Thesis (M.S., Animal and Veterinary Science)--University of Idaho, June 2014 | Rising hay expenses and long winters result in high winter feed costs to maintain beef cattle. Studies assessed forage yield and nutritional quality of warm season grasses and winter annual forages. Forage yield of warm season grasses differed amongst species (P< 0.001) and years (P< 0.05). Corn and sorghum x sudangrass had the highest three year averages (5859.3 ± 578 kg/ha and 5422 ± 605 kg/ha, respectively) of the warm season species. Winter annual production was a complete crop failure in year 1 with triticale/AWP (10,680 ± 602 kg/ha), triticale (8400 ± 602 kg/ha), and cereal rye (8250 ± 632 kg/ha) having the greatest yields (P = 0.001), followed by control (3440 ± 884 kg/ha) and AWP (3,360 ± 625 kg/ha) in year 2. Austrian winter pea had greater In situ dry matter degradation, CP and lower NDF and ADF than the cereal grains (P< 0.05).