The levets of zea.ralenone were investigated in total 99 various cornmerical fced mixtures and feed ingredients by using HPLC. The sensitivity of the method was found as 1 µg/kg.

were eollected in tıhe periods of January - February and April - May from Konya, Adana, Bursa regions.

In the first period, total 65 sampleıs which are 19 feeds and 46 feedstuffs were analysed. Zearnlenone was determine in 6 samples of tlhe feeds aınd 15 samples of the feedstuffs. The avarage level of zearalenone was calculated as 3.66 µg/kg in whole samples.

In the second period, total 34 samples which are 11 feeds and 23 feedstuffs were analysed. Zearalenone was determined in 6 sampleıs of the feeds and 8 samples of tıhe feedstufıfs. The average level of zearalenone was caleulated as 5.46 µg/kg in whole samples.

In both periods, the percentage of the samples included zearalenon was average 33 % and the mean zearalenone level was determined as 4.31 µg/kg feed.

The samples contained about 10 µg/kg zearalenone may cause hipercostrogenism in pigs. Same effects mıay be seen in the other animals when these feedstuffs fed for a long periods.