Nutritive value and fermentation characteristics of bermudagrass silage treated with propionic acid and microbial inoculant

The objective of this study was to evaluate the effects of propionic acid and microbial inoculant on nutritive value and fermentative characteristics of bermu-dagrass silage and its intake and digestibility when fed to beef heifers. The study was conducted at Ona, Florida, in 2018 and 2019. In Exp. 1 bermudagrass ( Cynodon dactylon [L.] Pers.) was ensiled with 3 levels of propionic acid (0% [control], 0.5%, and 1.0% of the forage fresh weight), and in Exp. 2 treatments were control or 0.5%, 1.0%, and 0.5% + Early Sile Advance (Micron Bio-Systems Inc.) of the forage fresh weight, distributed in a completely randomized design with 5 replicates. In Exp. 3, Angus × Brahman crossbred heifers (n = 18 heifers per year; 2 yr) were individually fed for 21 d. Treatments were bermudagrass silage treated with 3 levels of propionic acid (control or 0.5% or 1.0% of the forage fresh weight) distributed in a completely randomized design with 6 replicates. Propionic acid treatment at 0.5% and 1.0% increased silage CP and TDN while reduc-ing NDF and ADF. Treated silages had lower pH, butyric acid, and ammonia-N concentrations but greater lactic and acetic acid concentrations and aerobic stability com-pared with control. Despite improvements in fermentation characteristics and microbial communities, no differences were observed in DMI and in vivo forage digestibility. Mi-crobial inoculant did not affect bermudagrass nutritive value and fermentation characteristics. Treating bermudag-rass silage with 0.5% propionic acid is a feasible manage-ment practice to improve bermudagrass silage preserva-tion.