Effect of microencapsulated Minthostachys verticillata essential oil as an antibiotic substitute on broiler performance

Abstract

This study aimed to evaluate the effects of replacing antibiotics with microencapsulatedMinthostachys verticillata essential oil (M-Mv-EO) as a phytogenic feed additive (PFA) ongrowth performance, liver and intestinal histological changes, serum biochemicalparameters, genotoxic activity, and cecal microorganisms in broiler chickens. The Mv-EOwas microencapsulated using spray-dried wall material (WM) consisting of Gum Arabic,Maltodextrin, and Whey Protein Concentrate (1:1:1, w/w/w). Forty-eight Cobb broilersaging one-day-old were randomly assigned to four dietary treatments (three replicates pertreatment) and fed with a basal diet (CON), a diet supplemented with antibiotics (Bacitracinzinc salt, 7.5 mg/kg) (BZS), a diet supplemented with M-Mv-EO at a concentration of 100mg/kg, or a diet supplemented with WM only (CON-WM). The results showed that themicrocapsules obtained by spray drying remained stable without modifying the compositionof Mv-EO. Dietary supplementation with M-Mv-EO increased weight gain and feed intakeand improved the feed conversion ratio (FCR; P<0.05) compared to the CON, CON-WM,and BZS groups. Furthermore, M-Mv-EO supplementation did not cause histologicalchanges in the small intestine or the liver. M-Mv-EO supplementation reduced totalcholesterol levels and demonstrated non-cytogenotoxic effects in a bone marrowmicronucleus test. Moreover, supplementation with M-Mv-EO promoted the growth ofLactobacillus spp., Enterobacteria, and total aerobic bacterial proliferation compared to theBZS group (P<0.05). These findings suggest that M-Mv-EO as a PFA, at a concentration of100 mg/kg, could replace antibiotics in broiler chicken diets with comparable growthperformance and health parameters.