Dietary Isatidis Root Residue Improves Diarrhea and Intestinal Function in Weaned Piglets.

Simple Summary: Traditional Chinese herbal resources are abundantly available in China and have garnered significant attention owing to their distinctive pharmacological attributes, such as their antibacterial, anti-inflammatory, and antiviral properties, and their ability to regulate their host's health. Nevertheless, a considerable amount of residue remains after the extraction of these herbal medicines. Presently, limited research on the utilization of this residue has led to both resource wastage and environmental pollution. Numerous studies have indicated that the extracted residue of the Isatidis Root still contains various organic components, including amino acids, alkaloids, flavonoids, and other nutrients. Consequently, this study's objective was to explore the potential of Isatidis Root residue as an unconventional feed resource. Our findings revealed that Isatis Root residue positively impacted the diarrhea rate and intestinal health of weaned piglets. Weaning stress can trigger diarrhea, cause intestinal damage, and disrupt the intestinal flora of piglets, ultimately resulting in retarded growth or even the death of the animals. Traditional Chinese medicine residues encompass numerous bioactive compounds and essential nutrients; however, their efficient utilization remains a challenge. Consequently, our study sought to explore the impact of traditional Chinese medicine residues, specifically Isatidis Root residue (IRR), on the growth performance, intestinal function, and occurrence of weaning diarrhea in newly weaned piglets. Forty healthy, castrated Duroc × Landrace × Yorkshire males, weaned at 21 days old and exhibiting similar body conditions, were randomly allocated into five groups, with eight piglets in each group. The results indicated that the dietary inclusion of IRR at concentrations ranging from 0.5% to 4.0% notably decreased the incidence of diarrhea in weaned piglets compared to the control group (p < 0.05). Serum LDL-C and globulin (GLB) contents were reduced in response to dietary IRR concentrations (0.5% to 4.0%), while serum albumin (ALB) and albumin/globulin (A/G) contents were enhanced (p < 0.05). Dietary 0.5%, 1.0%, and 2.0% IRR resulted in significant increases in villus height (VH) and villus height/crypt depth (V/C) ratios in the jejunum, V/C ratios in the ileum, and the number of villi goblet cells both in the jejunum and ileum. IRR also led to a significant decrease in the crypt depth (CD) of the jejunum and ileum (p < 0.05). Furthermore, the expression of IL-6 in the jejunum was significantly increased in IRR-fed piglets (0.5% to 4.0%) (p < 0.05). IRR demonstrated inhibitory effects on harmful bacteria in the gastrointestinal microbiome, including Campylobacter, Actinobacillus minor, and Ralstonia pickettii, indicating its broad-spectrum bacteriostatic properties. In conclusion, dietary IRR alleviated diarrhea in weaned piglets and improved gut function and microbial compositions. [ABSTRACT FROM AUTHOR]