Yes, but you should forage test both the cornstalks and alfalfa hay to determine the proper mix to meet the nutritional demands of the cattle.

Test results from a number of cornstalk bales have been quite variable in both the protein and energy content. Crude protein as low as 2 percent and as high as 7 percent are normal. The variation is likely due to the differences in the stalk (stem)-to-leaf ratio. As the percent of stalk in the bale increases, the protein and energy levels decrease. The husk and leaf have the greatest protein and energy, and as those components are included in the bale at a greater percent, the quality will increase. Most bales had between 52 to 55% TDN. Nitrates could be a problem if the corn were grown in drought conditions, and they should be tested for.

Alfalfa quality is determined by plant maturity at harvest. Crude protein can range from 12 to 22% and energy from 52 to 67% TDN. Most alfalfa will be 16 to 18% crude protein and 55 to 58% TDN. Again, because of this variation, forage testing should be performed.

With the tests mentioned above, you are armed with the information needed to put together diets. If the stalks are in the 55% TDN range and 6% crude protein, then not much else may be needed for cows before calving. If the stalks are in the low 50% TDN range, then two-thirds cornstalk residue and one-third alfalfa would be close for March calving cows. After calving a 1:1 mixture of the two forages will still be a little short on energy. Corn (2 to 4 lb/hd per day; wouldn't go over 4 lb/hd/da of corn when feeding high-forage diets), distillers grains (2 to 3 of dry distillers or 6 to 8.5 lb/hd/da of the wet at 35% dry matter) or gluten feed (2 to 3 lb/hd/day of the dry CGF). There may be other energy sources in your area. Young females will especially need the extra energy.