Effects of microbial inoculants and by-product from amino acids production on fermentation, chemical composition and aerobic stability of corn silage

In recent years, the use of microbial inoculants has been increasing in Brazil, although the results have been conflicting. This study was conducted to evaluate the effects of adding a by-product from amino acid production or biological inoculants on fermentative characteristics, chemical composition and aerobic stability of corn silage. The treatments were: Control (control silage without additive); BAP (silage with addition of 1 % of by-product from monosodium glutamate amino acid production); Pionner (silage with addition of bacterial inoculant Pioneer 1174®, containing S. faecium and L. plantarum) and Mercosil (silage with addition of bacterial inoculant Mercosil Mais 11C33®, containing L. buchneri, L. plantarum and E. faecium). Silages were produced in laboratory silos, constituted of plastic buckets with suitable lids for sealing. Silos were opened after 60 days of ensiling. The contents of DM, WSC and IVDMD were not affected (p>0.05) by any of the additives. The BAP treatment increased (p<0.05) CP content of corn silage in 23.0 %, resulting in a drop (p<0.05) of 36.3 % in ADIN content. Moreover, BAP treatment decreased (p<0.05) the concentrations of ADF and NDF, while Mercosil decreased ADF and NIDA contents. The additives promoted adequate fermentation pattern according to pH values (3.48 to 3.54) and ammonia nitrogen concentration (11.07 to 13.30 % of total N) except that treatment with BAP increased N-NH3 in 88.30 %. Low fermentation losses were observed in the treatments Control, BAP and Pioneer when compared to Mercosil, so that Mercosil treatment increased in 49.70 % acetic acid concentration when compared to Control group. The additives had no effect on the other fermentation characteristics (concentration of ethanol, propionic, butyric and lactic acids) or aerobic stability. In conclusion, the additive BAP can be added to corn silage to improve only its chemical composition. However, Mercosil and Pioneer produced limited effects on improving the fermentation profile.