COMPARATIVE ANALYSIS OF PROBIOTIC-ENHANCED FEED ON IMMUNE MODULATION AND ANTIMICROBIAL RESISTANCE IN SWINE GUT MICROBIOTA

Abstract

Post-weaning diarrhea (PWD) remains a major threat to swine health and production, characterized by complex etiologies involving enteric pathogens, immune immaturity, and environmental stressors. This study employed a mixed-methods experimental design to evaluate the effectiveness of phytobiotic, probiotic, and combined interventions in mitigating PWD in piglets. A total of 120 piglets were randomly assigned to four groups: control, phytobiotic, probiotic, and phytobiotic-probiotic combination. Clinical monitoring revealed that the dual-treated group exhibited the most substantial improvement in average daily gain (0.58 g/day) and the lowest fecal consistency scores. Microbial analysis using qPCR and 16S rRNA sequencing showed a ~70% reduction in pathogen load, particularly targeting enterotoxigenic E. coli and Clostridium perfringens. Histological assessments demonstrated the most favorable villus-to-crypt ratios and goblet cell densities in the combined treatment group. Multivariate regression confirmed treatment group, pathogen burden, and gut morphology as key predictors of diarrhea severity (p < 0.05). Thematic analysis from qualitative interviews further validated the role of contextual farm management practices in influencing outcomes. Collectively, these findings endorse a synergistic, non-antibiotic intervention strategy for effectively reducing PWD and enhancing piglet health, offering a promising alternative to conventional prophylactic treatments.