Growth and reproductive performance of beef replacement heifers fed development diets containing soybean meal or wet distillers grains 1

grass rangeland pasture. Heifers from each treatment were exposed to ovulation synchronization and fixed-time AI 23 or 51 d after diets ended. Total DM delivered was 4,695 kg less (P < 0.01) for WDG (57,131 kg) than for CON (61,826 kg). Daily DMI by WDG (7.07 kg) was 0.58 kg less (P < 0.01) than that by CON (7.65 kg), resulting in greater (P < 0.01) ADG throughout the development period for CON heifers (0.47 kg/d) than for WDG heifers (0.32 kg/d). Proportion of pubertal heifers was greater (P < 0.01) for CON compared with WDG on d 28 and 56 but not on d 84 or at breeding (P > 0.10). Conception to fixed-time AI and overall pregnancy rates were not different (P > 0.60) between treatments. Under the conditions of our study, developing replacement heifer diets using WDG as the primary source of CP had negative temporal effects on growth performance and age at puberty; however, these effects were nullified when heifers were allowed to graze native range for at least 23 d before breeding.