Experimental porcine nephropathy: Changes of renal function and structure perorally induced by crystalline ochratoxin A. Acta path. microbiol. scand. Sect. A, 84: 429-434, 1976. Nine pigs were fed crystalline ochratoxin A in amounts corresponding to a feed level of 1 mg per kg for 3 months. The only observable lesion developed was a kidney damage, identical to the naturally occurring porcine nephropathy. The changes of renal function was characterized by impairment of proximal tubular function, indicated by a decrease of the ratio ?'mPAH/C,,,, of the ability to concentrate urine, and by an increased urinary excretion of glucose. The decrease of the ratio 1mpAH/CI,, is correlated with time of exposure to ochratoxin A. The changes of renal structure were characterized by degeneration of the proximal tubules, leading to tubular atrophy accompanied by interstitial fibrosis. At the end of the experiment the kidney, liver, adipose and muscular tissue of the slaughtered pigs contained sizable amounts of ochratoxin A residues. As the pigs would have passed the meat inspection this represents a possible health problem. T h e changes observed in this study are identical to those observed by feeding to pigs grains naturally contaminated with ochratoxin A.

The aim of this work was to investigatethe effect of stockingrate (0·6 m2 per pig or ≥1·2 m2 per pig) and faeces plus urine deposition on skatole concentration (boar taint)in subcutaneousfat. The study utilized pens with concrete flooring and different environmental temperatures.The experimental material consisted of 144 cross bred male and female pigs in each of two experiments. One experiment was carried out in the summer (temperature ≥ 22°C) and one in the winter (temperature approx. 17°C in the pig house). In both experiments, stocking rate and faeces deposition were kept constant up to first delivery to the abattoir. Then stocking rate and faeces deposition were changed to the opposite treatment a week before the last three of the four deliveries to the abattoir.The experiment confirmed the hypothesis that the pigs which lay in their faeces plusurine in pens with the high stocking rate for at least a week had a higher skatole level in subcutaneous fat than pigs kept clean in pens with the low stocking rate. It was feasible within a week before slaughter to increase or lower the skatole level by changing the treatment of the pigs.Male and female pigs showed similar differences. Air temperature (season) had a significant influence on skatole level. The level was significantly higher in subcutaneous fat at hight emperatures in the summer experiment compared to the winter experiment despite the fact that the pigs with high stocking rate in the winte rexperiment were as heavily fouled with faeces and urine as those in the summer experiment.Skatole concentrations in faeces of individual pigs were not influenced by different temperatures or treatments, and there was no significant correlation between the skatole level in faeces and in subcutaneous fat.High skatole levels in subcutaneous fat seemed to have a genetic component.It is hypothesized that skatole from faeces plusurine (excreta) especially at temperatures of 30° Cor more may pass through the skin of the pig and/or that skatole in a gaseous form may be absorbed through the lungs.

Abstract. Nine pigs were fed crystalline ochratoxin A in their feed at a concentration of about I mg/kg. Three pigs and their controls were killed after 3 months and 6 pigs and controls were killed after 2 years. A decrease of the ratio TmlB..tI1/CI,,. increased urinary glucose excretion and decreased ability to concentrate urine. occurred within a few weeks and aggravated slightly during the 2-year period. Changes in renal structure. characterized by degeneration and atrophy of proximal tubules. interstitial fibrosis and hyalinization of glomeruli, were progressive during time of exposure. but terminal renal failure was not reached. The kidney. liver. muscular and adipose tissue contained 3 to 27 p g ochratoxin A/kg after 3 months of exposure. N o further accumulation of ochratoxin A residue was found after 2 years of exposure.Mycotoxic nephropathy is a naturally occurring disease of pigs and poultry [5, 81. Ochratoxin A, a dihydroisocoumarin derivative linked through its 7 carboxy group to L-P-phenylalanine, is a nephrotoxic mycotoxin of several species belonging to the fungal genera Aspergillus and Penicillium. This compound. occurring in feeds and foods, has been observed as a major disease determinant of porcine and possibly also avian nephropathy [5, 61. Porcine nephropathy similar to that of naturally occurring cases [3, 141 has been reproduced by exposure to ochratoxin A during a 3-to 4-month period [7]. Ochratoxin A has been suggested as a causal determinant of Balkan (endemic) nephropathy [4]. A recent survey indicated that foodborn exposure to ochratoxin A is higher in an endemic area than in nonendemic areas [ 121.