image1

Brosh A (2009) The use of the heart rate technology for selection of cattle for higher production efficiency and lower methane emission. In ‘Livestock breeding for GHG outcomes. MAFF, PGGRC and Learn workshop, 3–5 March 2009’. (Ed. R Hegarty) (MAFF: Wellington, NZ) Available at http://www.livestockemissions.net/Publications/tabid/63/Default.aspx [Verified 8 April 2011]

Broudiscou L, van Nevel CJ, Demeyer DI (1990) Incorporation of soya oil hydrolysate in the diet of defaunated or refaunated sheep: effect on rumen fermentation in vitro. Archiv fur Tierernahrung 40, 329–337.

Buddle BM, Denis M, Attwood GT, Altermann E, Janssen PH, Ronimus RS, Pinares-Patiño CS, Muetzel S, Wedlock N (2010) Strategies to reduce methane emissions from farmed ruminants grazing on pasture. Veterinary Journal 188, 11–17.

Busquet M, Calsamiglia S, Ferret A, Carro MD, Kamel C (2005) Effect of garlic oil and four of its compounds on rumen microbial fermentation. Journal of Dairy Science 88, 4393–4404.
Effect of garlic oil and four of its compounds on rumen microbial fermentation.CrossRef | 1:CAS:528:DC%2BD2MXhtlSqtr3O&md5=232e7594993224e439d63c668a130fe2CAS | 16291631PubMed | open url image1

Callaway TR, Martin SA (1997) Effects of cellobiose and monensin on in vitro fermentation of organic acids by mixed ruminal bacteria. Journal of Dairy Science 80, 1126–1135.
Effects of cellobiose and monensin on in vitro fermentation of organic acids by mixed ruminal bacteria.CrossRef | 1:CAS:528:DyaK2sXjvFWns7g%3D&md5=30b601c8199b2a46c38e96866cf18639CAS | 9201583PubMed | open url image1

Callaway TR, Carneiro de Melo AMS, Russell JB (1997) The effect of nisin and monensin on ruminal fermentation in vitro . Current Microbiology 35, 90–96.

Cammack KM, Leymaster KA, Jenkins TG, Nielsen MK (2005) Estimates of genetic parameters for feed intake, feeding behaviour, and daily gain in composite ram lambs. Journal of Animal Science 83, 777–785.

Carulla JE, Kreuzer M, Machmüller A, Hess HD (2005) Supplementation of Acacia mearnsii tannins decreases methanogenesis and urinary nitrogen in forage-fed sheep. Australian Journal of Agricultural Research 56, 961–970.
Supplementation of Acacia mearnsii tannins decreases methanogenesis and urinary nitrogen in forage-fed sheep.CrossRef | 1:CAS:528:DC%2BD2MXhtVGjsL7K&md5=05cd300937ecf0549297f7360e8f74d9CAS | open url image1

Charmley E, Dove H (2007) Using plant wax markers to estimate diet composition and intakes of mixed forages in sheep by feeding a known amount of alkane-labelled supplement. Australian Journal of Agricultural Research 58, 1215–1225.
Using plant wax markers to estimate diet composition and intakes of mixed forages in sheep by feeding a known amount of alkane-labelled supplement.CrossRef | 1:CAS:528:DC%2BD2sXhsVentrbK&md5=fbd90b7110e2b699bc1533b8ea52eb10CAS | open url image1

Charmley E, Stephens ML, Kennedy PM (2008) Predicting livestock productivity and methane emissions in northern Australia: development of a bio-economic modelling approach. Australian Journal of Experimental Agriculture 48, 109–113.
Predicting livestock productivity and methane emissions in northern Australia: development of a bio-economic modelling approach.CrossRef | 1:CAS:528:DC%2BD1cXovV2i&md5=111d7dbb6214e875dcfbc1d0cc549a89CAS | open url image1

Chen M, Wolin M (1979) Effect of monensin and lasalocid-sodium on the growth of methanogenic and rumen saccharolytic bacteria. Applied Environmental Microbiology 72, 72–77.

Cheng Q, Fischetti VA (2007) Mutagenesis of a bacteriophage lytic enzyme PlyGBS significantly increases its antibacterial activity against group B streptococci. Applied Microbiology and Biotechnology 74, 1284–1291.
Mutagenesis of a bacteriophage lytic enzyme PlyGBS significantly increases its antibacterial activity against group B streptococci.CrossRef | 1:CAS:528:DC%2BD2sXks1agsrw%3D&md5=d20dd78ce0ade4193f276362ff20d830CAS | 17186236PubMed | open url image1

Clapperton JL (1974) The effect of trichloroacetamide, chloroform and linseed oil given into the rumen of sheep on some of the end-products of rumen digestion. The British Journal of Nutrition 32, 155–161.
The effect of trichloroacetamide, chloroform and linseed oil given into the rumen of sheep on some of the end-products of rumen digestion.CrossRef | 1:CAS:528:DyaE2cXltVeltL8%3D&md5=75e61947f670b90b1bf0aa68b76fe654CAS | 4408011PubMed | open url image1

Clemens J, Ahlgrimm H-J (2001) Greenhouse gases from animal husbandry: mitigation options. Nutrient Cycling in Agroecosystems 60, 287–300.
Greenhouse gases from animal husbandry: mitigation options.CrossRef | open url image1

Cohen RDH, Stevens JP, Moore AD, Donnelly JR, Freer M (2004) Predicted methane emissions and metabolizable energy intakes of steers grazing a grass/alfalfa pasture and finished in a feedlot or at pasture using the GrassGro decision support tool. Canadian Journal of Animal Science 84, 125–132.

Cottle DJ, van der Werf JHJ, Banks R (2009) Is methane production likely to be a consideration in future sheep breeding? Proceedings of the Australian Association of Animal Breeding and Genetics 22, 516–519.

Crews DH, Pendley CT, Carstens GE, Mendes EDM (2010) Genetic evaluation of feed intake and utilization traits of beef bulls. In ‘Ninth world congress on genetics applied to livestock production’. p. 30. (German Society for Animal Science: Liepzig)

Dalrymple BP, Kirkness EF, Nefedov M, McWilliam S, Ratnakumar A, Barris W, Zhao S, Shetty J, Maddox JF, O’Grady M, Nicholas F, Crawford AM, Smith T, de Jong PJ, McEwan J, Oddy VH, Cockett NE (2007) Using comparative genomics to reorder the human genome sequence into a virtual sheep genome. Genome Biology 8, R152
Using comparative genomics to reorder the human genome sequence into a virtual sheep genome.CrossRef | 17663790PubMed | open url image1

DCC (2008) ‘National GHG Inventory, 2006.’ (Emissions Analysis Team, Department of Climate Change: Canberra)

DCCEE (2010) National inventory report 2008, vol. 3. Canberra. Available at http://www.climatechange.gov.au/en/publications/greenhouse-acctg/~/media/publications/greenhouse-acctg/national-inventory-report-2008-vol3.ashx [Verified May 2011]

de Klein CAM, Eckard RJ (2008) Targeted technologies for nitrous oxide abatement from animal agriculture. Australian Journal of Experimental Agriculture 48, 14–20.
Targeted technologies for nitrous oxide abatement from animal agriculture.CrossRef | 1:CAS:528:DC%2BD1cXovVKi&md5=772faa73064579a24d66a2cfb58e0f7eCAS | open url image1

Dellow DW, Nolan JV, Hume ID (1983) Studies on the nutrition of the Macropodine marsupials. V. Fermentation in the forestomach of Thiogale thetis and Macropus eugenii. Australian Journal of Zoology 31, 433–443.
Studies on the nutrition of the Macropodine marsupials. V. Fermentation in the forestomach of Thiogale thetis and Macropus eugenii.CrossRef | 1:CAS:528:DyaL2cXitF2ktg%3D%3D&md5=95c5b1ed5767594e26677a1052d7fe9dCAS | open url image1

Demeyer DI, van Nevel CJ (1975) Methanogenesis, an integrated part of carbohydrate fermentation, and its control. In ‘Digestion and metabolism in the ruminant’. (Eds IW McDonald, ACI Warner) pp. 366–382. (The University of New England Publishing Unit: Armidale)

Department of Environment, Food and Rural Affairs (2009) ‘A study of the scope for the application of research in animal genomics and breeding to reduce nitrogen and methane emissions from livestock-based food chains.’ (Department for Environment, Food and Rural Affairs: London) Available at randd.defra.gov.uk/Document.aspx?Document=AC0204_7639_FRP.doc [Verified 20 June 2010]

DeRamus HA, Clement TC, Giampola DD, Dickison PC (2003) Methane emissions of beef cattle on forages: efficiency of grazing management systems. Journal of Environmental Quality 32, 269–277.
Methane emissions of beef cattle on forages: efficiency of grazing management systems.CrossRef | 1:CAS:528:DC%2BD3sXlslKrsg%3D%3D&md5=39bf36d5fd18c8746f95762ec6bce018CAS | 12549566PubMed | open url image1

Deswysen AG, Dutilleul P, Godfrin JP, Ellis WC (1993) Nycterohemeraleating and ruminating patterns in heifers fed grass or corn silage: analysis by finite Fourier transform. Journal of Animal Science 71, 2739–2747.

