Dietary synbiotic incorporation as an alternative to antibiotic improves growth performance, intestinal morphology, immunity and antioxidant capacity of broilers

Combined effects of sodium butyrate and xylo-oligosaccharide on growth performance, anti-inflammatory and antioxidant capacity, intestinal morphology and microbiota of broilers at early stage

This study aimed to evaluate the individual and combined effects of chemically protected sodium butyrate (CSB) and xylo-oligosaccharide (XOS) on performance, anti-inflammatory and antioxidant capacity, intestinal morphology and microbiota of broilers. A total of 280 one-day-old Arbor Acres broilers were randomly distributed into 5 treatments: basal diet (CON), basal diet supplemented with 100 mg/kg aureomycin and 8 mg/kg enramycin (ABX), 1000 mg/kg CSB (CSB), 100 mg/kg XOS (XOS), and mixture of 1000 mg/kg CSB and 100 mg/kg XOS (MIX), respectively. On d 21, ABX, CSB, and MIX decreased feed conversion ratio compared with CON (CON: ABX: CSB: MIX = 1.29: 1.22: 1.22: 1.22), whereas body weight of CSB and MIX was increased by 6.00% and 7.93%, and average daily gain was increased by 6.62% and 8.67% at 1-21 d, respectively (P < 0.05). The main effect analysis showed that both CSB and XOS treatments increased ileal villus height and villus height to crypt depth ratio (VCR) (P < 0.05). Moreover, broilers in ABX showed lower 21.39% ileal crypt depth and higher 31.43% VCR than those in CON (P < 0.05). Dietary CSB and XOS were added individually or collectively increased total antioxidant capacity and superoxide dismutase, and anti-inflammatory cytokines interleukin-10 and transforming growth factor-β, whereas decreased malondialdehyde, and proinflammatory cytokines IL-6 and tumor necrosis factor-α content in serum (P < 0.05). Meanwhile, MIX showed the best effect of antioxidant and anti-inflammatory capacity among the 5 groups (P < 0.05). There was an interaction between CSB and XOS treatments on increasing cecal acetic acid, propionic acid, butyric acid and total short-chain fatty acid (SCFA) (P < 0.05), and the one-way ANOVA showed that propionic acid in CSB was 1.54 times that of CON, whereas butyric acid and total SCFAs in XOS were 1.22 times and 1.28 times that of CON, respectively (P < 0.05). Furthermore, dietary combination of CSB and XOS changed phyla Firmicutes and Bacteroidota, and increased genera Romboutsia and Bacteroides (P < 0.05). In conclusion, dietary CSB and XOS improved growth performance of broilers, and the combined addition of them had the best effect on anti-inflammatory and antioxidant capacity, and intestinal homeostasis of broilers in current study, indicating that it may be a potential natural alternative to antibiotics.

Dietary supplementation with synbiotics improves growth performance, antioxidant status, immune function, and intestinal barrier function in broilers subjected to cyclic heat stress

