Digestibility studies with yearling wethers were conducted on native hays from three selected areas and on alfalfa from one. These samples were cut from adjacent plots at three monthly intervals, beginning about the third week in June. Digestibilities were determined by the conventional method and the results were compared with those obtained by the fecal nitrogen and forage protein indicator methods. Hay samples collected over a period of four years from various parts of the Interlake area were analysed for cobalt and copper. The effect of date of cutting on the level of cobalt and copper was also investigated. The digestibility of crude fibre, nitrogen-free extract, organic matter and dry matter and the total digestible nutrients of the hays decreased significantly with successive dates of cutting... The application of tbe forage protein and fecal nitrogen methods of estimating digestible organic an ddry matter of forages to the data obtained by the conventional method indicated that the indirect methods were not sufficiently accurate to provide reliable estimates of digestibility. The levels of cobalt and copper, as determined by chemical analysis, were found to be marginal when compared to recommended levels for catttle and sheep. Date of cutting had no consistent effect on the cobalt content of the samples, but the copper content decreased with advancing maturity. Variations in cobalt content were found between locations and between years.