Slide 1

Hi everybody, my name is Oscar Rojas, Ph. D. student at the University 
of Illinois at the Stein Monogastric Nutrition Laboratory. And today I 
have the pleasure to talk about energy, phosphorous, and amino acid 
digestibility in Lemna protein concentrate, fish meal and conventional 
soybean meal fed to weanling pigs.

Slide 2
 
This is the outline of my presentation. I will start with a brief 
introduction where I will explain how Lemna protein concentrate is 
produced. And then I will move on to the three digestibility 
experiments: energy, phosphorus, and amino acids. And then I will finish 
my presentation with some conclusions and the implications of this 
research.

Slide 3

To explain how Lemna protein concentrate is produced, it is important to 
mention that the Lemna plant is also known as a duckweed, and it is a 
flee floating aquatic plant that grows rapidly on the surface of water. 
Lemna has a relatively high concentration of nutrients and contains from 
35 to 45% of crude protein and crude fiber range from 7-10%. And 
commercial production of Lemna takes place mainly in tropical climates.

Slide 4

The production of Lemna protein concentrate begins when the Lemna plant 
is harvested. This process separates the liquid portion out of the the 
pulp portion. When in the process they use the liquid portion, Lemna 
protein concentrate is produced. And this product can be used as an 
ingredient in the animal feed field and it has been in testing to be 
included in human food. On the other hand, the pulp portion can be used 
either to produce Lemna meal or biocrude. The Lemna meal can be used as 
an animal feed ingredient, and this ingredient is quite similar to 
alfalfa meal and that is what can be used to feed cattle. And the 
biocrude is used to produce renewable fuels.

Lemna protein concentrate contains approximately 68% of crude protein. 
This has a relatively high concentration of indispensable amino acids. 
And it is therefore possible that Lemna protein concentrate can be used 
as a replacement for traditional protein sources in diets fed to pigs; 
but at this point, no data on the nutritional value of Lemna protein 
concentrate fed to pigs are available. And at this point, I would like 
to mention that this product is produced for a company called Parabel.


Slide 5

This table shows the nutritional composition of Lemna protein 
concentrate, fish meal, and conventional soybean meal. We observed that 
the Lemna protein concentrate contained 93.9% of dry matter, and in the 
case of fish meal and soybean meal, it's 89.9 and 89.4 respectively. As 
we can also see here, crude protein concentration in Lemna protein 
concentrate is 68%, in fish meal 63.2, and 48% in soybean meal. The 
concentration of acid hydrolyzed ether extract, phosphorus, and ash is 
numerically greater in fish meal than in Lemna protein concentrate and 
soybean meal. And the concentration of gross energy in kcal per kg in 
Lemna protein concentrate is 5800, in fish meal is around 4400, and in 
conventional soybean meal, 4300.

Slide 6

The objective of this research was to determine the concentration of DE 
and ME, and calculate the standardized total tract digestibility of 
phosphorus and the standardized ileal digestibility of crude protein and 
amino acids, in Lemna protein concentrate; and to compare these values 
with values in fish meal and soybean meal.

Slide 7

Let's start with the energy digestibility experiment.

Slide 8

For this experiment, we used 32 barrows with initial body weight of 16.8 
kg. We had four treatments with eight pigs per treatment, and fecals and 
urine samples were collected for five days after five days of adaptation 
period.

Slide 9

For this experiment, we formulated a corn basal diet in addition to 
three experimental diets which contained the test ingredient -- Lemna 
protein concentrate, fish meal, and soybean meal -- in addition with 
corn.

Slide 10

The data were analyzed by ANOVA using the Proc Mixed procedure of SAS. 
The fixed effect was the diet and the random effects were the pig and 
the replication.

Slide 11

Let's move on into the results.

Slide 12

In this slide, we observe the apparent total tract digestibility of 
gross energy. In the X axis, we have from left to right: corn, Lemna 
protein concentrate, fish meal, and conventional soybean meal; and in 
the Y axis we have the apparent total tract digestibility in percentage. 
We observe that the apparent total tract digestibility of gross energy 
was less in Lemna protein concentrate than in corn, fish meal, and 
conventional soybean meal, and no difference were observed among corn, 
fish meal and conventional soybean meal.

Slide 13

Now, we are looking at the DE concentration on a dry matter basis. The 
DE concentration was less in corn than in the other test ingredients, 
but the DE in fish meal was less than in soybean meal but not different 
than in Lemna protein concentrate.

Slide 14

However, when we are looking at the ME concentration, also on a dry 
matter basis, we observe that no difference were detected among test 
ingredients.

Slide 15

So the conclusion of this experiment is that the apparent total tract 
digestibility of gross energy was less in Lemna protein concentrate than 
in the other ingredients, but the ME was not different was not different 
from the ME in corn, soybean meal, and fish meal. And the implication of 
this research is that the concentration of ME will, therefore, not be 
changed if Lemna protein concentrate is used in diets fed to pigs.

