Inoculation with heterofermentative strains <i>Lentilactobacillus buchneri</i> CNCM 40788 and <i>Lentilactobacillus hilgardii</i> CNCM I-4785 either alone or combined improves fermentation and aerobic stability of ensiled triticale (X-triticosecale)

Abstract

Triticale, a small-grain forage, was harvested for an ensiling experiment evaluating different silage inoculants. Fresh material (mean dry matter 404.1 g kg−1) was wilted, chopped, and assigned to one of four treatment groups including water only (Control), heterofermentative strains Lentilactobacillus buchneri (LB), Lentilactobacillus hilgardii (LH), or combination (Combo) of both. Inoculants were applied at 4.0 x 105 CFU per g of fresh forage, and the Combo contained both strains at 2.0 x 105 CFU per g. Treated forage was packed into 7.57 L mini-silos for openings after 15, 30, and 130 d. Samples were collected at each opening for microbial enumeration of lactic acid bacteria, enterobacteria, yeasts, and moulds. Additional samples were collected for analysis of fermentation profiles, and nutritional analysis following dry matter determination and grinding. Aerobic stability was also evaluated at each opening through a 10-d period. Fermentation profiles were notably affected, including increases in acetic acid (g/kg DM) in LB and Combo treated silage after 15 d which resulted in reduced pH. Aerobic stability was vastly improved through inoculation by prolonging the time to reach 2˚ C above ambient, which was likely a result of decreased yeast counts. Our research validates the use of combined heterofermentative lactic acid bacteria strains on an ensiled small-grain specie, and further agrees with previous findings of prolonged aerobic stability through increases in lactate and acetate in response to co-inoculation.

Keywords

• silage inoculants
• small grain forage
• lactic acid bacteria
• silage quality