Ribonucleic acids
A limiting factor to the utilization of brewers yeast as a protein source is its high nucleic acid content, primarily ribonucleic acid (RNA), which may account for 33% of the total nitrogen. This can result in high uric acid in the blood of monogastric mammals fed brewers yeast (Ferreira et al., 2010). Uric acid has subsequent toxicological effects such as disturbances in the metabolism of fat, carbohydrates and uracil (Heaf et al., 1976). Some RNA-extracted brewers yeasts are thus sold to prevent this problem (Ferreira et al., 2010).