Effects of fermented mulberry leaves on growth performance, nutrient digestibility, diarrhea, and intestinal...

This study investigated the effects of dietary fermented mulberry leaves (FML) on growth metrics, nutrient digestibility, diarrhea incidence, and gut microbial ecology in weaned piglets. A total of 200 piglets (28 days old) were randomly allocated into five groups: a basal diet control group and four treatment groups receiving the basal diet supplemented with 5%, 10%, 15%, or 20% FML (co-fermented with Lactobacillus and cellulase) over a 28-day period. Growth performance, apparent nutrient digestibility, diarrhea rate, intestinal pH, short-chain fatty acid (SCFA) concentrations, and cecal microbiota (via 16S rRNA sequencing) were evaluated. No notable differences in growth performance were detected across groups (P > 0.05); however, the feed-to-gain ratio was significantly lower in the 5% and 20% FML groups (P < 0.05). Diarrhea incidence declined across all FML-supplemented groups, with the greatest reduction (52.46%) in the 15% group during days 28-42. Duodenal pH decreased significantly in all treatment groups (P < 0.05). Cecal acetate and propionate levels rose markedly in the 10%, 15%, and 20% groups (P < 0.05), with the 15% group showing a 47.05% increase in acetate. FML supplementation also altered cecal microbial diversity and community composition. At the genus level, the 15% group had the highest relative abundance of Prevotella (22.46%), while Lactobacillus and Bifidobacterium tended to increase in FML groups. Overall, dietary inclusion of 5-20% FML did not significantly enhance growth performance but effectively reduced diarrhea, optimized intestinal pH, increased cecal acetate and propionate production, and modulated cecal microbiota composition, with 15% FML identified as the optimal level.