Dietary fumonisin may compromise the nutritive value of feed and distort copper and zinc digestibility and retention in weaned piglets

Fumonisins (FUM) have been reported to impede gut functioning in pigs. However, investigations into the possible effect on mineral metabolism are limited. Thus, the trial studied the apparent total tract digestibility (ATTD) and retention of dietary nitrogen and minerals, intestinal architecture, digestive enzymes activity and heat-shock protein 70 (Hsp70) activity. Eighteen weaned piglets of 7 weeks old were assigned to three groups and their feed either contained 0, 15 or 30 mg FUM/kg for 21 days. ATTD and retention of dietary N and minerals were measured in a 5- day long balance trial between Day 17 and Day 21. The digestible and metabolisable energy (DE and ME) content of the feeds were also determined. The body weights, cumulative feed intake, relative organ weights, digestive enzymes activity and intestinal morphology were not affected (p > 0.05) by dietary treatments. The DE content was significantly lower (p < 0.05) when the feed contained 15 mg/kg FUM, but no statistically reliable treatment effect was confirmed for ME content. Dietary FUM significantly lowered (p < 0.05) the ATTD of Ca and P but not (p > 0.05) N, K, Mg and Na. The relative retention rate of N, Ca, P, K, Mg and Na in all groups were not impacted (p > 0.05) by treatments. The ATTD and relative retention of Cu and Zn were remarkably (p < 0.05) lower in piglets fed FUM-contaminated feed. In addition, the expression of Hsp70 activity in the liver was significantly elevated (p < 0.05) in the highest treatment group. These findings suggest that a dietary dose of 15 or 30 mg FUM/kg diet distorts the nutritive value of the mixed feed, results in poor ATTD and retention rates of Zn and Cu, and elevate Hsp70 activity in the liver without altering intestinal architecture or digestive enzymes' activity in weaned piglets.

A preliminary study on changes in heat shock protein 70 levels induced by Fusarium mycotoxins in rats: in vivo study

The heat shock protein (Hsp70) level was assessed after 14 days of oral gavage-exposure to fumonisin B₁ (FB₁: 150 µg/animal/day), deoxynivalenol (DON: 30 µg/animal/day) and zearalenone (ZEN: 150 µg/animal/day), alone or in combinations (in additive manner: FD = FB₁ + DON, FZ = FB₁ + ZEN, DZ = DON + ZEN and FDZ = FB₁ + DON + ZEN) in the liver, kidneys and lung of 24 adult male Wistar rats (n = 3/group). The liver was the most responsive tissue, as compared with kidney and lung. Except of DZ-treatment, mycotoxins elevated the Hsp70 levels in livers. The highest Hsp70-levels (≈ twofold) were in the DON, FD, FZ and FDZ treatments (additive effects). In the kidney, alterations (↑ ≈ twofold) were detected in ZEN, FD, FZ and DZ treatments. The least responsive organ was the lung (↑ only in FDZ, antagonistic effect). DON and ZEA exposures have altered the reduced glutathione concentration (↓) and glutathione peroxidase activity (↓) in the blood serum. The serum malondialdehyde level increased only after exposure to FD (synergistic effect), as compared with the DZ group (antagonistic effect). When the blood clinical chemistry was assessed, significant alterations were in alanine aminotransferase (80% increase in FDZ, antagonistic effect) and total protein (↓ ZEN). Results varied according to the organ, toxin type and interactions. Furthermore, oxidative stress was not the only key player behind the Hsp70 increase, in which another mechanism is suggested.