Effects of biological and chemical additives on fermentation progress in maize silage

Abstract

The objective of this study was to evaluate the effects of bacterial and chemical additives on the number of lactic acid bacteria (LAB) and on fermentation indicators in whole maize silage at 1, 3, 5, 10, and 90 days of fermentation. Maize forage was harvested at approximately 34% dry matter (DM) and treated with (1) no additive (control; C); (2) bacterial inoculant (2 g/t of forage; B) containing the homofermentative LAB Lactobacillus plantarum, Lactobacillus paracasei, and Pediococcus pentosaceus (1.5 × 1011 cfu/g of inoculant); and (3) chemical additive (4 l/t of forage; CH) containing formic acid, propionic acid, ammonium formate, and benzoic acid. Both treatments decreased pH of silage at day 1 of ensiling (P < 0.05), and the lowest value of 4.34 was observed in the CH-treated silage. All silages were well fermented and had pH < 4.0 by day 10 of fermentation. The concentration of lactic acid and the lactic acid : acetic acid ratio increased over time in all treatment groups, and the highest values were 87.5 and 3.62 g/kg of DM, respectively, observed for group B at day 90 (P < 0.05). The concentrations of water-soluble carbohydrates were higher (P < 0.05) for CH compared to C and B at days 3, 5, 10, and 90 of fermentation. The CH silage had fewer LAB (P < 0.05) than did either C or B silages regardless of the days of fermentation. Both additives used in the present study improved fermentation dynamics of the whole crop maize silage.

Keywords

• forage conservation
• lactic acid bacteria
• formic acid
• fermentation dynamics