THE PROTEIN AND ENERGY REQUIREMENTS OF YOUNG DAIRY CALVES

Abstract
The protein and energy requirements of pre-weanling dairy calves were studied through the use of growth and balance trial techniques. Various levels of protein and energy were fed in both purified and semi-purified diets. The nitrogen retention of calves fed diets adequate in protein was 3.22 gm. per 100 gm. of gain in body weight. Energy requirement for maintenance was 44.7 digestible Calories per kg. of body weight per day and 268 digestible Calories were required per 100 gm. of gain in weight. These factors, along with previously determined values for endogenous nitrogen, were used to calculate the practical digestible energy and apparent digestible protein requirements of dairy calves.