Each farm was sampled twice and a total of 30 feed samples and 285 serum samples were collected.
OTA levels were determined through extraction, immunoaffinity column purification and high-performance liquid chromatography analysis coupled with fluorimetric detection.
Results
All feed samples resulted to be contaminated with OTA at levels ranging from 0.22 to 38.4 µg per kg.
The OTA concentrations found in organic feed samples were significantly higher (P <0.05) than those found in conventional feed samples.
All serum samples resulted to be contaminated with OTA at levels ranging from 0.03 to 6.24 ng per mL.
The OTA concentrations found in organic serum samples were significantly higher (P <0.001) than those found in conventional serum samples.
Conclusion
None of the feed samples contained more than the maximum level (50 µg OTA per kg, considering a feed moisture content of 120 g per kg) recommended by the European Commission for OTA in complementary and complete pig feeds.
The OTA contamination of organic feed and serum samples was found to be significantly higher than that of conventional feed and serum samples.