Effects of sodium benzoate on thebquality of corn silage contaminated with listeria monocytogenes

This study was conducted to investigate the effect of sodium benzoate added to corn plant material contaminated with Listeria monocytogenes on L. monocytogenes and silage quality. The maize plant material was harvested at milking period, cut into 1.5-2.0 cm lengths, hand pressed into 1.5 liter plastic drums and kept at room temperature for 60 days. The study included 4 groups as control (Group A), L. monocytogenes positive group (Group B), L. monocytogenes+sodium benzoate group (Group C) and sodium benzoate group (Group D). L. monocytogenes was applied to groups B and C at a level of 105 cfu/g and sodium benzoate was applied to groups C and D at a rate of 0.1%. No additive was applied to the silages in the control group. The silages were opened on the 60th day of ensiling and chemical and microbiological analyzes were performed on the samples taken. In addition, the silages were subjected to aerobic stability test for 5 days after opening. As a result of the use of sodium benzoate as an additive in L. monocytogenes contaminated silages, the crude ash and crude fat ratios of the silages increased while the organic matter ratio decreased. Sodium benzoate increased the water soluble carbohydrate content of silages, while butyric acid, ethanol and ammonia nitrogen concentrations decreased (p<0,001). In the findings obtained from the silages after aerobic stability test, pH and CO2 levels and yeast and mold counts were significantly lower in group D compared to the control group. There was not any L. monocytogenes colony growth observed in the silages in microbiological analysis. In conclusion; sodium benzoate supplementation significantly improved the fermentation quality and aerobic stability of silages.