Thursday, July 3, 2014

Tannins reduce manure odours

Researchers in Illinois have found tannins that reduce manure odours and methane gas production.

Their discovery holds promise for farmers who face complaints from neighbours about the odours their livestock and field spreading generate.

Microbiologists Terry Whitehead and Mike Cotta came upon their idea by noticing that cattle that eat tannin-rich roughages such as tree leaves have poor digestive efficiency.

They speculated that the odour-producing bacteria in manure might also be slowed down by tannins.

They went looking for the tannins that block bacteria that make hydrogen sulphide, the offensive rotten-eggs odour that’s the main culprit with livestock manure.

They found that adding their tannins reduced hydrogen sulphide by 90 per cent within seven days and that the odours continued to decline for another three weeks.

Now they’re ready to undertake large-scale testing at hog barns to determine if their quebracho tannins work as well under practical farming conditions as they have in the lab.


Whitehead and Cotta work for the United States Department of Agriculture’s Agricultural Research Service at Peoria, Illinois.