FURTHER STUDIES ON THE PROTEIN AND ENERGY REQUIREMENTS OF YOUNG DAIRY CALVES

Abstract

To confirm laboratory estimates of protein and energy requirements, 32 newborn dairy calves were fed "filled milk" diets containing 18 to 35 per cent of the total calories as protein. A comparison was made between the actual growth rates and growth rates predicted from the consumption of protein and energy. A decline in the efficiency of protein utilization did not occur until the level of dietary protein exceeded 24 per cent of the total calories. Optimum energy efficiency, measured by weight gain, was obtained at intakes below 80 digestible Cal./kg./day. At energy intakes above this level each additional digestible Cal. did not result in the predicted increment in body weight.