Effect of Origanum chemotypes on broiler intestinal bacteria

Abstract

Essential oils have been proposed as alternatives to antibiotic use in food animal production. This study evaluated 3 chemotypes of the Origanum genus, containing varying amounts of secondary metabolites carvacrol, thymol, and sabinene, in the broiler chicken diet. Aerial parts of Origanum vulgare L. (OL), O. vulgare L. ssp. hirtum (OH), and O. majorana (OM) were collected from a greenhouse located in the high altitude Sabana de Bogotá (Savanna of Bogotá) and O. vulgare L. ssp. hirtum (OG) produced and ground in Greece. Oregano essential oils (OEO) from these plants were obtained by steam distillation and analyzed by gas chromatography coupled to a mass spectrometer. Six treatments were evaluated: 200 mg/kg of OEO from OH, OL, and OM, 50 mg/kg of OEO from OG, 500 mg/kg of chlortetracycline, and without additives. Broiler chicks were maintained at 2,600 m above sea level, placed in brooder cages under a completely randomized design. Template DNA was isolated from duodenal, jejunal, ileal, and cecal contents in each group and bacterial 16S rDNA patterns were analyzed by denaturing gradient gel electrophoresis. Dendrograms of denaturing gradient gel electrophoresis band patterns revealed 2 main clusters, OEO-treated chicks and nontreated control chicks, in each intestinal segment. Band patterns from different gut compartments revealed major bacterial population shifts in the foregut (duodenum, jejunum, and ileum) compared with the hindgut (cecum and colon) at all ages evaluated (P < 0.05). The OEO groups showed less shift (62.7% similarity coefficient) between these 2 compartments versus the control groups (53.7% similarity coefficient). A reduction of 59% in mortality from ascites was seen in additive-supplemented groups compared with the control group. This study represents the first work to evaluate the effects of the 3 main chemotypes of Origanum genus in broilers.

Examination of the Expression of Immunity Genes and Bacterial Profiles in the Caecum of Growing Chickens Infected with Salmonella Enteritidis and Fed a Phytobiotic

“…Introduction of essential oils into the diet led to the domination of Lactobacillus bacteria, and also improved the height of villi and the depth of crypts in the small intestine as compared with the control without the additive. Similar effects were also observed by other authors [143,144,145] and in this study.…”

Pharmacokinetic and antimicrobial activity of a new carvacrol-based product against a human pathogen,Campylobacter jejuni

“…45 kg T À1 of food) the decrease in C. jejuni load was less intense than with the other doses. The hypothesis that could explain that the product is less effective when added at a dose of 45 kg per tonne of food than at 5 kg per tonne of food would be that a large dose would disrupt the microbial caecal flora of the chickens (Betancourt et al 2014). By suppressing some bacteria, and thus limiting the competition pressure, the Campylobacter growth would be favoured.…”

Evaluation of a phytogenic feed additive on performance, nutrient digestion, and absorption in turkey poults

“…However, the antimicrobial activity is dependent on not only the chemical compound, but also the species of bacteria as compounds such as limonene are much less effective against E. coli and S. typhimurium compared to carvacrol and thymol. This in vitro antimicrobial activity has prompted several researchers to investigate if these compounds have in vivo antimicrobial effects in broiler chickens (Cross et al, 2007;Betancourt et al, 2014;Peng et al, 2016) and turkeys .…”