Background:: One of the most important principles in disease control is the health of livestock and poultry feed. Given the natural growth of Th. eriocalyx in Lorestan province, its essential oil can be added to the livestock and poultry feed and prevent the growth of the dominant filamentous fungi. Objective:: Therefore, this study aimed to identify the dominant moldy fungal agents of livestock and poultry feed, examine phytochemical compounds and analyze antifungal effects, anti-oxidant properties, as well as cytotoxicity against human white blood cells in Th. eriocalyx Methods:: Sixty samples were collected in 2016. The PCR test was used to amplify ITS1 and ASP1 regions. The analysis of essential oil was conducted by gas chromatography and gas chromatography–mass spectrometry devices. MIC and MFC were performed using the broth micro-dilution method. For the analysis of DDPH activity, DDPH was used. Cytotoxicity effect on healthy human lymphocytes was carried out by the MTT method. Results:: In this study, A. niger, F. verticilloides and F. circinatum, P. oxalicum, and P. chrysogenum were the most resistant species, and A. oryzae and A. fumigatus, F. prolifratum and F. eqiseti, P. janthnellum were the most susceptible ones. IC50 value of T. daenensis Celak was 41.33 μg/ml, and 100 μl/ml of the essential oil caused slight cell lysis. Conclusion:: Considering our results, compared with drugs and chemical additives, essential oils can be added to livestock and poultry feed to prevent the growth of filamentous fungi in the livestock and poultry feed