To determine the effect of heifer development system on pregnancy rates and feed efficiency as a pregnant first calf heifer a 3-yr study was conducted. In Yr 1, weaned heifers either grazed corn residue (CR) or were fed in a drylot (DLHI). In Yr 2 and 3 heifers either grazed CR, upland range (RANGE), or were fed diets differing in energy, high (DLHI) or low (DLLO), in a drylot setting. Percent of mature BW before the breeding season was similar among treatments except DLHI which was significantly greater (P = 0.04) at 66.6% compared with 60.0, 61.0, and 61.7% for RANGE, CR, and DLLO treatments, respectively. Pregnancy rates to AI were similar (P = 0.62) among treatments (58.6, 66.3, 59.9, 52.6 ± 9.7%; RANGE, CR, DLHI, DLLO). A subset of AI-pregnant heifers from each development treatment were placed in a Calan gate system; they were allowed a 20 d acclimation and training period before beginning the 90 d ad libitum hay treatment period on approximately gestational d 170. Offerings were recorded daily and orts collected weekly. Initial BW was not different (P = 0.62) among treatments (458, 468, 473, 464 ± 9 kg; RANGE, CR, DLHI, DLLO). Body weight at the end of the treatment period was also not different ([P = 0.55] 485, 497, 503, 491 ± 17 kg; RANGE, CR, DLHI, DLLO). Intake did not differ among treatments, either as DMI ([P = 0.59] 9.2, 9.4, 9.5, 9.4 ± 0.7 kg; RANGE, CR, DLHI, DLLO) or as a percentage of BW ([P = 0.98] 1.96, 1.95, 1.95, 1.96 ± 0.15%; RANGE, CR, DLHI, DLLO). There was no difference (P = 0.61) in ADG (0.28, 0.33, 0.32, 0.28 ± 0.17; RANGE, CR, DLHI, DLLO) or residual feed intake (P = 0.41) (−0.095, −0.096, 0.144, 0.113 ± 0.156; RANGE, CR, DLHI, DLLO) among treatments. Although there was no difference (P = 0.41) in the 3-mo-development cost among treatments ($166.06, 141.66, 160.63, 171.80 ± 12.52; RANGE, CR, DLHI, DLLO), there was a $30.14 numerical difference between the most expensive treatment, DLHI, and the least costly treatment, CR. Post-weaning heifer development system did not affect heifer pregnancy rate or feed conversion as pregnant first calf heifers.