Effects of a charcoal powder-wood vinegar compound solution in piglets for raw pigeon pea seed meal

Histological intestinal villus alterations were studied in piglets fed a raw pigeon pea meal (PM) diet including a powder mixture of amorphous charcoal carbon and wood vinegar compound solution (CWVC). Twenty-eight male castrated piglets were divided into seven dietary groups of four piglets each. The control group was fed raw PM supplemented to the basal diet (178 g/kg crude protein, 4.23 kcal/g gross energy) at 0 g/kg (CONT), 200 g/kg (PM200) and 400 g/kg (PM400). The treatment groups were fed CWVC in both PM200 and PM400 diet groups at levels of 10 g/kg and 30 g/kg (PM200 + CWVC10, PM200 + CWVC30, PM400 + CWVC10 and PM400 + CWVC30). With increasing dietary PM levels, daily feed intake tended to increase. In contrast, daily body-weight gain tended to decrease, significantly in the PM400 group (P < 0.05), resulting in a significant decrease of feed efficiency in PM groups (P < 0.05). Body-weight gain and feed efficiency were higher in the CWVC groups compared with the PM groups. The duodenum and ileum were longer (P < 0.05) in the PM400 group than in CONT, but were similar to CONT in CWVC groups. The liver was heavier (P < 0.05), whereas the weights of the heart, kidney and stomach were decreased in the CWVC groups than in other groups. Most values for the intestinal villus height, cell area and cell mitosis number were lower in PM groups than those in CONT (P < 0.05) for each intestinal segment; however, these values were higher in CWVC groups than in PM groups (P < 0.05). The epithelial cells on the duodenal villus surface of the PM200 group showed cell morphology almost similar to CONT. However, the PM400 group had a smooth villus surface due to the presence of flat cells. The epithelial cells of the CWVC groups were protuberated, resulting in a much rougher surface than CONT. The current growth performance and histological intestinal alterations in piglets fed PM and PM + CWVC diets demonstrate that the intestinal features might be atrophied by feeding PM, resulting in decreased growth performance. CWVC might prevent the harmful effects of PM dietary toxins on intestinal function, resulting in a normal growth performance.