Effects of monensin inclusion and the subspecies of cattle on utilization of bermudagrass hay (13.7% CP) were evaluated using ruminally cannulated steers (5 Bos indicus, BI and 5 Bos taurus, BT; 398 kg BW). Subspecies were concurrently subjected to a 2 period, 2 treatment crossover design. Treatments consisted of 0 (CON) or 200 (MON) mg·hd⁻¹ monensin (Rumensin 90; Elanco Animal Health, Greenfield, IN) fed daily in 0.91 kg DDGS. Steers were group housed during adaptation periods and moved to individual covered pens to facilitate sampling. Periods were 70 d in length: 20 d adaptation, 5 d sample collection, 17 d continuation of treatment application (for ruminal sampling), and 28 d withdrawal between periods. Hay, ort, and fecal grab samples were collected d 21–25 for determination of intake and digestion. Data were analyzed using the MIXED procedure of SAS 9.3 (SAS Inst. Inc., Cary, NC) with terms in the model including treatment, subspecies, subspecies × treatment and period, with animal as a random effect. No subspecies × treatment interactions were observed (P ≥ 0.21). Monensin tended to increase forage OM intake (FOMI; P = 0.08) from 19.5 to 20.3 g/kg BW and total OM intake (TOMI; P = 0.07) from 21.3 to 22.2 g/kg BW. No effect of subspecies (P ≥ 0.16) was observed for FOMI or TOMI. Organic matter digestibility was not affected by monensin (P = 0.97; 60.6 and 60.7 for CON and MON, respectively) and was not different (P = 0.28) between subspecies (58.0 and 63.3% for BI and BT, respectively). When the combined effects of TOMI and OMD were evaluated as total digestible OM intake (TDOMI), no response (P = 0.71) was observed from monensin supplementation. Bos taurus steers had greater (P = 0.04) TDOMI than BI steers (14.3 vs 12.2 g/kg BW). Monensin tended to increase forage NDF intake (FNDFI; P = 0.07) from 16.5 to 17.2 g/kg BW and total NDF intake (TNDFI; P = 0.08) from 17.4 to 18.1 g/kg BW, but had no effect (P ≥ 0.73) on NDF digestibility (NDFD; 66.4 and 66.0% for CON and MON, respectively) or total digestible NDF intake (TDNDFI; 11.7 and 11.9 g/kg BW for CON and MON, respectively). Although FNDFI, TNDFI, and NDFD were not different (P ≥ 0.16) between subspecies, total digestible NDF intake was greater (P = 0.02) for BT than BI steers (12.7 vs 10.9 g/kg BW). Overall, monensin increased FOMI and FNDFI and had no effect on OMD or NDFD. Bos taurus had greater TDOMI and TDNDFI compared with BI steers.