10 Occurrence of Mycotoxins in Wheat Middlings

Mycotoxins are harmful secondary fungal metabolites which can contaminate a variety of feedstuffs worldwide. Various negative effects in vivo are associated with these toxins and severity is dependent on the level, type, and duration of exposure and age, species, and health status of animals. Wheat middlings or “midds” are a by-product of flour milling and are used in a wide range of livestock rations including frequent inclusion in pelleted feeds. The objectives of the current study were to determine the occurrence of mycotoxins in wheat midds samples and to evaluate the potential risk posed to livestock. Since November 2015, 97 samples submitted from 21 states and provinces have been screened via LC-MS/MS technique for the presence of six major mycotoxin groups: aflatoxins, type A trichothecenes, type B trichothecenes (B-Trich), fumonisins, zearalenone, and ochratoxin A (OTA) at Romer Labs (Union, MO, USA) or Activation Laboratories (Ancaster, Ontario, Canada). A subset of samples were also screened for the presence of six ergot alkaloids. Parameters of the main mycotoxins detected are presented in Table 1. On average, 1.7 mycotoxin groups were detected per sample with 91.8% of samples testing positive for at least one mycotoxin. The B-Trich deoxynivalenol was detected in 89.7% of samples (mean 1871.5 ± 157.5 ppb). OTA was also frequently detected (30.9% positive), but at low risk levels (4.2 ± 0.5 ppb). Out of 33 samples screened for ergot alkaloids, 72.7% were positive (493.3 ppb ± 68.3 ppb). Wheat midds are a commonly used feed ingredient for various livestock species. The types and concentrations of mycotoxins detected may pose challenges to livestock health, performance, and reproduction. Special consideration for young animals which are especially susceptible to mycotoxin challenges, such as calves consuming starter feeds, is warranted.