Use of small grains such as rye (Secale cereale L.) grown in mixtures with annual ryegrass (Lolium multiflorum Lam.) has been recommended to provide early season grazing in winter forage systems, but recent production quotients are lacking.  This study quantified animal performance and carrying capacity at different grazing intensities of a rye-annual ryegrass mixture compared to monoculture annual ryegrass pastures.  Replacement beef heifers (average BW = 315 kg) grazed these two forage systems to achieve a low, medium, or high grazing pressure (GP) using variable stocking.  Animal responses and pasture productivity were measured across 28-d intervals during grazing from 31 January to 23 May 2007.  Herbage mass (HM) was not different between forage systems (P = 0.11).  During the first 28 d, GP did not affect HM, but average HM across the rest of the season was 2.66 (high GP), 2.99 (medium GP), and 3.37 Mg ha^‑1 (low GP). Resulting stocking rate was 6.3 (high GP), 4.5 (medium GP), and 3.4 heifers ha^‑1 (low GP).  Grazing pressure did not affect average daily gain (ADG; P = 0.36), but annual ryegrass (1.05 kg) had greater ADG (P = 0.02) than the rye-annual ryegrass mixture (0.90 kg).  During the 112-d grazing period, GP affected gain ha^‑1 (P = 0.03; high = 643, medium = 517, and low = 384 kg), but there was no effect of forage system or interactions (P > 0.10).  Results indicate that use of rye did not provide an advantage for animal production.  In the second year of the study, the grazing season will be initiated and ended based on forage allowance in pastures in order to quantify any advantages for length of grazing season or early grazing capability.