Deadstock disposal has been a hot topic in recent
years, mostly because of biosecurity concerns. Options for deadstock disposal in Ontario are currently
limited to rendering, composting and burial. Rendering is
a disposal method which now costs farmers money, rather
than providing a small source of income, as in previous
years. It is also becoming unpopular because of regulatory
restrictions.
As a result, farmers are eager to explore alternative disposal
methods for their dead livestock , especially on larger
operations where biosecurity is critical. Two methods rapidly
gaining popularity are composting and cremation.
Dr. Bill Van Heyst and graduate students Pat Linton and
Mike Thomson of the School of Engineering at the University
of Guelph have been studying the composting of deadstock,
an excellent disposal method if performed in a proper manner.
However, the emissions released during the composting
process need to be characterized to evaluate their impact
on the environment. Additionally, the nutrient availability in
the finished compost must be analyzed. The results indicate that, if best management practices
are implemented – such as the operation of a secondary
burner or after-burner at a prescribed temperature and
time – then the resulting environmental impacts are minimized.
“Upset conditions, such as frozen diesel lines, can
dramatically increase the emission of some toxic pollutants
such as dioxins and furans,” he notes.