203 Effects of Feeding Varying Levels of Mycotoxin-Containing Corn Fines on Diet Choice and Growth Performance of Nursery Pigs

Abstract

Abstract Mycotoxins in feed are known to negatively affect growth and other physiological processes in pigs. Two experiments were conducted to investigate the effects of feeding diets with varying levels of mycotoxins and boron (a nutrient reported to mitigate some aspects of mycotoxicosis). Screenings from the 2020 crop year corn contained mycotoxin levels of 23,038 ppb total fumonisin, 1,446 ppb zearalenone, and 5,032 ppb total deoxynivalenol (DON)l. The corn fines were added into a corn-soybean meal diet formulated to meet or exceed NRC (2012) nutrient requirements as a replacement for corn at 0, 10, and 20% for Diets 1-3. Diets 4-6 were Diets 1-3, respectively, plus 40 ppm boron from sodium tetraborate decahydrate (11.34% B). Diets 3 and 6 were formulated to approximate the cautionary levels of fumonisin and DON stated by the FDA. Exp. 1 used crossbred pigs (n = 144; mean initial BW = 10.20 ± 0.23 kg) blocked by sex and BW and randomly allotted to dietary treatments for a total of 6 replicates (4 pigs/pen) for a 21-day growth performance trial. On day 21, serum was collected from the heaviest and lightest pig in each pen for clinical chemistry assessment. Exp. 2 used crossbred pigs (n = 48; mean initial BW = 9.18 kg ± 0.12 kg) blocked by sex and BW and randomly allotted to 1 of 3 treatment comparisons including: Comparison 1) Diet 1 vs. Diet 2; Comparison 2) Diet 1 vs. Diet 3; and Comparison 3) Diet 2 vs. Diet 3. There were a total of 4 replicates (4 pigs/pen) for a 21-day preference trial. Performance and clinical chemistry data were analyzed by ANOVA using the GLM procedure of SAS with pen as the experimental unit. Preference data were evaluated via t-test. Increasing mycotoxin levels in Exp. 1 had no effect on overall ADG, ADFI, and GF (Table 1; P = 0.16, 0.53, and 0.92, respectively). The increasing mycotoxin levels did effect glucose and cholesterol (P = 0.03, and P < 0.01, respectively). There was no effect of boron on the same performance measures (P = 0.81, 0.59, and 0.76, respectively) although it did decreaser serum glucose (P = 0.02). Exp. 2 demonstrated the barrows ability to discern between diets in Comparisons 2 and 3 (P < 0.01) for each week while gilts only started to exhibit that ability during Week 3 for Comparison 2 (P = 0.06). In conclusion, pigs can differentiate and choose between diets containing these mixed mycotoxins but when not given a choice, the pigs do not have different growth performance using the particular mycotoxins and within the framework of this assessment.