Effect of Essential Oils and Feed Enzymes on Performance and Nutrient Utilization in Broilers Fed a Corn/Soy-based Diet

Dietary and phytogenic inclusion effects on the broiler chicken cecal ecosystem

Dietary modulation in broilers is crucial for the establishment of beneficial microbiota and, subsequently, the promotion of intestinal health. In this trial, a 2 × 2 factorial design was used with two different specifications with respect to dietary metabolizable energy (ME) and crude protein (CP) levels (i.e., 95% and 100% of recommendations) and phytogenic levels (0 and 150 mg/kg). Levels of total bacteria, Bacteroides spp., Lactobacillus spp., and Clostridium cluster XIVa attached to the cecal mucosa and in the cecal digesta were lower in broilers fed the 95% ME and CP specification diets, as was the molar ratio of butyric acid. In addition, the relative activity of autoinducers-2 (AI-2) and the expression levels of TLR4 and AvBD6 were increased. Phytogenic supplementation reduced cecal digesta levels of Escherichia coli and Clostridium cluster I levels, and increased Clostridium cluster IV levels. Moreover, the butyric acid molar ratio and the relative activity of AI-2 were increased, whereas the concentration of branched VFAs and the expression of AvBD6 and LEAP2 were reduced by phytogenic administration. Dietary specifications and phytogenic interactions were shown for the cecal-attached microbiota composition, metabolic activity of digesta microbiota, relative expression of autoinducers-2, and relative expression of toll-like signaling molecules and host antimicrobial peptides. In conclusion, it has been shown that ME and CP dietary specifications, combined or not with phytogenics, modulate multilevel gut biomarkers ranging from microbiota composition and metabolic activity to microbial communications and host signaling, inflammation, and defense.

Exploring the effect of a microencapsulated citrus essential oil on in vitro fermentation kinetics of pig gut microbiota

Essential oils (EOs) have emerged as a potential alternative to antibiotics in pig breeding due to their antimicrobial properties. Citrus EOs, a common by-product of the orange juice industry, can be an interesting alternative from a financial perspective due to their huge offer in the global market. Thus, the effect of a citrus EO, and specifically different formulations of Brazilian Orange Terpenes (BOT), on pig gut microbiota was evaluated by means of an in vitro fermentation model simulating different sections of the pig gut (stomach, ileum, and colon). Treatments consisted in: BOT in its unprotected form (BOT, 1.85 and 3.70 mg/mL), microencapsulated BOT (MBOT, 3.50 and 7.00 mg/mL), colistin (2 μg/mL), and a control. BOT and MBOT altered in a similar way the total bacterial 16S rRNA gene copies in the stomach only from 18 h of incubation onwards, and no metabolite production in terms of short-chain fatty acids (SCFAs) was detected. In ileal and colonic fermentations, BOT and MBOT affected ileal and colonic microbiota in terms of total bacterial 16S rRNA gene copies, reduced phylogenetic diversity, and altered composition (p < 0.05) as evidenced by the significant reduction of certain bacterial taxa. However, more pronounced effects were found for MBOT, indicating its higher antimicrobial effects compared to the unprotected BOT, and suggesting that the antibacterial efficiency of the unprotected BOT was probably enhanced by microencapsulation. Furthermore, MBOT stimulated lactate production in ileal fermentations and greatly stimulated overall SCFA production in colonic fermentations. This indicates that besides the shifts in ileal and colonic microbiota by the delivered EO (BOT), the wall material of microcapsules (chitosan/modified starch) might have worked as an additional carbon source with prebiotic functioning, stimulating growth and metabolic activity (SCFAs) of colonic bacteria.

Nature-identical compounds as feed additives in aquaculture

Aquaculture sustainable development is necessary since it is categorized as the most important source of aquatic products for human consumption and it is expected to keep growing shortly. For this reason, the addition of natural immunostimulants to fish diet to improve fish health and to preserve the environment have great importance in aquaculture. In this sense, new biotechnological tools as nature-identical compounds are now being used as feed additives to strengthen and stimulate the fish immune system to prevent and/or control diseases due to their lesser cost and higher availability than plant compounds. This review aims to present the most recent studies in which nature-identical compounds have been used in the fish diet to establish their possible use in aquaculture. Nature-identical compounds can be considered a promising alternative to be added to fish diets to promote growth performance, manipulate the gut microbiota, and improve the immune and oxidative status of fish as wells as control bacterial infections in this important aquatic industry.

