Slide 1
Hi, this is Ferdinando Almeida here at the Hans Stein Monogastric 
Nutritional Laboratory, and I am here today to discuss with you the 
results from two experiments in which we measured the amino acid 
digestibility and concentration of digestible and metabolizable energy 
in a threonine co-product fed to weanling pigs.

Slide 2
This is the outline of this presentation. I will first give you a brief 
introduction, followed by Experiment 1 and 2, discussing some of the 
materials and methods and results. And I will finally leave you with 
overall conclusions.

Slide 3
Success in feeding weanling pigs is dependent on the selection of high 
quality feed ingredients such as fish meal, which has been proven to be 
a good animal protein source due to its highly digestible crude protein 
and amino acid levels. However, the rise in cost of fish meal in the 
past few years has contributed to a continuous evaluation of potential 
protein and energy sources that can replace specialty feed ingredients 
such as fish meal.

Slide 4
Synthetic threonine has been supplemented to low crude protein diets to 
improve the nutritional value of these diets and also to meet the 
requirements of threonine for these animals. Because of that, the 
commercial production of synthetic threonine has continuously increased, 
and that's mainly due to the developments in large-scale fermentation 
technologies.

Slide 5
In this slide and the next one, I am going to try to briefly show you 
how the production of synthetic threonine occurs. And so the very first 
step: what we have is a fermentation broth that contains, for example, a 
bacteria E. coli and a carbon source. So in this case we have glucose. 
And glucose can be converted to oxaloacetate by this bacteria, and it's 
also further converted to aspartate. In the second series of reactions, 
aspartate is converted to aspartate semialdehyde, to homoserine, and 
finally to threonine. So that's the first step in this production of 
synthetic threonine. Now, let's move on to the following steps and we'll 
then describe what is the threonine co-product that we are using for 
these two experiments.

Slide 6
After the fermentation broth steps, if we look at the left side of this 
slide we see that there's a cell separation step, followed by a pH 
adjustment, crystallization, separation, drying of the product, and 
finally on the bottom on the right side we have the synthetic threonine. 
However, on the cell separation step, there is a biomass product that is 
left and that biomass can be further processed into the threonine 
co-product which is the product that we used in both experiments that we 
will be discussing here today.

Slide 7
This slide shows a picture of the threonine co-product and just showing 
a little bit of the physical characteristics, which is a flaky type of 
ingredient which contains dry matter of approximately 95%, crude protein 
of approximately 81%, 8.4% of fat, and also contains approximately 5800 
kcal/kg of dry matter of gross energy.

Slide 8
This graph shows the amino acid composition of the threonine co-product 
compared with fish meal. So on the Y-axis, we have the percentage of 
amino acid. On the X-axis we have just the first four limiting amino 
acids: lysine, methionone, threonine and tryptophan. And for all amino 
acids, for all these four amino acids, we can see that the threonine 
co-product contained greater levels of lysine, methionine, threonine, 
and tryptophan compared with fish meal. I want to point out that 
threonine co-product contains almost double the amount of threonine 
compared with fish meal -- 4.5% in the threonine co-product versus 2.4% 
in fish meal. And the reason for that may be that during the cell 
separation process in the steps of production of the threonine 
co-product, maybe not all the threonine that was produced in the 
fermentation broth step is removed from the cell separation step. And 
therefore, we may end up with greater concentration of threonine in this 
threonine co-product.

Slide 9
To this point, no experiments have been conducted to evaluate the 
nutritional value of the threonine co-product, and therefore our 
objectives here were first to determine the apparent and standardized 
ileal digestibility of amino acids in threonine co-product and fish 
meal; and also to determine the concentration of both digestible and 
metabolizable energy in corn, threonine co-product, and fish meal and to 
compare these values among these ingredients.

Slide 10
So for Experiment #1 ...

Slide 11
We had nine weanling barrows, with an initial body weight of 13.4 kg, 
and they were equipped with a T-cannula in the distal ileum. They were 
allotted in a triplicated 3x3 Latin square with three diets. The first 
diet had 20% inclusion of the threonine co-product, and therefore had a 
diet containing 18% of crude protein. The second diet contained 25% fish 
meal, and this diet contained also 19% crude protein. And the third diet 
was a nitrogen-free diet that was used to measure the basal endogenous 
losses of amino acids and crude protein. And we had three periods for 
this experiments.

Slide 12
For the statistical analysis, we used the MIXED procedure of SAS. The 
model included diet as a fixed effect, replicate as random effect, and 
we used the LSMeans option to calculate the means for each treatment. We 
used the Pdiff option to determine significant differences among the 
means, and an alpha level of 0.05.

