Ramirez-Ramirez, H. A., Geis, A. R., Heine, C. S., Clark, K. J., Gehman, A. M. and Kononoff, P. J. 2011. Storage conditions of wet corn distillers' grains with solubles in combination with other feeds and understanding the effects on performance of lactating dairy cows. Can. J. Anim. Sci. 91: 331-339. Wet distillers' grains are commonly stored in polyethylene silo bags until needed for feeding. The objective of the first experiment was to evaluate the nature of ensiling wet distillers' grains with soluble (WDGS) alone or in combination with other feeds. A 3×4×3 factorial experiment was conducted in which 36 mixtures were made using three loads of distillers' grains stored at varying levels with three feeds (corn silage, ground corn, and brome hay). In all mixtures, the addition of feeds to WDGS increased the pH of stored material. The objective of the second experiment was to evaluate the effects of feeding WDGS on milk production. Twenty Holstein cows were used in a 4×5 Youden square. Prior to initiation of the study, WDGS were stored alone (WDGS) or mixed with either 12% ground corn (DM basis) (WDGS C), 15% brome hay (DM basis) (WDGS H) or 15% corn silage (DM basis) (WDGS CS) in polyethylene silo bags. Animals were assigned to one of five treatments during each 21-d period. A diet not containing WDGS was formulated (Control), along with one containing 30% WDGS (DM basis) (WDGS). Three additional diets, similar to the WDGS treatment, were formulated to include one of the three blends of WDGS with corn (WDGS C), brome hay (WDGS H) or corn silage (WDGS CS). Dry matter intake (DMI) was affected by diet and, compared with Control (21.9 kg d^-1±0.70 kg d^-1), was greater for WDGS (23.8±0.70 kg d^-1) and WDGS C (23.7±0.70 kg d^-1). Milk yield, 3.5% FCM, and fat yield were not affected by treatment. These results suggest that dairy rations can be formulated to include stored WDGS at 30% DM without negative effects on milk production and composition.