Hello everyone, this is Yanhong Liu. I'm working with Dr. Stein as a postdoc.
Today I will show a small experiment with the title, "Effects of Sal CURB on
digestibility of energy and nutrients by growing pigs."

So this is the outline for this presentation. First, I will briefly introduce
Sal CURB, and then I will move to the objective of this experiment and briefly
show the materials and methods and results, and finally I will give several key
conclusions based on the results. Lastly, I will leave you with a key
implication based on this experiment.

The FDA lists 37% formaldehyde aqueous solution as a feed additive. The
recommended dose is 0.1% pure formaldehyde in feed. So the formaldehyde can be
used as an antimicrobial agent to maintain feed negative for salmonella. And
recently, research also reported formaldehyde can be used as a potential
alternative to reduce contamination with PEDV.

Sal CURB is a products from Kemin Industries. Sal CURB is a blend of 37%
formaldehyde aqueous solution and propionic acid . From the previous slide, you
know the formaldehyde can be sued to control salmonella and PEDV in the feed.
And the propionic acid is used as a chemical preservative for control of mold in
feed or feed ingredients.

A lot of research have been reported on the effects of formaldehyde used as a
feed disinfectant, but there are limited research on the effects of formaldehyde
on nutritional value of feedstuffs fed to pigs.

Therefore, the objective of this experiment was to determine effects of Sal CURB
on apparent total tract digestibility of energy, calcium, and phosphorus; and
apparent ileal digestibility of crude protein and amino acids in diets fed to
growing pigs. The second objective was to determine the effects of Sal CURB
treatment on phytase and vitamin stability in premix.

In the next few slides, I will briefly show how we conducted this experiment.
Form this slide, you can see a table for diet formulation. So we used two diets,
the control diet and the Sal CURB diet. Both diets were based on corn, soybean
meal, DDGS, and oats, and both diets contained 0.5% chromic oxide as in
indigestible marker. The only difference for theses two diets were, the control
diet contained saline treated base mix, and the Sal CURB diet contained 32.5%
Sal CURB treated base mix.

In this experiment, we used 8 growing pigs with initial body weight around 27
kg. All pigs were installed with T-cannulas in the distal ileum. The
experimental design was a 2-period switchback design, therefore at the end of
the experiment, we had 8 replicate pigs per treatment. In each period, the first
4 days were adaptation period, and the fecal samples were collected on day 5 and
6 in the morning, and the ileal collections were started on day 6 after the
fecals. We collected 8 hours per day on day 6 and day 7.

And this slide just showed how calculated the apparent ileal digestibility. T
his is a traditional equation we used for the AID of amino acids and crude
protein, so I will not show the detail about this equation. We calculated the
AID of crude protein and amino acids, and also we calculated the ATTD of energy,
calcium, and phosphorus based on the indigestible marker.

As I mentioned before, the second objective of this experiment was to determine
the effects of Sal CURB treatment on phytase and the vitamin stability in base
mix. So therefore, we collected 24 subsamples of each base mix during diet
mixing. We sent 3 random samples to analyze phytase and the vitamins on day 0,
and the remaining subsamples were stored in the feed mill during July to August.
And we sent another 3 random subsamples on days 7, 28, and 49 for phytase and
vitamin analysis.

For the statistical analysis for the digestibility trial, all data were analyzed
using Proc MIXED with a randomized complete block design. The model included
diet as fixed effect and pig and period as the random effects. And for phytase
and vitamin analysis, all data were analyzed using Proc MIXED also, with a
completely randomized design. The model included treatment, day, and day
interaction as fixed effects.

Now, let's move to the results.

In this slide, I have the apparent ileal digestibility data. And in this figure,
I have the AID of methionine. First, let me set up the figure. I have the orange
color represent control diet, and light blue represent Sal CURB diet. And the y
axis I have the ileal digestibility value. So from this figure, we can see Sal
CURB treatment increased the apparent ileal digestibility of methionine.

But there was no difference in the AID of crude protein and other amino acids
observed between control and Sal CURB diets.

This slide is for apparent total tract digestibility of energy, calcium, and
phosphorus. First, let me set up the figure again. So, we have the similar color
represent the same diets: orange color for control diet, and light blue for Sal
CURB diet. In the x axis, from the left to right, we have the apparent total
tract digestibility of energy, calcium, and phosphorus. Compared with the
control diet, Sal CURB treatment did not affect apparent total tract
digestibility of energy. But compared with the control diet, Sal CURB treatment
increased the digestibility of calcium and phosphorus. We do not have a good
explanation for this result, because based on the ruminant data, Sal CURB
treatment decreased the digestibility of phosphorus. So, more research in the
future will be needed to figure out the findings from this experiment.

So this slide shows the phytase concentration in base mix. So again, we have the
orange color represent the saline treated base mix, and light blue represent Sal
CURB treated base mix. And in x axis, from left to right, we have day 0, 7, 28,
and 49. And the y axis we have the concentration of phytase. So from this figure
we can see, as the storage time increased, the concentration of phytase was
decreased. And the Sal CURB treatment decreased the phytase concentration
regardless of storage time. But there was no interaction between day and
treatment.

The next two slides I will show the vitamin concentration in base mix. So from
this figure you can see we have the vitamin B1, B2, B3, B6, and vitamin K3. So
in  this figure I only show the day effects on vitamin concentration. As the
storage time increased, there was no difference in vitamin B1, B2, B6, and
vitamin K3 concentration. But as the storage time increased, the concentration
of vitamin B3 was linearly increased.

In this figure, we have the concentration of vitamins B7, B9, and B12. So from
here we can see as the storage time increased, the concentration of vitamin B12
was linearly increased. But the concentration of vitamin B7 and B9 was linearly
decreased.

In this figure we have the choline concentration and the vitamin D3
concentration. There was no difference from the day effects on the choline
concentration. And also as the storage time increased, the concentration of
vitamin D3 was linearly increased.

And the last figured showed the vitamin B5 and the vitamin E concentration. As
the storage time increased, again, the concentration of vitamin B5 and vitamin E
was linearly increased.

As I mentioned before, the last four figures only showed the effects of day on
vitamin concentrations, because we didn't find any difference from the Sal CURB
treatment on the concentration of vitamins compared with the saline treatment.
Except for vitamin B1 – Sal CURB treatment increased the vitamin B1
concentration compared with the saline treated base mix.

So based on the results from this experiment, we conclude supplementation of Sal
CURB does not affect the digestibility of energy, protein, and amino acid.
Addition of Sal CURB increased the digestibility of calcium and phosphorus. As I
mentioned before, more research will be needed in the future to clarify the Sal
CURB effects on the digestibility of phosphorus and calcium.

Base mix treated with Sal CURB can be stored for 49 days without degradation of
most vitamins. The phytase in base mix decreased over time, but not below
adequate levels. But the phytase concentration were less in the Sal CURB treated
base mix compared with the saline treated base mix.

The results of this experiment indicate that Sal CURB can be added to swine
diets without diminishing the nutritional value of the diets.

Finally, thank you so much for your listening this presentation. If you have
more questions, you may get more information from our website. We have a
research report related to this presentation.