Short communication: Metabolization of benzoxazinoids during silage fermentation of maize and their effects on silage quality

The metabolization of phytochemicals like benzoxazinoids (BXs) during ensiling and storage are largely unknown. By comparing wild-type and BX-deficient maize lines, the present study investigated the turnover of BXs during silage formation and their effects on silage. The fermentation pattern of maize silage was primarily related to the chemical composition of chopped forage and the mode of preservation. The presence of BXs in the plants affected dry matter loss and fermentation products. Concentrations of benzoxazinone glucosides declined within the first 3 days of ensiling, whereas respective benzoxazinone aglycons accumulated until 4 weeks of ensiling. Under long-term anaerobic conditions, 2-hydroxy-7-methoxy-1,4-benzoxazin-3-one (HMBOA) and 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) represented the major fractions of BXs in maize silage, with 6-methoxy-1,3-benzoxazol-2-one (MBOA) and 1,3-benzoxazol-2-one (BOA) becoming the long-term end products of BX turnover in silage. Because benzoxazinoid derivatives are highly bioactive in other systems, they warrant more in-depth research for eventual effects on silage-feeding animals.