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Two cow drylot wintering trials and a lamb digestion trial were conducted to evaluate wheat straw in maintenance diets for gestating beef cows. Wheat straw or sodium hydroxide (NaOH) treated wheat straw, when fed ad libiturn with one-third alfalfa hay, supported gestating cow weight gains equivalent to a limitfed alfalfa-bromegrass diet. Cows fed NaOH treated wheat straw supplemented with soybean meal and minerals gained less weight (P<.01) than cows on the other treatments. Calf birth weights, calving difficulty and subsequent reproductive performance of the cows were similar for all treatments. Apparent digestibility of wheat straw was increased (P<.01) by 4% NaOH treatment in a lamb digestion trial but was not altered by balancing the sodium intake with other specific minerals. The increase in digestibility of wheat straw due to NaOH treatment was greater in vitro than in vivo.