110 Dosage and not Time of Exposure to Deoxynivalenol Affects the Performance of Nursery Pigs Fed High Mycotoxin Diets up to 28 Days Post-Wean

The current experiment was conducted to determine if the dosage or timing of exposure to diets containing high deoxynivalenol (DON), a mycotoxin in a variety of feed ingredients, causes performance loss in nursery pigs. In total, 448 mixed-sex nursery pigs [initial BW = 6.18 ± 0.97 kg] weaned at 21 ± 1 d were allotted to 112 pens, with 4 pigs per pen, in a randomized complete block design. In a 3 x 2 + 1 factorial arrangement of treatments, diets with DON were fed continuously (CONT), at weeks 1 and 3 (WK13), and weeks 2 and 4 (WK24), targeting DON at 1.25 ppm fed (MED), or 2.5 ppm (HIGH), plus the positive control (CONTLOW) for 28 d. All pigs were fed a common, low DON diet from d 28 to 42 to complete the nursery phase. Pen weight and feed intake were measured on d 28 and 42 to calculate ADG and ADFI. Regardless of timing, d 28 BW decreased (P < 0.01) with feeding MED or HIGH diets compared with CONTLOW and markedly decreased (1.57 kg) in the HIGH. This was a response to the decreased ADG (P < 0.01) and ADFI (P < 0.01) from d 0 – 28 in MED or HIGH compared with CONTLOW and with HIGH compared with MED. Similarly, on d 42, performance metrics - BW (P < 0.01), ADG (P < 0.01), and ADFI (P < 0.01) were decreased in MED or HIGH compared with CONTLOW, with a 1.95 kg. decrease in BW in the HIGH compared with CONTLOW. A dose-response to DON was evident whereas, timing of exposure did not affect the performance metrics measured on d 28 or 42. Ultimately, exposure of nursery pigs to levels of DON over 1 ppm results in loss of performance, regardless of exposure timing.