-: My name is Brianna Buseman
and I'm the Youth Meat Extension Educator
here at University of Nebraska.
At UNL, we have a fully functioning meat lab
which provides awesome opportunities
for our students to gain hands-on experience
cutting meat, participating in research
and competing in carcass evaluation contests.
This also provides a great opportunity
to talk about market animals and the meat that they provide.
I'm excited to share with you today
and I hope that you enjoy this presentation.
This lesson will specifically be focused on
evaluating lamb and goat carcasses.
So before we get started too far into talking
about evaluation and the different things that we look at
when we are talking about lamb and goat carcasses,
we first need to just clarify a few terms,
starting with the primals.
So when we first have our whole carcass,
this is specifically from a lamb,
we don't just immediately go from the whole carcass
into cutting it into lamb chops,
there first needs to be a few steps in the fabrication
or the cutting process to get it to a point where
we can cut it into retail cuts.
And so during fabrication or that cutting process
is where we first start by breaking it down into primals.
And so the primals or the big muscle groups that we see
are the shoulder, so on the live animal,
it'd be right where it ties into that neck.
The rack, this is also referred to as the rib.
This is where your rack of lamb is going to come from.
The loin, this is where you'll get
a lot of the lamb chops from, will come from this region.
The leg. The flank.
So this is an important term to remember.
We'll talk about this location later
when we talk about quality grade.
As well as the breast and the shank.
So those are the primals that we start with and from there
it can be broken down further into retail cuts
or the cuts that you would see at the grocery store
or what you would get back home
if you brought a lamb to the local butcher.
So when we're talking about evaluation,
there's a few things that we prioritize,
the first being the percent of
boneless, closely trimmed, retail cuts,
also known as what you'll see on the screen as %BCTRC.
And so this is really evaluating
actually how much edible product
you're gonna be able to get from that carcass.
So remember at this point, following harvest,
the head and the hide and the wool have been removed
as well as the blood and the viscera or the internal organs.
So the weight from that has gone
and we're left with our carcass
and the carcass is made up of fat.
So that's this white covering that you see
over this lamb carcass, that's fat,
it's made of muscle which is then what is converted to meat.
So you can see really on this back leg
some of that purple-ish color that's coming through.
That's from that muscle, this muscle here on the side,
that's also what you see is being converted to that meat.
That's the edible product that we're going to see.
As well as the skeleton or the bones are still
within this carcass adding weight as well.
So to get to our percent of boneless
closely trimmed retail cuts, we need to remove the bone
and remove any excess fat to get to that meat
or that final edible product.
As well as quality grade and quality grade answers
the question of how good,
how good is that product actually going to taste?
Is it going to be palatable,
and palatable means, is it flavorful?
Is it juicy? Is it tender?
How good does that actually taste?
And so, to get started with determining our percent
of boneless closely trimmed retail cuts
there's a few factors that we look at
to determine this value,
to determine how much product we're actually going to get.
The first is hot carcass weight.
So that's basically, as it sounds,
it's the weight of the carcass
and that term hot is that it's coming
immediately following harvest.
And so it's before that carcass has been cooled down
it's coming right off of the harvest floor
and it's still warm.
And so that's where that hot carcass weight term
is coming from, weighing of that entire carcass.
Then we look at the 12th rib fat
and that's what we're seeing in this picture.
The carcass has been ribbed or cut in between
the 12th and the 13th rib to expose the longest miss muscle.
So the longest miss is what's also referred to as the loin
and carries and starts up
by that shoulder and is carried all the way through
to that back end portion of that lamb and goat.
And so it's exposing that longest miss muscle.
And this is really going to be our indicator
of how much muscle is on that entire carcass.
That muscle tells us a lot about what to expect.
So first we determine the 12th rib fat.
That measurement is taken halfway through
that longest miss muscle.
So you can see that black line here shows
where that measurement's taken.
And for every carcass, when we're doing this kind
of evaluation, we measure it on both sides
and take an average.
