The “dilution of maintenance” effect conferred by increasing growth rate in steers within the 2007 US beef production system when compared with the 1977 US beef system. Energy values represent the average maintenance and growth requirements for steers destined for slaughter within the beef system. Requirements were weighted according to the number of days spent within the cow-calf, stocker, and feedlot system, and in the case of the 2007 system, to account for the proportion of yearling-fed beef, calf-fed beef, and calf-fed dairy steers within the slaughter population.