Hi, everyone. 
My name is Su A Lee.
Today, we’ll be discussing Effects of a T-cannula on growth performance, digestibility of energy, and metabolizable energy in a corn-soybean meal diet.
This work was presented in 2025 ASAS Midwest meeting.

Even though nutrients from feed are broken down by digestive enzymes secreted from the body and absorbed in the jejunum and before the end of ileum, some nutrients undergo fermentation in the hindgut of pigs. 
Therefore, the byproducts of fermentation, along with some other nutrients, are absorbed in the lower part of the intestinal tract and may contribute to the pig's growth.
This is one of the reasons that a T-cannula is often inserted into the distal ileum of pigs to determine the ileal digestibility of amino acids (AA) and other nutrients
Sometimes we conduct experiments where both ileal digesta and fecal samples are collected to determine ileal and total tract digestibility. 
Therefore, if digesta are removed, it is possible that this will affect the total tract digestibility values and the growth performance of pigs because fewer nutrients move to the hindgut for further utilization.
However, there are no data to demonstrate this. 
Therefore, an experiment was conducted to test the null hypothesis that installing a T-cannula and collecting ileal digesta do not influence the apparent total tract digestibility of nutrients and concentrations of digestible and metabolizable energy in diets fed to pigs.
For this experiment, we used a corn-soybean meal based diet and all pigs were fed the same diet.
This diet contained all nutrients to meet requirements for 25 to 50 kg pigs and the diet was in a mash form.
A total of 24 pigs were used and the initial body weight was approximately 21 kg.
Pigs were fed for 56 days. These days were divided into 4 periods. We chose to go with the longer periods because we often use a latin square design due to the limited number of pigs. 
The pigs were allotted to 3 treatments to have 8 rep per treatment per period.
Therefore, there were a total of 32 replicate pigs per treatment.
First treatment was using pigs without cannulation
The second treatment was using pigs that were cannulated at the distal part of ileum,
 but any ileal digesta were not collected from these pigs.
The third treatment was using pigs that were cannulated at the distal part of ileum and ileal digesta were collected for 2 days in each period. Therefore, there were 4 collections throughout the experiment.
Moving on to the sample collection, 
In each collection period, after 5 days of adaptation, 
fecal and urine samples were quantitatively collected for 4 days. 
As explained earlier, ileal digesta were collected only from 8 pigs on the treatment with cannulated pigs used for ileal digesta collection. 
Apparent total tract digestibility of nutrients and concentrations of digestible and metabolizable energy were calculated using the analyzed nutrients and energy in diets, feces, and urine.
And average daily gain, average daily feed intake, and gain to feed ratio were also calculated for all treatments.
The statistical model included treatment as fixed variable and period as random variable. Means were separated using pdiff with Tukey’s adjustment if the model was significant. 
For the growth performance data, a repeated measures analysis was performed to evaluate the effects of treatment on growth performance over time, with pig as the subject.
Moving on to the results of the overall growth performance, the initial body weight was not different among the three treatments, but the final weight of pigs were reduced when pigs were cannulated.
However, collecting ileal digesta did not change the final weight of pigs. 
Average daily feed intake of non-cannulated pigs tended to be greater and average daily gain and gain to feed ratio of non-cannulated pigs were greater compared with cannulated pigs.
However, these were not influenced by ileal digesta collection. 
The apparent total tract digestibility, ATTD, of dry matter and gross energy were greater in diets fed to non-cannulated pigs compared with cannulated pigs, but there were no differences between cannulated pigs without or with ileal digesta collection. 
Concentrations of digestible and metabolizable energy were greater in diets fed to non-cannulated pigs compared with cannulated pigs, but, again, there were no differences between cannulated pigs without or with ileal digesta collection. 
The apparent total tract digestibility, ATTD, of nitrogen was greater in diets fed to non-cannulated pigs than in diets fed to cannulated pigs without ileal digesta collection. However, no differences were observed between non-cannulated pigs and cannulated pigs with digesta collected and between the two cannulated pig groups.
As observed in other criteria, the ATTD of fat and total dietary fiber was greater in non-cannulated pigs compared with cannulated pigs, but there were no differences between the two cannulated pig groups.
From the results, we concluded that
Inserting a T-cannula into the distal ileum reduced growth performance of pigs and digestibility of energy and nutrients. 
However, collecting ileal digesta from the cannulas did not affect digestibility, energy concentrations, or growth performance of pigs, which indicated that the amount of ileal digesta that are removed during a 2-day collection period, is not big enough to negatively affect total tract digestibility, or growth of pigs.
Future research is needed to evaluate the effects of cannulation and ileal digesta collection when high-fiber feed ingredients are used. High fiber may contribute significantly to energy through hindgut fermentation. Therefore, the removal of ileal digesta may alter the substrate availability for fermentation in the large intestines.
In this study, total feces were collected. However, in some experiments, fecal samples are collected partially from cannulated pigs, which may introduce variability and potentially affect the results. Therefore, future research is needed to compare total versus partial fecal collection methods and determine the impact.
Thank you for listening to my presentation and I would like to acknowledge everyone from Dr. Stein’s lab. 
If you want to learn more about our research that we are conducting in the Stein Monogastric Nutrition Laboratory, please visit our website. Thank you.