- All right, looks like
the signal is on, that we
are being recorded so welcome
to the Rancher's Thursday
Lunchtime Series.
My name is Brian Freking.
I'm servin' as your moderator today.
So, we're glad to have several of you back
and we've got a good program today
so it's my honor to
introduce our speaker today.
Dr. Wayne Coblentz is a
Research Dairy Scientist
with USDA ARS Dairy Research Center
in Marshfield, Wisconsin.
Dr. Coblentz received his
MS degree in Dairy Science
at Penn State and did his PhD work
at Kansas State University
in Forage Physiology.
Dr. Coblentz also has
some skin in the game
with a family dairy business
of approximately 500
cow dairy operation operated
by two of this brothers
in Middleton, Maryland, I believe.
He also has been an Adjunct Professor
of Animal Science from the
University of Arkansas,
so he is familiar with
our part of the country.
And so, with that kind of introduction
I'll just do some housekeeping real quick.
If you do have questions along the way,
make sure you either put
it in the Q&A session
or in the chat room, either one,
and we'll look at those and try
and answer those questions.
But, we wanna welcome Dr. Wayne Coblentz
to the program and the
screen is yours, Wayne.
- [Dr. Coblentz] Thank
you very much, it's great
to be with you today
under these somewhat unusual circumstances
that we're operating in these days.
But, I really appreciate the opportunity
to speak with you.
When I was both in
Kansas and on the faculty
at the University of Arkansas
I had occasional need
to wander into Oklahoma, so
I'm not totally unfamiliar
with Oklahoma, but I do again, appreciate
the opportunity to be with you.
We have done a lot of
work with baled silages
here in central Wisconsin
at the Marshfield unit
at the Dairy Forage Research Center.
It is particularly appropriate here,
in that there are a lot of
smaller farmin' operations
throughout the central part of the state
and is particularly well
suited for many of those,
either small dairies or beef operations.
So with that we'll to
ahead and get started here.
Okay.
- [Brian] The first a noise,
hesitates, Dr. Coblentz,
and then should be good after that.
- [Dr. Coblentz] Okay, here we go.
First question we need to answer,
probably would be
interested in, is why choose
baled silage over dry hay?
And there are a number of
reasons why this is attractive.
Some of them may be more appropriate
in central Wisconsin than
they might be in Oklahoma
where you've got a little better
drying weather, typically.
But, well-made baled
silage will often exhibit
better quality characteristics
than corresponding hays,
and there's some reasons
for that; reduced risk
and exposure to rain damage, which is
particularly relevant up here
where we have less drying units,
less leaf loss, particularly
if you're dealing
with legumes which I think is the topic
of this discussion or the
focus of this discussion.
You have improved opportunities
for harvesting forages
at the most desirable growth stage
because weather is less
of a risk or a problem.
There is little or no spontaneous heating
in these bales after they're
wrapped with plastic.
And there's no weathering, you have
virtually unlimited outdoor storage,
but that plastic must be maintained
which we'll talk about as we go along.
To further supplement this, the advantages
of baled silage over
hay, this is some work
that one of my students actually did
at the University of
Arkansas, Dean Scarbrough,
who's at Northwest Oklahoma
State University now
as a professor there.
But anyway, these were
orchard grass forages.
This was regrowth, so
they were all vegetative,
second cutting, and we
subjected these forages
to simulated rainfall in
13 millimeter increments,
which is a half an inch, so
if you look at this graph
on the X axis those are
half inch increments
across there from left to right.
And then we measured the dry matter loss
associated with those rainfall increments.
And Dean did this project
at three different moisture levels.
In other words, the forages were collected
and rained on at different
levels of moisture.
One of them was at 67%,
which is essentially
right behind a mower at that time of year
and that's represented by the green bars.
One was at 15%, which is ideal for baling
and one was excessively
dry, about 4% moisture.
What you'll notice very quickly is
that if you've got a
significant amount of rainfall
that in these relatively
highly sugared grasses
you have a lotta potential
for dry matter loss
when that material is dry enough to bale
or excessively dry and they can't exceed
10% of the total dry
matter as measured here.
What's also quite interesting
is that when it's wet
the damage is relatively minor,
never in this case exceeding
2% of the dry matter.
So, the potential for
damage to your hay crop
increases fairly dramatically the drier
that material gets and the closer it gets
to suitability for baling as dry hay.
Another project that kinda illustrates
some of the same kinds of things,
done by Dennis Hancock, who
as a curious twist of fate,
is now my boss, but he did
this as his graduate project
at the University of
Kentucky with Mike Collins
and in this project they did two trials
which are separated by
that vertical red line
in the center of your slide.
Trial one on the left,
they put up Alfalfa silage,
Alfalfa as both silage and hay
and they measured the quality,
both on a pre-storage
and post-storage basis.
And if you'll notice on the left,
the silage there's not a lotta difference
in NDF, and I trust everybody
here knows what NDF is,
that's the structural fiber in the plant,
as a function of fermentation,
very little change.
However, on the right with hay
you had a significant amount
of spontaneous heating in
those large hay packages
and what that does is it oxidizes sugars
and other things that
are highly digestible
within that plant and as a result
you wind up with much
greater concentration of NDF.