This study investigated the effects of synbiotics supplementation on growth performance, antioxidant status, immune function, and intestinal barrier function in broilers subjected to cyclic heat stress. One hundred and forty-four 22-day-old male broilers were randomly assigned to one of three treatment groups of six replicates each for a 21-day study, with eight birds per replicate. Broilers in the control group were reared at a thermoneutral temperature and received a basal diet. Broilers in the other two heat-stressed groups were fed a basal diet supplemented without (heat-stressed group) and with 1.5 g/kg synbiotic (synbiotic group). One and a half gram of the synbiotic consisted with 3 × 10⁹ colony forming units (CFU) Clostridium butyricum, 1.5 × 10⁹ CFU Bacillus licheniformis, 4.5 × 10¹⁰ CFU Bacillus subtilis, 600 mg yeast cell wall, and 150 mg xylooligosaccharide. Compared with the control group, heat stress increased rectal temperatures at 28, 35, and 42 days of age, respectively (P < 0.05). Birds subjected to heat stress had reduced weight gain, feed intake, and feed efficiency during 22 to 42 days (P < 0.05). In contrast, supplementation with the synbiotic decreased rectal temperature at 42 days of age and elevated weight gain of heat stress-challenged broilers (P < 0.05). Heat-stressed broilers exhibited a lower superoxide dismutase (SOD) activity in jejunal mucosa and a higher malondialdehyde accumulation in serum, liver and jejunal mucosa (P < 0.05), and the regressive SOD activity was normalized to control level when supplementing synbiotic (P < 0.05). Heat stress increased interleukin-1β (IL-1β) and interferon-γ (IFN-γ) levels in serum and IL-1β content in jejunal mucosa of broilers (P < 0.05). Synbiotic reduced IL-1β level in serum of broilers subjected to heat stress (P < 0.05). Compared with the control group, elevated serum diamine oxidase activity and reduced jejunal villus height were observed in broilers of the heat-stressed group (P < 0.05), and the values of these two parameters in the synbiotic group were intermediate (P > 0.05). Heat stress upregulated mRNA abundance of IL-1β and IFN-γ and downregulated gene expression levels of occluding and zonula occluden-1 (ZO-1) in jejunal mucosa of broilers (P < 0.05). The alterations in the mRNA expression levels of jejunal IL-1β and ZO-1 were reversed by the synbiotic (P > 0.05). In conclusion, dietary synbiotics could improve growth performance, antioxidant capacity, immune function, and intestinal barrier function in heat-stressed broilers.

Fabrication of bio-engineered chitosan nanoformulations to inhibition of bacterial infection and to improve therapeutic potential of intestinal microflora, intestinal morphology, and immune response in infection induced rat model

Overdosage of antibiotics used to prevent bacterial infections in the human and animal gastrointestinal tract would result in disturbing of intestinal barrier, significant misbalancing effects of intestinal microflora and persuading bacterial resistance. The main objective of the present investigation is to design and develop novel combinations of organic curcumin (Cur) and antimicrobial peptide (Amp) loaded chitosan nanoformulations (Cur/Amp@CS NPs) to improve significant effects on antibacterial action, immune response, intestine morphology, and intentional microflora. The antibacterial efficiency of the prepared nanoformulations was evaluated using Escherichia coli (E. coli) induced bacterial infections in GUT of Rat models. Further, we studied the cytocompatibility, inflammatory responses, α-diversity, intestinal morphology, and immune responses of treated nanoformulations in rat GUT models. The results indicated that Cur/Amp@CS NPs are greatly beneficial for intestinal microflora and could be a prodigious alternative of antibiotics.

Effect of a synbiotic supplement as an antibiotic alternative on broiler skeletal, physiological, and oxidative parameters under heat stress

The aim of this study was to examine if synbiotics can function as alternatives to antibiotics in broiler production under heat stress (HS). Day-old broiler chicks (528 birds) were randomly placed in floor pens within 2 identical temperature-controlled rooms (11 birds/pen and 24 pens/room). The pens of each room were evenly divided among 3 treatments (n = 8): basal diet (CON), the basal diet mixed with 50 ppm of bacitracin methylene disalicylate (BMD) or a synbiotic (50 ppm of PoultryStar me^US, SYN). From d 15, room 2 was under thermoneutral (TN) conditions (TN-CON, TN-BMD, and TN-SYN), while HS was applied to room 1 at 32^oC for 9 hrs/d (0800 to 1700) (HS-CON, HS-BMD, and HS-SYN). Treatment effects on footpad dermatitis and gait score were measured on 5 birds/pen, and latency to lie (LTL) test was measured on 2 birds/pen at d 27 and d 41; and 1 broiler/pen was sampled on d 28 and d 42, respectively. Body, liver, and spleen weight were determined. Plasma levels of interleukins (IL), heat shock protein 70, immunoglobulin (Ig)Y, liver superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzyme activities were examined. Heat stress suppressed BW and IgY concentrations on both d 28 and d 42, while suppressed plasma IL-6 concentrations, SOD activities, and LTL duration on d 28 only (P < 0.05). Among all treatments, SYN birds had the best foot and skeletal health scores on both d 27 and d 41 (P < 0.05). On d 42, SYN increased BW, and TN-SYN birds had higher relative spleen weight than both TN-BMD and TN-CON birds (P < 0.05). Antibiotic BMD increased BW (P < 0.05) but decreased SOD activities (P < 0.05) on d 42. These results indicate that the SYN supplementation decreases HS negative effect on broilers by improving BW, foot, and skeletal health, while BMD improves BW but also increases oxidative stress in broilers. The data suggest that synbiotic supplement may function as an alternative to antibiotics in broiler production during summer seasons, especially in the tropical and subtropical regions.

