Slide 1
Hi, I'm Ferdinando Almeida. I'm a Ph.D. student at the Hans Stein 
Monogastric Nutrition Laboratory, and I'm here today to talk about amino 
acid digestibility in blood products fed to weanling pigs.

Slide 2
This is the outline of this presentation. I'll give a background on the 
blood product that we're going to be using for this experiment, and 
discuss some of the materials and methods, show some results, and a 
little bit of a discussion and some final conclusions.

Slide 3
Because of the high nutritional quality of blood products which are 
produced from the slaughter industry, these products may be used in 
diets for pigs. However, the quality of blood products may be affected 
by the processing that is involved when producing these products. Such 
processes include spray drying, which yields spray dried products. We 
may also have other types of dryers, such as ring, drum, or disc, which 
may produce the meal products. And it has been shown that there is 
variation in pig performance when feeding one or another type of blood 
products.

Slide 4
So in this first diagram, I want to explain how the spray dried blood 
products are obtained. So, starting from the top left, we have whole 
blood. That whole blood can be spray dried, and then we have spray dried 
animal blood or SDAB. We may also take this whole blood and run it 
through a centrifuge to separate plasma, which is about 55% of whole 
blood, and also separate into blood cells, which is approximately 45% of 
whole blood. Now, if we take plasma and spray dry, then we have spray 
dried plasma protein, or SDPP, and if we take blood cells and spray dry, 
we have spray dried blood cells, or SDBC. Please get familiar with these 
abbreviations, as I will be using them throughout the rest of the 
presentation.

Slide 5
Now, to produce blood meal, we start off with whole blood, which can be 
obtained from avian species, from porcine, and also from bovine species, 
and this whole blood goes through an accumulation tank, which is 
followed by a coagulator, a decanter, and then, in the final processes, 
it goes through a dryer. And as I said in the beginning, this dryer can 
be a ring dryer, a drum dryer, or a disc dryer. And all these three 
types of dryers will produce a blood meal at the end.

Slide 6
But the problem with the drying process is the Maillard reactions that 
may occur. And these Maillard reactions, they may decrease the amino 
acid concentration and also digestibility, but specifically we're 
concerned about lysine, which is normally the amino acid most affected 
by heat processing of feed ingredients. The crude protein concentration, 
however, is relatively constant among feed ingredients that have been 
heat processed at different degrees of heat, and therefore, we can 
calculate the lysine:crude protein ratio and use that value to estimate 
the degree of heat damage in feed ingredients.

Slide 7
There is no comparative data on the amino acid digestibility in 
different blood products fed to weanling pigs, and therefore, the 
objectives of this experiment were to compare the AID, or apparent ileal 
digestibility, and the SID, or standardized ileal digestibility, of 
crude protein and amino acids in spray dried animal blood, spray dried 
blood cells, spray dried plasma protein, and two sources of blood meal: 
one from avian species, so avian blood meal, and another one from 
porcine species, so porcine blood meal.

Slide 8
Now for the materials and methods.

Slide 9
We used seven weanling barrows with an initial body weight of 11.5 kg. 
They were surgically equipped with a T-cannula in the distal ileum, and 
they were allotted to a 7x7 Latin square design with seven diets and 
seven periods.

Slide 10
This table shows the diet composition. And here, in the first column, we 
have the diet containing spray dried animal blood. That diet contained 
9% of casein, and 9% of spray dried animal blood. And we also included 
some cornstarch, about 34%, lactose at 20%, sugar 15%, and others making 
up for 13% of the diet. All diets containing the blood products, they 
contained 9% of the blood product that was used, and also 9% of casein. 
So we calculated the SID of amino acids and crude protein by the 
difference procedure. The last diet on the right was a casein diet, 
which contained 18% of casein. We also formulated a nitrogen-free diet, 
which was used to determine the basal endogenous losses of crude protein 
and amino acids.

Slide 11
Pigs were fed three times the daily maintenance energy requirement, and 
as I said before, we calculated AID and SID by the difference procedure 
as outlined by Fan and Sauer in 1995.

Slide 12
Data were analyzed using the mixed procedure of SAS. The model included 
diet as the fixed effect, pig and period as random effects. And we used 
LSMeans to calculate means and the PDIFF option to separate the means 
with an alpha level of 0.05.

Slide 13
Now, let's move on to the results.

Slide 14
In this first graph, we have the standardized ileal digestibility of 
crude protein. So, on the Y axis, we have digestibility in percent, and 
on the X axis, we have the first three bars in orange representing the 
spray dried products, and the two columns on the right represent the two 
sources of blood meal: avian blood meal or porcine blood meal. And what 
we observed here is that the SID of crude protein was not different 
among the three sources of spray dried blood products. However, the SID 
of crude protein in the spray dried blood products was greater than the 
SID of crude protein in the two sources of blood meal, which were not 
different among themselves.

Slide 15
For the SID of lysine, we observed again that there were no differences 
among spray dried blood products. However, the SID of lysine in the 
spray dried blood products was greater than the SID of lysine in blood 
meal.

Slide 16
Now for the threonine. We observed a similar pattern as for SID of crude 
protein and also as for SID of lysine.

Slide 17
And again, for tryptophan, we also observed that there were no 
differences among the spray dried blood products, but the SID of 
tryptophan in these products was greater than the SID of tryptophan in 
the two sources of blood meal.

Slide 18
Now, moving on to the discussion.

Slide 19
First, the SID values for spray dried plasma protein agree with previous 
data. And we did observe that the SID values for spray dried animal 
blood were slightly above 100%, and this has been observed previously 
for blood products as well. And some of this may be explained by the 
variability in endogenous amino acid losses among diets.

Slide 20
We also observed that the digestibility of amino acids and crude protein 
was greater for the spray dried products versus the blood meal products. 
And this may be explained by the drying processes, which may cause some 
heat damage. In this process, Maillard reactions occur, and the Maillard 
reactions are the condensation of reducing sugars and amino acids or 
protein, and as I said, lysine is the most affected. And because of 
these reactions, lysine becomes unavailable to pigs. There is also some 
protein cross-linkages that are formed during these Maillard reactions, 
and these cross links may reduce the digestibility of other amino acids. 
Therefore, from this, we believe that spray drying is a more gentle 
processing of drying feed ingredients, as it may cause less heat damage. 
And this is supported by the lysine:crude protein values that we 
calculated for the spray dried products, which was 9.3, versus 8.6 for 
blood meal. So this indicates that blood meal is indeed more heat 
damaged than spray dried products, and this may be the reason why we 
observed less digestible amino acids for blood meal compared with spray 
dried products.

Slide 21
So we conclude from this experiment that blood products are excellent 
sources of crude protein and amino acids, spray dried products have SID 
of crude protein and amino acids that is close to 100%, and blood meal 
is less digestible than spray dried products. And we also observed that 
there were no differences among animal sources, so if you have an avian 
blood meal or a porcine blood meal, we should not see any differences in 
the digestibility of crude protein and amino acids.

Slide 22
I would like to acknowledge Evonik Industries for funding this project.

Slide 23
And I thank you all for listening to today's presentation.