Creep-feeding soybean meal (SBM) to suckling calves grazing limpogras (Hemarthria altissima) pastures has been an effective management practice to improve calf average daily gain (ADG); however, it is not clear if the positive effect is result of a greater CP and energy intake or specifically the additional rumen degradable protein (RDP) supplied by the SBM. The objective of this study was to investigate the effects of creep-feeding different amounts of RDP to cow-calf pairs grazing limpograss pastures. The experiment was conducted at the Range Cattle Research and Education Center, Ona, FL from May to August 2014. Treatments were 400 g/d of SBM (65% RDP) or SoyPlus (40% RDP) distributed in a randomized complete block design with 4 replicates. Brangus crossbred cow-calf pairs (n = 16; calf initial BW = 160 ± 5 kg) were randomly assigned to 8 limpograss pastures (1.0 ha/pasture; 2 pairs/pasture). Average daily gain of cows and calves was recorded every 28 d. Body condition scores (BCS) of cows was measured at the beginning and ending of the experiment. Herbage mass (HM) and CP concentration were measured every 14 d. Data were analyzed using the Proc Mixed of SAS with treatment and month as fixed effects and block as random effect. There were no differences in HM (P = 0.48, 6800 ± 1200 kg DM/ha) and CP (P = 0.20, 12.2 ± 3.2% CP) between treatments. The CP concentration decreased (P < 0.01) from May to July and was similar in July and August (from 15 to 10% CP). There was no difference in ADG of cows (P = 0.71, 0.12 ± 0.14 kg/d) and calves (P = 0.24, 0.74 ± 0.03 kg/d) between treatments. Calf ADG decreased from May to August (P < 0.01, from 1.03 to 0.30 kg/d). There were no differences in the final cow BCS (P = 0.90, 5.34 ± 0.30) and change in BCS (P = 0.73, 0.51 ± 0.31) during the experimental period. In conclusion, the increase in performance of calves creep-fed with SBM observed in previous studies may be due to increase in CP and energy intake rather than the additional RDP provided by the SBM.