Introduction

Deoxynivalenol (DON) is a type B trichothecene mycotoxin produced primarily by Fusarium graminearum that commonly infects cereal grains in temperate growing regions (Radke et al. 2025). In North America, DON is one of the most prevalent mycotoxins contaminating corn and wheat-based swine diets, with concentrations varying substantially across years and geographic regions (Streit et al. 2013). A recent survey of U.S. new crop corn reported that DON was detected in 76% of grain samples (Weaver et al. 2021). Swine are considered the most sensitive domestic livestock species to DON, particularly during the nursery period (Andretta et al. 2012), when pigs exhibit heightened susceptibility to feed intake suppression and growth impairment (Eriksen and Pettersson 2004; Pestka 2010). Corn is typically an ingredient that makes up a large percentage of many U.S. pig diets, and even moderate DON contamination can impair performance. Additionally, DON is further concentrated in dried distillers’ grains with solubles from contaminated corn (Frobose et al. 2015a). The primary biological consequence of dietary DON exposure in pigs is a reduction in voluntary feed intake, which subsequently depresses average daily gain and final body weight (Friend et al. 1986; House et al. 2002). The United States Food and Drug Administration currently does not have advisory levels for DON in corn itself, only aflatoxin (USDA 2023). However, the most current guidance document states that 5 mg/kg DON on grains and grain by-products destined for swine with the added recommendation that these ingredients not exceed 20% of their diet, which equates to ∼1 mg/kg DON in finished feed (FDA 2010). In Europe, the guidance value for DON in swine feed is 0.9 mg/kg set by the European Food Safety Authority (EFSA COMTAM 2017).

Studies have demonstrated that dietary DON concentrations exceeding 1 mg/kg can negatively impact pig growth performance (Eriksen and Pettersson 2004), with more pronounced suppression observed as DON concentration increases (Rotter et al. 1996; Frobose et al. 2015a; Wilson et al. 2022). However, most performance-based investigations in swine have relied on single- or two-dose comparisons, typically contrasting a control diet with a diet containing a single elevated DON concentration (Chaytor et al. 2011; Alizadeh et al. 2015; Frobose et al. 2015b). While these studies confirm that DON impairs pig performance, they provide limited definition regarding the quantitative shape of the dose-response relationship across practical dietary concentrations. Wellington et al. (2020) modeled the relationship of average daily gain to DON exposure (0.1, 1.3, 3.6, and 5.7 mg/kg, respectively) in growing pigs, reporting decreased weight gain as DON concentration increased. This agrees with Andretta et al. (2012), who reported that for each mg/kg intake of DON, a 0.28% reduction in weight gain can be seen in growing pigs.

Establishing the quantitative relationship between dietary DON concentrations and nursery pig growth performance is essential to define biologically meaningful exposure thresholds and to provide a foundation for subsequent mechanistic and mitigation investigations. Therefore, the objective of this study was to characterize the dose-response effects of increasing dietary DON concentrations (0.2 to 5.1 mg/kg), which were naturally added through increasing levels of contaminated corn, on feed intake and growth performance in nursery pigs. We hypothesized that increasing dietary DON would reduce nursery pig feed intake and growth in a nonlinear manner, consistent with a biological breakpoint or threshold response.