Hays from stands top-dressed with 150 pounds of ammonium nitrate (33.5 per cent nitrogen) per acre and unfertilized stands of crested wheat-grass, Agropyron cristatum (L.) Gaertn., intermediate wheatgrass, A. intermedium (Host.) Beauv., streambank wheatgrass, A. riparium Scribn. and Smith, and Russian wild ryegrass, Elymus junceus Fisch., as well as hay from unfertilized stands of tall wheatgrass, A. elongatum (Host.) B. P., reed canary grass, Phalaris arundinacea L., and Ladak alfalfa, Medicago media Pers., were fed to 70-pound wethers in digestion stalls in a randomized incomplete-block experiment.Chemical analyses of the hays indicated differences in percentage organic matter, crude protein, and nitrogen-free extract, while feed-feces ratios showed differences in the percentage digestibility of crude protein, nitrogen-free extract, and crude fibre. Despite these results no differences were established in nutritive values as estimated by digestible dry matter, total digestible nutrients, digestible energy or starch equivalents.Calculations demonstrated that the nutrient intake of crested wheatgrass, streambank wheatgrass, Russian wild ryegrass, and Ladak alfalfa were sufficient to provide at least a maintenance ration, but that the voluntary nutrient intake of intermediate wheatgrass, tall wheatgrass, and reed canary grass did not do so.Top-dressing did not increase the digestibility nor the apparent palatability of any feed; apparently consumption was determined by species characteristics rather than fertilizer treatment.
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