Correction to: Essential oil and aromatic plants as feed additives in non-ruminant nutrition: a review

Effects of microencapsulated essential oils and organic acids preparation on growth performance, slaughter characteristics, nutrient digestibility and intestinal microenvironment of broiler chickens

To develop effective antibiotics alternatives is getting more and more important to poultry healthy production. The study investigated the effects of a microencapsulated essential oils and organic acids preparation (EOA) on growth performance, slaughter performance, nutrient digestibility and intestinal microenvironment of broilers. A total of 624 1-day-old male Arbor Acres broilers were randomly divided into 6 groups including the control group (T1) fed with basal diet, the antibiotic group (T2) supplemented with basal diet with 45 mg/kg bacitracin methylene disalicylate (BMD), and 4 inclusion levels of EOA-treated groups (T3, T4, T5, T6 groups) chickens given basal diet with 200, 400, 600, and 800 mg EOA/kg of diet, respectively. Results showed that compared with the control, the 200 mg/kg EOA group increased average daily gain (ADG) and average body weight (ABW) during the early stage (P < 0.05). EOA addition decreased crypt depth of the ileum (P < 0.05), but villus height to crypt depth ratio was increased by EOA addition at 200 and 400 mg/kg at d 21 (P < 0.05). Compared with the control, dietary addition EOA at 200, 400 and 600 mg/kg increased the lipase activity in the duodenum at d 21 (P < 0.05). Increased lactic acid bacteria population was found in cecal digesta of the 400 mg/kg EOA group at d 21 (P < 0.05), and higher concentration of butyric acid level was observed in cecal digesta at d 21 and d 42 in the 200 mg/kg EOA group compared with the control (P < 0.05). RT-PCR analysis found that dietary EOA addition decreased the gene expression of IL-1β, COX-2 and TGF-β4 in the ileum at d 21 (P < 0.05), while only the 200 mg/kg EOA increased the gene expression of IL-10, TGF-β4, Claudin-1, ZO-1, CATH-1, CATH-3, AvBD-1, AvBD-9 and AvBD-12 in the ileum at d 42 (P < 0.05) compared with the control. In summary, adding 200 mg/kg and 400 mg/kg of the EOA to the diet could improve the growth performance and intestinal microenvironment through improving intestinal morphology, increasing digestive enzymes activity and cecal lactic acid bacteria abundance and butyric acid content, improving intestinal barrier function as well as maintaining intestinal immune homeostasis. The improving effect induced by EOA addition in the early growth stage was better than that in the later growth stage. Overall, the EOA product might be an effective antibiotic alternative for broiler industry.

Protective effect and possible mechanism of arctiin on broilers challenged by Salmonella pullorum

This study was aimed to investigate the effects of dietary arctiin (ARC) supplementation (100, 200, and 400 mg/kg) on the growth performance and immune response of broilers after a Salmonella pullorum (S. pullorum) challenge, and we conducted in vitro antibacterial test to explore the bacteriostatic mechanism of ARC. The in vivo trial was randomly assigned to six groups: noninfected control (NC) group and positive control (PC) group received a basal diet; TET group, received a basal diet supplemented with 100 mg/kg chlortetracycline; ARC100, ARC200, and ARC400 groups received a basal diet containing 100, 200, and 400 mg/kg ARC, respectively. From days 14 to 16, all birds (except the NC group) were infected with 1 mL (1 × 108 CFU per mL) fresh S. pullorum culture by oral gavage per day. In vivo results showed that dietary supplementation of 200 mg/kg ARC significantly increased average daily gain (P < 0.05) and decreased feed-to-gain ratio of broilers vs. the PC group during days 15 to 28 after being challenged with S. pullorum (P < 0.05). The jejunal crypt depth (CD) was decreased by supplementing 100 or 200 mg/kg ARC in diets compared with PC birds at day 19 (P < 0.05). The jejunal villi height (VH) was increased by supplementing 100, 200, or 400 mg/kg ARC in diets compared with PC birds at day 28 (P < 0.05). Besides, dietary supplementation of 200 mg/kg ARC increased the jejunal VH to CD ratio than the PC group both at days 19 and 28 (P < 0.05). Notably, the broilers had lower serum lipopolysaccharide and diamine oxidase levels in the ARC100 and ARC200 groups at day 28 than those in the PC group (P < 0.05). Furthermore, in comparison to PC birds, the birds in ARC groups (100, 200, and 400 mg/kg) had higher serum contents of IgM and IL-10, and the birds in the ARC200 group had higher serum contents of IgA at day 19 (P < 0.05). At day 28, the birds in ARC groups (100, 200, and 400 mg/kg) had lower serum contents of IL-8, and the birds in the ARC200 group had lower serum contents of IFN-γ compared with PC birds (P < 0.05). The in vitro experiment showed that ARC significantly inhibited the biofilm formation and adhesion of S. pullorum (P < 0.05). Metabonomics analysis revealed that ARC can restrain the formation of the biofilm by affecting a variety of metabolic pathways of S. pullorum. Therefore, dietary supplementation of 200 mg/kg ARC might be a potential way to substitute antibiotics to control S. pullorum infection in broilers.

