As in previous studies, a lower milk AFM1 excretion was expected for cows receiving no AF (Xiong et al., 2015; Sulzberger et al., 2017; Pate and Cardoso, 2018). This was supported in the present study, as cows without an AF challenge had no AFM1 excretion or transfer in milk. Previous studies reported that cows that received clay during an AF challenge had lower concentrations of AF excreted in the milk, urine, and feces (Kutz et al., 2009; Kissell et al., 2013; Barrientos-Velazquez et al., 2016). Sulzberger et al. (2017) and Maki et al. (2016) both reported that milk AFM1 concentrations decreased as the concentration of clay included in the diet increased.