Effects of essential oils and their combinations added to broiler diets on the mineral contents of some tissues and bone breaking strength

At the end of the experiment, approximately 5 cc of blood was taken from broilers, and the serum was separated by centrifugation at 3000 rpm for 5 min. Serum mineral concentrations were determined directly in an atomic emission spectrometer (AX-ICP, Varian Vista). Subsequently, the tibia was removed from the slaughtered broilers, and the meat and bone marrow were cleaned and dried at 105°C for 24 h. Samples were taken from similar parts of each tibia (middle axis). The mineral content of the tibias was determined with an atomic emission spectrometer (ICP, VISTA AX CCD Simultaneous ICP-AES) after wet decomposition of the tibia in a microwave (Mars Xpress Technology Inside).

Thymol nanoemulsion promoted broiler chicken's growth, gastrointestinal barrier and bacterial community and conferred protection against Salmonella Typhimurium

The present study involved in vivo evaluation of the growth promoting effects of thymol and thymol nanoemulsion and their protection against Salmonella Typhimurium infection in broilers. One-day old 2400 chicks were randomly divided into eight groups; negative and positive control groups fed basal diet without additives and thymol and thymol nanoemulsion groups (0.25, 0.5 and 1% each). At d 23, all chicks except negative control were challenged with S. Typhimurium. Over the total growing period, birds fed 1% thymol nanoemulsion showed better growth performance even after S. Typhimurium challenge, which came parallel with upregulation of digestive enzyme genes (AMY2A, PNLIP and CCK). Additionally, higher levels of thymol nanoemulsion upregulated the expression of MUC-2, FABP2, IL-10, IgA and tight junction proteins genes and downregulated IL-2 and IL-6 genes expression. Moreover, 1% thymol nanoemulsion, and to lesser extent 0.5% thymol nanoemulsion and 1% thymol, corrected the histological alterations of cecum and liver postinfection. Finally, supplementation of 1% thymol, 0.5 and 1% thymol nanoemulsion led to increased Lactobacilli counts and decreased S. Typhimurium populations and downregulated invA gene expression postinfection. This first report of supplying thymol nanoemulsion in broiler diets proved that 1% nano-thymol is a potential growth promoting and antibacterial agent.

Broiler gut microbiota and expressions of gut barrier genes affected by cereal type and phytogenic inclusion

The present study assessed the effects of cereal type and the inclusion level of a phytogenic feed additive (PFA) on broiler ileal and cecal gut microbiota composition, volatile fatty acids (VFA) and gene expression of toll like receptors (TLR), tight junction proteins, mucin 2 (MUC2) and secretory immunoglobulin A (sIgA). Depending on cereal type (i.e. maize or wheat) and PFA inclusion level (i.e. 0, 100 and 150 mg/kg diet), 450 one-day-old male broilers were allocated in 6 treatments according to a 2 × 3 factorial arrangement with 5 replicates of 15 broilers each, for 42 d. Significant interactions (P ≤ 0.05) between cereal type and PFA were shown for cecal digesta Bacteroides and Clostridium cluster XIVa, ileal digesta propionic and branched VFA, ileal sIgA gene expression, as well as cecal digesta branched and other VFA molar ratios. Cereal type affected the cecal microbiota composition. In particular, wheat-fed broilers had higher levels of mucosa-associated Lactobacillus (P _CT = 0.007) and digesta Bifidobacterium (P _CT < 0.001), as well as lower levels of total bacteria (P _CT = 0.004) and Clostridia clusters I, IV and XIVa (P _CT ≤ 0.05), compared with maize-fed ones. In addition, cereal type gave differences in fermentation intensity (P _CT = 0.021) and in certain individual VFA molar ratios. Wheat-fed broilers had higher (P ≤ 0.05) ileal zonula occluden 2 (ZO-2) and lower ileal and cecal TLR2 and sIgA levels, compared with maize-fed broilers. On the other hand, PFA inclusion at 150 mg/kg had a stimulating effect on microbial fermentation at ileum and a retarding effect in ceca with additional variable VFA molar patterns. In addition, PFA inclusion at 100 mg/kg increased the ileal mucosa expression of claudin 5 (CLDN5) (P _PFA = 0.023) and MUC2 (P _PFA = 0.001) genes, and at 150 mg/kg decreased cecal TLR2 (P _PFA = 0.022) gene expression compared with the un-supplemented controls. In conclusion, cereal type and PFA affected in combination and independently broiler gut microbiota composition and metabolic activity as well as the expression of critical gut barrier genes including TLR2. Further exploitation of these properties in cases of stressor challenges is warranted.

