Effects of an exogenous enzyme-containing inoculant on fermentation characteristics of barley silage and on growth performance of feedlot steers

This study investigated the effects of an inoculant on silage fermentation, aerobic stability, and the growing and finishing performance of feedlot steers. Whole-crop barley (Hordeum vulgare L.) was chopped, wilted [350-400 g kg(-1) dry matter (DM)], and ensiled without (Control) or with (Treated) a bacterial inoculant containing a mixture of Pediococcus pentosaceus, Lactobacillus plantarum, and Propionibacterium freudenreicheii (1.3 x 105 CFU g(-1) forage), as well as enzymes applied to fresh forage ensiled in mini or Ag-Bag (R) silos. Inoculation resulted in a pH decline (P < 0.05) from 6.0 on the day of ensiling to < 4.0 after 3 d. In contrast, it required more than 20 d for the pH of the Control silage to fall below 4.0. Inoculant reduced (P < 0.05) the concentration of acetic acid and aerobic stability of silage, as evidenced by a higher (P < 0.05) temperature and pH in aerobically exposed silage. Although the inoculant accelerated pH decline during ensiling, it did not improve the growth performance (P < 0.05) or alter the carcass traits of steers. It is possible that a reduction in the aerobic stability of the inoculated silage may have contributed to this outcome.