Effects of the fermented juice of epiphytic lactic acid bacteria (FJLB) and molasses on digestibility and rumen fermentation characteristics of ruzigrass ( Brachiaria ruziziensis) silages

Abstract

In the present study, we aimed to determine the effects of the fermented juice of epiphytic lactic acid bacteria (FJLB) and molasses on ruzigrass silage digestibility and rumen fermentation characteristics in dairy cows. The FJLB was prepared from ruzigrass juice with the addition of 2% glucose and anaerobically incubated for 2 d before use as a silage additive. Ruzigrass silages were prepared with 5% molasses (MO), 1% FJLB (FJLB), and 5% molasses + 1% FJLB (MO-FJLB) and compared with the control (CO) silage (untreated silage). Three silos of each type of silage were prepared and stored for 45 d. The effects of these ruzigrass silages on voluntary feed intake, digestibility, rumen fermentation characteristics, and microbial rumen fermentation were determined in 4 fistulated cows using a 4 × 4 Latin square design. Cows were randomly assigned to 1 of 4 ad libitum diets: 1) CO silage, 2) MO silage, 3) FJLB silage, or 4) MO-FJLB silage. The 28-d experimental period consisted of a 21-d feed intake and 7 d of sampling. Silage treated with MO or MO-FJLB had lower pH and higher lactic acid content than CO and FJLB silages. Butyric acid was not detected in the FJLB silage. Ammonia-nitrogen content was similar for all diets; neutral detergent fiber (NDF) and acid detergent fiber (ADF) also did not differ significantly. The CP digestibility of the FJLB silage was higher than the other silages. However, rumen acetic acid, propionic acid, butyric acid, and blood urea nitrogen contents did not differ significantly among the silages. The cellulolytic bacteria populations were significantly higher in cows fed FJLB and MO-FJLB silages than in cows fed CO silages. We found that adding FJLB to ruzigrass silage improved digestibility of crude protein and increased cellulolytic bacteria population in cows. Thus, FJLB may be an alternative way to use as a silage additive for tropical areas.