Dobos RC (2007) Quantitative analysis of behaviour of grazing dairy cows. PhD Thesis, University of New England, Animal Science, Armidale.

Dobos R, Herd R (2008) Spectral analysis of feeding patterns of steers divergent in residual feed intake. Australian Journal of Experimental Agriculture 48, 843–846.
Spectral analysis of feeding patterns of steers divergent in residual feed intake.CrossRef | open url image1

Dohme F, Machmuller A, Wasserfallen A, Kreuzer M (2000) Comparative efficiency of various fats rich in medium-chain fatty acids to suppress ruminal methanogenesis as measured with RUSITEC. Canadian Journal of Animal Science 80, 473–484.
Comparative efficiency of various fats rich in medium-chain fatty acids to suppress ruminal methanogenesis as measured with RUSITEC.CrossRef | 1:CAS:528:DC%2BD3cXos1Ohtrg%3D&md5=181778e0583e03ff78ba2a096f2adfa3CAS | open url image1

Eatwild (2009) Grassfarming benefits the environment. Available at http://eatwild.com/environment.html [Verified 29 May 2009]

Eckard RJ (2009) Greenhouse accounting spreadsheets. Available at http://www.greenhouse.unimelb.edu.au/site/Tools.htm [Verified 12 May 2009]

Eckard RJ, Grainger C, de Klein CAM (2010) Options for the abatement of methane and nitrous oxide from ruminant production: a review. Livestock Science 130, 47–56.
Options for the abatement of methane and nitrous oxide from ruminant production: a review.CrossRef | open url image1

Entenza JM, Loeffler JM, Grandgirard D, Fischetti VA, Moreillon P (2005) Therapeutic effects of bacteriophage Cpl-1 lysin against Streptococcus pneumoniae endocarditis in rats. Antimicrobial Agents and Chemotherapy 49, 4789–4792.
Therapeutic effects of bacteriophage Cpl-1 lysin against Streptococcus pneumoniae endocarditis in rats.CrossRef | 1:CAS:528:DC%2BD2MXht1Siu7vK&md5=635a52db92d38c68ccde6e5e86b58c7bCAS | 16251333PubMed | open url image1

Eugene M, Archimede H, Sauvant D (2004) Quantitative meta-analysis on the effects of defaunation of the rumen on growth, intake and digestion in ruminants. Livestock Production Science 85, 81–97.
Quantitative meta-analysis on the effects of defaunation of the rumen on growth, intake and digestion in ruminants.CrossRef | open url image1

Ferrell CL, Jenkins TG (1984) Energy utilisation by mature, non-pregnant, non-lactating cows of different types. Journal of Animal Science 58, 234–243.

Fievez V, Mbanzamihigo L, Piattoni F, Demeyer D (2001) Evidence for reductive acetogenesis and its nutritional significance in ostrich hindgut as estimated from in vitro incubations. Journal of Animal Physiology and Animal Nutrition 85, 271–280.
Evidence for reductive acetogenesis and its nutritional significance in ostrich hindgut as estimated from in vitro incubations.CrossRef | 1:STN:280:DC%2BD3Mnjs1OltA%3D%3D&md5=06d6dca676a2864330e7d50081a356bdCAS | 11686800PubMed | open url image1

Finlay BJ, Esteban G, Clarke KJ, Williams AG, Embley TM, Hirt RP (1994) Some rumen ciliates have endosymbiotic methanogens. FEMS Microbiology Letters 117, 157–161.
Some rumen ciliates have endosymbiotic methanogens.CrossRef | 1:STN:280:DyaK2c3jslCnug%3D%3D&md5=7c3b8d527f173bccd038ce7eb4950ed5CAS | 8181718PubMed | open url image1

Fogarty NM, Lee GJ, Ingham VM, Gaunt GM, Cummins LJ (2006) Variation in feed intake of grazing crossbred ewes and genetic correlations with production traits. Australian Journal of Agricultural Research 57, 1037–1044.
Variation in feed intake of grazing crossbred ewes and genetic correlations with production traits.CrossRef | open url image1

Freer M, Jones DB (1984) Feeding value of subterranean clover, lucerne, phalaris and Wimmera ryegrass for lambs. Australian Journal of Experimental Agriculture and Animal Husbandry 24, 156–164.
Feeding value of subterranean clover, lucerne, phalaris and Wimmera ryegrass for lambs.CrossRef | open url image1

Galbraith EA, Antonopoulos DA, White BA (2004) Suppressive subtractive hybridization as a tool for identifying genetic diversity in an environmental metagenome: the rumen as a model. Environmental Microbiology 6, 928–937.
Suppressive subtractive hybridization as a tool for identifying genetic diversity in an environmental metagenome: the rumen as a model.CrossRef | 1:CAS:528:DC%2BD2cXnvFWlsrc%3D&md5=fa3a6a76e7e354d4162ec9603261019bCAS | 15305918PubMed | open url image1

García-González R, López S, Fernándeza M, González JS (2008) Dose-response effects of Rheum officinale root and Frangula alnus bark on ruminal methane production in vitro . Animal Feed Science and Technology 145, 319–334.
Dose-response effects of Rheum officinale root and Frangula alnus bark on ruminal methane production in vitro .CrossRef | open url image1

Goodrich RD, Garrett JE, Gast DR, Kirick MA, Larson DA, Meiske JC (1984) Influence of monensin on the performance of cattle. Journal of Animal Science 58, 1484–1498.

Goopy JP, Hegarty RS (2004) Repeatability of methane production in cattle fed concentrates and forage diets. Journal of Animal and Feed Sciences 13, 75–78.

Grainger C, Auldist NJ, Clarke T, Beauchemin KA, McGinn SM, Hannah MC, Eckard RJ, Lowe LB (2008) Use of monensin controlled release capsules to reduce methane emissions and improve milk production of dairy cows offered pasture supplemented with grain. Journal of Dairy Science 91, 1159–1165.
Use of monensin controlled release capsules to reduce methane emissions and improve milk production of dairy cows offered pasture supplemented with grain.CrossRef | 1:CAS:528:DC%2BD1cXivFemtb8%3D&md5=a9de3d5ed2da2de6e61e632510495801CAS | 18292272PubMed | open url image1

Guan H, Wittenberg KM, Ominski KH, Krause DO (2006) Efficacy of ionophores in cattle diets for mitigation of enteric methane. Journal of Animal Science 84, 1896–1906.
Efficacy of ionophores in cattle diets for mitigation of enteric methane.CrossRef | 1:CAS:528:DC%2BD28Xmt1aqtLw%3D&md5=7f6631e1f99e36dc70fa258347a60e55CAS | 16775074PubMed | open url image1

Guan LL, Nkrumah JD, Basarab JA, Moore SS (2008) Linkage of microbial ecology to phenotype: correlation of rumen microbial ecology to cattle’s feed efficiency. FEMS Microbiology Letters 288, 85–91.
Linkage of microbial ecology to phenotype: correlation of rumen microbial ecology to cattle’s feed efficiency.CrossRef | 1:CAS:528:DC%2BD1cXhtlans7bN&md5=0a05e1564c43d915f01930b955bd9483CAS | 18785930PubMed | open url image1

Gunsett FC (1986) Problems associated with selection for traits defined as a ratio of two component traits. Applied Livestock Production 11, 437–442.

Guo WS, Schaefer DM, Guo XX, Ren LP, Meng QX (2009) Nitrate as a sole dietary nitrogen source to improve rumen microbial nitrogen synthesis and to inhibit methane production in vitro . Asian-Australasian Journal of Animal Sciences 22, 542–549.

Hackstein JHP (1997) Genetic and evolutionary aspects of methanogenesis. Reproduction Nutrition Development 37, 5–8.

Hao Trinh Phuc, Do Ho Quang, Preston TR, Leng RA (2009) Nitrate as a fermentable nitrogen supplement for goats fed forage based diets low in true protein. Livestock Research in Rural Development 21(1). Available at http://www.lrrd.org/lrrd21/1/trin21010.htm [Verified 4 April 2011]

Hayes B, Goddard M, Macleod I, Chamberlain A (2006) Selection markers for net feed intake. PCT/AU2006/001842. Available at http://www.wipo.int/pctdb/en/wo.jsp?WO=2007065206 [Verified 4 April 2011]

Hegarty RS (1999a) Reducing rumen methane emissions through elimination of rumen protozoa. Australian Journal of Agricultural Research 50, 1321–1327.
Reducing rumen methane emissions through elimination of rumen protozoa.CrossRef | open url image1

Hegarty RS (1999b) Mechanisms for competitively reducing ruminal methanogenesis. Australian Journal of Agricultural Research 50, 1299–1306.
Mechanisms for competitively reducing ruminal methanogenesis.CrossRef | 1:CAS:528:DyaK1MXotVOlu7Y%3D&md5=cf1ae07c45a6de5c6056b2641359c378CAS | open url image1

Hegarty RS (2002) Strategies for mitigating methane emissions from livestock–Australian options and opportunities. In ‘Proceedings of the first international conference greenhouse gases and animal agriculture’. (Eds J Takahashi, BA Young) pp. 61–66. (Elsevier: Amsterdam)

Hegarty RS (2004a) Genetic diversity in function and microbial metabolism of the rumen. Australian Journal of Experimental Agriculture 44, 1–9.