Now, you're not actually making more NDF,
but what you're doin' is burning up
the most desirable parts of the plant
from a nutritional standpoint.
The trial on the right, it
was a little bit different.
The Alfalfa was mowed and baled and siled,
which is represented there
on the left hand side
of trial two, and you can see again,
there's very little change in NDF
as a function of fermentation.
On the right, with hay,
you have two problems.
One of them is that it
rained between the time
they baled the silage
and they baled the hay
and you see an increase in
NDF as a result of that.
And in addition, there was a modest amount
of spontaneous heating that occurred
in the large hay packages, so you got
another bump in NDF as a result of that.
So, you can see that silage offers
some advantages in terms
of preserving the quality
of these forages.
Regardless of silo type,
most management principles
are the same.
And the first one is you need to start
with high quality forage,
or at least a forage
that's suitable for
whatever class of livestock
you intend to feed.
So, buying really expensive equipment
is not gonna substitute for or improve
a really poor quality forage.
Ideally, the goal in any
silage fermentation is
to establish a stable silage mass
by lowering the pH,
that's just creating acid,
and then maintaining anaerobic conditions.
Now, I've underlined
maintaining anerobic conditions
because there are some things that are
somewhat different about baled silages
compared to traditional
precision chop silages,
and we're gonna talk about those
as we go along here.
Our goal is essentially
to take plant sugars
and have them converted to lactic acid
by bacteria that are adhered to that plant
at the time it is ensiled.
And while the fermentation
process, obviously,
is considerably more complicated
in terms of producing lactic acid,
which is the strongest acid produced
and that's why it's important and favored.
There're two pathways.
One is a homofermentative pathway,
and if you look at the products
of that pathway it's primarily acetate,
which is what we're lookin' for.
The other possibility
is heterofermentatives
which is multiple pathways and you see
you get a whole host of
less desirable products
as a result of that.
However, it is important to note,
some of you may have heard
of the inoculant, Bukner I,
and that is a heterofermentative
type of product
and the reason that improves bunk life is
it does produce some acetate, which is
a strong antimicrobial property.
So, all heterofermentative fermentations
are not bad, necessarily.
There're a couple primary factors
that effect fermentation
that I wanna mention to you
and the two of them are the concentration
of water soluble carbohydrates, or sugars,
in the plant, and the other
is the buffering capacity
of that plant.
If you look at the fermentable sugars
or water soluble carbohydrates,
these are generally simple sugars.
Sources of variation are pretty wide.
There's a lotta things that can effect
the pool of sugars
available for fermentation,
includes the species of the plant,
cultivar within species, stage of growth,
time of day, climate,
drought, frost events.
Up here that's a
relatively significant one.
You'll see a big increase in sugar content
as a result of frost
events in a lotta cases.
Nitrogen fertilization
rate will actually depress
sugar content in plants.
Rain damage will leech
sugars out of plants.
Poor and extending wilting conditions
will reduce the sugar content in a plant
and there's a whole host
of management variables
that also can effect the sugar content
within these plants.
If you look at a comparative slide
of various forage classes,
need to give credit here
to the folks at the University of Florida.
This is their table.
I wanna make sure they're noted for that.
You'll note that corn
silage has a relatively high
concentration of sugar,
10% to 20%, typically.
Forage Sorghum is comparable.
Some of the summer annuals
also are very high in sugar.
Cool season grasses tend to
be somewhat intermediate.
And then, you'll notice
that Alfalfa in particular
is down toward the bottom.
This is one of the contributing factors
that make Alfalfa a difficult
crop actually to ensile.
Another thing that's
relatively significant
I think for Oklahoma is
planting a warm season grass
such as Bermudagrass or Bahiagrass,
they typically have very
low concentrations of sugar
which make them difficult
to ensile as well.
Just one example of
this, and it's probably
the most common frustration
that most forage producers have,
some work that Rich Muck and I did
several years ago and in
this particular example,
we looked at the water soluble
carbohydrate concentrations
in Alfalfa depicted by the green bars
and the starch concentrations depicted
by the yellow bars, and we evaluated
that on both an initial and
after a two inch essentially
rainfall increment and you'll notice
that the water soluble carbohydrates
are depressed by almost two thirds
and there's very little
starch left at all.
Now, starch is not typically considered
a substrate for fermentation, but there's
quite a bit of circumstantial evidence
that some of that starch in the plant
is mobilized into simple sugars
during that wilting process,
particularly if it's prolonged,
so I included that there.
But, the take home message is that forage
on the right there that's incurred
a lotta rainfall is severely compromised
with respect to any
potential fermentation.
The other inherent plant characteristic
we kinda need to talk about
is buffering capacity.
And a simple definition of that is
just the inherent resistance of any kind
of a plant to a pH change
and in this circumstance
with this response variable, so to speak,
a lower number is better.
So, if you look at the
top of the list there
corn silage is not heavily buffered,
at least not compared to other forages
and that contributes to again to it being
a very easy crop to ensile.
Cool season grasses tend to
be somewhat intermediate,
intermediate in this respect.
And if you look down at the bottom
you see a lotta legumes down there
and Alfalfa, there's a
couple estimates there,
but that Alfalfa is very
very highly buffered.