Dietary supplementation with Clostridium butyricum improves growth performance of broilers by regulating intestinal microbiota and mucosal epithelial cells

Clostridium butyricum has been widely considered an antibiotic substitute in recent years. It can promote growth performance, improve the immune response and enhance the intestinal barrier function of the host. In the present study, 1-d-old Arbor Acres (AA) broilers were fed C. butyricum (1 × 10⁹ cfu/kg) for 28 d. The transcriptomic characteristics of epithelial cells of the cecal mucosa were determined by RNA-sequence, and the cecal microbiota composition was explored by 16S ribosomal RNA gene sequencing. The changes in the intestinal mucosa of broilers were then analyzed by tissue staining. Gene Ontology (GO) annotations identified substance transport and processes and pathways that might participate in intestinal development and cell viability. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the differentially expressed genes are involved in numerous pathways related to amino acid and vitamin metabolism and antioxidant and defensive functions, among others. The relative expression of some genes associated with intestinal barrier function (claudins 2, 15, 19, and 23, tight junction proteins 1, 2, and 3 and mucin 1) was significantly increased in the treatment group (P < 0.05 or P < 0.01). Moreover, the proportion of Firmicutes was higher in the C. butyricum-treated group, whereas the proportion of Proteobacteria was higher in the control group. At the genus level, the relative abundances of Butyricicoccus and Lactobacillus, among other bacteria, were increased after C. butyricum supplementation. The tissue staining analysis showed that the cecal mucosa of broilers was significantly ameliorated after the addition of C. butyricum (P < 0.05 or P < 0.01). These results showed that dietary supplementation with C. butyricum can enhance the antioxidant capacity, mucosal barrier function, and stabilize the cecal microbiota, resulting in improving the growth performance.

Bacillus subtilis DSM29784 Alleviates Negative Effects on Growth Performance in Broilers by Improving the Intestinal Health Under Necrotic Enteritis Challenge

Along with banning antibiotics, necrotic enteritis (NE), especially subclinical enteritis (SNE), poses a significant threat to the chicken industry; however, probiotics are a potentially promising intervention. We aimed to investigate the beneficial effects of Bacillus subtilis DSM29784 (BS) on the treatment of Clostridium perfringens (CP)-induced SNE in broilers. A total of 360 1-day-old broiler chicks were divided into three treatment groups, namely control (Ctr), SNE, and BS treatment (BST) groups, all of which were fed with a basal died for 21days, and then from day 22 onward, only the BST group had a BS supplemented diet (1×10⁹ colony-forming units BS/kg). On day 15, all chicks, except the Ctr group, were challenged with a 20-fold dose coccidiosis vaccine and 1ml CP (2×10⁸) on days 18–21 for SNE induction. Beneficial effects were observed on growth performance in BST compared to SNE broilers. BST treatment alleviated intestinal lesions and increased the villus height/crypt depth ratio. Further, BST broilers showed increased maltase activity in the duodenum compared with SNE chicks, and a significantly decreased caspase-3 protein expression in the jejunum mucosa. Moreover, an increased abundance of Ruminococcaceae and Bifidobacterium beneficial gut bacteria and an altered gut metabolome were observed. Taken together, we demonstrate that the manipulation of microbial gut composition using probiotics may be a promising prevention strategy for SNE by improving the composition and metabolism of the intestinal microbiota, intestinal structure, and reducing inflammation and apoptosis. Hence, BS potentially has active ingredients that may be used as antibiotic substitutes and effectively reduces the economic losses caused by SNE. The findings of this study provide a scientific foundation for BS application in broiler feed in the future.

Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 12: Tetracyclines: tetracycline, chlortetracycline, oxytetracycline, and doxycycline

The specific concentrations of tetracycline, chlortetracycline, oxytetracycline and doxycycline in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. The FARSC for these four tetracyclines was estimated. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for tetracycline, chlortetracycline, oxytetracycline, whilst for doxycycline no suitable data for the assessment were available. Uncertainties and data gaps associated with the levels reported were addressed. It was recommended to perform further studies to supply more diverse and complete data related to the requirements for calculation of the FARSC for these antimicrobials.

Protective effects of dietary synbiotic supplementation on meat quality and oxidative status in broilers under heat stress

This study evaluated protective effects of synbiotic on meat quality and oxidative status of breast muscle in heat-stressed broilers. Twenty 2-day-old broilers were allocated in a 2×2 factorial design, and the main factors consisted of synbiotic level (0 (basal diet) or 1.5 g/kg synbiotic) and temperature (thermoneutral or high temperature), resulting in 4 treatments. From 22 to 42 days, chickens were raised at thermoneutral temperature (22 °C) or subjected to cyclic high temperature (heat stress, HS) by keeping them at 32-33 °C for 8 h and 22 °C for rest 16 h daily. Cyclic HS decreased relative weight, redness (45 min), and pH values (45 min and 24 h) but increased contents of moisture and ether extract, lightness (45 min and 24 h), drip loss (24 h and 48 h), and cooking loss in breast muscle of broilers compared with those under thermoneutral temperature. It also increased malondialdehyde content and mRNA abundances of heat shock protein 70 (HSP70) and HSP90 but decreased glutathione (GSH) concentration and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), as well as mRNA abundances of nuclear factor (erythroid 2)-like 2 (Nrf2), NAD(P)H quinone dehydrogenase 1 (NQO1), GSH-Px, and copper and zinc superoxide dismutase in breast muscle in broilers. Dietary synbiotic supplementation was effective in increasing weight and reducing lightness (45 min), drip loss (24 h and 48 h) and cooking loss of breast muscle in heat-stressed broilers compared with those fed the basal diet. It also reduced malondialdehyde content and HSP70 mRNA abundance and increased GSH-Px activity, GSH content, and mRNA abundances of Nrf2, NQO1 and GSH-Px in breast muscle of heat-stressed broilers. These results suggested that synbiotic supplementation at a level of 1.5 g/kg could ameliorate compromised meat quality and oxidative status in broilers under cyclic HS.

Effects of Wheat Bran and Clostridium butyricum Supplementation on Cecal Microbiota, Short-Chain Fatty Acid Concentration, pH and Histomorphometry in Broiler Chickens

Simple Summary

Antimicrobial resistance issues and growing consumer demand promote the need for antibiotic-free meat production. Fostering animal productivity without antibiotic growth promoters accelerates the use of non-antibiotic feed additives and encourages researchers to gain a deeper understanding of diet-gut microbiota interactions. Little information is available about the effects of single strain probiotic bacteria Clostridium butyricum and wheat bran on the gut microbiota of chickens using next-generation sequencing. Therefore, these components were evaluated in the present study on gut microbiota composition and other gut health characteristics of broiler chickens. Results showed that probiotic supplementation decreased cecal Akkermansia spp. abundance, whereas wheat bran supplementation increased the relative abundance of Akkermansia spp. compared to the control and symbiotic groups, respectively. Dietary treatment also altered cecal crypt depth and had a trend to modify cecal fermentation profiles. Besides, the combination of probiotic and wheat bran supplementation did not have further effects on any investigated parameters. Members of the Akkermansia genus have several beneficial health effects in mammals, but less is known about its role in chicken health. The results of the present study expand our understanding of diet-gut microbiota interaction in chickens, which helps to approximate antibiotic-free meat production.