It's going to be very small,
probably some pretty slight differences,
but it gives you a better view
of what that whole carcass is.
Additionally, we look at body wall thickness,
and so that's this dark line over top of that rib.
You can kind of see when you look at this picture
into that body cavity, those lines that you're seeing are
from the ribs.
So that's what's being exposed there.
And that body wall thickness is fat cover over the ribs.
So think about,
when we're looking at these different things,
of if you either showed
or if you've maybe watched a sibling or a friend
show their lamb or their goat at the County or state fair
and think about how that judge was handling that animal,
what they were feeling for.
What did they talk about on the mic?
First, when they felt that animal,
they probably felt down along the top from the shoulder
to the hind end.
At that point, they're feeling for two things,
they're feeling for muscling.
So they're trying to feel for the shape
of this ribeye or that longest miss muscle,
they're feeling for any shape there
and any, you know, thickness, the shape.
How is it filling up at muscle region?
They were also a feeling for fat.
And so muscle is going to be firmer than fat.
Fat melts at a higher temperature.
It's going to be softer on a live animal.
And so they can really feel differences.
Additionally, the judge probably felt
on the side of the ribs of that animal.
And again, they were feeling for fat.
Bone is a lot harder than fat.
And so if it's a trimmer animal,
you'll really be able to feel the definition of those ribs.
Whereas if it's fatter,
if it has a ton of covering over the body wall,
it's going to be harder to feel that bone,
gonna indicate that there's a lot of excess fat.
The last thing that we look for
when determining the boneless closely trimmed retail cuts
is ribeye area.
So that's actually the distance around the surface area
of that muscle and gives you an indication of the muscling
on the remainder of the carcass.
Once we know those numbers,
so the hot carcass weight, the 12th rib back fat,
the body wall thickness and the ribeye area.
We can plug it into this big, long equation.
We won't go through all of those numbers
or how they got those numbers, but there is a set equation
that will then give us our estimated percent
of boneless closely trimmed retail cuts.
And so you have to keep in mind that this is an estimation.
It's not going to necessarily be a hundred percent accurate.
There can be some differences that you see.
We're not actually taking the final weight
and determining it compared to the hot carcass weight.
This is just supposed to be an estimate.
I should also mention that this is something that we do
maybe in a smaller plant
or if we're doing specifically carcass evaluation.
So say for a judging team or getting some practice like that
in the class.
This is not something that will be done
on a industry wide standard just because
it is not very efficient and takes a lot of time,
as well as can actually devalue that carcass.
They're cutting through a really valuable portion
in that loin in order to try to get these measurements.
So just keep that in mind as we go through this today.
It's an estimation and not necessarily
going to be a hundred percent accurate,
but just gives us a place to go from.
So these pictures just give you a little bit better view
of estimating that body wall thickness.
So actually using a probe to take that measurement
as well as the back fat and the ribeye area.
So to measure the ribeye area,
we use a grid that each dot is counted
and then tallied up to give us
our final ribeye area measurement.
So average for that loin eye that you're going to see
on a lamb is going to be about a two and a half inch.
So really very, very small,
not necessarily a lot of product there.
I should also mention that the pictures
that you are going to see today are from very fat lambs.
You want to see them actually really trim,
as the fat from lamb does not have a great flavor,
especially when you compare it to beef or pork.
Pork fat is something people love.
They like to include it into sausages and ground product.
Lamb fat can develop some off flavors really quickly.
And so we prefer to see it trimmer
And so that way we don't have to have further waste
down the line.
So we want to see a big line eye,
a small amount of fat cover.
So once we determine our percent
of the boneless closely trimmed retail cuts,
or answer that question of how much,
how much product did we actually have,
we can talk about how good that it pays.
And so that's where quality grade comes in.
And again, quality grade is the palatability
or an estimation of flavor, tenderness, juiciness,
how good that meat from that carcass is going to taste.
And so when we're talking about quality grade,
there's three main factors that we evaluate,
and that's coming from maturity.
