Effects of corn kernel hardness and grain drying temperature on particle size and pellet durability when grinding using a roller mill or hammermill

•Two corn hybrids were planted and harvested under similar conditions.•Corn fragmentation at grinding was affected by endosperm hardness (vitreousness).•Drying temperature affected particle size distribution in new crop and stored corn.•Hammermilling hard kernels mostly yielded larger particle size geometric mean and affected the pellet durability index.•Particle size was reduced as storage time is increased regardless grinding method.