EFFECT OF BREWERS' YEAST (SACCHAROMYCES CEREVISIAE) EXTRACT ON SELECTED PARAMETERS OF HUMORAL AND CELLULAR IMMUNITY IN LAMBS

The objective of this study was to determine the stimulating effect of the brewers' yeast Saccharomyces cerevisiae dietary supplement on selected parameters of specific and non-specific humoral and cellular immunity in lambs. The study involved 32 lambs aged 30 +/- 3 d, divided into two equal groups: control and experimental. Animals in the experimental group were fed a C-J concentrate mixed with a prebiotic, the extract of dried brewers' yeast containing 10%-15% MOS and 25%-30% beta-1,3/1,6-D-glucan in the amount of 3 g/kg of the concentrate. At the beginning of the experiment (day 0) and on the 15(th), 30(th), and 60(th) d of the study, blood was sampled from the jugular vein to determine gamma-globulin levels, lysozyme and ceruloplasmin activity, proliferative response of blood lymphocytes (MTT) after stimulation with LIDS or ConA, metabolic activity (RBA), and potential killing activity (PKA) of phagocytes. As regards humoral immunity parameters, significantly higher gamma-globulin levels and higher lysozyme and ceruloplasmin activity were noted in the blood serum of experimental lambs supplemented with the yeast extract, in comparison with control lambs not fed the supplement. No statistically significant differences in serum total protein were found between the control and experimental groups. The analysis of cellular immunity indicators revealed significantly higher levels of RBA and PKA, and higher MTT rates after stimulation with LPS or ConA in the experimental group, in comparison with the control group.