Evaluation of the Feeding Value of Dry‐Crushed Corn Grain Treated Using a Feed Rice Grain‐Crushing Machine in Lactating Cows

A feeding trial was conducted with lactating cows to evaluate the feed value of domestic dry-crushed corn grain. The corn grains were treated using a feed rice grain-crushing machine with a roll clearance of 0.2 mm. Six lactating cows were assigned to diets ensiled into a total mixed ration containing either steam-flaked (SF) or dry-crushed corn (DC). Group DC tended to have increased milk protein concentration and nitrogen secretion in milk, and decreased blood non-esterified fatty acid concentrations (p = 0.05, 0.06, and 0.08). Whereas, this group showed significantly higher dry matter intake per kg body weight, non-fiber carbohydrate, and starch digestibility (p = 0.04, 0.03, and < 0.001). No significant differences were found between the treatments in terms of lactation performance, nitrogen balance, rumen fluid profile, or total tract digestibility, suggesting that in lactating cows, the feeding value of dry-crushed corn was equal to or greater than that of steam-flaked corn. This finding suggests that crushing is an effective and practical method for processing domestic corn grain in dairy diets and that dry-crushed domestic corn grain can serve as an effective alternative to imported steam-flaked corn, potentially enhancing nutrient utilization in lactating cows.