Slide 16 

Now let's move on to the second experiment: phosphorus digestibility.

Slide 17

In this experiment, we used 24 barrows with initial body weight of 12.5 
kg. We have three treatments with eight pigs per treatment, and in this 
experiment feces were collected for five days after five days of 
adaptation period. And data were analyzed as explained for Experiment 1.

Slide 18

This slide shows the ingredient composition of the experimental diets. 
As mentioned before, we formulated three experimental diets where each 
test ingredient was the only source of phosphorus in the diet. We 
observed in the first row the test ingredient -- Lemna protein 
concentrate, fish meal, and conventional soybean meal -- and in the 
second row we have several ingredient such as corn starch, sugar, 
soybean oil, vitamins and minerals, and salt.
 
Slide 19

Now, let's move on into the results.

Slide 20

In this slide, we can see the standardized total tract digestibility of 
phosphorus. The orange bars represent, from left to right in the X axis: 
Lemna protein concentrate, fish meal, and conventional soybean meal. And 
in the Y axis we have the standardized total tract digestibility in 
percentage. We see here that no differences were observed among 
ingredients. However, the standardized total tract digestibility of 
phosphorus has a tendency to be greater in Lemna protein concentrate 
than in conventional soybean meal. And the reason of this observation 
could be explained due to the less concentration of phytate in Lemna 
protein concentrate than in soybean meal. And this indicates that there 
is a greater concentration of non-phytate bound phosphorus in Lemna 
protein concentrate, and this means that the more phosphorus is 
available to be absorbed in this ingredient.

Slide 21

And the conclusion of this experiment is that the standardized total 
tract digestibility of phosphorus had a tendency to be greater in Lemna 
protein concentrate than in soybean meal.

Slide 22

Now, let's move on to the last experiment of today's presentation: amino 
acid digestibility.

Slide 23
 
In this experiment, we used eight barrows with initial body weight of 
21.4 kg. Four diets were formulated. Each period was considered seven 
days; and the first five days were the adaptation period, and ileal 
samples were collected for eight hours on days 6 and 7.  The design of 
this experiment was a repeated 4x4 Latin square design with four periods 
and four diets.

Slide 24 

Here, we can see the composition of the experimental diets. A 
nitrogen-free diet was formulated to calculated the basal endogenous 
losses of crude protein and amino acids. And these values were corrected 
the apparent ileal digestibility of amino acids and crude protein to 
calculate the standardized ileal digestibility of amino acid and crude 
protein. In this experiment we used the difference procedure. And that 
is why we formulated a soybean meal basal diet in addition to the Lemna 
protein concentrate and fish meal diets. And that's why you observe that 
soybean meal was included also in the test ingredients: to be able to 
calculate the amino acids and crude protein digestibility by difference.

Slide 25 

The data were analyzed by ANOVA using the Proc Mixed procedure of SAS. 
The fixed effect was the diet and the random effects were the pig and 
the replication.

Slide 26

Now, let's move on into the results.

Slide 27

Now, we are looking at the standardized ileal digestibility of lysine. 
We have, on the X axis: in green, Lemna protein concentrate, in orange, 
fish meal, and in blue, conventional soybean meal. And in the Y axis we 
have the standardized ileal digestibility in percentage. The SID of 
lysine was greater in fish meal than in Lemna protein concentrate, but 
less than in conventional soybean meal.

Slide 28

Now, when we are looking at the SID of methionine, this follows the same 
pattern as the SID of lysine: it was greater in soybean meal than the 
other test ingredients.
 
Slide 29
 
And the SID of threonine here also followed this pattern of the two 
previous amino acids: it was less in Lemna protein concentrate than in 
the other ingredients, but it was less in fish meal than in conventional 
soybean meal.

Slide 30

And the conclusion of this experiment is that there was some difference 
in the SID of amino acids between fish meal and Lemna protein 
concentrate, but in average, most of the amino acids were not different 
between these two ingredients. But the SID of most amino acids was 
slightly less in Lemna protein concentrate than in conventional soybean 
meal.

Slide 31

So the overall conclusions for these three experiments are that the ME 
concentration in Lemna protein concentrate was not different from the ME 
in corn, fish meal, and conventional soybean meal. Also that the 
standardized total tract digestibility of phosphorus had a tendency to 
be greater in Lemna protein concentrate than in soybean meal, the amino 
acids in Lemna protein concentrate were relatively well digested, but 
for most amino acids, there were no differences between the amino acids 
in Lemna protein concentrate and fish meal.

Slide 32

And with this, I would like to thank you for your attention. And you are 
welcome to view and read other information in our website.