Rehydrated Corn Grain Silage and Exogenous Protease: Effects on Dairy Cow Performance, Metabolism, and Starch Digestibility

Twenty-four Girolando cows (107 ± 56 days in milk, milk yield 22.0 ± 10.25 kg/d, and 529 ± 103 kg body weight) were used in a completely randomized design. The cows were divided according to the following experimental diets: 1—CON (basal diet with ground dry corn) 2—RCS (diet with total replacement of ground corn by rehydrated corn grain silage) 3—RCSP (diet with total replacement of ground corn by rehydrated corn grain silage + 500 g ton−1 of CINBENZA DP100®, NOVUS International, Inc (Chesterfield, Missouri, U.S.A.). enzymatic extract of Bacillus licheniformis, protease activity 600 IU g−1). Cows fed RCS + RCSP showed higher DMI, milk yield, and better efficiency (MY/DMI) compared to animals fed CON diet. Cows fed the CON diet had higher fecal concentration, and lower total starch digestibility and milk protein content compared to animals supplemented with RCS + RCSP. Cows fed RCSP showed a 2.96% superiority in total starch digestibility compared to animals fed RCS. Animals supplemented with RCSP presented higher milk yield (17.45%) and milk fat content (13.76%) than cows fed RCS. The inclusion of protease in rehydrated corn silage improved dairy cow performance, enhancing dry matter intake, milk yield, and productive efficiency. It also increased starch digestibility and milk protein and fat content, optimizing nutrient utilization.