Increased dietary protein rather than fiber supports key metabolic and intestinal tissue functions in pigs, without increasing post-weaning diarrhea

The postweaning period in pigs is a critical window where nutritional interventions are implemented to prevent postweaning diarrhea (PWD) and antibiotic use. One common strategy is feeding low-protein diets immediately following weaning. This intervention may reduce protein fermentation and pathogen proliferation, therefore decreasing the incidence of postweaning diarrhea. These effects may also be mitigated by providing dietary fiber. However, studies examining the role of protein and fiber on gastrointestinal microbiota and metabolism are complicated by the presence of other substrates, including polyphenols and antinutritional factors in complex ingredients. In this study, semipurified diets formulated to meet nutrient requirements were fed to 40 weaned pigs (