Preconditioning reduces stress, maintains health, and adds value to feeder calves. Calf response to pasture nutritive value and supplementation was studied on 17 farms in 2002, 8 farms in 2003, and 9 farms in 2004. Calves were weaned in late August and backgrounded on pasture to mid-October. Calves were fed a commercial concentrate (0.0 to 1.5% bodyweight [BW]), hay, and on some farms haylage, ground shelled corn (Zea mays L.), or soybean (Glycine max L.) hulls. Calf average daily gain (ADG) was evaluated across farms relative to animal, pasture, and supplement characteristics using multiple regressions. Commercial supplement intake, corn intake, and pasture total digestible nutrient (TDN) or pasture neutral detergent fiber (NDF) significantly influenced calf ADG. Based on regression coefficients, 4.4 lb of commercial supplement or 4.1 lb of corn were required to produce 1 lb of additional gain. Increasing pasture TDN or decreasing pasture NDF by 10 percentage units increased ADG 0.86 or 0.48 lb/day, respectively. Regressions were tested against 2004 data. Regression-estimated gains were not significantly different from measured ADG 67% of the time. Calf performance during backgrounding can be cost effective when management ensures adequate pasture quantity and nutritive value and supplements are used judiciously relative to their cost and the value of calf gain.