Impact of Lactiplantibacillus plantarum on the aerobic deterioration of ensiled total mixed ration inoculated with Pichia kudriavzevii upon aerobic exposure

Ensiling is a common method for preserving total mixed ration (TMR), although exposure to air upon opening often leads to aerobic deterioration associated with fungal community succession. This study evaluated the impacts of Lactiplantibacillus plantarum inoculation during ensiling followed by Pichia kudriavzevii challenge upon opening on the fermentation characteristics, aerobic stability, and fungal community dynamics of the TMR throughout the ensiling and subsequent aerobic exposure phases. L. plantarum inoculation improved fermentation quality by increasing lactic acid content, reducing pH and NH 3 -N accumulation, and lowering aerobic bacteria counts ( P < 0.05). However, L. plantarum inoculation significantly reduced aerobic stability ( P < 0.05). P. kudriavzevii inoculation significantly decreased aerobic stability in the control group ( P < 0.05), whereas it exerted no significant negative impact on the L. plantarum inoculation group ( P > 0.05). Although remaining low in relative abundance, P. kudriavzevii exhibited a negative association with lactic acid concentrations ( P < 0.05), matching the gradual pH rise observed during aerobic phase. Under aerobic exposure, P. kudriavzevii inoculation altered fungal community in control group, whereas its impact was mitigated in L. plantarum inoculated group. Ensiling TMR with L. plantarum enhances fermentation quality but reduces aerobic stability. P. kudriavzevii inoculation acts as an initiator of nutrient degradation, significantly compromising aerobic stability in ETMR. However, prior L. plantarum inoculation reduced the relative magnitude of stability loss caused by P. kudriavzevii challenge and stabilized fungal community dynamics. These findings suggest that targeting key spoilage yeasts such as P. kudriavzevii provides a valuable direction for developing functional inoculants that balance fermentation quality with extended aerobic stability.