The journey of protein and starch through the gastrointestinal tract of pigs: Studying digestion kinetics by in vitro methodology

Summary

This thesis aimed to quantify the impact of dietary fibers on protein digestibility, assess a modified in vitro assay for distinguishing protein digestion kinetics across feed ingredients, and examine how grinding and pelleting affect the kinetics of protein and starch breakdown. Results showed that soluble dietary fibers decreased ileal protein digestibility more pronounced than insoluble fibers in pigs. The modified in vitro assay, which included pH adjustments during stomach incubation, more effectively differentiated the protein digestion properties of various feed ingredients and processed diets. Processing also had varying effects on starch digestion kinetics, depending on the starch source. These findings can help optimize animal feeds by balancing fiber, protein, and starch to improve digestion efficiency, ultimately supporting more sustainable feed production.