61 Impact of broken kernels and foreign matter content of corn on nutrient and energy composition and mycotoxin levels

Abstract

Abstract The objective of this experiment was to determine the impact of elevated broken kernels and foreign material content (BCFM) on energy and nutrient content and mycotoxin levels of corn delivered to a commercial feed mill in southern Minnesota. Corn was sourced from Central Region Cooperative (Sleepy Eye, MN) to meet BCFM specifications: medium (M), averaging 4.9% BCFM and high (H), averaging 7.9% BCFM. Each of 20 deliveries of M were individually sampled at the time of delivery; half was cleaned using a 2.4 mm screen. The clean (CC) and the uncleaned (UC) corn were assayed for moisture, ash, crude protein, ether extract, neutral detergent fiber, and phosphorus. The net energy content was determined using pooled samples of CC and UC using NIR (Cargill, Elk River, MN; Dutch Net Energy formula, CVB). Twenty-six deliveries of H were processed as above, except that the fines (CF) were retained, and CC, CU and CF were assayed for deoxynivalenol and zearalenone. The nutrient data and mycotoxin data were analyzed using ANOVA in which delivery was the experimental unit. There were no differences (P > 0.10) between CC and UC for moisture (14.2 vs 14.1 % for CC and UC, respectively), ash (1.1 vs 1.1%), crude protein (6.6 vs 6.6%), ether extract (3.2 vs 3.1%), neutral detergent fiber (8.9 vs 8.4%), and phosphorus (0.2 vs 0.2%). The net energy of CC and UC were both 2.63 Mcal/kg. The CF contained the highest levels of DON (2,856 vs 425 vs 138 ppb for CF, UC and CC, respectively; P < 0.01) and the highest levels of zearalenone (385 vs 61 vs 15 ppb; P < 0.01). In conclusion, cleaning corn with 4.9% BCFM provided no benefit in terms of nutrient and energy levels. Cleaning corn with 7.9% BCFM reduced mycotoxin content and therefore health risks.