EN
Thirteen grain samples and 35 samples of mixed meals for pigs were evaluated. The number of colonies of Aspergillus, Penicillium and Fusarium genera were determined according to Polish Standard PN-76/R 64791. In the successive quarters of the year the norm in respect to 1 g of grain was exceeded by 2.4; 31.2; 57.0 and 0.6 times, respectively. In case of other fungi the norm was exceeded by 0; 2.8, 5.0 and 0.3 times. In 1 g of mixed meals in the successive quarters of the year the amount of mould fungi exceeded the standard norm by 34.5; 128.0; 265.3 and 125.7 times, respectively while the amount of other fungi by 12.6; 104.9; 271.9 and 578.2 times. In older and younger pigs fed in the course of fattening with contaminated mixed meals for 1.5 and 3 month daily gains were lower at 146 and 133 g in comparison to the period in which they were given mixed meals of good quality (P<0,01). The food conversion in the both groups aggravated by 1.85 and 2.58 kg per 1 kg of body weight (P<0,01).