Diets fed during the transition period can play an important role in the cow’s reproductive tract recovery and function following parturition. We aimed to compare the effects of feeding a fully acidified DCAD diet prepartum to Holstein cows (n = 70) at 2 different concentrations of dietary calcium (Ca) inclusion versus a non-acidified, positive DCAD diet prepartum on uterine environment postpartum. Multiparous Holstein cows were enrolled at 50d before expected calving and followed until 75 DIM. Treatments began at 28d before expected calving and were: CON (n = 23), a positive DCAD diet with low dietary Ca (0.4% DM); LOW (n = 22), a fully-acidified, negative DCAD diet (urine pH = 5.7) with low dietary Ca (0.4% DM); HIGH (n = 25), a fully-acidified, negative DCAD diet (urine pH = 5.7) with high dietary Ca (2.0% DM). Endometrial tissue samples were collected at 30 DIM and analyzed for glutathione peroxidase (GPX) and superoxidase dismutase (SOD) activity, and glandular morphology. Data collected were analyzed using PROC MIXED in SAS. Treatment, day and block were considered fixed effects. Cow was the experimental unit and considered as a random effect. Contrasts included CONT1 (CON vs average of LOW and HIGH) and CONT2 (LOW vs HIGH). Cows fed HIGH had greater (P = 0.02) epithelial height (22.47 ± 1.08m) than cows fed LOW (18.67 ± 1.08m) and cows fed CON (18.01 ± 1.08 m) tended (P = 0.06) to have shorter epithelial height than the average of cows fed LOW and cows fed HIGH. Cows fed HIGH had a greater (P = 0.05) number of epithelial cells per gland (25.93 ± 1.07) than cows fed LOW (22.93 ± 1.07). Anti-oxidative enzymes SOD and GPX relieve oxidative stress in cells. Cows fed HIGH had increased (P = 0.05) activity of SOD (73.50 ± 2.83%) and decreased (P < 0.001) activity of GPX (32.89 ± 5.05%) than cows fed LOW (69.49 ± 2.83% and 68.31 ± 2.83%, respectively). In conclusion, cows fed HIGH had improved glandular epithelial cells, greater SOD activity, and lower GPX activity than cows fed LOW indicating an improved redox environment in the uterine tissue, which may lead to improved postpartum fertility.