So the age of that animal, the physiological age,
flank streaking, which is going to show us some of the fat
that's actually within the muscle,
as well as carcass conformation.
And that's what you see in these pictures.
So carcass conformation is the shape of that carcass
and it's going to be determined based on
the amount of muscling and the amount of fat
that that carcass has on it.
Lamb carcasses can be divided into four quality grades.
Prime, choice, good and utility,
however, 95% of the lambs in the US grade prime and choice.
So the majority of the time, if it is from a young lamb,
you will see it in the prime and choice category.
So looking specifically at carcass conformation,
you can really see differences
when you compare prime to good.
So think back, as we talked about to how that judge felt,
handled and talked about these lambs and goats
during the live show.
So probably felt around that back leg.
They were feeling for that muscle shape.
In a prime carcass
you can see there's a lot more shape, a lot more dimension
in that back leg compared to a good carcass,
very, very little shape, very flat.
Additionally, you look over that rib,
a lot more shape in the rib and thickness
that carries out through the shoulder.
It has some more of that hourglass figure shape,
compared to a good carcass, which had very little rib shape,
very, very flat in the shoulder
and really is a pretty good straight line
from that back leg, all the way to the shoulder.
More than likely there's very, very little product or meat
or actual edible product that you would be able to get
from a good carcass.
So prime confirmation really shows a lot more
of that muscle definition as well as
an adequate amount of fat compared to a good.
Then we look at maturity.
So when animals are harvested, they don't go to the plant
with a birth certificate.
We don't know how old they actually are.
And so we have to look at physiological signs of maturity.
And so that's indicators on their carcass
of how old they are.
When you think about people, we show our age
by getting gray hairs or getting wrinkles.
Lambs show their age through bone ossification.
And so when we're looking at their carcasses,
we look for either a break joint or a spool joint.
A break joint is what you see in this top picture,
as well as in this first illustrated picture.
Right there, the bone has not ossified.
It has not joined together.
You're actually able to break that joint.
You're able to snap that front leg off in a young animal.
So if it has both break joints on those front legs,
it's referred to as a lamb or a young animal.
As that animal ages, that bone ossifies.
So you can see here, it's still separated.
That spool part is still at the top.
It's not connected.
In an older animal that has ossified
or it's really joined into one.
It's become one bone.
And the spool joint is the joint
that you'll have to cut around.
And that's what will be exposed.
Can really see some differences in terms of shape and color.
And a young animal is going to have that break joint.
And it's going to be that bright red color.
There's no ossification.
An older animal is going to have the spool joint,
and it will be more of a bright pearly white color.
And that is coming from its age.
So two spool joints is going to be referred to as mutton.
And so that's an older classification of lamb
and is not going to be as valuable
as that young lamb.
Young lamb is going to be expected to taste better,
gonna have better color.
It's going to be more tender compared to mutton
or that older animal's going to be a darker,
less eye appealing color.
It's going to probably have some tenderness issues
as well as some problems with flavor.
And then we look at flank streaking.
So think back to the beginning of this presentation,
when we talked about the primals,
one of them that I pointed out was the flank.
They're really right in front of that back leg.
And then it ties into the belly.
So the flank is this muscle here,
and we're going to look for streaking
or streaks of intramuscular fat
or fat that's actually within that muscle.
So looking at these pictures,
trace amounts of flank streaking.
It's all red.
There's really no signs of any fat
that's actually within that muscle.
If we compare that to a moderate amount of flank streaking,
there's still a lot of red here in the flank,
but we're seeing more of that intramuscular fat
actually moving into that muscle.
That's an indicator that the other cuts
in that lamb carcass will also have intramuscular fat.
This is especially important
when we aren't able to rib that carcass,
when we're not able to cut it.
Like I said before,
that's something that on a plant wide basis,
you're not necessarily able to do.
And even sometimes if say you're participating
in a meat judging contest, they may not always be ribbed.
And so this flank, it's opened up
from when they removed the viscera
or the internal organs during harvest
and that flank muscle is opened up and exposed.
