Technical Abstract: First-calf heifers experience longer postpartum intervals following calving and have lower pregnancy rates to defined breeding seasons than older cows. Both prepartum and postpartum nutrition have major effects on subsequent reproduction. Recent studies have suggested that dietary fat may play an important role in reproduction and cow productivity. Prepartum diets high in linoleic acid improved subsequent pregnancy rates and weaning weights in one study, but had no effect on these traits in another study. The objective of this study was to identify potential mechanisms by which prepartum diets high in linoleic acid might increase calf weaning weight and heifer re-breeding performance. This study was designed to identify the mechanism(s) by which supplemental fat in the prepartum diet might improve calf and rebreeding performance. Other than improved calf vigor, no differences were detected that would suggest any beneficial effect of providing first calf heifers a prepartum diet high in fat. However, given the typical variability among animals for many of the phenotypes observed, concluding that these diets had similar effects may be premature.