The objectives of this study were to determine the effects of daily injection of bovine somatotropin (bST) on the metabolism of N and 1-[14C]leucine and on hormone and metabolite concentrations in growing beef steers. Injection of bST increased N retention (P less than .05) primarily through decreased (P less than .10) urinary N excretion. Plasma concentration of somatotropin, insulin and gluco...