Investigations into the time- and dose-dependent effect of fumonisin B1 in order to determine tolerable limit values in pigs

Abstract Fumonisin B 1 (FB 1 ), a metabolite of Fusarium moniliforme , is known to cause oesophageal cancer in humans (carcinogen class 2B in the IARC classification), pulmonary oedema in pigs, and encephalomalacia in horses [Riley et al., Nat. Toxins 4 (1996) 3–15]. Experiments were carried out with weaned piglets, in order to study the dose- and time-dependent effect of FB 1 . Fungal culture of Fusarium moniliforme was added to the diet so that the FB 1 exposure was 0, 10, 20 and 40 mg/kg feed (ppm) for 4 weeks; 0, 1, 5 and 10 ppm for 8 weeks; and finally 0, 1, 5, and 10 ppm for 20 weeks. None of the toxin concentrations and the periods examined had any significant effect on feed consumption, body weight gain, and feed conversion of weaned pigs. The haematological parameters proved to be within the range of the physiological limit values. When applying higher doses (20 and 40 ppm), there was a time- and dose-dependent increase in the AST activities. In case of lower doses (1 and 5 ppm) some of the blood parameters (AST, ALT, ALKP, CREA) of the animals that developed toxin-related gross and histopathological changes were outside the physiological range. One ppm dietary FB 1 concentration was the lowest one that failed to increase the SA/SO ratio significantly. Ten to 40 ppm FB 1 fed for 4 weeks caused mild or severe pulmonary oedema, while even lower doses (1–10 ppm) fed for 2–20 weeks caused irreversible fibrosis in the lung (detected by CT examination, dissection, and histopathology).