Hi, my name is Carly Rundle and you are listening to the Hans H Stein Monogastric Nutrition Laboratory Podcast.
Today I will be presenting my poster from the 2022 Midwest Meeting of the American Society of Animal Science in Omaha Nebraska titled “Isoquinoline alkaloids improve intestinal function of weanling pigs fed corn-soybean meal diets formulated below amino acid requirements”. 
Previous findings have indicated that addition of isoquinoline alkaloids or IQ to diets fed to swine increases the apparent ileal digestibility of amino acids by nursery, growing, and finishing pigs – thereby increasing the bioavailablity of amino acids in the diet. Furthermore, improvements in intestinal health have been observed, including a reduction in neutrophils, increased transepithelial resistance, and morphological improvements such as an increase in villus height and a decreased lamina propria thickness. It has also been reported through numerous studies that reducing crude protein in the diet results in improvements in intestinal health as well. 
Therefore, it was the objective of this experiment to test the hypothesis that IQ fed to weanling pigs in diets formulated below amino acid requirements improves intestinal health and maintains growth performance. 
There were 2 phases in this experiment, with phase 1 lasting from d 0 to d 14, and phase 2 being from d 15 to d 27. Within each phase, there were four dietary treatments, starting with a control diet based on corn and soybean meal and formulated to be at the amino acid requirements for pigs in both life stages. The second diet was formulated to be based on the control diet, but with the addition of 120 mg/kg IQ. The third diet was formulated to be 10% below amino acid requirements for each phase of the experiment and the fourth experimental diet was based on the third diet so that it was also formulated to be 10% below amino acid requirements, but also had the addition of 120 mg/kg isoquinoline alkaloids.
Two hundred pigs with an average initial body weight of 6.11 kg were allotted to one of the four dietary treatments for the entire duration of the experiment.  Individual body weights were collected on d 14 and 27 and feed intake was calculated for phase 1, phase 2, and the overall experimental period. Plasma samples were collected on d 14 and 27, and ileal and jejunal samples were collected from 1 pig per pen on d 27.
Setting up the graphs, we have the orange bars representing the positive control groups formulated at amino acid requirements and the navy bars representing the negative control treatment groups formulated to be 10% below amino acid requirements. The stripes on the bars then indicate the inclusion of IQ to the diet. There was no effect on average daily gain by reducing the amino acids in the diet or including IQ. However, average daily feed intake tended to increase when IQ was added to the diet. Additionally, gain:feed was reduced when diets were formulated below amino acid requirements compared with the positive control diets.
Villus height tended to increase with dietary IQ and also tended to increase as amino acids were reduced in the diet; however, an interaction between the two was not observed. Lamina propria thickness was not affected when diets were formulated at amino acid requirements, but when diets were formulated below amino acid requirements, lamina propria thickness was reduced with inclusion of IQ to the diet. 
Expression of occluding, a tight junction protein in the intestine, was not affected when diets were formulated at amino acid requirements, however, when amino acids were reduced in the diet, dietary IQ tended to increase OCLN expression, indicating an improvement in intestinal barrier function.
On d 14 of the experiment, when amino acids were formulated at requirements, interleukins 4 and 10 were reduced when IQ was added in the diet, but when amino acids were below the requirement, IQ did not influence concentrations of plasma interleukins 4 and 10. Reducing amino acids in the diet reduced TNF alpha in the plasma and tended to reduce inferferon gamma and interleukin 2, indicating that reducing amino acids in the diet reduces systemic inflammation. 
In conclusion, when amino acids are provided below requirements in diets for weanling pigs, dietary inclusion of isoquinoline alkaloids modulates systemic inflammation and improves intestinal function as observed by the changes in cytokine expression in plasma  and tight junction proteins in the intestine.
Thank you so much for listening, and if you have any questions or want to learn more about our research you can email me at rundle2@illinois.edu or visit our website at nutrition.ansci.illinois.edu.