Intestinal Microbiome-Metabolome Responses to Essential Oils in Piglets

This study investigated the effects of dietary essential oils (EOs) on intestinal microbial composition and metabolic profiles in weaned piglets. The piglets were fed the same basal diet supplemented with EOs (EO) or without EOs (Con) in the current study. The results showed that the body weight gain was significantly increased, while the diarrhea incidence was significantly reduced in the EO group. In addition, EOs could modify the intestinal microbial composition of weaned piglets. The relative abundances of some beneficial bacterial species such as Bacilli, Lactobacillales, Streptococcaceae, and Veillonellaceae were significantly increased in the EO group. Metabolomics analysis indicated that protein biosynthesis, amino acid metabolism, and lipid metabolism were enriched in the EO group. And correlation analysis demonstrated that some gut bacterial genera were highly correlated with altered gut microbiota-related metabolites. Taken together, this study indicated that dietary EOs not only altered microbial composition and function but modulated the microbial metabolic profiles in the colon, which might help us understand EOs' beneficial effects on intestinal health of weaned piglets.

Antimicrobial Activity of Chitosan Film Forming Solution Enriched with Essential Oils; an in Vitro Assay

Background: The resistance of the bacteria and fungi to the innumerous antimicrobial agents is a major challenge in the treatment of the infections demands to the necessity for searching and finding new sources of substances with antimicrobial properties. The incorporation of the essential oils (EOs) in chitosan film forming solution may enhance antimicrobial properties. However, its use as the feeding additive in the poultry nutrition needs to clarify the product's activity against both pathogen and the useful microbes in the gastrointestinal tract. Objectives: In the present study, we carried out an in vitro investigation and evaluated the antimicrobial activity of chitosan film forming solution incorporated with essential oils (CFs+EOs) against microbial strains including Staphylococcus aureus, Escherichia coli, Enterococcus faecium, Lactobacillus rahmnosus, Aspergillus niger and Alternaria alternate. Material and Methods: In three replicates, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of different treatments including: 1- essential oils (EOs), 2- chitosan film solution (CFs), and 3-chitosan film solution enriched with EOs (CFs+EOs) were determined against above mentioned microbes. Results: The results indicated that the chitosan solution enriched with essential oils (CFs+EOs) is capable of inhibiting the bacterial and fungal growth even at the lowest concentrations. The MIC and MBC for all the antimicrobial agents against Escherichia coli and Staphylococcus aureus were very low compared to the concentrations needed to inhibit the growth of useful bacteria, Lactobacillus rahmnosu and Enterococcus faecium. The antifungal activity of chitosan was enhanced as the concentration of EOs increased in the film solution. Conclusion: Chitosan-EOs complexes are the promising candidate for novel contact antimicrobial agents that can be used in animal feeds.

Growth performance and endogenous losses of broilers fed wheat-based diets with and without essential oils and xylanase supplementation

An experiment was conducted to compare the effect of a supplementary mixture of essential oils, with and without exogenous xylanase, on performance, carcass composition, dietary nitrogen (N)-corrected apparent metabolizable energy (AMEn), dry matter retention (DMR), N retention (NR), fat digestibility (FD) coefficients, and endogenous mucin losses (measured as sialic acid, SA) when fed to broiler chickens. Three hundred male Ross 308 broilers in total were reared in floor pens from 0 to 21 d of age. Birds were fed 1 of 3 wheat-based diets: basal diet (215 g/kg CP, 12.12 MJ/kg AME) with either no additive (control diet; C) or 100 g/tonne of a standardized combination of 5% carvacrol, 3% cinnamaldehyde, and 2% capsicum oleoresin (diet XT); or a combination of XT and commercial xylanase enzyme at a rate of 100 g of XT and 2,000 units (U) of xylanase/kg (diet XYL), respectively. Each diet was randomly allocated to 10 pens with 10 birds. Feeding XT and XYL diets improved birds' growth performance (P<0.05). Birds fed XT and XYL diets had an improved caloric conversion ratio (P<0.05) and consumed 1.3 MJ less AMEn per kilogram of growth compared to birds fed the control diet only. Feeding XT improved only the dietary FD coefficient (P<0.05) compared to control-fed birds, but the dietary FD coefficient did not differ for XYL diet (P>0.05). Birds fed XYL diet excreted 35% less endogenous mucin compared to control-fed birds (P<0.05). Birds fed XT alone gained more carcass protein than the control-fed birds (P<0.05) but did not differ from the birds fed XYL diet (P>0.05). There was no indication of a negative interaction between dietary essential oils and xylanase.