So this is a great place to look
to determine the final quality grade of that carcass.
Using the maturity that we determined
as well as its amount of flank streaking,
we can determine the actual quality grade of that carcass.
So if it came from a young lamb, so it had both break joints
and it had a modest amount of flank streaking,
it would qualify as prime.
If it came from a yearling mutton and had a modest amount,
it would qualify as choice.
So really understanding that maturity as well
as that flank streaking matter
in determining that final quality grade.
Again, 95% fall within that prime and choice category.
So the majority of the lambs that will be harvested
in the US will fall in this category, prime and choice.
So looking at a few examples today, first off,
we have a lamb that had a hot carcass weight of 86 pounds,
had 0.25 inches of back fat.
So that was measured right here.
.95 inches for the body wall.
So almost a full inch and a 3.9 inch ribeye area.
It ended up with a 47.8%
boneless closely trimmed retail cuts.
So that means that we would estimate
that of the 86 pound carcass,
47.8% of it is actual product that is edible.
We can sell it, we can bring it to the retail store
and take it home and feed to our families.
So to get that, we did 86 pounds times 47.8%
and it equals about 41.4 pounds of final edible product.
This one had a bit heavier carcass weight at 93 pounds.
0.35 inches of back fat, 1.2 inch body wall.
So this one was really fat
and not just looking over top of that loin,
but you can also see it when we look at the full carcass.
Sure, you see some signs of that muscle popping through,
but you really can see a lot of fat.
There's really a ridge of fat over top
of this sirloin and into that loin region.
Very, very fat lamb, ended up with a 3.4 inch eye,
and 44.6% BCTRC.
This one ended up also at 41.5 pounds of product.
So almost the same as the first one
that we looked at in terms of final end product.
Number three was an 88 pound carcass,
0.3 inches of back fat and a 1.3 inch body wall.
This one was overall, had lighter pounds
in terms of hot carcass weight,
but was really really similar in its measurements
compared to number two.
A 3.4 inch eye, and ended up with a 44.9%
boneless closely trimmed retail cuts,
or only about 39.5 pounds of product.
In our final picture was an 87 pound carcass
with 0.35 inches of back fat, a 1.15 body wall.
So this one you can really see,
really fat over top of that rib.
How many, 4.2 inch eye, so this one,
although it was quite a bit fatter, it also had more muscle.
So this one ended at a 47.2%
boneless closely trimmed retail cuts,
ending at about 41.1 pounds of product
that we would estimate would come from this animal.
So remember, this is not going to be an exact science
or not exact numbers,
but they're an estimation that we can use.
So this shows all four of them together,
and something I really want to point out to you
is that we saw some variation in their BCTRCs, okay?
So ranged from 44.6 to 47.8.
So there was some slight variation there,
but in the end these four only ended
with two pounds different in what we would estimate
that they would have for their final product.
Okay. So lowest was 39 and a half and the highest was 41.5.
So really, really similar, really consistent
even though we saw differences in terms of fat thickness,
body wall and their loin eye size.
They still ended up having similar estimations
in terms of their overall final product.
One thing I also want to point out
is that number two had the heaviest carcass weight.
Now it really was only about seven pounds different
in terms of its carcass weight.
So really not that huge of a difference
when you compare it to number one, which was 86 pounds,
but still, even though they were only about
seven pounds different,
they end up with only a 0.1 pound difference
in terms of their estimation
for what they would have for a final product.
So this one, there was some extra weight put on it,
excess fat that really wasn't needed.
And for that reason, it still ended up
with almost the same amount of product
that we would estimate it would have
compared to one that was trimmer and lighter weight.
So then I'd like to show also differences between
lamb and goat.
So this first picture, this is a lamb carcass.
This is what we've been talking about so far.
You can tell in terms of the shape of its leg,
the width across its top,
as well as the color of the fat,
that looks a little bit different,
just has a little bit different shape to its body.
Whereas our goat hanging next to it was much trimmer.