And then at the bottom is White Clover,
which is pretty much entirely leaf
and that would be the highest estimate
that I have there.
Now, a couple things about Alfalfa,
it tends to be more highly buffered
in less mature plants.
As that plant matures and
the leaf to stem ratio
goes down, it tends to
be less highly buffered
or less buffered.
Anything that would reduce
the leaf to stem ratio
will tend to depress buffering capacity
so if that crop is rained
on, although that's
highly undesirable, that
actually would reduce
the buffering capacity
in most circumstances.
Okay, let's take a minute here and compare
baled silage with
precision-chopped haylage.
These are a couple take home points
I think it's kind of
important to keep in mind.
There's some distinct differences between
these two silage types.
Fermentation within baled silage is,
baled silage is almost always restricted
and it's restricted by lower
moisture concentrations,
lack of chopping action and reduced dry
matter density, maybe.
I wanna talk a little bit about
the last two just briefly.
Most of the bacteria that's
for encourage fermentation
or adhere to the outside of the plant,
if there's no chopping action the sugars
that are located within that plant,
they have to somehow
diffuse to the outside
of that plant in order
for fermentation to occur.
With respect to the dry matter density,
although certainly balers have improved
and I think baler operation
within this context
has improved, often times
the dry matter density
is just not as high in baled silages
as it is in really well
packed bunkers and so forth.
All right, what does this look like
in terms of a trial?
This was work that was done
in Canada 30 years ago now,
but it is one of the best illustrations
that compare directly baled
to chopped Alfalfa silages.
And the mean moisture concentration
for these forages was 61%.
It's one of the very few trials
that I know of where baled
and chopped silages have been compared
at the same moisture
level, which is important.
So, if you look at the graph on the left
what we have there is the
concentration of lactic acid
and on the X axis is days of fermentation.
What you'll notice there
is that the chopped silage
increases production of lactic acid
at a much more aggressive rate
and at the final
concentration of lactic acid
is much much higher than
it is in the baled silage.
If you move to the graph on the right
you'll notice that the
total fermentation acids,
which would include acetic
acid, systemic propionic
and a few others in minor proportions.
Again, you see the same kind of a thing.
The accumulation of
these fermentation acids
occurs at a much slower
rate in baled silages
and the final end point,
or the final concentration
of acids is much lower with baled silages
compared to chopped silages.
And this is a very very common response.
What does that do to the final pH,
which we'd really like to
see as low as possible?
Well, it's fairly predictable,
the chopped silage
has a much more rapid
descent in pH over time
and the final end point
is significantly lower
than it is for baled silages.
Another thing that's really important
when you talk about any
kinda silage management
is the management of moisture.
And generally, baled
silage should be packaged
at 45% to 55% moisture,
according to Kevin Jenners,
who I believe has spoken in
one of your Extension programs
down there recently.
The average for the whole
field or group of bales
should be about 50%.
Now, in terms of management
that's a relatively
important statement there.
In my experience in Arkansas with people
who are outstanding hay producers,
but have never made
silage, their inclination
was always to go out
and mow everything down
and then hook up to the
rake and rake everything
and then hook up to the baler and think
they were gonna bale everything
and often times they wound up
with very very dry kind of a silage
or wrapped material even at that point
because moisture
management is not something
in that context that they
typically thought about.
So, you might require individuals
to mow and attack the amount of material
that they can handle in one day
or in one situation
without getting too far
outside of the bounds
of a good moisture range
for these bales.
It takes a little bit of practice
if it's not something that's
typically thought about.
Most moisture recommendations
for precision-chopped
silages are wetter than baled silages,
generally less than
70% is a rule of thumb.
So, production of silage
fermentation acids
is positively associated
with moisture concentration,
which I think we've mentioned
a little bit already.
And as a result, baled silage fermentation
is inherently restricted,
resulting in a slower
fermentation and a greater
less acidic final pH.
Again, let's go back to
the same work by Nicholson
and in this particular
illustration he ensiled
both high moisture and ideal moisture
baled silages, where high is defined
as 60% to 65% or ideal is 49% to 54%
and you will notice on the left
the production of lactic
acid is much greater
and it occurs at a much
more aggressive rate
with the higher moisture material
compared to the ideal moisture material
and the production of
total acids on the right
follows a similar pattern.
If you look at the final
pH in these forages
you'll notice that the descent of pH
works acidic conditions that reflects
the production of those acids,
is more accelerated at higher moisture
and the final end point is much lower
than it is in the ideal moisture range.
Now, this is a thing we have to kinda work
at a little bit in explaining
and it's gonna take a progression
of a number of slides to explain
all that's involved here.
But, I wanted to include a quote here
from Dr. Muck, who was the silage guru
at the Dairy Forage Research Center
for many many years before
he recently retired.
But he said at one point,
"A second implication
"for management silage
is that fermentation,
"or decreasing pH, is
relatively unimportant
"in producing high quality, dry silages."
And, as a followup, my observational trend
here in Wisconsin and
I think it's probably
broader than that, is that producers
generally are moving
towards drier baled silages
placing increased
emphasis on excluding air
and less on fermentation.
I think our natural inclination,
based on research and what you may read
in the popular press, is to prioritize
things like anything
that drives down the pH
and creates stability with
a very acidic condition
within the silage and so forth.
