INVESTIGATION INTO THE EFFECT OF TOXINS P RODUCED BY FUSARIUM-MONILIFORME IN PIGS - I - DEFINITION OF TOLERANCE LIMIT VALUES IN WEANED PIGLETS - PRELIMINARY PUBLICATION

In this experiment, in order to define tolerance limit values, the eff ect of exposure to fumonisine B-1 in low doses for relatively brief pe riod (4 weeks) was examined in weaned piglets. Fusarium moniliforme fu ngal culture was mixed into the diet fed to the animals such as to set daily intake of fumonisine B-1 at levels of 0, 10, 20 and 40 mg per k g diet. Feeding with the toxin was observed to exert no significant ef fect on body weight gain and feed consumption in the animals. During t he experimental period there was no change in the behaviour of the pig lets, no clinical signs (rapid, difficult breathing) were observed and no mortality traceable to toxic effect occurred. In computer tomograp hic examinations performed in the second and fourth weeks mild and mor e severe pulmonary oedema was diagnosed in the experimental animals (F igure 1) although no symptoms of difficulty in breathing were observed . Using the data obtained from the experiments performed 90 HU variabl es within the range (-) 850 to 40 on the Haunsfield scale, used to cha racterise tissue density, were defined to refer to the pulmonary paren chyma, and from these variables so-termed HU indices were determined ( Figure 2), in accordance with the following relation: Sigma(-) 400 - 4 0 HU /Sigma (-) 850 - 40 HU. On the basis of results of the T-test per formed using the HU indices calculated, in the groups subjected to the toxin treatment significant difference (P < 0.05) between the 1st-3rd and the 2nd-3rd point of examination was statistically proven. In the images obtained from the magnetic resonance (MR) examinations perform ed at the same points in time as the CT examinations - presumably in c onsequence of the relatively brief experimental period - no group show ed significant change in cerebral tissue with the use of either native or contrast material. Dissection revealed mild cases of pulmonary oed ema in 3 of the animals subjected to a dosage of 10 ppm (n=4), 2 mild and 2 severe cases in those exposed to 20 ppm (n=5) and severe cases i n all 5 animals given 40 ppm (Table 1). In the case of mild pulmonary oedema serous infiltration and a minor degree of widening of the septa between the lobules in one lobe of the lung or extending into the who le lung a ere observed. The lungs were found to be slightly enlarged a nd stiff to the touch. In cases of severe pulmonary oedema the lungs d id not collapse on opening up of the thorax; they were shown to be enl arged and their weight greater (Table 2), while being more compact to the touch and showing a greater degree of widening in the septa betwee n the lobules.