The study aimed to determine the effect of three different levels of Boswellia serrata resin added to broiler diets on the fundamental production parameters, dry matter digestibility, organic matter digestibility, energy digestibility, microbiological condition of the gastrointestinal tract, and histomorphology of the walls of the small intestine. Two hundred Ross 308 chicks were assigned into 4 groups (50 birds of equal body weight) in 5 replications of 10 chicks each (5 females and 5 males). The experiment lasted 6 weeks. The control group (B0) was fed a standard mixture, without supplementation, whereas in groups B1.5, B2, and B2.5, the Boswellia serrata resin was added at the levels of 1.5, 2.0, and 2.5% of the complete feed mixture, respectively. The dietary supplementation with 2.0 and 2.5% of Boswellia serrata resin contributed to a significant increase in the length of the duodenum and total intestine and in the digestibility of dry matter and organic matter in feed. In these groups, the values of FCR and EEI were positively influenced (P<0.05) and an improvement in the structure of the jejunal wall was also recorded (P<0.05). An increase in the count of Lactobacillus and Enterococcus in the intestinal contents in broilers fed with the Boswellia serrata resin supplemented diets was observed. In conclusion, the Boswellia serrata resin can be considered as an effective feed additive, which stimulates production and has a positive effect on intestinal microflora and morphology of broilers.
