Fermentation Characteristics and Feeding Value of Ammonia-Treated Corn Silage

Chopped whole corn plants (Zea mays L.) were treated with 3.2 or 4.5 kg anhydrous ammonia per ton at ensiling and compared to untreated silage. Total numbers of anaerobic microorganisms were greater in ammonia-treated silage than in untreated, and volatile fatty acids production shifted to less acetic and propionic acids and more butyric acid. Lactic acid increased in the low ammonia-treated silage but decreased in the high ammonia-treated silage compared to control silage. This, along with the increased pH of the silage, indicated a different type of fermentation in the ammonia-treated silages. Silages were fed in a split plot design to 12 cows fed 12, 14, 16, and 18% protein in the diet. Milk production was not different among silages; however, the high ammonia-treated silage resulted in a 3.7% increase of milk protein over the control silage. Daily dry matter intake was not affected by treatment; however, animals consuming the high ammonia-treated silage as the only feed ate more silage at each meal and ate less often during the day, causing a larger interval between meals. Factors causing these changes in meal patterns were not determined.