Slide 13
Now let's take a look at the results.

Slide 14
All of the graphs in the results part follow the same pattern, so I'll 
just take a moment here to explain the pattern. On the Y-axis, we have 
digestibility in percent. On the X-axis, we have, on the left apparent, 
and on the right standardized ileal digestibility. And this first result 
here is for the apparent and standardized ileal digestibility of lysine. 
And we can see that threonine co-product had greater apparent and 
standardized ileal digestibility compared with fish meal -- 87.2% for 
the AID versus 81.2% in fish meal, and 92.7% standardized ileal 
digestibility in the threonine co-product versus 85.3% for fish meal.

Slide 15
The second graph shows the results for methionine. And here, once again, 
we observed that threonine co-product had greater apparent and 
standardized digestibility of methionine compared with fish meal.

Slide 16
These are the results for threonine. The threonine co-product had 88.4% 
AID compared with 66.1% in fish meal, and for standardized ileal 
digestibility we had a digestibility of 93.9% in the threonine 
co-product versus 76.8% in fish meal.

Slide 17
Now this graph shows the mean standardized ileal digestibility for 
indispensable amino acids on the left, dispensable amino acids in the 
center, and all amino acids on the right. So we observe here that 
threonine co-product had greater standardized ileal digestibility of 
indispensable, dispensable, and also mean of all amino acids compared 
with fish meal.

Slide 18
If we take the results from this experiment to calculate the 
concentration of standardized ileal digestible amino acids in threonine 
co-product and fish meal, we have these numbers shown in this table. So 
for lysine, threonine co-product would contain 4.82 g/kg compared with 
4.06 in fish meal. For methionine, the threonine co-product would have 
1.98 g/kg compared with 1.45 in fish meal. For threonine, we would have 
4.25 g/kg in the threonine co-product compared with 1.84 g/kg in fish 
meal, and for tryptophan we would have 0.94 g/kg in the threonine 
co-product versus 0.53 g/kg in fish meal. So it's consistent here that 
the threonine co-product would contain greater standardized ileal 
digestibility of at least the first four limiting amino acids compared 
with fish meal.

Slide 19
So in conclusion from this first experiment, the threonine co-product 
had greater AID and standardized ileal digestibility of amino acids 
compared with fish meal.

Slide 20
Now let's look at Experiment 2. And in this experiment our objectives 
were to measure the digestible and metabolizable energy in the threonine 
co-product compared with digestible and metabolizable energy in corn or 
in fish meal.

Slide 21
For this experiment, we used 24 barrows with an initial body weight of 
18.1 kg, and they were placed in metabolism cages and allotted to a 
randomized complete block design with three diets. The first diet was a 
corn basal diet containing 96.4% of corn. The second diet was also based 
on corn with 79.3% corn and 17% of the threonine co-product. So in this 
diet, we had approximately 4000 kcal/kg of gross energy and 21.2% crude 
protein. And the third diet we had 75.3% corn plus 25% of fish meal, and 
this diet contained also approximately 4000 kcal/kg of gross energy and 
21.4% of crude protein. And we had eight replicates for each diet.

Slide 22
The pigs were allowed for a five-day adaptation to the diet, and to the 
crates, followed by five days of total collection of feces and urines. 
And the statistical analyses that we used for this experiment were the 
same as described for Experiment 1.

Slide 23
Now let's take a look at the results.

Slide 24
This first graph shows the DE concentration, and we have on the Y-axis 
DE in kcal/kg of dry matter. The orange bar, again, is threonine 
co-product, the blue fish meal, and yellow represents corn. And these 
results show that threonine co-product had greater concentration of 
digestible energy compared with both fish meal and corn. And fish meal 
also had greater concentration of digestible energy compared with corn.

Slide 25
The results for ME concentration show that threonine co-product was not 
different from fish meal; however, both threonine co-product and fish 
meal contained more metabolizable energy compared with corn.

Slide 26
Therefore, the overall conclusions from these two experiments were that 
the threonine co-product has been shown to be an excellent source of 
crude protein and indispensable amino acids. And also it's a product 
that contains high concentration of digestible and metabolizable energy 
which are greater than in corn, and in the case of ME, is similar to 
fish meal. Therefore, this is a high value alternative feed ingredient 
for weanling pigs that can potentially replace, either partially or 
totally, the fish meal for starter diets.

Slide 27
With that, I would like to thank ADM for funding our research.

Slide 28
And I would like to thank you for listening to this podcast. You may 
visit our website at nutrition.ansci.illinois.edu and find out more 
about this ingredient and others that our lab conducts research on.