Corn silage is the most common forage used to feed dairy cows with inclusion rates typically around 20–40% of the diet DM. In recent years, the use of corn shredlage has been proposed as a substitute for corn silage. Corn shredlage is produced by a method that involves shredding the corn plant into unusually long sections and crushing the corn kernels. The objective of this study was to provide additional data on the effect of feeding shredlage (SDL) vs corn silage (CS) on milking performance and rumen microbial ecosystem. A total of 212,000 kg of whole plant were harvested on the same day an ensiled in 2 adjacent bunker silos of ~100,000 kg each. One silo was processed using a theoretical LOC of 26 mm (SDL) and other was harvested using a 16-mm LOC (CS). Both corn plants were treated at the rate of 100 mL/ton with a commercial inoculant (Lasil eFresh, Lallemand, France) to supply 150,000 cfu of Lactobacillus hilgardii and 150,000 cfu of L. buchneri per gram of fresh material. Sixty lactating Holstein cows (648 ± 66.6 kg of BW; 44.4 ± 9.9 kg/d of milk yield; 155 ± 75 DIM) were split in 2 groups and fed the same TMR (15.2% CP, 30.8% NDF on a DM basis) containing either 32.7% CS or 32.7% SDL, on a DM basis, for 21 weeks. Individual feed intake and milk production and composition was monitored daily. Also, at 50 d of study, a rumen sample was obtained from every cow, and DNA extracted and submitted to high-throughput sequencing to evaluate potential changes in rumen microbiota. Data were analyzed using a mixed-effects model which accounted for the fixed effects of treatment, week of study, and their 2-way interaction, plus the random effect of cow. Cows on SDL had a greater (P < 0.05) DMI toward the end of the study, but milk yield and composition were not affected by dietary treatments. As result, feed efficiency was greater (P < 0.05) in cows fed CS than in those fed SDL toward the end study. There were no changes in the relative abundances of the different microbial populations in the rumen between both groups of cows. It is concluded that SDL increases DMI of cows, but this increase is not followed by improvements in production.