We evaluated the effect of length of ensiling (LOE) on fresh whole plant corn shredlage (CS) that was fermented for 0, 45, 90, or 180 d at a temperature of 20 to 23°C using 3-L capacity PVC mini-silos fitted with mechanics to vent gas. Mini-silos were filled with approximately 1.9 kg of the crop at about 33% DM, >3.1% soluble carbohydrates (fresh matter). Four mini-silos were opened at each LOE to determine nutritional characteristics and in vitro NDF digestibility (NDFd) during 3 in vitro fermentation endpoints (FEP, 0, 30 or 120 h.) at a commercial laboratory. Statistical analysis for nutritional characteristics was performed using a completely randomized design (CRD) for 4 LOE. Data for NDFd was analyzed using a CRD with a 4 LOE by 3 FEP factorial arrangement. Significance (P < 0.05) is denoted by ^{a, b, c}. There were no LOE differences (P > 0.5) on the % content of ADF, NDF, lignin and ash, which averaged, 24.19, 36.71, 1.76, and 3.96, respectively. There were significant differences in the % content of DM, CP, ADF bound protein (ADFBP), fat and cell wall protein (CWP). Increasing LOE led to a decrease in the DM content from 0 d (36.68^a), to 90 d (32.25^b), and 180 d (32.51^b), but did not differ from 45 d (34.04^ab). The content of CP increased for LOE 90 d (8.78^a) and 180 d (8.16^a) compared with LOE at 0 d (7.19^b) or 45 d (7.32^b). The amount of ADFBP was 0.52^b at 0 d, similar to ADFBP at 90 d (0.62^b,c). The ADFBP content at 90 d did not differ from 45 d (0.74^a) and 180 d (0.67^a,c). Fat content increased at 90 d (3.40^a) and 180 d (3.45^a) compared with 0 d (1.95^b) or 45 d (2.36^b). At 0 d (0.18^b) CWP did not differ from 45 d (0.47^b), or 180 d (0.28^b), but all 3 did differ from 90 d (1.20^a). Increasing the LOE led to an increase in IVNDFd from 0 d (40.39^a) and 45 d (34.91^a) to 90 d (50.46^b) or 180 d (60.83^c). Ensiling leads to various nutritional changes over time, which can affect ration balancing and on-farm ration preparation. This calls for continuous silage nutritional monitoring over time to proper balance rations and feed cows.