I'm not sure that that really applies
and I would confess to have suffered
from some of the same biases that I think
people outside of research
probably would suffer
from in thinking that we needed
to maximize fermentation.
I think in reality what
we're really doing here
with these baled silages is we're placing
more and more emphasis on excluding air
and essentially preserving that material
largely on that basis
rather than a stable pH,
because you're not really gonna attain
that at the dry matter
moisture concentration
within those bales.
Okay so, we'll take a
look at this a little bit.
This is a summary of a couple projects
that we did, two trials, that we did
here in Marshfield.
I have on my left a
concentration of lactic acid
in these bales and on the X axis
the moisture concentration of those bales
and you will notice that until you get up
to what is basically the lower limit
of the standard recommendation
that Dr. Shinners
has put forward, about 45% moisture,
when you're below that you may not detect
any lactic acid at all
or it may be very very
minimal concentration.
Once you get above that you start
to pick up significant
amounts of lactic acid.
Now, it's important to note here
that when you're to the left
of that vertical black line,
that does not mean that those silages
are no good, that they won't be preserved.
Far to the contrary.
As long as the integrity of that plastic
is maintained those would
be perfectly acceptable feed
and it's also frankly,
less water to haul around
and a little bit less of a safety issue
trying to haul around
very heavy hay packages.
Now, just to cement this thought,
some months ago, back in February,
there was an article in
"Hay and Forage Grower"
that I'm sure some of you
actually get that magazine.
It's a summary of an Extension project
that Dr. Hang did at the
University of Kentucky,
where he did a producer survey
and what he has there
in that summary graph,
as depicted by those green dots,
are bales of silage bales that he sampled
from various producers in Kentucky
and you'll notice that that response there
looks very much like the one I showed you
in the preceding slide, or previous slide.
So, I hope that cements in your mind
that you know, when you get very dry
moisture content you're not gonna get
a lotta lactic acid and
what that really means is
you're preserving that forage by excluding
the air and making sure that that plastic
maintains its integrity.
I also want you to note
on the far right there's
a couple of green dots
that have very very low
concentrations of lactic acid
and this leads into the
next point of discussion.
You're probably sittin' there asking,
if you get better
fermentation with a little bit
more moisture, a lot more moisture,
why not bale the forage wetter?
Well, there's a couple reasons for that.
I think the first two are not as important
as they were 20 years ago, but I know
back when I was at the
University of Arkansas
there was a lot of silage bales
that were hauled around
in relatively undersized tractors
and anybody that knows anything
about the greater Fayetteville area
knows that that's not
exactly level terrain.
And that's a significant safety issue
'cause those bales can be quite heavy.
The second issue is equipment
and specifically, the baler.
Now, most balers handle, even now,
most balers handle dry forages
better than wet ones, although the design
of silage special, so to
speak, has made handling
wetter forages much
better than it used to be.
But still, those balers are at least
co-equally designed to handle dry hay
and they generally handle
forages better if they're drier.
But, the real reason
that we don't recommend
higher moisture concentrations is
the potential for
clostridial fermentations.
They're often times called
secondary fermentations
in that they don't occur immediately
and forages can be at risk
for this type of fermentation
if it has a particularly
slow fermentation pattern
and the pH is not depressed rapidly,
which fits into the description
of round bale silage.
But, in this process these clostridia
will attack sugar, lactic acid and protein
and the end results is
production of butyric acid
and ammonia and it can
cause, in bad cases,
it can cause really
significant depressions
in intake by cattle.
So, this is a fairly significant problem.
It's much more common in
Europe where they typically
don't wilt forages, or
at least historically
have not wilted them like
we do in this country
before ensiling them.
But, please notice that one of the things
that these clostridial will attack is
lactic acid, so after lactic is produced
it can also be metabolized.
If you look up here on the previous slide
I think what's occurring
is very very wet forage
is that there is clostridial activity,
which is secondary and the lactic acid
that may have been
produced has been converted
to butyric acid or something else.
So, what are some characteristics
of high risk forages?
High moisture concentration,
anything that's direct cut,
immature rapidly growing forages,
highly contaminated forages
with dirt, manure or both,
low sugar content, high
buffering capacity,
high protein, anything that's a legume.
If this sounds like a
description of Alfalfa,
you'd be correct in assuming that.
Anything that's
non-homogenous, which is true
for baled silages.
If you think about ensiling anything
that's precision chopped, when you chop
that material and blow it into a wagon
or a truck there's a certain amount
of mixing and homogenization that occurs
and when you blow that into a blower
or dump that into a blower
or dump it into a bunker and then layer
it within that bunker,
there's an additional amount
of mixing that occurs and what you wind up
with is a fairly homogenous
blend, so to speak,
or at least far more than it
can be with baled silages.
With baled silages as
you go across that field
there's potential for different pockets
of moisture within that bale,
depending on where you were in the field,
there's also potential
in mixed species stands
for higher concentrations of legumes
in certain parts of that
bale as opposed to others.
So, the best prevention
is to wilt the forage
prior to ensiling.
As such, baled silages
are generally at low risk
for clostridial fermentations,
but there has to be a significant
amount of wilting occur
to limit that risk.
