Effects of activated charcoal-herb extractum complex on the growth performance, immunological indices, intestinal morphology and microflora in weaning piglets

Abstract

This study was conducted to evaluate the effects of activated charcoal-herb extractum complex (CHC) on the growth performance, immunological indices, intestinal morphology and microflora in weaning piglets to determine the optimal supplemental dose. A total of 216 weaned piglets (Duroc × Landrace × Large White) with an initial body weight of 8.55 ± 1.18 kg were randomly assigned to six treatment groups; each treatment group had six pens, with six pigs per pen. The study period was 28 d. Pigs were fed a corn-soybean meal-based diet supplemented with 500, 1000, 1500 or 2000 mg kg^-1 of CHC over two 14-d periods. Two additional diets containing 0 and 1000 mg kg^-1 of montmorillonite were set as the negative and positive controls, respectively. Supplementation with 500 mg kg^-1 of CHC significantly increased average daily gain compared with the positive and negative controls during phase I and the entire experimental period (P < 0.05). During phase I, 500 and 1000 mg kg^-1 of CHC significantly decreased diarrhea incidence compared with the negative control, and increased serum IGF-1 and serum IgM levels compared with the controls (P < 0.05). CHC at 500 mg kg^-1 significantly decreased the diarrhea score during the entire experimental period compared with the negative control (P < 0.05). On day 28, supplementation with 500 and 1000 mg kg^-1 of CHC increased serum IgG, IL-1β, and duodenum and jejunum secretory IgA compared with the negative control and decreased duodenum and jejunum MDA levels compared with the controls (P < 0.05). Increased duodenum and jejunum villus height and an increased ratio of villus height to crypt depth were observed compared with the negative control and decreased viable counts of E. coli in the cecum were detected compared with the controls (P < 0.05). Collectively, the optimal dose of CHC was found to be 500 to 1000 mg kg^-1 in this study.

Fig. 1. The physical characteristics of MMT and CHC. (A) The pore development of MMT and CHC as analyzed by high-resolution scanning electron microscopy (SEM). (B) The physical characteristics, including surface area and iodine sorption value, of MMT and CHC.

Fig. 2. Effects of graded levels of CHC on the intestinal mucosa SIgA and MDA levels in weaned piglets (n = 6). *Represents a significant difference between groups (P < 0.05), **represents a significant difference between groups (P < 0.01). CHC, 500, 1000, 1500 and 2000 indicate the amount of CHC added as a dietary supplement, i.e., 500, 1000, 1500 and 2000 mg kg⁻¹ of CHC per group, respectively.