Hegarty RS (2004b) Genotype differences and their impact on digestive tract function of ruminants: a review. Australian Journal of Experimental Agriculture 44, 459–467.
Genotype differences and their impact on digestive tract function of ruminants: a review.CrossRef | open url image1

Hegarty RS, McEwan JC (2010) Genetic opportunities to reduce enteric methane emissions from ruminant livestock. In ‘Ninth world congress on genetics applied to livestock production’. p. 181. Available at http://www.kongressband.de/wcgalp2010/assets/pdf/0515.pdf [Verified 11 April 2011]

Hegarty RS, Goopy JP, Herd RM, McCorkell B (2007) Cattle selected for lower residual feed intake have reduced daily methane production. Journal of Animal Science 85, 1479–1486.
Cattle selected for lower residual feed intake have reduced daily methane production.CrossRef | 1:CAS:528:DC%2BD2sXls1ant7c%3D&md5=4f56d1a006ef4ccfa685270f9a18e8d9CAS | 17296777PubMed | open url image1

Hegarty RS, Bird SH, Vanselow BA, Woodgate R (2008) Effects of the absence of protozoa from birth or from weaning on the growth and methane production of lambs. British Journal of Nutrition 100, 1220–1227.

Hegarty RS, Alcock D, Robinson DL, Goopy JP, Vercoe PE (2010) Nutritional and flock management options to reduce methane output and methane per unit product from sheep enterprises. Animal Production Science 50, 1026–1033.

Henderson G, Naylor GE, Leahy SC, Janssen PH (2010) Presence of novel, potentially homoacetogenic bacteria in the rumen as determined by analysis of formyltetrahydrofolate synthetase sequences from ruminants. Applied and Environmental Microbiology 76, 2058–2066.
Presence of novel, potentially homoacetogenic bacteria in the rumen as determined by analysis of formyltetrahydrofolate synthetase sequences from ruminants.CrossRef | 1:CAS:528:DC%2BC3cXltVCrtrs%3D&md5=a88183d7dce6ed0e3e8e801a6be0a20dCAS | 20118378PubMed | open url image1

Herd RM, Arthur PF (2009) Physiological basis for residual feed intake. Journal of Animal Science 87, E64–E71.
Physiological basis for residual feed intake.CrossRef | 1:STN:280:DC%2BD1M3mtVWksA%3D%3D&md5=b7dcbeae76ea634b9b478f2cb7c94c58CAS | 19028857PubMed | open url image1

Herd RM, Bishop SC (2000) Genetic variation in residual feed intake and its association with other production traits in British Hereford cattle. Livestock Production Science 63, 111–119.
Genetic variation in residual feed intake and its association with other production traits in British Hereford cattle.CrossRef | open url image1

Herd RM, Arthur PF, Hegarty RS, Archer JA (2002) Potential to reduce GHG emissions from beef production by selection for reduced residual feed intake. Applied Livestock Production 31, 281–284.

Herd RM, Oddy VH, Richardson EC (2004) Biological basis for variation in residual feed intake in beef cattle. I. Review of potential mechanisms. Australian Journal of Experimental Agriculture 44, 423–433.
Biological basis for variation in residual feed intake in beef cattle. I. Review of potential mechanisms.CrossRef | open url image1

Herd RM, Arthur PF, Archer JA (2006) Repeatability of residual feed intake and interaction with level of nutrition in Angus cows. Proceedings of the Australian Society of Animal Production. Short Communication, Number 80. Available at http://www.asap.asn.au/livestocklibrary/2006/SC80-herd.pdf [Verified 4 April 2011]

Hinrichs K-U, Hayes JM, Sylva SP, Brewer PG, DeLong EF (1999) Methane-consuming archaebacteria in marine sediments. Nature 398, 802–805.
Methane-consuming archaebacteria in marine sediments.CrossRef | 1:CAS:528:DyaK1MXjtVSrsLc%3D&md5=e5801d4af28086020435b1745d819804CAS | 10235261PubMed | open url image1

Holloway PE, Baker SK (2002) Natural immunity in sheep to methangenic archaea. Reproduction, Nutrition, Development 42, S13

Howden SM, White DH, McKeon GM, Scanlan JC, Carter JO (1994) Methods for exploring management options to reduce GHG emissions from tropical grazing systems. Climatic Change 27, 49–70.
Methods for exploring management options to reduce GHG emissions from tropical grazing systems.CrossRef | 1:CAS:528:DyaK2cXmvVGmsL8%3D&md5=16c361d7b60c3d8216fb96f6a37dc110CAS | open url image1

Humphreys MO (1989) Water-soluble carbohydrates in perennial ryegrass breeding. 1. Genetic differences among cultivars and hybrid progeny grown as spaced plants. Grass and Forage Science 44, 231–236.
Water-soluble carbohydrates in perennial ryegrass breeding. 1. Genetic differences among cultivars and hybrid progeny grown as spaced plants.CrossRef | open url image1

Hungate RE (1966) ‘The rumen and its microbes.’ (Academic Press: New York)

Hunter RA, Neithe GE (2009) Efficiency of feed utilisation and methane emission for various cattle breeding and finishing systems. Recent Advances in Animal Nutrition in Australia 17, 1–5.

Immig I (1996) The rumen and hindgut as source of ruminant methanogenesis. Environmental Monitoring and Assessment 42, 57–72.
The rumen and hindgut as source of ruminant methanogenesis.CrossRef | 1:CAS:528:DyaK28Xltlars78%3D&md5=0e02d3d127b28dbb6e86c33a445932e8CAS | open url image1

Immig I, Demeyer D, Fiedler D, Van Nevel C, Mbanzamihigo L (1996) Attempts to induce reductive acetogenesis into a sheep rumen. Archives of Animal Nutrition 49, 363–370.

Intergovernmental Panel on Climate Change (1997) ‘Revised 1996 IPCC guidelines for national greenhouse inventories.’ (Eds Houghton J, Meira Filho L, Lim B, Treanton K, Mamaty I, Bonduki Y, Griggs D, Callander B) (IPCC/OECD/IEA: Paris)

Inthapanya S, Preston TR, Leng RA (2011) Mitigating methane production from ruminants; effect of calcium nitrate as modifier of the fermentation in an in vitro incubation using cassava root as the energy source and leaves of cassava or Mimosa piga as source of protein. Livestock Research for Rural Development 23(1). Available at http://www.lrrd.org/lrrd23/2/sang23021.htm [Verified 4 April 2011]

Iqbal MF, Cheng Y-F, Zhu W-Y, Zeshan B (2008) Mitigation of ruminant methane production: current strategies, constraints and future options. World Journal of Microbiology & Biotechnology 24, 2747–2755.
Mitigation of ruminant methane production: current strategies, constraints and future options.CrossRef | 1:CAS:528:DC%2BD1cXht1OksLnE&md5=4f369749e2c33eea586c81e2a788ec9bCAS | open url image1

Iwamoto M, Asanuma N, Hino T (1999) Effects of nitrate combined with fumarate on methanogenesis, fermentation and cellulose digestion by mixed ruminal microbes in vitro. Animal Science Journal 70, 471–478.

Janssen PH (2010) Influence of hydrogen on rumen methane formation and fermentation balances through microbial growth kinetics and fermentation thermodynamics. Animal Feed Science and Technology 160, 1–22.
Influence of hydrogen on rumen methane formation and fermentation balances through microbial growth kinetics and fermentation thermodynamics.CrossRef | 1:CAS:528:DC%2BC3cXhtV2itLvF&md5=b1bb5a6c581dbf490cb74934bc1b9202CAS | open url image1

Joblin KN (1999) Ruminal acetogens and their potential to lower ruminant methane emissions. Australian Journal of Agricultural Research 50, 1307–1313.
Ruminal acetogens and their potential to lower ruminant methane emissions.CrossRef | open url image1

Johnson KA, Johnson DE (1995) Methane emissions from cattle. Journal of Animal Science 73, 2483–2492.

Johnson DE, Hill TM, Ward GM, Johnson KA, Branine ME, Carmean BR, Lodman DW (1993) Ruminants and other animals. In ‘Atmospheric methane: sources, sinks and role in global change’. (Ed. MAK Khalil) pp. 219–229. NATO ASI Series 1: Global Environmental Change, Vol. 13. (Springer-Verlag: Berlin)

Johnson DE, Johnson KA, Ward GM, Branine ME (2000) Ruminants and other animals. In ‘Atmospheric methane: its role in the global environment’. (Ed. MAK Khalil) pp. 112–133. (Springer-Verlag: Berlin)

Johnson IR, Chapman DF, Snow VO, Eckard RJ, Parsons AJ, Lambert MG, Cullen BR (2008) DairyMod and EcoMod: biophysical pastoral simulation models for Australia and New Zealand. Australian Journal of Experimental Agriculture 48, 621–631.
DairyMod and EcoMod: biophysical pastoral simulation models for Australia and New Zealand.CrossRef | open url image1

Kahn LP (1994) The use of lithium chloride for estimating supplement intake in grazing sheep: estimates of heritability and repeatability. Australian Journal of Agricultural Research 45, 1731–1739.
The use of lithium chloride for estimating supplement intake in grazing sheep: estimates of heritability and repeatability.CrossRef | 1:CAS:528:DyaK2MXitlGqtbs%3D&md5=6ec3d6d4363e9b5b190fdb55be82cf51CAS | open url image1

Kajikawa H, Valdes C, Hillman K, Wallace RJ, Newbold CJ (2003) Methane oxidation and its coupled electron-sink reactions in ruminal fluid. Letters in Applied Microbiology 36, 354–357.
Methane oxidation and its coupled electron-sink reactions in ruminal fluid.CrossRef | 1:CAS:528:DC%2BD3sXlsFeltLc%3D&md5=4d6bf09b394129d69ec4fd2e4cafd718CAS | 12753241PubMed | open url image1

Kalmokoff ML, Bartlett F, Teather RM (1996) Are ruminal bacteria armed with bacteriocins? Journal of Dairy Science 79, 2297–2306.
Are ruminal bacteria armed with bacteriocins?CrossRef | 1:CAS:528:DyaK2sXls1OmsQ%3D%3D&md5=51e20ce35e3e7867302bbb881098c7f9CAS | 9029368PubMed | open url image1

Kempton TJ, Murray RM, Leng RA (1976) Methane production and digestibility measurements in the grey kangaroos and sheep. Australian Journal of Biological Sciences 29, 209–214.