Antioxidant and Anti-Atherogenic Activities of Essential Oils from Myrtus communis L. and Laurus nobilis L. in Rat

Essential oils (EOs) from aromatic and medicinal plants, such as myrtle (Myrtus communis L.) and Laurel (Laurus nobilis L.), are gaining popularity as a potential ingredient in functional foods and nutraceuticals. This study aims to investigate whether the essential oils (EOs) could be effective in weight control, antioxidative and antilipidemic status of rats by affecting microbiota and its enzymes activity and whether changes in intestinal enzyme activity affect the health of rats. The intragastric application of laurel and myrtle EOs to rats for two weeks affects weight loss, reduces glycolytic activity, lipid parameters (cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C) and very low-density lipoprotein cholesterol (VLDL-C)) and atherogenic indicators, leading to cardiovascular protection. Laurel EO can be an excellent candidate for the treatment of drug-induced obesity and related diseases, since it affects lipid metabolism in the liver and inhibits the enzymes responsible for the metabolism of carbohydrates into glucose in the digestive tract, leading to weight loss. In contrast, myrtle EO shows a better antioxidant capacity in most tissues, except kidneys, where it causes a pro-oxidative effect, compared to laurel EO. Myrtle EO increases the permeability and instability of the erythrocyte membrane, resulting in a loss of selectivity for the entry of toxic substances into the cell. On the other hand, myrtle EO leads to intestinal inflammation by reducing the number of probiotic bacteria and increasing Enterobacter.

Chemical Composition and Bioactivity of Essential Oil of Ten Labiatae Species

Using antibiotics as feed additives have been successively banned worldwide from 1986; therefore, it is an urgent task to finding safe and effective alternatives. As natural products of plant origin, essential oils (EOs) are an outstanding option due to their reported bioactivity. In this research, ten EOs of Labiatae species were extracted by steam distillation and its chemical constituents were identified by gas chromatography-mass spectrometry (GC-MS). A total of 123 chemical compounds, including alkenes, phenols, aldehydes and ketones, were identified. The results of antioxidant activity carried out through DPPH free radical scavenging (DPPH) and ferric reducing antioxidant power (FRAP), showing that EOs of Ocimum basilicum Linn. (ObEO), Thymus mongolicus Ronn. (TmEO), Origanum vulgare Linn. (OvEO) and Mosla chinensis Maxim. (McEO) have strong antioxidant activities. Their 50%-inhibitory concentration (IC₅₀) value was <1.00, 1.42, 1.47 and 1.92 μg/mL, respectively; and their FRAP value was 1536.67 ± 24.22, 271.84 ± 4.93, 633.71 ± 13.14 and 480.66 ± 29.90, respectively. The results of filter paper diffusion showing that McEO, OvEO and TmEO inhibition zone diameter (IZD) are all over 30 mm. The results of two-fold dilution method showed that McEO, OvEO and TmEO have strong antibacterial activities against Staphylococcus aureus (S. aureus) and their minimal inhibitory concentrations (MIC) value was 1 μL/mL, 2 μL/mL, and 2 μL/mL, respectively. In conclusion, the results in this work demonstrate the possibility for development and application of EOs as potential feed additives.