Grain mixtures for older heifers need to be balanced according to the type of forages being fed. Examples of typical forages fed to older heifers are shown in Tables 3a and 4a. Regardless of the forage type, a grain mixture must be fed in order to provide the recommended levels of energy, protein, minerals, and vitamins. It is important to keep heifers growing at the desired rates. Tables 3b and 4b represent sample grain mixtures depending on the heifers age and proportion of forage fed.
Forage is assumed to be offered free-choice.
Urea is generally not recommended for heifers younger than six months old. Trace mineral salt should be offered free-choice and added to the grain mixture at recommended rates. Calcium and phosphorus requirements should be balanced throughout the growing period of the dairy heifer. Pasture and green, leafy hay are good sources of vitamin A and vitamin E, however even green hay loses its vitamin A and vitamin E content during storage. Heifers housed indoors for extended periods need to have their diets supplemented with vitamin D. As soon as the heifer's rumen becomes functional, the rumen microbes produce all the B vitamins, vitamin K, and vitamin C needed in the diet.