Influence of storage length and inoculation with Lactobacillus buchneri on the fermentation, aerobic stability, and ruminal degradability of high-moisture corn and rehydrated corn grain silage

The objective of this study was to compare the conservation of rehydrated corn grain silage (RCGS) and high-moisture corn (HMC), treated or not with Lactobacillus buchneri, and to determine the minimum storage length necessary to improve ruminal in situ dry matter (DM) degradability. The treatments consisted of two grain sources, HMC and RCGS (rehydrated to 350 g/kg of moisture), inoculated with L. buchneri NCIMB 40788 at 1 × 105 cfu/g (LB) or chlorine free water (Control), and stored for 15, 30, 60, 90, 120, 180, 240, and 300 days. The concentrations of lactic, acetic, and propionic acids, and 1,2-propanediol were higher (P < 0.044), whereas butyric acid was lower (P < 0.001) in RCGS compared with HMC. Inoculation with LB reduced (P < 0.001) the concentration of lactic acid and increased (P < 0.001) the pH, acetic acid, and lactic acid bacteria counts. Therefore, silages inoculated with LB had prolonged aerobic stability. Silages inoculated with LB had more (P < 0.001) ammonia and less (P < 0.001) prolamin than that in Control silage, although ruminal in situ DM degradability was not affected by inoculation (P > 0.588). The content of ammonia and ruminal in situ DM degradability increased (P < 0.001) with the storage length, which coincided with a gradual decrease (P < 0.001) in prolamin concentration. According to a broken-line regression, higher gains in ruminal in situ DM degradability occurred up to 71 and 52 days of storage for HMC and RCGS, respectively. In summary, RCGS is an alternative to HMC, and L. buchneri improved the aerobic stability of RCGS and HMC. Based on the ruminal in situ DM degradability, it is recommended storing corn grain silages for at least two months before feeding.