Swiss-type cheese quality is dependent on the formation of ideal shape, size and distribution of eyes. Late-blowing defects have a negative impact for both processors and consumers. Feeding dried distillers grains with solubles (DDGS) to lactating dairy cows has been implicated as a cause of late blowing defects but has limited scientific support. Our objectives were to test the impact of feeding reduced-fat dried distillers grains with solubles (RF-DDGS) to lactating dairy cows on the composition of milk and the suitability of milk for production of high-quality baby Swiss cheese. We hypothesized that feeding 20% RF-DDGS to dairy cows would not result in adverse effects in milk composition or in quality of baby Swiss cheese produced from that milk. Thirty-five multiparous and lactating Holstein dairy cows were assigned randomly to 1 of 2 dietary treatments in a 2 × 2 crossover design. Each period lasted 35 d. Treatment 1 was a standard corn/corn silage/hay diet and treatment 2 was based on the same diet with the exception of 20% of dry matter (DM) being RF-DDGS. Diets were isonitrogenous, isoenergetic, and contained similar limiting dietary amino acids. There was no treatment effect on milk yield (35.66 and 35.39 kg/day, control and RF-DDGS, respectively), milk fat percentage (3.65 and 3.61%), lactose percentage (4.62 and 4.64%), and milk total solids (12.19 and 12.28%). However, milk protein percentage increased (3.01 and 3.11%). For cheese production, milk was collected and pooled 6 times for each dietary treatment. Regarding appearance, cheeses were atypical, but the only significant differences were in eye size, with the control being closer to ideal than RF-DDGS cheese. There were significant interactions between production day and treatment, but no clear trend emerged, indicating that the make procedure has a greater impact on cheese quality than RF-DDGS. These results indicate that RF-DDGS can effectively be fed to cows at a 20% inclusion rate (DM) without negatively influencing suitability of milk for production of quality baby Swiss cheese.