Effects of Chronic Exposure to Low Levels of Dietary Aflatoxin B1 on Growth Performance, Apparent Total Tract Digestibility and Intestinal Health in Pigs

Abstract

This study aimed to investigate the effects of chronic exposure to low levels of dietary aflatoxin B₁ (AFB₁) on growth performance, apparent total tract digestibility and intestinal health in pigs. In a 102-day experiment, fourteen barrows (Duroc×Landrace×Yorkshire, initial BW = 38.21 ± 0.45 kg) were randomly divided into control (CON, basal diet) and AFB₁ groups (the basal diet supplemented with 280 μg/kg AFB₁). Results revealed that the AFB₁ exposure decreased the final BW, ADFI and ADG in pigs (p < 0.10). AFB₁ exposure also decreased the apparent total tract digestibility of dry mater and gross energy at 50 to 75 kg and 105 to 135 kg stages, and decreased the apparent total tract digestibility of ether extract at 75 to 105 kg stage (p < 0.05). Meanwhile, AFB₁ exposure increased serum diamine oxidase activity and reduced the mRNA abundance of sodium-glucose cotransporter 1, solute carrier family 7 member 1 and zonula occluden-1 in the jejunal mucosa (p < 0.05). Furthermore, AFB₁ exposure decreased superoxide dismutase activity (p < 0.05) and increased 8-hydroxy-2'-deoxyguanosine content (p < 0.10) in jejunal mucosa. AFB₁ exposure also increased tumor necrosis factor-α, interleukin-1β and transforming growth factor-β mRNA abundance in jejunal mucosa and upregulated Escherichia coli population in colon (p < 0.05). The data indicated that chronic exposure to low levels of dietary AFB₁ suppressed growth performance, reduced the apparent total tract digestibility and damaged intestinal barrier integrity in pigs, which could be associated with the decreased intestinal antioxidant capacity and the increased pro-inflammatory cytokine production.

Keywords: aflatoxin B1; apparent total tract digestibility; growth performance; intestinal health; pigs.