Effects of Chronic Exposure to Low Levels of Dietary Aflatoxin B(1) on Growth Performance, Apparent Total Tract Digestibility and Intestinal Health in Pigs

SIMPLE SUMMARY: Aflatoxin B(1) (AFB(1)) is one of the most toxic mycotoxins compounds produced by Aspergillus, a common fungi contaminant in food and animal feed. Although there are many studies on AFB(1), most of them are focused on the acute toxic effects of high-dose AFB(1) ingestion. The symptoms of acute AFB(1) mycotoxicosis are rarely observed in actual animal production. However, long-term exposure to low levels of AFB(1) is common in swine production and may contribute to chronic diseases. Therefore, this study investigated the effects of chronic exposure to low levels of dietary AFB(1) on growth performance, apparent total tract digestibility and intestinal health in pigs. We found that chronic exposure to low levels of dietary AFB(1) suppressed growth performance, reduced 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. These results could provide new insights for future studies on the prevention and treatment of AFB(1) poisoning. ABSTRACT: This study aimed to investigate the effects of chronic exposure to low levels of dietary aflatoxin B(1) (AFB(1)) 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 AFB(1) groups (the basal diet supplemented with 280 μg/kg AFB(1)). Results revealed that the AFB(1) exposure decreased the final BW, ADFI and ADG in pigs (p < 0.10). AFB(1) 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, AFB(1) 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, AFB(1) exposure decreased superoxide dismutase activity (p < 0.05) and increased 8-hydroxy-2′-deoxyguanosine content (p < 0.10) in jejunal mucosa. AFB(1) 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 AFB(1) 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.