So it had a lot less fat.
You can see a lot more of that blooming,
almost that purplish color shining through
or coming through that fat
because it was a lot, lot trimmer.
You can really see that across the back and on the leg.
There was a lot more lean product coming through.
This picture again lets you see some differences.
This one, that back leg,
that's that purplish color you're seeing,
that's meat, that's lean product that is poking through
and not being covered by fat.
I also want to point out that even between
the goats that we had here,
there's quite a bit of differences,
a huge difference in terms of weight.
This one I believe is about 59 pounds,
its carcass compared to this one only being about 34 pounds.
So seeing some major differences
and when they are this light of weight,
even if they showed a lot of muscle,
it showed a lot of expression.
It may have been smaller framed.
It's still going to be almost
the same amount of work to actually do the harvest process.
It's gonna still take quite a bit of time
and the effort to do the cutting,
compared to that large carcass,
but you're going to be getting a lot less actual product
from this smaller one.
When comparing the carcasses side by side,
it's a little bit more difficult to see
the actual differences in weight.
Number three here is that carcass that was much smaller
and that's why I included it on the previous slide.
These pictures make that a little bit more difficult to see
but really did want to point out that weight difference.
Now looking across this group,
there is some consistency in terms of final carcass weight,
with one, two, and four being pretty similar
in terms of their final, hot carcass weight.
These weighed 57 pounds for number one,
51 pounds for number two,
the lighter weighted one at number three at 34 pounds,
and then 59 pounds for number four.
With these carcasses when we compare them to the lambs,
you can see that we did not rib them.
So we did not take actual fat measurements
or loin measurements.
And so because of that,
we just took an estimated yield of 43%
to give us an estimation
for what their final pounds of product would look like.
So keeping that across the board
left us with 24.5 pounds of product for number one,
21.9 pounds for number two,
only 14.6 pounds of product for number three,
and 25.4 pounds for number four.
So as I said previously, a lot of that fixed cost
in order to harvest these animals is going to stay the same.
Having labor there to do the harvest and the fabrication,
the amount of time that it's going to take to clean up.
That's a big part of it that we don't talk about either,
but all of those costs are going to be pretty similar
regardless of what you actually get for your final product.
So although this one,
it was a smaller framed animal to start with.
We would expect it to have less pounds of product.
It's going to be harder to recoup that cost
if you were consistently harvesting these smaller animals.
So a few other things that we can point out
when talking about these carcasses
is variations in terms of their fat and their muscling.
So it's a little bit more difficult to see on these
compared to what the lambs looked like.
However, you can notice that on these goat carcasses,
you see a little bit more of that bluing,
so that blue color that's coming through the fat
or up here on the legs looks to be a little bit purple,
that's that lean tissue or that meat
that's actually showing through the fat cover.
And so on number one and two,
you can see quite a bit of that bluing coming through
on the loin.
Compare that to number four,
you see a little bit less of that color showing through.
And we would anticipate that if we were to rib these
and take measurements, that four would probably have
more back fat across that loin,
just due to those visual indicators.
Again, tying back to the live side during the show,
how the judge felt along their back from their shoulder
onto the end of that loin and probably around that leg,
we're feeling for some differences in terms of muscle.
And so on the carcass we can evaluate that
looking at width in that shoulder,
in the really the shape of that muscle
and the muscle expression,
as well as really looking in that back leg.
Number four shows a little bit more shape.
There's a lot of shape here in that back leg.
It isn't flat at all.
Flat is usually equivalent to not as much muscle definition,
not as much shape as we would like to see.
So just those couple things to point out,
when looking at these four carcasses,
although we didn't rib them and actually see measurements
we can still see a few different indicators
in terms of muscle and fat differences
and overall weight of their product,
differences between these four carcasses.
With that, I want to thank you
for taking the time today to listen to this presentation.
I hope that it helped make some connections
between market animals and the meat they provide.
If you have any questions about today's presentation,
please feel free to reach out using the contact information
provided on the slide.