Effect of Bacterial Inoculant on Alfalfa Haylage: Ensiling Characteristics and Milk Production Response When Fed to Dairy Cows in Early Lactation

Third-cutting alfalfa hay harvested at bud stage and wilted to approximately 45% DM was treated with live bacterial inoculant at the rate of 200,000 cfu/g of alfalfa haylage.Hay was chopped and packed in polyethylene bonded bags.Samples were taken at ensiling and 14, 35, and 56 d postensiling.Samples were analyzed for pH, CP, ADF, acid detergent-insoluble nitrogen, and mold count.Treatment affected pH (5.29 and 5.11 for control and treated haylage, respectively).The ADF content of alfalfa haylage, regardless of treatment, was lower at ensiling (30.19, 33.32, 34.40, and 34.66% ADF for d 1, 14, 35, and 56, respectively).In vitro DM disappearance and ammonia N were not affected by treatment.During in vitro fermentation, molar percentages of acetate, isobutyrate, butyrate, and isovalerate differed using treated versus control alfalfa haylage as the substrate.The DM intake of dairy cows in early lactation fed treated haylage did not differ from that of cows fed untreated haylage.