Kennedy BW, van der Werf JHJ, Meuwissen THE (1993) Genetic and statistical properties of residual feed intake. Journal of Animal Science 71, 3239–3250.

Kentaro I, Nishimori K, Keiji O, Jun Y (2003) Comparison of diurnal variation of the rumen fluid character between the different sampling sites or feeding systems in dairy cows. Japanese Journal of Veterinary Clinics 26, 47–52.
Comparison of diurnal variation of the rumen fluid character between the different sampling sites or feeding systems in dairy cows.CrossRef | open url image1

Keogh M, Cottle DJ (2009) The implications of greenhouse emission reduction policies for the Australian sheep industry. Recent Advances in Animal Nutrition in Australia 17, 91–100.

Kerr DE, Plaut K, Bramley AJ, Williamson CM, Lax AJ, Moore K, Wells KD, Wall RJ (2001) Lysostaphin expression in mammary glands confers protection against staphylococcal infection in transgenic mice. Nature Biotechnology 19, 66–70.
Lysostaphin expression in mammary glands confers protection against staphylococcal infection in transgenic mice.CrossRef | 1:CAS:528:DC%2BD3MXjslGmtA%3D%3D&md5=a705f2ef9671938c44413a6e426c90a1CAS | 11135555PubMed | open url image1

Kijas JW, Townley D, Dalrymple BP, Heaton MP, Maddox JF, McGrath A, Wilson P, Ingersoll RG, McCulloch R, McWilliam S, Tang D, McEwan J, Cockett N, Oddy HV, Nicholas FW, Raadsma H (2009) A genome wide survey of SNP variation reveals the genetic structure of sheep breeds. PLoS ONE 4, e4668
A genome wide survey of SNP variation reveals the genetic structure of sheep breeds.CrossRef | 19270757PubMed | open url image1

Kirchgessner M, Windisch W, Muller HL (1995) Nutritional factors for the quantification of methane production. In ‘Ruminant physiology: digestion, metabolism, growth and production’. (Eds W von Engelhardt, S Leonherd-Marke, G Breves, D Giesecke) pp. 333–334. (Delmar Publishers: Albany, Germany)

Klieve AV, Ouwerkerk D (2007) Comparative greenhouse gas emissions from herbivores. In ‘Proceedings of the VII international symposium on nutrition of herbivores’. (Ed. QX Meng) pp. 1–15. (China Agricultural University Press: Beijing)

Knight TW, Molano G, Clark H, Cavanagh A (2008) Methane emissions from weaned lambs measured at 13, 17, 25 and 35 weeks of age compared with mature ewes consuming a fresh forage diet. Australian Journal of Experimental Agriculture 48, 240–243.
Methane emissions from weaned lambs measured at 13, 17, 25 and 35 weeks of age compared with mature ewes consuming a fresh forage diet.CrossRef | 1:CAS:528:DC%2BD1cXovVyr&md5=004d84c848cc4c20efee5d8d25eeedb0CAS | open url image1

Koots KR, Gibson JP, Wilton JW (1994) Analyses of published genetic parameter estimates for beef production traits. 2. Phenotypic and genetic correlations. Animal Breeding Abstracts 62, 825–853.

Kurihara M, Magner T, Hunter RA, McCrabb GJ (1999) Methane production and energy partition of cattle in the tropics. The British Journal of Nutrition 81, 227–234.

Lanna DP (2009) Evaluation of net feed intake, biological efficiency, profit and greenhouse gas emissions in the Brazilian Beef Cattle Industry. In ‘Livestock breeding for GHG outcomes. MAFF, PGGRC and Learn workshop, 3–5 March 2009’. (Ed. R Hegarty) (MAFF: Wellington, NZ) Available at http://www.livestockemissions.net/Publications/tabid/63/Default.aspx [Verified 8 April 2011]

Lassey KR (2007) Livestock methane emission: from the individual grazing animal through national inventories to the global methane cycle. Agricultural and Forest Meteorology 142, 120–132.
Livestock methane emission: from the individual grazing animal through national inventories to the global methane cycle.CrossRef | open url image1

Lassey KR, Ulyatt MJ, Martin RJ, Walker CF, Shelton ID (1997) Methane emissions measured directly from grazing livestock in New Zealand. Atmospheric Environment 31, 2905–2914.
Methane emissions measured directly from grazing livestock in New Zealand.CrossRef | 1:CAS:528:DyaK2sXkslertL0%3D&md5=d5168a16c8c7c5d4649576ea1712ce57CAS | open url image1

Laubach J, Kelliher FM, Knight TW, Clark H, Molano G, Cavanagh A (2008) Methane emissions from beef cattle – a comparison of paddock- and animal-scale measurements. Australian Journal of Experimental Agriculture 48, 132–137.
Methane emissions from beef cattle – a comparison of paddock- and animal-scale measurements.CrossRef | 1:CAS:528:DC%2BD1cXovVyk&md5=d0df2b607cb37e486a71a871e537fb75CAS | open url image1

Leahy SC, Kelly WJ, Altermann EH, Ronimus RS, Yeoman C, Pacheco DM, Li D, Kong Z, McTavish S, Sang C, Lambie SC, Janssen PH, Dey D, Attwood GT (2010) The genome sequence of the rumen methanogen Methanobrevibacter ruminantium reveals new possibilities for controlling ruminant methane emissions. PLoS ONE 5, e8926
The genome sequence of the rumen methanogen Methanobrevibacter ruminantium reveals new possibilities for controlling ruminant methane emissions.CrossRef | 20126622PubMed | open url image1

Lee GJ, Atkins KD, Mortimer SI (1995) Variation between Merino ewes in pasture intake. 1. Between-flock differences and some environmental sources of variation. Livestock Production Science 41, 133–142.
Variation between Merino ewes in pasture intake. 1. Between-flock differences and some environmental sources of variation.CrossRef | open url image1

Lee MRF, Jones EL, Moorby JM, Humphreys MO, Theodorou MK, MacRae JC, Scollan ND (2001) Production responses from lambs grazed on Lolium perenne selected for an elevated water soluble carbohydrate content. Animal Research 50, 441–449.
Production responses from lambs grazed on Lolium perenne selected for an elevated water soluble carbohydrate content.CrossRef | 1:CAS:528:DC%2BD38XitVGnsbc%3D&md5=0af4ec0c957e19f65ecf3a48b073126fCAS | open url image1

Lee MRF, Theobald VJ, Tweed JKS, Winters AL, Scollan ND (2009) Effect of feeding fresh or conditioned red clover on milk fatty acids and nitrogen utilization in lactating dairy cows. Journal of Dairy Science 92, 1136–1147.
Effect of feeding fresh or conditioned red clover on milk fatty acids and nitrogen utilization in lactating dairy cows.CrossRef | 1:CAS:528:DC%2BD1MXivVaktb0%3D&md5=3b17d46212e5eacfa459309bb3334ca5CAS | 19233806PubMed | open url image1

Lee SJ, Nuberg IK, Pitchford WS (2010) Interdisciplinary research raises concerns about selection for production on energy reserves in beef cows. In ‘Ninth world congress on genetics applied to livestock production’. p. 30.

Leng RA (2008) Report to Department of Climate Change, Commonwealth Government, Canberra. Available at http://www.penambulbooks.com/Downloads/Leng-Final%20Modified%20%2017-9-2008.pdf [Verified 4 August 2010]

Le Thi Ngoc Huyen, Ho Quang Do, Preston TR, Leng RA (2010) Nitrate as fermentable nitrogen supplement to reduce rumen methane production. Livestock Research for Rural Development 22(8). Available at http://www.lrrd.org/lrrd22/8/huye22146.htm [Verified 7 April 2011]

Le Van TD, Robinson JA, Ralph J, Greening RC, Smolenski WJ, Leedle JAZ, Schaeffer DM (1998) Assessment of reductive acetogenesis with indigenous ruminal bacterium populations and Acetitomaculum ruminis. Applied and Environmental Microbiology 64, 3429–3436.

