EN
The objective of the present study was to evaluate the activity of fatteners« immune system through the determination of changes in the serum immunoglobulin levels against the background of the microbial pollutants in the fattening house air. The studies performed revealed a very high level of microbial exposure in the air of a fattening house, where the total count of mesophylic bacteria reached the 2.5 × 10⁶ CFU/m³ level. A high contribution of Gram-negative bacteria was established, whose mean concentration in the air was 5.2 × 10³ CFU/m³. The first experimental series showed the immune activity level to be stable and similar in all the investigated animal groups. Age-dependent differences were noted within each class, the most marked within class G proteins. Moreover, the immunoglobulin concentrations differed statistically between the animal groups assessed and the differences referred mainly to the class M and G immunoglobulin. A level of IgA determined at similar levels may imply that, irrespective of a genotypic structure, a local humoral response of the animals was activated with the same force. A stable and high level of IgG concentration may prove the production of the secondary humoral immune response in fatteners. A simultaneous sustaining growth of IgA and IgM antibodies suggested that throughout the fattening period, the animals were exposed to ever newer antigens.