Here's some work that we
did here in Marshfield
where I've monitored the concentration
of butyric acid in primarily
Alfalfa round baled silages,
function of bale moisture and you can see
that as you get below 45% or 50% moisture
the risk of accumulating
a lot of this acid
is fairly low.
When you start bumping
up against the upper end
of Dr. Shinners' recommendation range,
the potential for picking
up a significant portion
of butyric acid is greatly increased.
So, if you're put in a
position where you may need
to bale and wrap silages,
particularly Alfalfa,
when you start bumpin' up against
about a 60% moisture range,
that might be a real good time
to put a lactic acid inoculant on there
if you have the capacity to do that.
I know Dr. Muck typically would recommend
it with baled silages, you wanna be
about 10 points in moisture lower
than you would be if you chopped it.
I think that's a pretty
good rule of thumb.
Now, we go back to Dr. Henning's report
in "Hay and Forage
Grower" what you see there
in that graph is
essentially the same thing
I just showed you in the previous slide
that occurred in Kentucky.
And when you get out
here and start bumpin'
up against 60% or so you start picking up
a fairly significant
amount of butyric acid.
I also want you to note, if you think back
to the previous slide on his work
where these extreme
moisture concentrations
had very low concentrations
of lactic acid,
you'll note that there's
very high concentrations
of butyric acid in there which indicates
that there's some secondary
fermentation occurring there.
Another thing that can
impact the potential
for clostridial fermentation
is, and this occurs
fairly commonly in
Wisconsin, is what happens
if I put dairy slurry, or if I have
to put dairy slurry on Alfalfa?
This happens occasionally when a producer
gets into a situation
where his pit is full
and weather has not been cooperative
for one reason or another
and he has to go somewhere
with this dairy slurry.
We did a study up here some years ago
and we had four treatments in that study
and one on the left there was no slurry,
which is a control.
And then, we applied slurry,
about 4500 gallons per acre
to stubble immediately
after the preceding harvest
and then after a delay
of one week or two weeks,
and we did clostridial
counts on these forages
or silages on a pre-ensiled
and post-ensiled basis.
A couple things become pretty obvious.
Number one, if you don't
put any manure on there
the clostridial counts are gonna be lower.
Secondly, the longer you
delay the application
the higher those counts are likely to be.
And thirdly, the counts
are gonna be higher
after the material is in silage.
I don't think it surprises anybody.
Now these particular silages
did not go clostridial.
We did not have a lotta evidence
of clostridial products 'cause they were
relatively dry when we baled them,
but this does indicate a
significant amount of risk
and if you're in a situation
where you're trying to bale something
that's had a manure application,
this again, would be a real good time
to either get 10 points
drier before you bale
the material and ensile it or apply
a lactic acid bacteria type of inoculant.
The last thing I wanna talk about really
is the elimination of air in these forages
and as we mentioned before,
I think the industry, just
based on my observation,
is it's moving more and
more toward drier silages
which are preserved essentially
by continued elimination of air.
On pre-ensiled basis before
sealing what happens is
there is a great deal of air
access to that forage mass.
You get respiration of plant
sugars to carbon dioxide,
water and heat.
This reduces the pool
of fermentable sugars,
increases dry matter loss,
increases indirectly the
fiber content of the silage
because the sugars are
leeched from the material
and then as a result of
leeching of those sugars
and highly digestible
portions of the plant
the energy density of silage is depressed.
What are some management things
that you can do to restrict the air access
to your bales before they are wrapped?
The most important one,
or a very important one,
is to get a bulk density of greater
that 10 pounds of dry
matter per cubic foot.
There's a number of ways that you could do
that or insure that.
One is to reduce the ground
speed of your tractor.
Thinner windrows will increase
the number of revolutions
in that bale chamber
assuming you're talkin' about round bales
as opposed to square ones.
If you manage moisture appropriately
that will help.
You wanna maintain a constant bale size.
If you look at this picture that was taken
back when I was at the
University of Arkansas,
we had a cooperator down there that did
a number of projects with us
and he was very very good at this.
He had a lot of experience very early on
at round baled silage, and these bales
were wrapped with an inline wrapper
which is a continuous row, as opposed
to individually wrapped bales.
But, if you look at the top
line on this row of bales,
if you put a level on that, that bubble
would be right between those two marks.
Every one of those bales
is almost identical
and that's really what you'd like to see
in terms of excluding
air because if you have
a top line that goes up and down
and all over the place, very jagged,
number one, you're gonna
trap air when you wrap them.
And number two, if you have a situation
like that the potential for the plastic
to separate is also much greater.
So, that's kind of an
idea of what you might
be shooting for if you're
using an inline wrapper.
Baler operator experience
is very very important
in making solid and consistent bales.
With practice it is really noticeable
what a really good operator can do.
We did a little bit of
work fairly recently
up here in Marshfield
where the baler operator
maintained at my direction, by the way,
a five and a half mile per
hour constant ground speed
and we looked at some
Alfalfa grass forages
as a function of different
moisture concentrations
which you see in the graph at the bottom.
The horizontal red line
there is the 10% threshold
or marker that you'd really like to see.
Notice that when you're down here
in this ideal range, 46%, 50% moisture,
we're well above that threshold
and even at 62% we're above that.
