Twenty four Holstein bull calves were the subject of a commpletely randomized experimental design with a 2x2 factorial arrangement (weaning at the age of 28 or 56 days, with or without mannanoligosaccharide additive) and six replicates per treatment. There was no interaction between weaning periods and additive use. Weaning at 28 days of age, as compared to 56 days, resulted in lower final body weight, lower daily weight gain, higher concentrate intake, lower total dry matter intake and lower feed efficiency. Initial and final body measurements of withers heights, thoracic and abdominal girth presented no differeces, in spite of a lower average daily growth rate of thoracic girth in calves weaned at 28 days. Total individual and per kg costs of feeding, medication and veterinary care were lovwer for28 days weaned calves. Additive use did not affect body measurements but increased final and daily body weight gains, improved feed conversion and reduced average cost per kg body weight gain.
additive; performance; weaning ages
