Evaluation of the effects of two Lactobacillus buchneri strains and sodium benzoate on the characteristics of corn silage in a hot-climate environment

Abstract

This study determined the effectiveness of two Lactobacillus buchneri strains(commercial and indigenous) and sodium benzoate (SB) in improving the aer-obic stability of corn silage under laboratory and field conditions. Two experi-ments were carried out to test the following treatments: untreated forage,commercial L. buchneri (CLB), indigenous L. buchneri (ILB) and SB at a2gkg1concentration. Both inoculants were applied at a rate of 1 9 106col-ony forming units of bacteria per gram of forage. In experiment 1, five repli-cates of each treatment were ensiled in 15-L laboratory silos. The nutritional,fermentation and microbiological characteristics and aerobic stability of thesilage were determined. In experiment 2, the top of a bunker silo was dividedinto four parts (blocks) along its length before it was sealed, and the treatmentswere randomly applied. Three bags were buried in each experimental unit (twoat the top and one at the core) to determine the loss of dry matter (DM) andthe silage characteristics. In experiment 1, ILB exhibited a lower lactic acidconcentration and higher 1,2-propanediol and acetic acid levels, which pro-vided intermediate aerobic stability (67 h). In both experiments, treatment SBexhibited higher residual water-soluble carbohydrate levels and longer aerobicstability relative to the other treatments. In experiment 2, there were lower DMlosses and higher digestibility coefficients when SB was applied, similar to thatfound at the core. Overall, SB was the most effective additive for improvingfermentation, preserving nutrients and reducing the aerobic deterioration ofcorn silage at the top of a bunker silo in a hot-climate environment.