Loh Z, Chen D, Bai M, Naylor T, Griffith D, Hill J (2008) Measurement of greenhouse gas emissions from Australian feedlot beef production using open-path spectroscopy and atmospheric dispersion modelling. Australian Journal of Experimental Agriculture 48, 244–247.
Measurement of greenhouse gas emissions from Australian feedlot beef production using open-path spectroscopy and atmospheric dispersion modelling.CrossRef | 1:CAS:528:DC%2BD1cXovVOl&md5=77307a69b6eb3c9ace7716e0d121a195CAS | open url image1

Lovett DK, Bortolozzo A, Conaghan P, O’Kiely P, O’Mara FP (2004) In vitro total and methane gas production as influenced by rate of nitrogen application, season of harvest and perennial ryegrass cultivar. Grass and Forage Science 59, 227–232.
In vitro total and methane gas production as influenced by rate of nitrogen application, season of harvest and perennial ryegrass cultivar.CrossRef | 1:CAS:528:DC%2BD2cXptVensLs%3D&md5=d780ac01e4bd164d75393f989c624b7bCAS | open url image1

Machmuller A, Ossowski DA, Wanner M, Kruezer M (1998) Potential of various fatty feeds to reduce methane release from rumen fermentation in vitro (RUSITEC). Animal Feed Science and Technology 71, 117–130.
Potential of various fatty feeds to reduce methane release from rumen fermentation in vitro (RUSITEC).CrossRef | 1:CAS:528:DyaK1cXhvVSntLk%3D&md5=477eedf85584d02a3fb647f03881b692CAS | open url image1

Machmuller A, Soliva CR, Kreuzer M (2003) Methane-suppressing effect of myristic acid in sheep as affected by dietary calcium and forage proportion. The British Journal of Nutrition 90, 529–540.
Methane-suppressing effect of myristic acid in sheep as affected by dietary calcium and forage proportion.CrossRef | 13129458PubMed | open url image1

Mackie RI, Bryant MP (1994) Acetogenesis and the rumen: syntropic relationship. In ‘Acetogenesis’. (Ed. HL Drake) pp. 331–364. (Chapman and Hall: New York)

Martin SA, Macy JM (1985) Effects of monensin, pyromellitic diimide and 2-bromoethanesulfonic acid on rumen fermentation in vitro. Journal of Animal Science 60, 544–550.

Martin C, Morgavi DP, Doreau M (2010) Methane mitigation in ruminants: from microbe to the farm scale. Animal 4, 351–365.
Methane mitigation in ruminants: from microbe to the farm scale.CrossRef | 1:CAS:528:DC%2BC3cXhslWgs7k%3D&md5=c5e885b314a0864a294abae1a4cfa262CAS | open url image1

Matukumalli KL, Lawley CT, Schnabel RD, Taylor JF, Allan MF, Heaton MP, O’Connell J, Moore SS, Smith TPL, Sonstegard TS, Van Tassell CP (2009) Development and characterization of a high density SNP genotyping assay for cattle. PLoS ONE 4, e5350
Development and characterization of a high density SNP genotyping assay for cattle.CrossRef | 19390634PubMed | open url image1

Mbanzamihigo L, Demeyer DI, Van Nevel CJ (1995) Adaptation of rumen fermentation to monensin administration. Reproduction, Nutrition, Development 35, 353–365.
Adaptation of rumen fermentation to monensin administration.CrossRef | 1:CAS:528:DyaK2MXpsFGgurc%3D&md5=551feaae76714f98e34b831e3baac078CAS | 7546227PubMed | open url image1

Mbanzamihigo L, Van Nevel CJ, Demeyer DI (1996) Lasting effects of monensin on rumen and caecal fermentation in sheep fed a high grain diet. Animal Feed Science and Technology 62, 215–228.
Lasting effects of monensin on rumen and caecal fermentation in sheep fed a high grain diet.CrossRef | 1:CAS:528:DyaK28XntlSqt7s%3D&md5=7d6cf5d16cdb88aaca09193e2b5c004dCAS | open url image1

McAllister TA, Newbold CJ (2008) Redirecting rumen fermentation to reduce methanogenesis. Australian Journal of Experimental Agriculture 48, 7–13.
Redirecting rumen fermentation to reduce methanogenesis.CrossRef | 1:CAS:528:DC%2BD1cXovVKh&md5=8bc4ce758190f69a2514d2a7577303bcCAS | open url image1

McAllister TA, Mathison E, Cheng K-J (1996) Dietary, environmental and microbiological aspects of methane production in ruminants. Canadian Journal of Animal Science 76, 231–243.
Dietary, environmental and microbiological aspects of methane production in ruminants.CrossRef | 1:CAS:528:DyaK28XkslKjsrg%3D&md5=6ebfe6981c66559858d00a8e12219d44CAS | open url image1

McCaughey WP, Wittenberg K, Corrigan D (1997) Methane production by steers on pasture. Canadian Journal of Animal Science 77, 519–524.
Methane production by steers on pasture.CrossRef | open url image1

McCaughey WP, Wittenberg K, Corrigan D (1999) Impact of pasture type on methane production by lactating beef cows. Canadian Journal of Animal Science 79, 221–226.
Impact of pasture type on methane production by lactating beef cows.CrossRef | open url image1

McCrabb GJ, Berger KT, Magner T, May C, Hunter RA (1997) Inhibiting methane production in Brahman cattle by dietary supplementation with a novel compound and the effects on growth. Australian Journal of Agricultural Research 48, 323–329.
Inhibiting methane production in Brahman cattle by dietary supplementation with a novel compound and the effects on growth.CrossRef | 1:CAS:528:DyaK2sXislals7Y%3D&md5=96cb06539e499f2e21308f5b8afcd820CAS | open url image1

McGinn SM, Flesch TK, Harper LA, Beauchemin KA (2006) An approach for measuring methane emissions from whole farms. Journal of Environmental Quality 35, 14–20.
An approach for measuring methane emissions from whole farms.CrossRef | 1:CAS:528:DC%2BD28XhtFGisL8%3D&md5=27de33f09efd823f2b4c1094e3543e3aCAS | 16391273PubMed | open url image1

McGinn SM, Chen D, Loh Z, Hill J, Beauchemin KA, Denmead OT (2008) Methane emissions from feedlot cattle in Australia and Canada. Australian Journal of Experimental Agriculture 48, 183–185.
Methane emissions from feedlot cattle in Australia and Canada.CrossRef | 1:CAS:528:DC%2BD1cXovVGk&md5=0999e0aabc4e13330c939059de1c8832CAS | open url image1

Meuwissen TH, Hayes BJ, Goddard ME (2001) Prediction of total genetic value using genome-wide dense marker maps. Genetics 157, 1819–1829.

Meyer AM, Kerley MS, Kallenbach RL (2008) The effect of residual feed intake classification on forage intake by grazing beef cows. Journal of Animal Science 86, 2670–2679.

Miller TL, Wolin MJ (2001) Inhibition of growth of methane-producing bacteria of the ruminant forestomach by hydroxymethylglutary-SCoA reductase inhibitors. Journal of Dairy Science 84, 1445–1448.
Inhibition of growth of methane-producing bacteria of the ruminant forestomach by hydroxymethylglutary-SCoA reductase inhibitors.CrossRef | 1:CAS:528:DC%2BD3MXktlKgs7k%3D&md5=3d8a4fbe2fca05ccaf7b465342d577e4CAS | 11417704PubMed | open url image1

Moate PJ, Williams SRO, Grainger C, Hannah MC, Eckard RJ (2010) Comparison of cold pressed canola, brewers grains and hominy meal as dietary supplements suitable for reducing enteric methane emission from lactating cows. In ‘Proceedings of the 4th international conference on greenhouse gases and animal agriculture’. (Eds EJ McGeough, SM McGinn) p. 137.

Moe PW, Tyrell HF (1979) Methane production in dairy cows. In ‘Proceedings of the 8th symposium on energy metabolism’. Publication No. 26. (Ed. L Mount) pp. 59–62. (European Association of Animal Production)

Molano G, Clark H (2008) The effect of level of intake and forage quality on methane production by sheep. Australian Journal of Experimental Agriculture 48, 219–222.
The effect of level of intake and forage quality on methane production by sheep.CrossRef | 1:CAS:528:DC%2BD1cXovVyn&md5=01462715a4ada47f2872d2c646010fd1CAS | open url image1

Montaldo-Bermudez M, Nielsen MK, Deutscher GH (1990) Energy requirements for maintenance of crossbred beef cattle with different potential for milk. Journal of Animal Science 68, 2279–2288.

