Contents lists available at ScienceDirect Livestock Science journal homepage: www.elsevier.com/locate/livsci Effects of dietary lavender essential oil on growth performance, intestinal function, and antioxidant status of broiler chickens S. Yarmohammadi Barbarestani a , V. Jazi b , H. Mohebodini c, ⁎ , A. Ashayerizadeh b , A. Shabani b , M. Toghyani d a Department of Animal and Poultry Physiology, Faculty of Animal Science, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan 49189-4364, Iran b Department of Animal and Poultry Nutrition, Faculty of Animal Science, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan 49189-4364, Iran c Department of Animal Sciences, University of Mohaghegh Ardabili, Ardabil 56199-11367, Iran d Department of Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia ARTICLEINFO Keywords: Antioxidant status Antibiotic Broiler chickens Lavender Gut health ABSTRACT A total of 480 one-day-old male broiler chickens were used in a 42-d study to assess the effects of different inclusion levels of lavender essential oil (LEO) supplementation in comparison with an antibiotic growth pro- moter on growth performance and physiological characteristics of broiler chickens. On d 1, broiler chickens were randomly assigned into 4 experimental treatments (6 replicates of 20 broiler chickens each) including a basal diet without any additive (control, CON), the basal diet supplemented with 200 mg/kg virginiamycin (VIM), and the basal diet supplemented with either 300 (LEO 300 ) or 600 (LEO 600 ) mg/kg LEO. The results showed that experimental treatments had no significant effect on feed intake at any stage of the study. In addition, no effect of experimental treatments was observed on body weight gain (BWG) and feed conversion ratio (FCR) over the starter period (d 0–21). However, broiler chickens fed diets supplemented with LEO 600 and VIM had greater BWGandexhibitedalowerFCRduringgrower(d21–42)andtheentireproductionperiod(d0–42; P < 0.05). Likewise, feeding LEO 600 and VIM diets decreased Escherichia coli population in the ileum and cecal contents and increased villus height and villus height to crypt depth of jejunum compared with the CON diet (P < 0.05). Dietary supplementation of LEO increased activity of superoxide dismutase in serum and liver and glutathione peroxidase activity in serum, but reduced concentrations of malondialdehyde in the serum (P < 0.05). In conclusion, addition of 600 mg/kg LEO to broiler chicken diets has the potential to improve growth perfor- mance, gut microbiota balance, intestinal morphology, and antioxidant activity. 1. Introduction In recent years, the increase of awareness of the adverse effects of antibiotic growth promoters (AGP) in animal feed has led to increased interest in producing animals without using AGP. However, by re- moving AGP from diets diseases problems may increase, negatively affecting growth performance (Liu et al., 2018). Hence, to prevent the undesirable effects of the removal of AGP from poultry diets, it is ne- cessary to apply proper nutritional strategies. Medicinal plants or herbal extracts and essential oils are among the non-antibiotic feed additives commonly used for poultry production that could help in maintaining general health and growth performance (Toghyani et al., 2010; Shirani et al., 2019). The potential beneficial effects of essential oils and/or phytogenic products in poultry production have been ex- tensively researched (Windisch et al., 2008). Mechanistically, phytogenic additives improve productivity in multiple and diverse pathways such as modifying mucosa architecture (Murugesan et al., 2015; Zeng et al., 2015a), enhancing antioxidant capacity and digestive enzymes activity (Hashemipour et al., 2013; Zeng et al., 2015a), sta- bilizing the enteric microbiota, as well as reducing lipid oxidation (Hashemipour et al., 2013; Shirani et al., 2019). However, results have not always been consistent and there are studies which failed to observe any positive responses of phytogenic inclusion in poultry diets on productive traits (Lee et al., 2003; Toghyani et al., 2010). Lavender (Lavandula angustifolia) is a strongly aromatic shrub, be- longs to the Lamiaceae family, which grows in various regions world- wide. Lavender essential oil (LEO) is extracted from lavender flowers, has therapeutic properties and is used as natural preservatives in the food industry (Jamroz et al., 2018). The main active compounds of LEO are linalool, linalyl acetate, lavandulyl acetate, alpha-terpineol, geranyl https://doi.org/10.1016/j.livsci.2020.103958 Received 14 August 2019; Received in revised form 17 January 2020; Accepted 4 February 2020 ⁎ Corresponding author. E-mail addresses: Jazi.vahid@gmail.com (V. Jazi), mohebodini@yahoo.com (H. Mohebodini), mtoghya2@une.edu.au (M. Toghyani). Livestock Science 233 (2020) 103958 Available online 05 February 2020 1871-1413/ © 2020 Elsevier B.V. All rights reserved. T