Stemmy, moldy, or other poor-quality hay reduces forage intake and retards growth. Fermented feeds such as haylage and corn silage can be fed to calves four to six months of age provided they are high quality. Heifers younger than six months are usually better off kept in the barn, as they obtain most of their nutrients from grain and since they tend to suffer more than older heifers from heat, competition from other heifers, and external and internal parasites. When weaning time arrives, the liquid feed portion of the calves' diet should be reduced and supplemented with a good free-choice grain mixture. Calves should be consuming a minimum of 1.5 pounds per head per day before they are completely taken off liquid feed.
Young heifers consume much less forage than grain on a dry matter basis.
As the animals mature and grow larger, forages can make up a greater part of their diet. For heifers up to six months old, free-choice grain is recommended at a maximum rate of 5 to 6 pounds per head per day. The quality of forages fed to these young animals will determine how much protein and other nutrients are needed in the grain mix. The types of forages commonly fed to heifers up to six months are shown in Table 1a. Grain mixtures for heifers may be as simple as corn, soybean meal, vitamins, and minerals, or may be as complex as desired.