Beauchemin, K.A., McGinn, S.M., Benchaar, C. and Holtshausen, L. (2009) Crushed sunflower, flax, or
canola seeds in lactating dairy cows diets: effects on methane production, rumen fermentation, and
milk production. Journal of Dairy Science 92, 2118-2127.
Bergen, W.G. and Bates, D.B. (1984) Ionophores: their effect on production efficiency and mode of action.
Journal of Animal Science 58, 1465-1483.
Biello, D. (2011) Another Inconvenient Truth: The World's Growing Population Poses a Malthusian Dilemma.
Available at: http://www.scientificamerican.com/article.cfm?id=growing-population-poses-malthusian-dilemma
(accessed 9 September 2013).
Bird, S.H. and Leng, R.A. (1978) The effects of defaunation of the rumen on the growth rates of cattle on
low protein high energy diets. British Journal of Nutrition 40, 163-167.
Bird, S.H. and Leng, R.A. (1983) The influence of the absence of rumen protozoa on ruminant production.
In: Farrel, D.J. and Vohra, P. (eds) Recent Advances in Animal Nutrition in Australia . UNE Publishing
Unit, Armidale, Australia, pp. 110-118.
Bird, S.H. and Leng, R.A. (1984) Further studies on the effects of the presence or absence of protozoa in
the rumen on live-weight gain and wool growth of sheep. British Journal of Nutrition 52, 607-611.
Bird, S.H., Hill, M.K. and Leng, R.A. (1979) The effects of defaunation of the rumen on the growth of lambs
on low-protein-high-energy diets. British Journal of Nutrition 42, 81-87.
Bird, S.H., Romulo, B. and Leng, R.A. (1994) Effects of lucerne supplementation and defaunation on feed
intake, digestibility, N retention and productivity of sheep fed straw based diets. Animal Feed Science
and Technology 45, 119-129.
Brulc, J.M., Antonopoulos, D.A., Berg Miller, M.E., Wilson, M.K., Yannarell, A.C., Dinsdale, E.A., Edwards, R.E.,
Frank, E.D., Emerson, J.B., Wacklin, P., Coutinho, P.M., Henrissat, B., Nelson, K.E. and White, B.A.
(2009) Gene-centric metagenomics of the fiber-adherent bovine rumen microbiome reveals forage
specific glycoside hydrolases. Proceedings of the National Academy of Sciences USA 106,
Burt, S. (2004) Essential oils: their antibacterial properties and potential applications in food - a review.
International Journal of Food Microbiology 94, 223-253.
Calsamiglia, S., Busquet, M., Cardozo, P.W., Castillejos, L. and Ferret, A. (2007) Invited review: Essential
oils as modifiers of rumen microbial fermentation. Journal of Dairy Science 90, 2580-2595.
Carulla, J.E., Kreuzer, M., Machmüller, A. and Hess, H.D. (2005) Supplementation of Acacia mearnsii tan-
nins decreases methanogenesis and urinary nitrogen in forage-fed sheep. Australian Journal of
Agricultural Research 56, 961-970.
Coleman, G.S. (1975) The interrelationship between rumen ciliate protozoa and bacteria. In: McDonald, I.W.
and Warner, A.C.I. (eds) Digestion and Metabolism in the Ruminant . University of New England
Publishing Unit, Armidale, Australia, pp. 149-164.
Czerkawski, J.W., Blaxter, K.W. and Wainman, F.W. (1966) The metabolism of oleic, linoleic and linolenic
acids by sheep with reference to their effects on methane production. British Journal of Nutrition 20,
De Oliveira, S.G., Berchielli, T.T., Pedreira, M.D., Primavesi, O., Frighetto, R. and Lima, M.A. (2007) Effect
of tannin levels in sorghum silage and concentrate supplementation on apparent digestibility and
methane emission in beef cattle. Animal Feed Science and Technology 135, 236-248.
Dehority, B.A. (1978) Specificity of rumen ciliate protozoa in cattle and sheep. Journal of Protozoology 25,
Dehority, B.A. (1993) The rumen protozoa. In: Kreier, J.P. and Baker, J.R. (eds) Parasitic Protozoa . Academic
Denman, S.E., Tomkins, N.W. and McSweeney, C.S. (2007) Quantitation and diversity analysis of ruminal
methanogenic populations in response to the antimethanogenic compound bromochloromethane.
FEMS Microbiology Ecology 62, 313-322.
Dohme, F., Machmülller, A., Wasserfallen, A. and 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, 473-482.
Dohme, F., Machmüller, A., Wasserfallen, A. and Kreuzer, M (2001) Ruminal methanogenesis as influ-
enced by individual fatty acids. Letters in Applied Microbiol ogy 32, 47-51.
Eadie, J.M. (1962) The development of rumen microbial populations in lambs and calves under various
conditions of management. Journal of General Microbiology 29, 563-578.
Environmental Protection Agency (2010) Inventory of US greenhouse gas emissions and sinks: 1990-2008.
EPA 430-R-10-006, Washington, DC.