Research Note: Characterization of Two Samples of Corn that Vary in Bushel Weight

Two samples of corn differing substantially in bushel weight were obtained from a commercial feed mill. The light weight sample (606 g/L; 47 lb/bu) was higher in protein (9.3%) and lower in ether extract (2.95%) than the normal weight corn (696 g/L; 54 lb/bu), which contained 8.1% protein and 3.43% ether extract. The determined TME of the corn samples on a dry matter basis did not differ significantly (3.81 vs. 3.83 kcal/kg). The normal corn had increased levels of lysine, methionine, and methionine plus cystine when the amino acid levels were compared as a percentage of total amino acids. No differences were observed when comparisons were made as a percentage of the total sample. In the light corn sample, the analyzed lysine and sulfur amino acid concentrations (percentage amino acids/percentage CP) were 13 to 16% lower than calculated values derived from published prediction equations. In the normal corn, the differences were only 8 and 3%, respectively.