Slide 1
Hi, my name is John Mathai, I'm a Master's student at the University of 
Illinois under Dr. Hans Stein, and today I'm going to present to you on 
the energy concentration and amino acid digestibility in corn and corn 
co-products fed to growing pigs.

Slide 2
We'll start off with an outline. We'll start with an introduction, then 
we'll move into the nutrient composition of the ingredients that we 
used. We'll follow up with the first experiments, that determines the 
energy concentration of these ingredients. And the second experiment 
deals with amino acid digestibility of these ingredients. And we'll 
follow with the overall conclusions, then I'll leave you with the 
take-home message.

Slide 3
For this experiment, we used four wet milling byproducts. And those 
ingredients were corn bran, which we'll call bran, high fat corn germ, 
which we'll call germ, liquid corn extractives, which we will refer to 
as LCE, and then a mixture of corn germ meal and the corn extractives, 
that we'll call CGM-LCE.

Slide 4
So the first ingredient was corn bran. And what this really is, is the 
pericarp of the corn. It's the most fibrous component of the corn 
kernel. And it's being investigated as a separate feedstuff, or as one 
that can be blended with other ingredients.

Slide 5
Next ingredient is high fat corn germ. And how this corn germ differs 
from typical dry grind corn germ is that it has a higher fat content. 
Typical dry grind corn germ has about 16-18% fat, while wet milled corn 
germ, which is what this is, has between 30-40% fat.

Slide 6
The next ingredient is liquid corn extractives. And this is really 
composed of the soluble portion of the corn that has been removed in the 
steeping process. And it's important to investigate because there's very 
little data available.

Slide 7
And the next ingredient is corn germ meal and liquid corn extractives. 
And corn germ meal is different from corn germ in that it's been 
de-oiled. So it has a lower oil concentration and higher fiber 
concentration. And so, this ingredient is important because it absorbs 
large quantities of liquid corn extractives, so it serves as a kind of 
vector for the ingredient.

Slide 8
So why are we looking at these ingredients in particular? As with any 
industry, in the wet milling industry we're trying to maximize the 
economies of that process, and so we want to make the most out of the 
co-products. As nutritionists, it's our job to determine which 
co-products are effective to use in swine. And as any nutritionist 
knows, the greatest cost of raising swine is in feed. We want to 
minimize the cost of formulating the diets.

Slide 9
We'll start off with the nutrient composition of the ingredients on an 
as-fed basis, and we're going to be reporting the dry matters in 
percentage. For the corn, we have an 87.21% dry matter, the bran was at 
89.94%, the germ at 93.59%, the liquid corn extractives at 60.84%, and 
corn germ meal plus liquid corn extractives at 90.87%.

Slide 10
The GE on an as-fed basis in kcal/kg was about 4,000 in corn, 4,368 in 
bran, 5,929 in germ, 2,018 in the liquid corn extractives, and 4,211 in 
the corn germ meal mixture.

Slide 11
Again on an as-fed basis, we'll talk about crude fat. And what stands 
out here is the corn germ, and you see that has about 30.6%. And that's 
as we expected, between 30 and 40%, from the wet milling. And then we 
have corn at 3.2%, bran at 3.1%, liquid corn extractives at just over 
2%, and the corn germ meal plus liquid corn extractives at 2.5%.

Slide 12
So we'll go into the first experiment and look at the energy 
concentration of these ingredients.

Slide 13
The objective of these experiments was to determine the digestible and 
metabolizable energy in all four of the corn co-products.

Slide 14
So how do we go about doing this? Well, we had 40 growing barrows with 
an initial body weight of about 33 kg in metabolism cages. We used a 
5-day adaptation and a 5-day collection, using the marker-to-marker 
method.

Slide 15
The design was set up as a randomized complete block design with 5 diets 
and 8 replications per diet. Our 5 diets were a corn-based basal diet; a 
corn plus corn bran diet; a corn plus high fat corn germ diet; a corn 
plus the liquid corn extractives, and a final diet of corn plus the corn 
germ meal and the liquid corn extractives.

Slide 16
The statistics were analyzed using the MIXED procedure of SAS, with the 
fixed effect of diet and the random effect of block. The treatment means 
were found using the LSMEANS function, and the means were separated 
using the PDIFF function. The differences among the diets were tested by 
pairwise comparisons when the effect of diets was significant at an α of 
0.05.

Slide 17
So what are the results from this first experiment?

