EN
In experiment carried out on 800 broiler chickens, divided into 4 groups, it was estimated the feeding value of fodder yeast grown up on medium composed with oiled up fuller soil /OFS/ in comparison with vinasse fodder yeast. The protein content was similar in both kinds of the yeast. The OFS yeast contained less nucleic acids and heavy elements as compared to the vinasse yeast. In groups given 5 % of OFS or vinasse yeast the productive results were almost even. Application 10 % of OFS yeast reduced body weight gains by 7 % /P≤ 0,01/ and feed utilization by 4 %. The nutrients digestibility of concentrate mixtures was high, exept crude fiber in groups given OFS yeast. In birds fed mixture with 10 % of OFS yeast the small intestine was longer.