Abstract: The objective of this study was to investigate the effects of feeding carbohydrates sources with different fermentation rate on reproduction performance of Khalkhali does under pasture. Sixty Khalkhali does were randomly allocated to three nutritional groups including 1) without supplemental feeding (CONTROL), 2) feeding 500 g whole barley grain per day (BARLEY) or 3) feeding 500 g whole corn grain per day (CORN). There were no significant differences between supplemented groups for fecundity, prolificacy and twinning rate. Twinning rate was 33.3, 58.8 and 61.11 percent for control, barley and corn groups, respectively. Feeding carbohydrate supplement increased blood glucose concentration after 8 days feeding relative to control group (P<0.05). The results showed that carbohydrate supplement feeding as short term nutrition during second week of estrus synchronization improved the energy situation of does and therefore their reproductive performance whereas there was no difference between carbohydrate sources with different fermentation rate. Therefore, applying short term nutrition program during synchronization programs can be recommended.