UNASSIGNED: Ruminant animals (domesticated or wild) emit @entity577 ( @entity578 ) through enteric fermentation in their digestive tract and from decomposition of manure during storage. These processes are the major sources of greenhouse gas (GHG) emissions from animal production systems. Techniques for measuring enteric @entity578 vary from direct measurements (respiration chambers, which are highly accurate, but with limited applicability) to various indirect methods (sniffers, laser technology, which are practical, but with variable accuracy). The @entity9809 (SF6)  tracer gas method is commonly used to measure enteric @entity578 production by animal scientists and more recently, application of an Automated Head-Chamber System (AHCS) (GreenFeed, C-Lock, Inc., Rapid City, SD), which is the focus of this experiment, has been growing. AHCS is an automated system to monitor @entity578 and @entity544 ( @entity3158 ) mass fluxes from the breath of ruminant animals. In a typical AHCS operation, small quantities of baiting feed are dispensed to individual animals to lure them to AHCS multiple times daily. As the animal visits AHCS, a fan system pulls air past the animal's muzzle into an intake manifold, and through an air collection pipe where continuous airflow rates are measured. A sub-sample of air is pumped out of the pipe into non-dispersive infra-red sensors for continuous measurement of @entity578 and @entity3158 concentrations. Field comparisons of AHCS to respiration chambers or SF6 have demonstrated that AHCS produces repeatable and accurate @entity578 emission results, provided that animal visits to AHCS are sufficient so emission estimates are representative of the diurnal rhythm of rumen gas production. Here, we demonstrate the use of AHCS to measure @entity3158 and @entity578 fluxes from dairy @entity291 given a control diet or a diet supplemented with technical-grade cashew nut shell liquid.

The Use of an Automated System (GreenFeed) to Monitor Enteric XXXX and @entity544 Emissions from Ruminant Animals.

@entity9809 :: ('MESH:D013459', 'Chemical') :: ['sulfur hexafluoride'] @entity3158 :: ('D002245', 'Chemical') :: ['CO2'] @entity577 :: ('MESH:D008697', 'Chemical') :: ['methane'] @entity544 :: ('MESH:D002245', 'Chemical') :: ['carbon dioxide'] @entity578 :: ('CHEBI:16183', 'Chemical') :: ['CH4'] @entity291 :: ('9913', 'Species') :: ['cows']
@entity577 :: (MESH:D008697,Chemical) :: ['Methane']