Effect of dietary supplementation of essential oils mixture on performance, eggshell quality, hatchability, and mineral excretion in quail breeders

The main aim of this study was to investigate the effect of six different levels (0, 50, 100, 200, 400, and 600 mg/kg) of phytogenic feed additive containing a mixture essential oils from thyme, black cumin, fennel, anise and rosemary on performance, eggshell quality, reproductive traits, and mineral excretion in quail breeders. In this trial, a total of 60 male and 120 female quails, 91 days old, were randomly distributed in six experimental groups. During the 60-day experiment period, birds were fed with six treatment diets. Performances, eggshell qualities, hatchability, and mineral excretion data were evaluated at the end of the experiment. Results showed that the different dietary levels of essential oil mixture had no significant effect on performance parameters, damaged eggs, eggshell weight, fertility, hatchability of fertile eggs, hatchability of set eggs, and lead and boron excretion. On the other hand, 50 mg/kg supplementation of essential oil mixture (EOM) significantly improved egg-breaking strength and eggshell thickness, and ash, calcium, phosphorus, magnesium, manganese, zinc, and cadmium excretion was significantly depressed in quail breeders supplemented with the two higher doses (400 or 600 mg/kg) of EOM. These results concluded that supplementing diets with EOM improved egg-breaking strength and decreased excretion of minerals in breeder quails.

Effects of essential oil supplementation of a low-energy diet on performance, intestinal morphology and microflora, immune properties and antioxidant activities in weaned pigs

A total of 144 weaned piglets were used to evaluate the effects of essential oil (EO) supplementation of a low-energy diet on performance, apparent nutrient digestibility, small intestinal morphology, intestinal microflora, immune properties and antioxidant activities in weaned pigs. Pigs received a low-energy diet (negative control, NC, digestible energy = 3250 kcal/kg), NC plus 0.025% EO or a positive control diet (PC, digestible energy = 3400 kcal/kg) for 28 days. Growth performance was similar between the EO group and PC group. However, EO supplementation increased (P < 0.05) average daily gain and the apparent digestibility of dry matter, crude protein and energy compared with pigs fed the NC diet. Greater (P < 0.05) villus height and lower (P < 0.05) counts of Escherichia coli and total anaerobes in the rectum in the EO group were observed compared with NC or PC groups. Pigs fed EO diet had higher (P < 0.05) concentrations of albumin, immunoglobulin A (IgA), IgG and total antioxidant capacity and lower fecal score than pigs fed the PC and NC diets. Above all, this study indicates that supplementation of EO to a low-energy pig diet has beneficial results and obtains similar performance compared with normal energy (PC) diet.

Effect of xylanase and a blend of essential oils on performance and Salmonella colonization of broiler chickens challenged with Salmonella Heidelberg

The present experiment examined the influence of xylanase supplementation and a blend of essential oils (EO; cinnamaldehyde and thymol) on performance and Salmonella horizontal transmission in broiler chickens challenged with Salmonella. Two thousand 1-d-old broiler chicks were randomly assigned to 5 dietary treatments (8 pens/treatment of 50 male broilers each). Four dietary treatments were challenged with Salmonella: 1) control, 2) basal diets supplemented with EO, 3) basal diet supplemented with xylanase (2,000 U/kg of feed), and 4) basal diet supplemented with a combination of EO and xylanase (2,000 U/kg of feed). One treatment served as an unchallenged control and was not supplemented with either additive. Broiler starter and finisher diets, based on wheat and soybean meal, were formulated, pelleted, and fed ad libitum. At d 1, before placement, half of the birds from each pen were tagged and dosed with Salmonella enterica serovar Heidelberg (5 × 10(5) cfu/mL). On d 42, 5 random untagged birds from each pen were killed and their ceca removed and tested for Salmonella. Performance data were analyzed as a completely randomized design using GLM. The frequency of positive Salmonella in the untagged birds was compared between treatments by using a chi-squared test of homogeneity. Challenging the birds with Salmonella had no effect (P > 0.05) on any of the measured performance parameters. Xylanase and EO supplementation improved (P < 0.05) the 42-d BW gain and feed efficiency, with no effect (P > 0.05) on feed intake, compared with that of the control treatment. Xylanase supplementation improved (P < 0.05) BW gain and feed efficiency compared with the results of EO supplementation. The combination treatment of xylanase and EO numerically improved BW gain and feed efficiency compared with the xylanase treatment. Xylanase and EO supplementation reduced (P < 0.05) the incidence of horizontal transmission of Salmonella infection between birds by 61 and 77%, respectively, compared with the control. The results of the current study suggested that dietary addition of EO and xylanase could improve broiler performance and contribute to food safety by lowering the incidence of horizontal transmission of Salmonella infection.