Samples from steers fed a high-energy diet for 185 days prior to slaughter were used to compare collagen solubility and palatability of beef from youthful and mature carcasses. Carcasses representing the two maturity classes were selected specifically to have similar levels of intramuscular and subcutaneous fat, but distinctly different maturity indicators. Under the conditions of this study, maturity class had no effect on sensory properties or shear force values of cooked rib steaks. Total collagen content of samples from the longissimus muscle was higher for mature carcasses, but maturity class means for percentage of soluble collagen were not different. The relationships of these findings to preslaughter feeding regimen and collagen metabolism are discussed.