Slide 18
Well, the DE, and this on a dry matter basis, in corn was the highest at 
3,986 kcal/kg. Then the next was in germ at 3,631 kcal/kg, followed by 
bran at 3,204 kcal/kg.

Slide 19
Now we're looking at the ME of the ingredients. And we see that the corn 
has the highest ME at 3,871 kcal/kg, followed by the bran, germ, liquid 
corn extractives, and corn germ meal + liquid corn extractives, all 
between 3,000 and 3,200 kcal/kg.

Slide 20
Now, you may be wondering, if you're looking at the DE and ME, how come 
the GE of that germ didn't really translate into a DE and ME as high as 
you might expect? And that's answered here. And if you look at the ATTD 
of the GE, we see that it's lowest in the corn germ at 72.67% and it's 
highest in the corn.

Slide 21
So now, let's move into the second experiment, where we're trying to 
determine the amino acid digestibility of these ingredients.

Slide 22
The objective of the experiment was to determine the SID and AID of 
crude protein and amino acids in the four corn co-products.

Slide 23
So, we went about this with six growing barrows with an initial body 
weight of 96 kg. They were surgically equipped with a T-cannula in the 
distal ileum, and they had 7-day periods with 5-day adaptation and 2 
days of collection.

Slide 24
The experiment was set up as a 6x6 Latin square with 6 treatments. Our 
first diet was just a corn-based basal diet; our second was one based on 
corn bran; third, on the high fat corn germ; the fourth was actually a 
50% corn and 50% liquid corn extractives diet. And that's because if you 
remember that our liquid corn extractives had about 60% dry matter. And 
so to make it a little more viscous, we had 50% corn added in. And our 
next diet, we had corn germ meal + the liquid corn extractives. And then 
our sixth diet, so we could determine our standardized amino acid 
digestibility, we have a nitrogen-free diet.

Slide 25
We analyzed the statistics of this experiment using the MIXED procedure 
again of SAS, with a fixed effect of diet, and random effect of pig and 
period. Differences among the means were tested by pairwise comparisons 
when the effect of diets was significant at an α of 0.05.

Slide 26
So what are the results from this experiment?

Slide 27
The first thing that stands out, I'm sure, when you look at the slide is 
the low SID lysine of corn bran. And we don't really have a solid 
explanation for this. Our best guess is that there were some Maillard 
reactions during the processing of these ingredients. But, the corn had 
the highest at 73%, followed by our liquid corn extractives and corn 
germ meal + liquid corn extractives with about 44-53%.

Slide 28
We'll follow up with the SID of methionine, which is the highest in corn 
at 92%, and then no significant difference between the other ingredients 
at about 73%.

Slide 29
For the SID threonine, we see our corn has the highest at 87%, followed 
by the corn germ meal plus liquid corn extractives at 66%, and then the 
corn bran at 48%.

Slide 30
We'll follow up with tryptophan. We see it's the highest, again, in corn 
at 88%, followed by bran, germ, and the liquid corn extractives at about 
75%.

Slide 31
So what are the overall conclusions? Well, from our DE and ME 
experiments, we see the concentrations of DE and ME were less in the 
bran, germ, liquid corn extractives, and the corn germ meal plus the 
liquid corn extractives than they were in corn. But among the corn 
co-products, we see the concentration of DE was greater in germ than in 
bran, but there were no difference in the ME among the corn co-products.

Slide 32
For the amino acid digestibility, we see the SID of crude protein and 
all indispensable amino acids was greater in corn than in all of the 
corn co-products, with the exception of the SID lysine in germ and the 
SID of tryptophan in corn germ meal plus liquid corn extractives. Among 
the corn co-products, we see the SID of crude protein, lysine, and 
valine were greater in germ, liquid corn extractives, and the corn germ 
meal plus liquid corn extractives than they were in bran. There was no 
difference in the remaining amino acids among the corn co-products.

Slide 33
So what does this leave us with? Well, compared with corn, the corn 
co-products used contain less ME and a reduced SID of most amino acids. 
However, the high fat corn germ, liquid corn extractives, and the corn 
germ meal plus the liquid corn extractives are all promising ingredients 
for the swine diets. Corn bran, however, because of its low SID of 
lysine and high fiber, may better suit ruminants.

Slide 34
And so with that, I would like to acknowledge ADM for their financial 
support, and the supply of the ingredients...

Slide 35
...and would like to remind you that if you enjoyed this presentation, 
to visit our web site at nutrition.ansci.illinois.edu. Thank you for 
your attention.