The effect of length of ensiling (LOE) on fresh whole-plant corn Shredlage was evaluated after it was fermented for 0, 45 or 180 d at a temperature of 20–23°C using 3 L capacity PVC mini-silos fitted with mechanics to vent gas. Mini-silos were filled with about 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 starch characteristics and in vitro starch digestibility (IVSd) during 2 in vitro fermentation endpoints (FEP, 3 or 7 h.). Statistical analysis for nutritional characteristics was performed using a completely randomized design (CRD) for 3 LOE. Data for IVSd was analyzed using a CRD with a 3 LOE by 2 FEP factorial arrangement. Different superscripts denote statistical significance (P < 0.05). The structure of the starch granule was documented using a scanning electron microscope (SEM) at each LOE. Ammonia-N (% of CP) and IVSd increased as LOE increased, while sugar decreased (Table 1). There were no changes for starch content across LOE. Increasing the FEP from 3 to 7 h. increased IVSd from 72.4^a to 84.1^b%. The 2,000× micrograph at ensiling (0 d) shows starch granules with a smooth surface and a spherical shape surrounded by protein bodies. After 45 d of ensiling, the starch granules lost their sphericity and some of the protein bodies start to break down into small pieces (supported by increases in ammonia-N). After 180 d of ensiling, starch agglutination may be observed as well as some pitting of the starch granule due to hydrolytic enzyme activity. In summary, structural changes in the starch-protein matrix and in the starch granule during ensiling result in increased starch digestibility. Table 1. Effects of length of ensiling (0, 45, or 180 d) on nutrient characteristics and starch digestibility of corn Shredlage

Item	Length of ensiling, d
0			45			180
Mean	SD		Mean	SD		Mean	SD
N	4			8			8
Ammonia-N, % of CP	0.65c	0.1		2.54b	0.04		4.5a	0.39
Starch, % of DM	34.2	2.39		30.4	1.58		32.2	1.84
Sugar, % of DM	8.7a	0.21		1.9b	0.26		2.8c	0.22
In vitro starch digestibility, % of starch	65.4a	11.2		76.5ab	10.8		84.1b	8.1