Encapsulated blends of essential oils and organic acids improved performance, intestinal morphology, cecal microflora, and jejunal enzyme activity of broilers

This study investigated effects of encapsulated blends of essential oils (EO) and organic acids (OA) on performance, intestinal morphology, cecal microflora, and jejunal mucosal enzyme activity and secretory IgA (s-IgA) level of broilers. Three hundred one-day-old male broilers were divided into 5 treatments with 5 replicates each. Control group received basal diet. Three additional groups received basal diets supplemented with 150, 200, or 250 mg/kg encapsulated blends of EO and OA. Antibiotic group received basal diet supplemented with 30 mg/kg bacitracin zinc. On days 21 and 70 of trial, 2 broilers from each replicate were weighed, and then blood, duodenum, jejunum, ileum, and cecum samples were collected. Results showed that broilers fed blends of EO and OA had greater average daily gain (ADG) (linear, P = 0.043) and gain-to-feed ratio (G : F) (linear, P = 0.052) at day 21 compared to broilers fed the control diet. Blends of EO and OA reduced cecal Escherichia coli and Salmonella level of 21- and 70-day-old broilers (linear, P < 0.01). Jejunum villus height-to-crypt depth ratio (VCR) of 21-day-old broilers was elevated by blends of EO and OA (linear, P = 0.041) compared to control. Blends of EO and OA promoted chymotrypsin activity at day 21 (quadratic, P = 0.014), jejunal mucosal s-IgA content at day 70 (linear, P = 0.012), α-amylase activity at day 70 (quadratic, P = 0.043), and chymotrypsin activity at day 70 (quadratic, P = 0.037). Compared to control, antibiotic group increased ADG at day 21 (P = 0.039), decreased cecal Salmonella level at day 21 (P = 0.018), enhanced jejunum VCR at day 21 (P = 0.049), and elevated jejunal mucosal s-IgA content at day 21 (P = 0.016). It can be stated that EO and OA blends enhanced performance, increased jejunal s-IgA level and enzyme activity, improved intestinal morphology, and balanced intestinal microflora of broilers.