Moore S, Crews DH, Nkrumah D (2006) Multiple and candidate gene approaches to genetic evaluation of feed efficiency in beef cattle. In ‘Proceedings of the 8th world congress on genetics applied to livestock production’. (Belo Horizonte: Brazil)

Moore SS, Sherman EL, Nkrumah JD (2008) Associations of single nucleotide polymorphisms and haplotypes with feed intake and feed efficiency in beef cattle. PCT/IB2008/000558. Available at http://www.wipo.int/pctdb/en/wo.jsp?WO=2008084404 [Verified 4 April 2011]

Morgavi DP, Jouany JP, Martin C (2008) Changes in methane emission, and rumen fermentation parameters induced by refaunating sheep. Australian Journal of Experimental Agriculture 48, 69–72.
Changes in methane emission, and rumen fermentation parameters induced by refaunating sheep.CrossRef | 1:CAS:528:DC%2BD1cXovVKr&md5=6cf2d57d64870fe8703952fe4aa32ad4CAS | open url image1

Mosier AR, Duxbury JM, Freney JR, Heinemeyer O, Minami K, Johnson DE (1998) Mitigating agricultural emissions of methane. Climatic Change 40, 39–80.
Mitigating agricultural emissions of methane.CrossRef | 1:CAS:528:DyaK1cXmslWgu70%3D&md5=783e318f0ff30b4dc4604adaaf126737CAS | open url image1

Munger A, Kreuzer M (2008) Absence of persistent methane emission differences over time as found in dairy cows of three different breeds. Australian Journal of Experimental Agriculture 48, 77–82.

Murray RM, Bryant AM, Leng RA (1976) Rates of production of methane in the rumen and large intestine of sheep. The British Journal of Nutrition 36, 1–14.
Rates of production of methane in the rumen and large intestine of sheep.CrossRef | 1:CAS:528:DyaE28XkvFSqt7o%3D&md5=de8c2bcbd622e92d7234af630e2cd34fCAS | 949464PubMed | open url image1

Newbold CJ, Lassalas B, Jouany JP (1995) The importance of methanogenesis associated with ciliate protozoa in ruminal methane production in vitro. Letters in Applied Microbiology 21, 230–234.
The importance of methanogenesis associated with ciliate protozoa in ruminal methane production in vitro.CrossRef | 1:STN:280:DyaK28%2FjtVartw%3D%3D&md5=a7f20e0f0bd11f961768628603c440d2CAS | 7576513PubMed | open url image1

Nkrumah JD, Li C, Wang Z, Bartusiak R, Murdoch B, Basarab J, Crews D, Moore SS (2005a) Full genome scan of quantitative trait loci QTL for net feed efficiency in beef cattle. Journal of Animal Science 83, 13

Nkrumah JD, Li C, Yu J, Hansen C, Keisler DH, Moore SS (2005b) Polymorphisms in the bovine leptin promoter associated with serum leptin concentration, growth, feed intake, feeding behaviour, and measures of carcass merit. Journal of Animal Science 83, 20–28.

Nkrumah JD, Sherman EL, Li C, Marques E, Crews DH, Bartusiak R, Murdoch B, Wang Z, Basarab JA, Moore SS (2007) Primary genome scan to identify putative QTL for feedlot growth rate, feed intake and feed efficiency of beef cattle. Journal of Animal Science 85, 3170–3181.
Primary genome scan to identify putative QTL for feedlot growth rate, feed intake and feed efficiency of beef cattle.CrossRef | 1:CAS:528:DC%2BD2sXhtl2ru7nM&md5=e83a3071282c22bf1e664d874c0984cdCAS | 17709790PubMed | open url image1

Nolan JV, Hegarty RS, Hegarty J, Godwin IR, Woodgate R (2010) Effects of dietary nitrate on fermentation, methane production and digesta kinetics in sheep. Animal Production Science 50, 801–806.
Effects of dietary nitrate on fermentation, methane production and digesta kinetics in sheep.CrossRef | 1:CAS:528:DC%2BC3cXhtVyrtbzP&md5=68bcd673d8a99f6f140a91c6b22b058dCAS | open url image1

O’Connor EM, Shand RF (2002) Halocins and sulfolobicins: the emerging story of archaeal protein and peptide antibiotics. Journal of Industrial Microbiology & Biotechnology 28, 23–31.

Odongo NE, Or-Rashid MM, Kebreab E, France J, McBride BW (2007) Effect of supplementing myristic acid in dairy cow rations on ruminal methanogenesis and fatty acid profile in milk. Journal of Dairy Science 90, 1851–1858.
Effect of supplementing myristic acid in dairy cow rations on ruminal methanogenesis and fatty acid profile in milk.CrossRef | 1:CAS:528:DC%2BD2sXjs1ahs7Y%3D&md5=2f8cd5a0de035aeb3bcc06b64b19015dCAS | 17369226PubMed | open url image1

O’Hara P, Freney J, Ulyatt M (2003) ‘Abatement of agricultural non-carbon dioxide greenhouse gas emissions. A study of research requirements.’ (MAFF: Wellington, NZ) Available at http://www.maf.govt.nz/mafnet/rural-nz/sustainable-resource-use/climate/abatement-of-agricultural-greenhouse-gas-emissions/greenhouse-gas-emissions.pdf [Verified 24 August 2010]

Okine EK, Basarab JA, Baron V, Price MA (2001) Net feed efficiency on young growing cattle: III. Relationship to methane and manure production. Canadian Journal of Animal Science 81, 614

Okine EK, Basarab JA, Laki A, Goonewardene LA, Mir P (2004) Residual feed intake and feed efficiency: differences and implications. Florida Ruminant Nutrition Symposium. University of Florida. Available at http://dairy.ifas.ufl.edu/files/rns/2004/Okine.pdf [Verified 4 August 2010]

Ouwerkerk D, Maguire AJ, Klieve AV (2005) Reductive acetogenesis in the foregut of macropod marsupials in Australia. In ‘Publication series. Vol. 27’. (Eds CR Soliva, J Takahashi, M Kreuzer) pp. 98–101. (Institute of Animal Science, ETH: Zurich, Switzerland)

Ouwerkerk D, Maguire AJ, McMillen L, Klieve AV (2009) Hydrogen utilising bacteria from the forestomach of eastern grey (Macropus giganteus) and red (Macropus rufus) kangaroos. Animal Production Science 49, 1043–1051.
Hydrogen utilising bacteria from the forestomach of eastern grey (Macropus giganteus) and red (Macropus rufus) kangaroos.CrossRef | 1:CAS:528:DC%2BD1MXht1Gmtb%2FK&md5=30d126d480d40341aed49a936f40312fCAS | open url image1

Pelchen A, Peters KJ (1998) Methane emissions from sheep. Small Ruminant Research 27, 137–150.
Methane emissions from sheep.CrossRef | open url image1

Pelletier N, Pirog R, Rasmussen R (2010) Comparative life cycle environmental impacts of three beef production strategies in the Upper Midwestern United States. Agricultural Systems 103, 380–389.
Comparative life cycle environmental impacts of three beef production strategies in the Upper Midwestern United States.CrossRef | open url image1

Peters GM, Rowley HV, Wiedemann SG, Tucker RW, Short MD, Schulz MS (2010) Red meat production in Australia: life cycle assessment and comparison with overseas studies. Environmental Science & Technology 44, 1327–1332.
Red meat production in Australia: life cycle assessment and comparison with overseas studies.CrossRef | 1:CAS:528:DC%2BC3cXkt1agug%3D%3D&md5=4be048aa1e0e01a4479fc6c312975492CAS | 20067280PubMed | open url image1

Peyraud JL, Astigarraga L, Faverdin P (1997) Digestion of fresh perennial ryegrass fertilized at two levels of nitrogen by lactating dairy cows. Animal Feed Science and Technology 64, 155–171.
Digestion of fresh perennial ryegrass fertilized at two levels of nitrogen by lactating dairy cows.CrossRef | open url image1

Pinares-Patiño CS, Clark H (2008) Reliability of the sulfur hexafluoride tracer technique for methane emission measurement from individual animals: an overview. Australian Journal of Experimental Agriculture 48, 223–229.
Reliability of the sulfur hexafluoride tracer technique for methane emission measurement from individual animals: an overview.CrossRef | open url image1

Pinares-Patiño CS, Clark H (2009) New Zealand studies of low methane yield sheep. In ‘Livestock breeding for GHG outcomes. MAFF, PGGRC and Learn workshop, 3–5 March 2009’. (Ed. R Hegarty) (MAFF: Wellington, NZ) Available at http://www.livestockemissions.net/Publications/tabid/63/Default.aspx [Verified 8 April 2011]

Pinares-Patiño CS, Ulyatt MJ, Lassey KR, Barry TN, Holmes CW (2003a) Persistence of differences between sheep in methane emission under generous grazing conditions. The Journal of Agricultural Science 140, 227–233.
Persistence of differences between sheep in methane emission under generous grazing conditions.CrossRef | open url image1

Pinares-Patiño CS, Ulyatt MJ, Lassey KR, Barry TN, Holmes CW (2003b) Rumen function and digestion parameters associated with differences between sheep in methane emissions when fed chaffed lucerne hay. The Journal of Agricultural Science 140, 205–214.
Rumen function and digestion parameters associated with differences between sheep in methane emissions when fed chaffed lucerne hay.CrossRef | open url image1

Pinares-Patiño CS, Waghorn GC, Machmüller A, Vlaming B, Molano G, Cavanagh A, Clark H (2007) Methane emissions and digestive physiology of non-lactating dairy cows fed pasture forage. Canadian Journal of Animal Science 87, 601–613.

Pitchford W (2004) System efficiency in Australia’s sheep industry. MLA Report Project number SHGEN 117. MLA, Sydney.

