Estimation of fungal growth using the ergosterol assay: a rapid tool in assessing the microbiological status of grains and feeds

Aim: To use ergosterol assay as a rapid tool to assess the extent of fungal contamination in grains and feeds. Methods and Results: Ergosterol was extracted from moulds and quantified using a modified method based on Seitz et al. (1977). A good correlation coefficient of 0·9998 was obtained for ergosterol standards and a strong correlation (R2 = 0·9645) was established between the ergosterol content and the growth of Aspergillus niger ATCC 24126. This shows that this assay can be used to estimate fungal growth. The ergosterol contents and amount of carbon dioxide produced in both Control and Myco CURB®brand liquid‐treated corns were measured over 36 days. Ergosterol contents of pelleted pig feeds were also determined. In both experiments, the levels of ergosterol in the control samples were significantly higher than those of the mould‐inhibitor‐treated samples. Conclusions: A strong positive correlation (Spearman, Rs = 0·7241) was observed between the ergosterol content and the degree of fungal growth. Hence, ergosterol assay can be used as a rapid tool to assess the microbiological status of grains and feeds. Significance and Impact of the Study: This study affirms that ergosterol assay is a rapid and accurate tool that can be used for the assessment of the feed quality.