ARS | Publication request: Impacts of flavanoid monomers and simple hydrolyzable tannins on ammonia emissions from dairy manure

Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: December 20, 2012
Publication Date: N/A

Technical Abstract: Inhibition of ammonia production in manure provides for a healthier environment for dairy farmers working in confined quarters. The resulting conservation of urea provides for an enhanced nitrogen concentration, and thus, fertilizing capacity, of the manure. The use of a mixture of tannins from quebracho (condensed) and chestnut (hydrolyzable) trees has been shown to reduce ammonia production in manure during simulated barn floor experiments. In an effort to determine the types of tannin structures responsible for this ammonia abatement activity, we examined a series of commercially available flavanoid monomers and hydrolyzable tannins for urease inhibition/ammonia abatement activity. In vitro IC50 determinations of these compounds against Jack bean urease showed that urease inhibitory activity follows epigallocatechin gallate > tannic acid > quercitin > pentagalloglucose > catechin. In ammonia emissions chambers, epigallocatechin gallate, at 0.28 and 0.56% by weight, afforded 50% and 76% reduction of ammonia emissions, respectively, from manure samples over a 48-h period.