Intake, digestion and daily gain by cattle consuming bermudagrass ( Cynodon dactylon; BER) and receiving different concentrate supplements were determined. In one study, 6 tethered Holstein steers (204.5 kg) were fed BER hay ad libitum and in another trial 72 beef cattle (261 kg) grazed BER for 84 days. Animals were not supplemented (control) or received 0.25% body weight of ground corn (LC), 0.75% body weight of corn (HC), 0.25% body weight of corn plus 0.50% body weight of corn mixed with 0.056% body weight of vegetable oil (blend of soybean and coconut oils) and 0.011% body weight of calcium carbonate (HCF), the HCF supplement plus 0.017% body weight of urea (HCFU) or the HCFU supplement plus 0.051% body weight of corn gluten meal and 0.017% body weight of blood meal (HCFUGB; dry matter basis). The low amount of corn appeared to correct a ruminal insufficiency of readily fermentable substrate, presumably increasing nitrogen capture and flow of microbial protein to the small intestine to increase daily gain when nitrogen in BER was not extremely low. In the second 42-day period of the performance trial (Period 2) when forage nitrogen was low, little excess nitrogen from ruminal forage degradation escaping microbial capture probably prevented the low amount of corn from improving gain. The high level of supplemental grain increased performance in Period 2 with low-nitrogen forage but not in Period 1 with forage of higher nitrogen content. Thus, in Period 1 protein status of control and LC calves seemed first-limiting to gain, whereas additional energy was needed for faster gain of control and LC animals in Period 2. Fat mixed with grain may have lessened the deleterious effects of grain on fiber digestion by protecting concentrate from ruminal degradation, but did not greatly affect performance. Supplementation with urea improved gain with low-nitrogen BER but did not affect digestion or daily gain with BER higher in nitrogen. Supplementation with ruminal escape protein sources improved daily gain in both periods, suggesting that with prior inclusion of other supplement ingredients, intestinal amino acid supply limited performance.