Fine chopping during harvest improves silage packing density and fermentation, and aids in preserving nutritive value (McDonald, 1981). However, feedstuffs with small particle size may have adverse effects on digestion, e.g. decreasing ruminal pH, salivary buffer secretion, fibre degradation and dry matter digestibility reduction (Allen and Mertens, 1988). Physical effectiveness of silage-based rations can be improved by increasing forage chop length (Couderc et al. 2006). A novel method of harvesting whole-plant maize silage, shredlage, may increase kernel processing and physically effective neutral detergent fibre (peNDF). Also, potential improvements in total-tract starch digestibility by dairy cows appear to be an important benefit (Ferrareto and Shaver 2012). The objective of the study was to compare particle sizes, chemical composition and in vivo nutrient digestibility of whole plant maize silages made as conventional silage or shredlage.