Ponzoni RW (1988) The derivation of economic values combining income and expense in different ways: an example with Australian Merino sheep. Journal of Animal Breeding and Genetics 105, 143–153.
The derivation of economic values combining income and expense in different ways: an example with Australian Merino sheep.CrossRef | open url image1

Puchala R, Min BR, Goetsch AL, Sahlu T (2005) The effect of a condensed tannin-containing forage on methane emission by goats. Journal of Animal Science 83, 182–186.

Richardson EC, Herd RM (2004) Biological basis for variation in residual feed intake in beef cattle. 2. Synthesis of results following divergent selection. Australian Journal of Experimental Agriculture 44, 431–440.
Biological basis for variation in residual feed intake in beef cattle. 2. Synthesis of results following divergent selection.CrossRef | open url image1

Robinson DL, Oddy VH (2004) Genetic parameters for feed efficiency, fatness, muscle area and feeding behaviour of feedlot finished beef cattle. Livestock Production Science 90, 255–270.
Genetic parameters for feed efficiency, fatness, muscle area and feeding behaviour of feedlot finished beef cattle.CrossRef | open url image1

Rowlinson P, Steele M, Nefzaoui A (Eds) (2008) ‘Proceedings of the international conference livestock and global climate change.’ British Society of Animal Science, May 2008, Hammamet, Tunisia.

Russell JB, Mantovani HC (2002) The bacteriocins of ruminal bacteria and their potential as an alternative to antibiotics. Journal of Molecular Microbiology and Biotechnology 4, 347–355.

Rutherford WC (2010) Evaluation of residual feed intake in centrally-tested bulls and related steers. MSc Thesis. Auburn University, Auburn, AL.

Safari E, Fogarty NM, Gilmour AR, Atkins KD, Mortimer SI, Swan AA, Brien FD, Greeff JC, van der Werf JHJ (2007) Genetic correlations among and between wool, growth and reproduction traits in Merino sheep. Journal of Animal Breeding and Genetics 124, 65–72.
Genetic correlations among and between wool, growth and reproduction traits in Merino sheep.CrossRef | 1:STN:280:DC%2BD2s3nvVCrsw%3D%3D&md5=a8d3dd04ff97784be6785ef6f53a81b6CAS | 17488356PubMed | open url image1

Santoso B, Kume S, Nonaka K, Kimura K, Mizukoshi H, Gamo Y (2003) Methane emission, nutrient digestibility, energy metabolism and blood metabolites in dairy cows fed silages with and without galacto-oligosaccharides supplementation. Asian-Australasian Journal of Animal Sciences 16, 534–540.

Sar C, Mwenya B, Santoso B, Takaura K, Morikawa R, Isogai N, Asakura Y, Toride Y, Takahashi J (2005) Effect of Escherichia coli wild type or its derivative with high nitrite reductase activity on in vitro ruminal methanogenesis and nitrate/nitrite reduction. Journal of Animal Science 83, 644–652.

Schaeffer LR (2006) Strategy for applying genome-wide selection in dairy cattle. Journal of Animal Breeding and Genetics 123, 218–223.
Strategy for applying genome-wide selection in dairy cattle.CrossRef | 1:STN:280:DC%2BD28vlvFCitA%3D%3D&md5=baf38b72655ef765385a0c797a65c8a6CAS | 16882088PubMed | open url image1

Schuch R, Nelson D, Fischetti VA (2002) A bacteriolytic agent that detects and kills Bacillus anthracis. Nature 418, 884–889.
A bacteriolytic agent that detects and kills Bacillus anthracis.CrossRef | 1:CAS:528:DC%2BD38XmtlWlur4%3D&md5=000b593d65da5bc4d596edd9456e5cf0CAS | 12192412PubMed | open url image1

Seman DH, Stuedemann JA, Anderson JE (1997) Spectral analysis of bovine grazing behaviour on Neotyphodium coenophialum infested tall fescue. Applied Animal Behaviour Science 54, 73–87.

Seman DH, Stuedemann JA, Hill NS (1999) Behaviour of steers grazing monocultures and binary mixtures of alfalfa and tall fescue. Journal of Animal Science 77, 1402–1411.

Sherman EL, Nkrumah JD, Bartusiak C, Murdoch BM, Moore SS (2008a) Fine mapping quantitative trait loci QTL for feed intake and feed efficiency in beef cattle. Journal of Animal Science 87, 37–45.
Fine mapping quantitative trait loci QTL for feed intake and feed efficiency in beef cattle.CrossRef | 18791150PubMed | open url image1

Sherman EL, Nkrumah JD, Murdoch BM, Moore SS (2008b) Identification of polymorphisms influencing feed intake and efficiency in beef cattle. Animal Genetics 39, 225–231.
Identification of polymorphisms influencing feed intake and efficiency in beef cattle.CrossRef | 1:CAS:528:DC%2BD1cXnslGrtbg%3D&md5=f68a78cf55fa7db93031b8cbae002beaCAS | 18318789PubMed | open url image1

Sherman EL, Nkrumah JD, Murdoch BM, Li C, Wang Z, Fu A, Moore SS (2008c) Polymorphisms and haplotypes in the bovine NPY, GHR, GHRL, IGF2, UCP2 and UCP3 genes and their associations with measures of growth, performance, feed efficiency and carcass merit in beef cattle. Journal of Animal Science 86, 1–16.
Polymorphisms and haplotypes in the bovine NPY, GHR, GHRL, IGF2, UCP2 and UCP3 genes and their associations with measures of growth, performance, feed efficiency and carcass merit in beef cattle.CrossRef | 1:CAS:528:DC%2BD2sXhsVOru7rI&md5=aa61bc25274fe2a4c19c415c0e4e5c69CAS | 17785604PubMed | open url image1

Shibata M, Terada T (2010) Factors affecting methane production and mitigation in ruminants. Animal Science Journal 81, 2–10.
Factors affecting methane production and mitigation in ruminants.CrossRef | 1:CAS:528:DC%2BC3cXjsFeku7k%3D&md5=a2ba7c68c2cd422ca14666e144ed4594CAS | 20163666PubMed | open url image1

Slyter LL (1979) Monensin and dichloroacetamide influences on methane and volatile fatty acid production by rumen bacteria in vitro. Applied and Environmental Microbiology 37, 283–288.

Smith P, Martino D, Cai Z, Gwary D, Janzen H, Kumar P, McCarl B, Ogle S, O’Mara F, Rice C, Scholes B, Sirotenko O (2007) Agriculture. In ‘Climate Change, 2007, Mitigation’. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. (Eds B Metz, OR Davidson, PR Bosch, R Dave, LA Meyer) pp. 499–540. (Cambridge University Press: Cambridge)

Snelling W, Rolfe K Nielsen M, Freetly H, Ferrell C, Jenkins T (2010) Genetic and phenotypic parameter estimates for feed intake and other traits in growing beef cattle. In ‘Ninth world congress on genetics applied to livestock production’. p. 84.

Soliva CR, Hindrichsen IK, Meile L, Kreuzer M, Machmüller A (2003) Effects of mixtures of lauric and myristic acid on rumen methanogens and methanogenesis in vitro. Microbiology 37, 35–39.

Stumm CK, Gijzen HJ, Vogels GD (1982) Association of methanogenic bacteria with ovine rumen ciliates. The British Journal of Nutrition 47, 95–99.
Association of methanogenic bacteria with ovine rumen ciliates.CrossRef | 1:STN:280:DyaL387jsFCmsw%3D%3D&md5=c5aec8251b7794fd579d992d70c0429bCAS | 6800402PubMed | open url image1

Tavendale MH, Meagher LP, Pacheco D, Walker N, Attwood GT, Sivakumaran S (2005) Methane production from in vitro rumen incubations with Lotus pedunculatus and Medicago sativa, and effects of extractable condensed tannin fractions on methanogenesis. Animal Feed Science and Technology 123–124, 403–419.
Methane production from in vitro rumen incubations with Lotus pedunculatus and Medicago sativa, and effects of extractable condensed tannin fractions on methanogenesis.CrossRef | open url image1

Tavendale MH, Jayanegara A, Togtokhbayar N, Makkar HPS, Becker K (2009) Tannins determined by various methods as predictors of methane production reduction potential of plants by an in vitro rumen fermentation system. Animal Feed Science and Technology 150, 230–237.
Tannins determined by various methods as predictors of methane production reduction potential of plants by an in vitro rumen fermentation system.CrossRef | open url image1

Teather RM, Forster RJ (1998) Manipulating the rumen microflora with bacteriocins to improve ruminant production. Canadian Journal of Animal Science 78, 57–69.

