Chemical, nutritive, deoxynivalenol and zearalenone content of corn relative to the site of inoculation with different isolates of Fusarium graminearum

Abstract

AbstractKernels from two samples of 18 ears of corn were hand‐shelled into three fractions (Fl, F2 and F3) relative to the site (F3) where the ears had previously been inoculated with one of four isolates of Fusarium graminearum (Schwabe). F3 and Fl were from the nearest and remotest parts of the ear, respectively, to the inoculation site. Ears of uninoculated control corn were processed in the same manner. The resulting 30 samples were analysed, after grinding (20 mesh), for deoxynivalenol (DON), zearalenone (ZEA), ergosterol (EGS), dry matter (DM), 200 kernel weight, Kjeldahl nitrogen (N), ether extract, ash, sugar, starch, acid and neutral detergent fibre (ADF, NDF, respectively), cellulose, hemicellulose and lignin. The true metabolisable energy (TME), TME corrected to zero N balance (TMEn), true available amino acid (TAAA) and true DM digestibility (TDMD) contents of these samples and corn to which 4, 16 or 64 mg purified DON kg−1 were added, were determined using adult White Leghorn chickens.The DON, ZEA, EGS, N and ash contents were higher (P<0.001), and ether extract, TME and TMEn values were lower (p<0.01) in F3 than in Fl. Higer avilabilites accured for aspartic and glutamic acids, isoleucine, leucine and histidine in F2 and F3 than F1 (P<0.05). Carbohydrate and fibre values varied little (p>0.05) among fractions either within or among incoulation treatments. Sources of Fusarium inoculate influenced (P<0.05) the DON, ZEA, N, fat and TDMD of the corn. The TMEn and total TAAA of corn decreased (P<0.001) when purified DON was added. Moderate relationships (r=0.57−0.73) occurred between DON and ZEA, EGS and N. In general, these results are similar to those for wheat, and indicate that chemical and nutritive content of feedingstuffs may be increased when they are infected by toxigenic fungi.