Perhaps y'all would do well to read this

Methane production by ruminants: its contribution to global warming Moss AR, Jouany JP, Newbold J ANNALES DE ZOOTECHNIE 49 (3): 231-253 MAY-JUN 2000

Abstract: The aim of this paper is to review the role of methane in the global warming scenario and to examine the contribution to atmospheric methane made by enteric fermentation, mainly by ruminants. Agricultural emissions of methane in the EU-15 have recently been estimated at 10.2 million tonnes per year and represent the greatest source. Of these, approximately two-thirds come from enteric fermentation and one-third from livestock manure. Fermentation of feeds in the rumen is the largest source of methane from enteric fermentation and this paper considers in detail the reasons for, and the consequences of, the fact that the molar percentage of the different volatile fatty acids produced during fermentation influences the production of methane in the rumen. Acetate and butyrate promote methane production while propionate formation can be considered as a competitive pathway for hydrogen use in the rumen. The many alternative approaches to reducing methane are considered, both in terms of reduction per animal and reduction per unit of animal product. It was concluded that the most promising areas for future research for reducing methanogenesis are the development of new products/delivery systems for anti-methanogenic compounds or alternative electron accepters in the rumen and reduction in protozoal numbers in the rumen. It is also stressed that the reason ruminants are so important to mankind is that much of the world's biomass is rich in fibre. They can convert this into high quality protein sources (i.e. meat and milk) for human consumption and this will need to be balanced against the concomitant production of methane. Author Keywords: methane, ruminants, global warning, reduction strategies

Identification of gases responsible for the odour of human flatus and evaluation of a device purported to reduce this odour Suarez FL, Springfield J, Levitt MD GUT 43 (1): 100-104 JUL 1998

Abstract: Background/Aims-While the social significance of flatus derives mainly from its odour, previous studies have focused on the non-odoriferous components of rectal gas. The aims of the present study were to determine the role of sulphur-containing gases in flatus odour and test the efficacy produced of a device purported to reduce this odour. Methods-Flatus was quantitatively col-methyl dis lected via rectal tube from 16 healthy subjects who ingested pinto beans and lactulose to enhance flatus output. The concentrations of sulphur-containing gases in each passage were correlated with odour intensity assessed by two judges. Odour intensity was also determined after treatment of flatus samples with zinc acetate, which binds sulphydryl compounds (hydrogen sulphide and methanethiol), or activated charcoal. Utilising gastight Mylar pantaloons, the ability of a charcoal lined cushion to adsorb sulphur-containing gases instilled at the anus of eight subjects was assessed. Results-The main sulphur-containing flatus component was hydrogen sulphide (1.06 (0.2) mu mol/l), followed by methanethiol (0.21 (0.04) mu mol/l) and dimethyl sulphide (0.08 (0.01) mu mol/l) (means (SEM)). Malodour significantly correlated with hydrogen sulphide concentration (p less than or equal to 0.001). Zinc acetate reduced sulphur gas content but did not totally eliminate odour, while activated charcoal removed virtually all odour. The cushion adsorbed more than 90% of the sulphur gases. Conclusion-Sulphur-containing gases are the major, but not the only, malodorous components of human flatus. The charcoal lined cushion effectively limits the escape of these sulphur-containing gases into the environment.