The objective of this work was to study the effects of age at the beginning of forage supply (4 or 60 days) and weaning age (35 or 56 days) on the digestibility of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and gross energy (GE) and nitrogen balance, in the post weaning period, in Holstein and Holstein x Zebu crossbred bull calves. The animals were maintained in metabolism cages for feces and urine collection. A unique diet containing 33.0% of forage, 67.0% of concentrate and 16% of crude protein on DM basis was used. The previous treatment did not affect the apparent digestibility coefficients of DM, CP, NDF and GE, and nitrogen balance, when evaluated in the period from 72 to 78 days of age.
nitrogen balance; calves; concentrate; digestibility; forage