However, when you got
into very wet material
it fell below that standard
and these were all done
at the same ground speed.
Also, in that particular experiment,
we'll touch on this I think
in the upcoming slides,
but many balers now have mechanisms
in them that allow you to cut the forage
or not to cut it.
There has been some discussion
that cut forages, you
may get more dry matter
into the bale that way.
It also may improve fermentation.
There's been some discussion
about that, which we'll touch
on here in a second.
But, with these cut forages you were able
to achieve a little bit
higher dry matter density,
but it's usually on the order of about 4%,
so it's not really huge in my experience.
Because we just touched
on the presence or absence
of a cutting mechanism in the baler,
I thought this would be a good place
to throw this slide in.
In this project we baled Alfalfa grass
over a wide range of
moisture concentrations
and on the left hand graph here I plotted
the concentration of lactic acid's
function of bale moisture.
The solid line there represents material
that was cut and the hash
line represents material
that was baled long stem.
You'll notice across this moisture range
that there is a statistically
significant increase
in the amount of lactic acid produced.
Now, it's not a huge amount,
but it is statistically significant.
Those two lines are
statistically distinct.
If you look at the pH on the right graph
you'll notice that the cut material
has a lower pH across
that entire moisture range
compared to the uncut material
or the long stem material
and that ranged in this study
from about .1 to 1.5 pH units.
The reason I put this in here is
you may hear some discussion about whether
a cutter will improve fermentation.
From a technical statistical standpoint
that's probably true.
From a practical standpoint
is that justifiable reason
to pay for a cutter?
There may be a whole lotta reasons
why that's a really good idea,
such as if you need to plan this material
into a total mix diet of some kind,
that would be a real big one.
But, payin' that extra money
for improved fermentation
is fairly questionable
based on our work.
What about sealing these bales?
You like to wrap them as quickly
as possible after baling.
You'll see recommendations
as short as two hours.
Obviously, the quicker the better.
However, some works
which I'm gonna show you
we've done here would suggest that there's
relatively minimal damage
up to about 24 hours.
So, if you have, you do
have some flexibility
in how quickly you get this plastic on.
You'd like to use at least four layers
of 1 mil or 25 micron plastic.
That's probably adequate
for a good fermentation
in most cases.
I'm not sure that that provides you
with the kinda security
for long term storage
or in the warmer southern states,
that you might like it to have.
Your storage site selection is important.
You don't want rocks,
tree limbs, junk metal,
other undesirable things
that could potentially
could compromise your plastic.
That just is basic common sense I think.
You don't wanna puncture your plastic.
You wanna make sure it's, obviously,
you wanna isolate it from
cattle, pets, vermin,
skunks, snakes, rats, that sorta stuff.
It's important to monitor
that plastic periodically
and make sure that it's
not been compromised
by one of these problematic situations
when you're not aware of.
You also wanna patch any holes
with an appropriate tape.
That's UV resistant silage
tape, not duct tape.
Also, I wanna point out very very quickly,
one of the things that we
have certainly noticed,
if you look in this red circle here
on the left hand photograph, you'll see
in the middle of that right on the line
between the flat surface
and the rounded surface
of that bale what looks like a couple
of pimples on there.
And what that is, in
certain kinds of forages,
and I think a mature Alfalfa forage
would certainly be one of them,
what you can observe with inadequate
amount of plastic is
puncture from the inside out
by rigid stems.
And that's the first place
I would look for that.
You see it fairly commonly.
With more plastic put on
the risk of that is lower.
But, that's just something you might
wanna be aware of.
I mentioned a little bit
about delays in wrapping,
this can occur and it's a
very common question actually.
People will go out and
they'll bale their material
and it'll rain before they
can get it out of the field
and how long do I have
before it's no good,
that sorta question.
Another situation that can
occur is you're renting
a bale wrapper of some
sort and it doesn't arrive
when it's supposed to and you have a large
number of bales that
where wrapping is delayed.
We did a study in Marshfield here to kind
of address that and the
next couple of slides
are gonna illustrate some
of the things that occur.
In this particular study we
wrapped bales immediately,
or after a one, two or three day delay
and what I've plotted in these figures is
the bale temperature which we monitored,
at the time the bale was actually wrapped,
so you're gonna see a
little bit of segregation
in these responses.
This is kind of the control,
it was wrapped immediately.
You have a little more
heating here after one day,
and then two days and then three days
as you move to the right.
And by the time you get to three days
you have a fairly hot internal
bale temperature there,
up around 150 degrees.
These forages were also
about 60% moisture.
If you look at the total production
of acids you see that there's much higher
with no delay in wrapping,
but then falls off significantly
as you get to a two and three day delay.
Same thing really occurs with respect
to lactic acid production and if you look
at the bottom right there in association
with this delay you're gonna see
an elevated pH because the fermentation
is not gonna be quite what it was
in the positive control.
Now, you may ask about the quality
with these delays, so I did look
at two things, or at least
I've presented two things here.
One is heat damage protein on the left.
You'll notice there, although
that's not a linear response,
that there's relatively little change
between zero and one day.
But then after that you start to pick up
more heat damage as a function
of that elevated temperature.
And then on the right hand graph there,
there's really not a lotta
change in the energy content
of those forages through a one day delay.
