A.O.A.C. 1990. Official methods of analysis (14th Ed.). Association of official analytical chemists. Washington, D.C.
Birkelo, C. P., D. E. Johnson, and G. M. Ward. 1986. Net energy value of ammoniated wheat straw. J. Anim. Sci. 63:2044-2052.
Blaxter, K. L. and J. L. Clapperton. 1965. Prediction of the amount of methane produced by ruminants. Br. J. Nutr. 19:511-522.
Bonhomme, A. 1990. Rumen ciliates: their metabolism and relationships with bacteria and their hosts. Anim. Feed Sci. Technol. 30:203-266.
Crutzen, D. J. and W. Seiler. 1986. Methane production by domestic animals, wild ruminants, other herbivorous fauna, and humans. Tellus. 38B:271-284.
Crutzen, P. J. 1995. The role of methane in atmospheric chemistry and climate. In : Ruminant physiology: digestion, metabolism, growth and reproduction. (Ed. W. V. Engelhardt, et al.) Ferdinand Erke Verlag. pp. 291-314
Czerkawski, J. W., K. L. Blaxter and F. W. Wainman. 1966. The metabolism of oleic, linoleic, and linolenic acids by sheep with reference to there on methane production. Br. J. Nutr. 20:349-362.
Demeyer, D. I., C. J. VanNevel. 1975. Methanogenesis, an integrated part of carbohydrate fermentation, and its control. In Digestion and Metabolism in the ruminant (Ed. I. W. Mcdonald and A. C. I. Warner) The University of New England Publishing Unit. Armidale, N. S. W., Australia. pp. 366-382.
Getachew, G., M. Blummel, H. P. S. Makkar and K. Becker. 1998. In vitro gas measuring techniques for assessment of nutritional quality of feeds: a review. Anim. Feed Sci. Technol. 72:261-281.
Haaland, G. L. and H. F. Tyrrell. 1982. Effects of limestone and sodium bicarbonate buffers on rumen measurements and rate of passage in cattle. J. Anim. Sci. 55:935-942.
Herrer-Saldana, R., R. Gomez-Alarcon, M. Torabi and J. T. Huber. 1990. Influence of synchronizing protein and starch degradation in the rumen on nutrient utilization and microbial protein synthesis. J. Dairy Sci. 73:142-148.
Holter, J. B. and A. J. Young. 1992. Methane prediction in dry and lactating Holstein cows. J. Dairy. Sci. 75:2165-2175.
Kirchgessner, M. W. and H. L. Muller. 1994. Methane release from dairy cows and pigs. In: Proc. XIII. Symp. on Energy Metabolism of farm animals. (Ed. J. F. Aguilera) EAAP Publ. No. 76. CSIC, Spain. pp: 333-348
Kurihara, M., M. Shibata, T. Nishida, A. Purnomoad and F. Terada. 1997. Methane production and its dietary manipulation in ruminants. In: In rumen microbes and digestive physiology in ruminants. (Ed. R. Onodera, et al.) Japan Sci. Soc. Press. Tokyo/S. Karger, Basel.
Leng, R. A. 1991. Improving ruminant production and reducing methane emissions from ruminants by strategic supplementation. Europian patents 400-1-91-004.
McAllister, T. A., E. K. Okine, W. G. Mathison and K. J. Cheng. 1996. Dietary, environmental and microbiological aspects of methane production in ruminants. Can. J. Anim. Sci. 76:231-243.
Menke, K. H., L. Raab, A. Salewski, H. Steingass, D. Fritz and W. Schneider. 1979. The estimation of the digestibility and metabolizable energy content of ruminant feedingstuffs from the gas production when they are incubated with rumin liquor in vitro. J. Agric. Sci. Camb. 93:217-222.
Miller T. L. 1995. Ecology of methane production and hydrogen sinks in the rumen. Ruminant physilology: Digestion, Metabolism, Growth and Reproduction: Proceeding of the eight international symposium on ruminat physiology. pp. 317-331.
Moe, P. W. and H. F. Tyrrell. 1979. Methane production in dairy cows. J. Dairy Sci. 62:1583-1586.
O'Kelly, J. C. and W. G. Spiers. 1992. Effect of monensin on methane and heat productions of steers fed lucerne hay either ad libitum or at the rate of 250 g/hour. Aust. J. Agric. Res. 43:1789-1793.
Roger, W., G. Fonty, C. Andre and P. Gouet. 1992. Effects of glycerol on the growth, adhesion, and cellulolytic activity of rumen cellulolytic bacteria and anaerobic fungi. Current Microbiol. 25:197-201.
SAS. 1995. User' s guide: Statistics, Statistical analysis system. Inst. Inc. Cary, NC.
Shibata, M. 1994. Methane production in ruminants. In: $CH_4$ and $NO_2$. Global emissions and controls from rice fields and other agricultural and industrial sources. (Ed., K. Minami, et al.) NIAES, Yokendo, Tokyo, Japan pp 105-115
Shibata, M., F. Terada, K. Iwasaki, M. Kurihara and T. Nishida. 1992. Methane production in heifers, sheep and goats consuming diets of various hay-concentrate ratios. Anim. Sci. Technol. Japan. 3:1221-1227.
Tyler S. C. 1991. The global methane budget. In microbial production and consumption of green house gases: methane, nitrogen oxide, and halomethane (Ed. J. E. Roger and W. B. Whiteman) American Society of Microbiology. Washington D. C. US pp. 7-38.
Whitelaw, F. G., J. M. Eadie, L. A. Bruce and W. J. Shand. 1984. Methane formation in faunated and ciliate-free cattle and its relationship with rumen volatile fatty acid proportions. Br. J. Nutr. 52:261-275.