351 Mycotoxin Trends in US Total Mixed Rations and Corn Silage

Abstract

Abstract Mycotoxins are secondary fungal metabolites identified in a variety of feed ingredients and may affect animal health and productivity. This study investigated occurrence and contamination levels of mycotoxins in 2022 US total mixed ration (TMR) and 2021 corn silage samples. Corn silage samples harvested in 2021 and submitted through March 2022 and TMR samples submitted between January through March 2022 were screened via the LC-MS/MS technique for the presence of six major mycotoxin groups: aflatoxins, type A trichothecenes, type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN) and ochratoxin A. Detailed information for each sample was provided including, state of origin and whether or not clinical signs of mycotoxicosis was observed on-farm. Parameters of the main toxins found for corn silage and TMR samples were analyzed for effect of clinical concern (yes/no) and harvest year on contamination levels using LSMeans statement with Tukey's adjustment in the GLIMMIX procedure (SAS 9.4, Cary, NC). Main effects of mean contamination by harvest year are presented in Table 1, since no interactions were significant (P > 0.05). To date, 20 TMR samples from seven states have been submitted for analysis in 2022. Preliminary results show detectable amounts of B-Trich in 95% of TMR samples, with ZEN and FUM detected less frequently in 55 and 10%, respectively. Mean contamination concentrations (parts per billion, ppb) are presented on dry matter basis and were greater in 2022 compared with 2021 for B-Trich and ZEN (P < 0.05) and similar for FUM (P = 0.022). Preliminary results for 72 corn silage samples show detectable quantities of B-Trich in 90% of samples with ZEN and FUM detected less frequently in 67 and 24%, respectively. Mean contamination levels are greater than the last two years and approaching those observed in the challenging 2018 crop for B-Trich, FUM, and ZEN.