But then it tends to fall off
somewhat more rapidly thereafter.
So, our recommendation here is while bales
should be wrapped as soon as possible,
this study suggests damage
within the first 24 hours
is relatively minor.
In a number of the other studies
that I've looked at I think that tends
to hold as a fairly good rule of thumb.
You're gonna see different responses
depending on the forage conditions
and all that's gonna matter,
but I think if you can get
that plastic on within one day
damage is probably relatively minor,
although sooner is certainly better.
All right, to wrap up and summarize here,
most principles of
management for conventional
chopped silage still
apply to baled silage.
Moisture management is important.
Generally baled silage techniques
will accommodate drier forages
better than the wet ones.
Fermentation occurs at a slower rate
for baled silages because
forages are ensiled
on a whole plant basis
where they're usually drier
and less dense than chopped silages.
As a result, producers
should diligently address
other management details
such as maximizing
bale density, consider
an inoculant, lactic acid
bacteria or lactic acid
producing inoculant,
particularly if the forage is damaged,
typically that's by rain,
manure has been applied
or if bale moisture
approaches 60% for Alfalfa,
grasses because they have more sugar
and are less highly buffered, may be
a bit more forgiving in terms
of preventing clostridic activity.
You wanna apply plastic
wrap promptly and properly.
Damage is relatively minor up to 24 hours.
Protect the product
with four plastic layers
to insure a pretty good fermentation,
but six or eight are better to maintain
the integrity of the plastic.
And general observations
suggest that forages
are baled at increasingly
lower moisture concentrations,
which places additional emphasis
on exclusion of air and
monitoring conditions
around those bales so that you
don't compromise the plastic.
The last thing I wanna mention,
I've talked about a number of studies
done here at Marshfield, I'd like you
to just briefly turn your attention
to the photo in the bottom center there.
None of those things are possible
without an outstanding field crew
and the University of Wisconsin staff
that works the research
station where I work,
is really outstanding and they deserve
a whole lotta credit for the numbers
that you saw today.
So, with that I'll turn
it over to some questions.
- Thank you, Dr. Wayne Coblentz.
Excellent presentation.
We do have a few questions.
I'm gonna start with
the Q&A session question
and there's some that are
in the chat room as well
and I'll take a look at those in a minute.
But, if others have
questions they wanna ask
this is the time to do it.
Put 'em in that Q&A and we'll
try and get 'em answered.
So, the first question
was, could you comment
a little bit on equipment requirements?
And this picture that you've still got up
kind of leads right into that.
So, what is required?
They've heard that
there's increased weight
because of the moisture, that kinda thing.
So, what's kinda required?
I know you already touched
on some of the things
with Arkansas, just haulin' them around,
but what does it take to wetter forages?
- [Dr. Coblentz] I think
that obviously depends
on the given situation.
If you intend to do a
lot of baling of silages
it might be worth considering
a silage baler which doesn't prohibit you
from making dry hay by any
stretch of the imagination.
But, it does, it is beefed up with respect
to the weight bearing so forth.
It's designed to handle wetter material
better than the more typical kinda baler.
In terms of hauling the material around,
just use appropriate safety for the size
of the bale package.
I didn't actually mention this.
Most people, when they make silage bales,
will make only four foot diameter bales
because of the weight.
Usually they're not made out of five foot
or six foot diameter bales.
So, one thing that is
probably fairly important is
to reduce the diameter so you don't have
to deal with as much of the weight
if you have the capacity to do that.
As far as the wrapper is concerned,
there are pros and cons
of both an inline type
which I showed you a
picture of silage bales
wrapped that way, or
individually wrapped bales,
if you wanna market the material,
in some ways the individual wrapped bales
might be an advantage because anything
that's an inline wrapper, at some point
you're gonna expose it
before you haul it anywhere.
And so, in that sense, it's perishable.
You probably will need some
kind of a grapple attachment
that does not puncture the material
after you wrap it if
you're gonna haul around,
particularly individual bales.
That's like a squeeze,
typically the design,
I think I had a picture of one of them
in one of the photographs.
But, that'll, it's like
a hydraulic squeeze
that doesn't puncture
the bale or the plastic.
It's fine to use a hay
spike before you wrap it.
After you wrap it it's a problem.
So, those are some things
you might wanna think about.
The efficiency of wrapping
with an inline wrapper
is gonna be much faster.
The problem you may have,
depending on what you
wanna do with it is if you wanna market
that material you're gonna
have to expose it to air,
which in the winter time
is not as big a deal
as you might think.
You do have some latitude.
We did an experiment, I didn't have time
to talk about it here.
Actually, in Arkansas
one of my students did
an experiment which published
in the "Journal of Dairy
Science" where we exposed
silage bales in January
and really didn't have
a lot of deterioration in Fayetteville
for really up to a month.
So, there is some latitude in the winter.
Now, in the summer time that's
a whole different discussion.
Obviously, in Wisconsin
we have a lot of latitude
in the winter because it's not gonna be
too much deterioration
when it's 10 below zero.
But, anyway.
I hope that helped.
- Very good, I'll get to
one of the other questions.
Wayne, you said to shoot for 50% moisture
for wrap silage.
Does that apply to both high
protein, low sugar Alfalfa
and low protein, high sugar forages?
