During the 1983/84 season, under steppe climatic conditions (Cerro la Virgen, latitud 45º50'S), an experiment was carried out with oat, barley and rye, harvested as hay, at two maturity stages (heading and milk), in order to maintain steer weights during the winter period. The hay was evaluated with weaned calves, that received cereal hay ad libitum, in a yard enclosed by an electric fence and with no weather protection. Teatments were: I. Dat hay harvested at heading; II. Oat hay harvested at the miLk stage; III. Barley at heading; IV. Barleyat milk; V. Ryeat heading; and VI. Ryeat milk. Protein values were: 7,5; 5,0; 5.5; 8.7; 6.2; and 4.4%, respectively. In vitiro digestibility values were: 69; 71; 65; 57; 60; and 50°/o, respectively. Liveweight gains/day, during the 56 days period, were: 0.250a; 0.214a; 0.232a; 0.136 b; 0.248a; and0.163 b, respectively (P < 0.05). The results were obtained with cereal hay plus bone meal and salt (2:1) as the only feeds. These are thefirst experimental data obtained under very hard winter local conditions, at the Xl Region of Chile.