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.
