Hi, my name is Dr. Bob Charlie. I'm the
Forage
Products Manager with Lallemand
Animal Nutrition and I was invited here
for the Nebraska Beef Conference
to talk about the corn silage fermentation process.
Now the most important thing to understand when
trying to make high-quality corn silage,
is that the most major determinant of
the quality of the material that you
going to produce is the quality of the
material that comes in from the field.
So you really need to get that stage of
harvest right to optimize the quality of
the material that you get.
That being said, my talk was about the corn silage
fermentation process and that process is
an anaerobic process, fermentation by
definition is anaerobic, so it doesn't
start until we've got the silage into
the pit,
we've got it covered and sealed, and all
of the oxygen has been displaced or
consumed from the body of the silage.
So the quicker that we can do that, we can
achieve that, the better is because the
faster we get the fermentation started.
So the kind of factors that impact that
are obviously the speed at which you
bring the material in from the field,
the chopping length, the moisture
content, the amount of packing effort that was
put into packing the silage, and of
course the speed at which you cover it
and seal it, and it should be covered
and sealed effectively, efficiently in
order to maximize the speed at which
we get that anaerobic conditions.
So now we've got the anaerobic
conditions, ensiling process can begin.
And what we want to dominate, the start
of that ensiling process, is homolactic
lactic acid bacteria, because under anaerobic conditions all
they produce is lactic acid from six
carbon sugars.
So it's a very efficient process and
lactic acid is the strongest of the
fermentation acids, so we're going to
bring the pH down quickly to below the
critical control point of pH five, which is
where we knock out things like
Clostridia, E.Coli, Listeria, and also the
enzymes that the plant is secreting to
try and break the plant down and return it to the soil.
We shut all those things down as we get below pH five.
So we want to get down below that as
quickly as possible, and as I say,
producing lots and lots of lactic acid
is the key to that.
So having a homolactic domination to the fermentation.
Okay, so we've produced all our lactic acid, we've got the pH down below five quickly,
we've reached somewhere around four let's say,
and now we go into storage, and then we
get to feed out, and feed out is where
our next potential problem occurs.
Because during feed out we re-expose the silage
to oxygen and if we've got high levels
of yeasts in the silage those can then
grow and use up dry matter and burn energy
and things like that, so that we lose the
valuable nutrients that we've preserve
during the ensiling fermentation, and
the losses at this end can be
significantly higher than the
fermentation losses.
We can get twenty-five, forty,
fifty percent dry matter losses during this
feed out stage compared to maybe ten,
fifteen percent losses in the
fermentation stage.
So we need to control that, we need to keep the silage as,
as stable as possible, treat it with an
inoculant to give that stability, and
manage the feed out right so that we
don't get heating and spoilage.