Thompson JM, Barlow R (1986) The relationship between feeding and growth parameters and biological efficiency in cattle and sheep. In ‘Proceedings of the 3rd world congress on applied livestock production’. (Eds G Dickerson, R Johnson) pp. 271–282. (University of Nebraska: Lincoln, Nebraska)

Tiemann TT, Lascano CE, Wettstein H -R, Mayer AC, Kreuzer M, Hess HD (2008) Effect of the tropical tannin-rich shrub legumes Calliandra calothyrsus and Flemingia macrophylla on methane emission and nitrogen and energy balance in growing lambs. Animal 2, 790–799.
Effect of the tropical tannin-rich shrub legumes Calliandra calothyrsus and Flemingia macrophylla on methane emission and nitrogen and energy balance in growing lambs.CrossRef | 1:CAS:528:DC%2BD1MXhvFertbs%3D&md5=aced468832e80cca9706eb0577f1e532CAS | open url image1

Uden P, Colucci PE, Van Soest PJ (2006) Investigation of chromium, cerium and cobalt as markers in digesta. Rate of passage studies. Journal of the Science of Food and Agriculture 31, 625–632.
Investigation of chromium, cerium and cobalt as markers in digesta. Rate of passage studies.CrossRef | open url image1

Ulyatt MJ, Baker SK, McCrabb GJ, Lassey KR (1999) Accuracy of the SF6 tracer technology and alternatives for field measurements. Australian Journal of Agricultural Research 50, 1329–1334.
Accuracy of the SF6 tracer technology and alternatives for field measurements.CrossRef | open url image1

Ungerfeld EM, Kohn RA (2006) The role of thermodynamics in the control of ruminal fermentation. In ‘Ruminant physiology: digestion, metabolism and impact of nutrition on gene expression, immunology and stress’. (Eds K Sejrsen, T Hvelplund, MO Nielsen) pp. 55–64. (Wageningen Academic Publishers: Wageningen, The Netherlands)

United Nations Framework Convention on Climate Change (2009) ‘National reports.’ Available at http://unfccc.int/national_reports/items/1408.php [Verified 5 April 2011]

Ushida K, Jouany JP (1996) Methane production associated with rumen-ciliated protozoa and its effect on protozoan activity. Letters in Applied Microbiology 23, 129–132.
Methane production associated with rumen-ciliated protozoa and its effect on protozoan activity.CrossRef | 1:CAS:528:DyaK28XlsFSks7s%3D&md5=30f0663d7f06f8618efd235dbfff36e7CAS | 8987455PubMed | open url image1

van der Werf JHJ (2009) Potential benefit of genomic selection in sheep. Proceedings of the Association for Advances in Animal Breeding and Genetics 22, 38–41.

van der Westhuizen RR, van der Westhuizen J, Schoeman SJ (2004) Genetic variance components for residual feed intake and feed conversion ratio and their correlations with other production traits in beef bulls. South African Journal of Animal Science 34, 257–264.

van Nevel CJ, Demeyer DI (1977) Effect of monensin on rumen metabolism in vitro. Applied and Environmental Microbiology 34, 251–257.

van Nevel CJ, Demeyer DI (1996) Control of rumen methanogenesis. Environmental Monitoring and Assessment 42, 73–97.
Control of rumen methanogenesis.CrossRef | 1:CAS:528:DyaK28Xltlars7w%3D&md5=27deea4d63594241345f9dfea7d0ac62CAS | open url image1

van Zijderveld SM, Dijkstra J, Gerrits WJJ, Newbold JR, Perdok HB (2010a) Dietary nitrate persistently reduces enteric methane production in lactating dairy cows. Greenhouse Gases and Animal Agriculture Conference, Banff, Canada, 3–8 October 2010.

van Zijderveld SM, Gerrits WJ, Apajalahti JA, Newbold JR, Dijkstra J, Leng RA, Perdok HB (2010b) Nitrate and sulfate: Effective alternative hydrogen sinks for mitigation of ruminal methane production in sheep. Journal of Diary Science 93, 5856–5866.

Vercoe P (2009) Greenhouse gas abatement and feed efficiency. Available at http://www.sheepcrc.org.au/research/sheep-and-their-management/greenhouse-gas-abatement.php [Verified 20 June 2010]

Vlaming JB, Lopez-Villalobos N, Brookes IM, Hoskin SO, Clark H (2008) Within- and between-animal variance in methane emissions in non-lactating dairy cows. Australian Journal of Experimental Agriculture 48, 124–127.
Within- and between-animal variance in methane emissions in non-lactating dairy cows.CrossRef | 1:CAS:528:DC%2BD1cXovV2r&md5=64a59d375a4c21b22ec97d711562e449CAS | open url image1

Vogels GD, Hoppe WF, Stumm CK (1980) Association of methanogenic bacteria with rumen ciliates. Environmental Microbiology 40, 608–612.

von Engelhardt W, Wolte S, Lawrenz H, Hemsley JA (1978) Production of methane in two non-ruminant herbivores. Comparative Biochemistry and Physiology. A. Comparative Physiology 60, 309–311.
Production of methane in two non-ruminant herbivores.CrossRef | open url image1

Waghorn GC, McNabb WC (2003) Consequences of plant phenolic compounds for productivity and health of ruminants. The Proceedings of the Nutrition Society 62, 383–392.
Consequences of plant phenolic compounds for productivity and health of ruminants.CrossRef | 1:CAS:528:DC%2BD3sXmt1Gmu7Y%3D&md5=d389448533c78ae588232e70887629c5CAS | 14506885PubMed | open url image1

Waghorn GC, Woodward SL, Tavendale M, Clark DA (2006) Inconsistencies in rumen methane production – effects of forage composition and animal genotype. International Congress Series 1293, 115–118.
Inconsistencies in rumen methane production – effects of forage composition and animal genotype.CrossRef | 1:CAS:528:DC%2BD1cXhs1amsbs%3D&md5=91b19f9897a8baeba39d9a0984dc6ab1CAS | open url image1

Waghorn GC, Clark H, Taufa V, Cavanagh A (2008) Monensin controlled-release capsules for methane mitigation in pasture-fed dairy cows. Australian Journal of Experimental Agriculture 48, 65–68.
Monensin controlled-release capsules for methane mitigation in pasture-fed dairy cows.CrossRef | 1:CAS:528:DC%2BD1cXovFSn&md5=1fb74a0555fa5a1dddd66e6a695e1a96CAS | open url image1

Wall E, Simm G, Moran D (2010) Developing breeding schemes to assist mitigation of greenhouse gas emissions. Animal 4, 366–376.
Developing breeding schemes to assist mitigation of greenhouse gas emissions.CrossRef | open url image1

Whitelaw FG, Eadie JM, Bruce LA, Shand WJ (1984) Methane formation in faunated and ciliate-free cattle and its relationship with rumen volatile fatty acid proportions. The British Journal of Nutrition 52, 261–275.
Methane formation in faunated and ciliate-free cattle and its relationship with rumen volatile fatty acid proportions.CrossRef | 1:CAS:528:DyaL2cXlsFSmsr8%3D&md5=c16f1af2b72fb6338eda2eb16878a1bdCAS | 6433970PubMed | open url image1

Williams Y, Wright A (2005) Variation in methane output between sheep. In ‘Abstracts greenhouse, 2005, Action on climate change, Melbourne, Victoria, 13–17 November, 2005’. p. 110. (CSIRO)

Williams YJS, Popovski RSM, Skillman LC, Toovey AF, Northwood KS, Wright AG (2009) A vaccine against rumen methanogens can alter the composition of archaeal populations. Applied and Environmental Microbiology 75, 1860–1866.
A vaccine against rumen methanogens can alter the composition of archaeal populations.CrossRef | 1:CAS:528:DC%2BD1MXksFWlsb0%3D&md5=b11eee25e756d4e448ea0e1277e9c9c7CAS | 19201957PubMed | open url image1

Wilson GR, Edwards MJ (2008) Native wildlife on rangelands to minimize methane and produce lower-emission meat: kangaroos versus livestock. Conservation Letters 2008, 1–10.

Wilson S, Dobos RC, Fell LR (2005) Spectral analysis of feeding and lying behaviour of cattle kept under different feedlot conditions. Journal of Applied Animal Welfare Science 8, 13–24.
Spectral analysis of feeding and lying behaviour of cattle kept under different feedlot conditions.CrossRef | 1:CAS:528:DC%2BD2MXntVOqsb8%3D&md5=457c1e3efa65821b711f5b5e715431e3CAS | 16004542PubMed | open url image1

Wood BJ, Archer JA, van der Werf JHF (2004) Response to selection in beef cattle using IGF-1 as a selection criterion for residual feed intake under different Australian breeding objectives. Livestock Production Science 91, 69–81.
Response to selection in beef cattle using IGF-1 as a selection criterion for residual feed intake under different Australian breeding objectives.CrossRef | open url image1

Wright A-DG, Kennedy P, O’Neill CJ, Toovey AF, Popovski S, Rea SM, Pimma CL, Kleina L (2004) Reducing methane emissions in sheep by immunization against rumen methanogens. Vaccine 22, 3976–3985.
Reducing methane emissions in sheep by immunization against rumen methanogens.CrossRef | 1:CAS:528:DC%2BD2cXnsFGns7s%3D&md5=c8dd5cc589e0411adb39bfd0e3f76768CAS | 15364447PubMed | open url image1

Yoong P, Schuch R, Nelson D, Fischetti VA (2004) Identification of a broadly active phage lytic enzyme with lethal activity against antibiotic-resistant Enterococcus faecalis and Enterococcus faecium. Journal of Bacteriology 186, 4808–4812.
Identification of a broadly active phage lytic enzyme with lethal activity against antibiotic-resistant Enterococcus faecalis and Enterococcus faecium.CrossRef | 1:CAS:528:DC%2BD2cXmtVemsbk%3D&md5=f6e74f09af9e47d56138fb5b1038a74aCAS | 15231813PubMed | open url image1



Export Citation