I thought that the less than 65 silages
was important for Alfalfa.
And in the next slide you
stated that expelling oxygen
was very important and
less important to generate
a lot of fermentation.
So, does the lower moisture percent
refer to both high protein
and low protein silages?
- [Dr. Coblentz] I would
say generally, yes.
There's more risk of a clostridial problem
at higher moisture with Alfalfa,
much greater risk than
there is with grasses.
So, that's an area of concern
when you're talking about a really
high dollar crop like Alfalfa.
It's just a perception largely with me,
but I can also tell you
that our recently retired
Extension forage specialist
actually suggested
out loud that in an
environment like Wisconsin
where it's typically
fairly easy to get hay,
dry hay, down to about 25% and often times
impossible to get it down to 18% to wrap
it in a fairly large package.
Maybe the best thing to
do is actually just take
it down to 25% and then wrap it.
You don't care whether it ferments
as long as you keep the
air out of it it's fine.
That's the point I was trying to make.
This is not a crisis to do that.
One thing that may occur
when you try to wrap really dry silages
that I have observed
off and on and I can't
give you a real good
reason as to why it occurs
sometimes and not at others, but at times
with a very very dry silage bale,
when you take the plastic
off of it, it's not uncommon
to see a very thin layer of white mold
across part of the outside of it.
It's usually very very
thin and if you're feeding
beef cattle or something it's
probably completely insignificant.
But, if you're trying to
sell that to somebody,
ah, then that's a little different.
That might attract undesired
attention, so to speak.
So, be aware of that.
We've actually done a few things up here
that are in progress now to kinda look
at that a little bit and
see what it might take
to prevent that, but it
does happen periodically
and just be aware of it if you have
the intention of selling it.
- Excellent, let's go
to one more question.
Regarding the cut versus
uncut bales, what is
your summary of any
advantages for either hay
or balage in terms of forage intake
and forage digestibility?
- [Dr. Coblentz] Well
typically, the response
to any kind of particle size reduction
is an improvement in intake.
In this environment
here the primary reason
someone would want a cutting mechanism
in their baler and be
willing to pay for it is
if they want to include that material
in a total mixed ration
that they're feeding
to dairy cows.
I mean, that would be
the most common reason.
And that's an important reason if you want
to use this kind of storage
or conservation method.
The reason that we kind of attacked
that particular problem, put some effort
into evaluating it is
that there is discussion
and talk, some of it's industry related
that you hear periodically about reduction
of the particle length should
theoretically improve fermentation.
Well, that begs the question, how much
and is it worth payin' for
it for that specific reason?
And, I'm a federal employee,
I can't endorse things,
but you saw the response
in terms of pH difference.
If I was farming on my own I would not pay
for that mechanism based on a pH response.
Let's put it that way.
In terms of blending it
in a total mixed ration,
that's pretty important
if you need to do that.
So, on that basis it's well worth it.
- Maybe on a followup
of my own on that one.
You showed a picture of
possibility of puncture
from the stems.
Would that have helped in any storage
for maybe minimizing that from happening?
- [Dr. Coblentz] It
might, but I don't know
the answer to that question.
I have no, my gut feeling would be
that it could, but I don't have anything
to back that up, that's
just a gut feeling.
- All right, let's finish up with maybe
one last question here.
It says, assuming good air exclusion
how dry can you go with balage
before we become concerned?
- [Dr. Coblentz] I don't
think there's really a limit
as long as you keep the air out.
I have a trial going right now
where we intentionally
dried a Alfalfa grass mix
down to 25% and wrapped
it, just specifically
to address that question and some
of the discussion we had earlier.
In this environment up
here that's, that might be
a really good way for people to go
because there's just a lotta times
they can't get it dry enough here.
It's just not hot enough and so forth.
In Oklahoma that might be a bit different.
I mean, a justification for choosing
to do that with really dry material
might be quite different
because you do have much better
drying environment down there.
- Thank you, Dr. Coblentz.
We sure appreciate all the information
you provided with us.
We've had a poll shared and producers
have responded to it.
Always, we wanna thank the participants
for comin' on here and listenin'
and if you ever have any questions
reach out to your local
County Extension educators
and if they can't get the answer
we'll reach to the state
specialists and so forth
and we appreciate this.
Our next webinar series for next Thursday
will be some of our own local talent,
Dr. Lowman and Alex Rokatelli.
So, these have been very good sessions
and so Dave or Alex, you got anything you
wanna add to this?
- [Participant] No sir, great
presentation, Dr. Coblentz.
We'll, these are gonna be recorded
and folks will get a lot of good use
out of this presentation
for a long time to come,
so thank you.
- [Dr. Coblentz] One
thing I would add here
kind of parallels the
comments that Brian made.
At the Dairy Forage Research Center we do
work for producers all over this country
and we can take questions, too, and we're
supposed to answer them and try
to make that a priority.
So, if you have questions,
please don't hesitate
to speak up, we're not
tryin' to hide from you.
- Excellent, so again, we've gone
to about our hour mark, so again,
we wanna thank you Dr. Coblentz
for taking your time and we hope
to follow up with you in the future
and we hope to see everyone
next time next Thursday.
- [Dr. Coblentz] Thank you.
