Calves under six weeks of age should not be weaned unless absolutely necessary. At that age, calves would not likely have a functional rumen and thus are dependent on milk to supply the majority of their nutrient needs. Artificially replacing those nutrients can be extremely costly, labor intensive, and potentially detrimental to the life of the calf. Calves that are between six weeks and three months of age can be weaned but should be monitored closely to ensure they consume at least 3% of their body weight. Generally, diets for these calves should be at least 14% protein and be extremely palatable. The calves should be growing at a rate similar to what would be expected if they were still nursing. Calves between three and six months of age should receive highly palatable diets containing 12% to 14% protein. Those calves that are over six months of age can be weaned without special management practices. In any case, calves should be started on feed approximately three weeks prior to weaning to ensure they will eat.