The present study evaluated the interaction of forage provision (F) and sodium butyrate (SB) supplementation in pre-weaning lambs on performance, structural growth, blood metabolites and rumen fermentation characteristics. Twenty eight 3-days old individually housed Chaal breed lambs averaging BW of 6.02 ± 0.57 kg were randomly assigned to 4 treatments (n=7 lambs/ treatment: 4 males and 3 females). Experimental treatments were; 1) starter diet provided neither with F nor with SB (NF-NSB), 2) starter diet supplemented only with SB (NF-SB), 3) starter diet provided only with forage (F-NSB), and 4) starter diet simultaneously provided by forage and SB (F-SB). The F provision was 10% chopped alfalfa hay included in whole concentrate starter based diet (DM basis) and the SB supplementation was 3 g of SB/kg of starter DM. The manual milk feeding was performed for all lambs. The lambs were weaned on d 59 of age but the study lasted until d 73 of age. Performance statistical analysis was carried out for pre-weaning (8 weeks), post-weaning (2 weeks) and entire experimental periods (10 weeks). The results show that starter intake influenced with SB (P=0.03) and weaning weight was greater in lambs supplemented with SB (P < 0.01). Neither intake nor gain was influenced with forage provision (P > 0.05). The interaction was observed between SB and F for gain in overall period of experiment (P=0.03). The interaction of SB and F caused the greatest wither height in F-SB treatment (P=0.03). Body barrel was greater in forage fed lambs (P=0.01). No blood parameter was influenced with separate or simultaneous provision of F and SB in the current study. The short chain fatty acid (SCFA) concentration (P=0.02) as well as butyrate concentration (P < 0.01) was increased by SB supplementation. Forage inclusion improved ruminal fluid pH (P=0.02) and increased acetate (P < 0.01); however both butyrate (P=0.02) and propionate (P=0.01) concentrations were reduced. In conclusion we found that F
