The use of bacterial inoculants for grass silage: their effects on nutrient composition and fermentation parameters in grass silages

Abstract

The effect of three microbial inoculants (Lactobacillus plantarum CCM 4000, L. fermentum LF2, and Enterococcus faecium CCM 4231) on the fermentation and nutritive value of orchard grass silage was studied under laboratory conditions. The first-cut orchard grass (280 g of dry matter/kg) was ensiled at 21°C for 105 days. All inoculants were applied at 1.0 × 10(9) CFU/ml. Uninoculated silage served as control. After inoculation, the chopped orchard grass was ensiled in 40 (1 l) plastic jars divided into four groups. The counts of the silage inoculants dominated on day 21 of ensiling: CCM 4231 strain amounted to 9.40 ± 0.30 (log10) CFU/g followed by LF2 (8.69 ± 0.39 CFU/g) and by CCM 4000 (7.55 ± 0.39 CFU/g). However, on day 105 (the end of ensiling) the highest counts of L. plantarum CCM 4000 were determined. Overall, microbial inoculants generally had a positive effect on orchard grass silage characteristics in terms of lower pH and higher lactic acid concentration. The inoculants significantly increased the lactic to acetic acid ratio in inoculated silages. The total concentration of acids (acetic, propionic, n-butyric, lactic acid) was 2-3 times higher in inoculated silages compared to control silage. The percentage proportion of fatty acids - SFA, UFA, SCFA and MCFA - was similar in all grass silages. Only the proportions of LCFA - α- linolenic acid (C18:3) were lower (P < 0.001) while those of oleic acid (C18:1) and linoleic acid (C18:2) were higher (P < 0.001) in inoculated silages in comparison with control silage.

Keywords

• orchard grass
• silage
• bacterial inoculants
• quality