Abstract

Feed additives that can improve intestinal health and maintain a diverse and resilient intestinal microbiota of poultry are of great importance. Thus, the current study investigated the effects of a single strain butyric acid-producing Clostridium (C. butyricum) with (symbiotic) or without wheat bran supplementation on cecal microbiota composition and gut health characteristics of broiler chickens. In total, 384 male Ross 308 day-old chickens were divided into four dietary treatment groups and fed ad libitum until day 37 of life. Cecal samples were taken for Illumina sequencing and pH and short-chain fatty acid analyses, as well as for histological analysis at the end of the experimental period. Neither of the supplemented diets improved chicken growth performance. Caecum was dominated by the members of Bacteroidetes phyla followed by Firmicutes in each dietary group. At the genus level, Bacteroides, Oscillospira, Akkermansia, Faecalibacterium, Ruminococcus and Streptococcus genera exceeded 1% relative abundance. Dietary treatment influenced the relative abundance of the Akkermansia genus, which had a lower relative abundance in the C. butyricum group than in the other groups and in the symbiotic group compared to the wheat bran supplemented group. Dietary treatment also altered cecal crypt depth and had a trend to modify the cecal fermentation profile. Additive effects of wheat bran and C. butyricum supplementation were not detected. Our results suggest that Akkermansia muciniphila colonization in chicken can be influenced by diet composition.

Effects of antibiotic growth promoter and dietary protease on growth performance, apparent ileal digestibility, intestinal morphology, meat quality, and intestinal gene expression in broiler chickens: a comparison

This study aimed to evaluate the effects of supplementing broiler diets with a dietary protease on growth performance, digestive function, intestinal morphology, and meat quality as compared with feeding diets with or without an antibiotic growth promoter (AGP). A total of 240 1-day-old male chicks (Cobb 500, 48.3 ± 3.3 g) were distributed to three treatments with eight replicates (10 birds per replicate). Three treatments were: 1) corn-soybean meal basal diets (CTRL), 2) basal diets with 0.003% avilamycin (AB), and 3) basal diets with 0.0125% protease (PRT). The diets were provided as mash form, and birds were fed ad libitum during the whole experimental period. On day 45, birds were euthanized, and tissue and digesta samples were collected. On day 46, the remaining birds were processed in a commercial slaughterhouse, and breast muscle samples were collected. Despite a trend for a decreased feed conversion ratio (FCR) in the AB group during the whole phase (P = 0.071), no significant differences in growth performance parameters and relative weights of organs were observed (P > 0.05) among the groups. The AB and PRT groups showed significantly greater apparent ileal digestibility of amino acids (AA) compared with the CTRL group (P < 0.05). The PRT group significantly improved the morphology of duodenum and jejunum (P < 0.05). No differences were detected for meat quality, white striping, and woody breast among the groups (P > 0.05). For the gene expressions, the AB group showed a greater level of B0-system neutral amino acid co-transporter 1 and excitatory amino acid transporter 1 mRNA abundance compared with PRT group, while a significantly lesser level of cationic amino acid transporter 1 mRNA abundance was observed in the AB group compared with CTRL group (P < 0.05). The PRT group had a lesser level of peptide transporter 1 mRNA abundance in the jejunum than the CTRL group (P < 0.05). The highest mRNA abundances of zonula occludens-1 and cadherin 1 were observed in the CTRL group (P < 0.05). In conclusion, supplementation of avilamycin tended to reduce FCR and significantly improved AA utilization, and supplementation of dietary protease significantly enhanced intestinal morphology and AA utilization in broilers. In that respect, exogenous protease use appears to be an interesting tool to be considered in AGP reduction strategies.

Antibiotics promote abdominal fat accumulation in broilers

Antibiotics stimulate the growth of animals but result in drug residues and bacterial resistance. In this study, the negative effect of antibiotics on abdominal fat deposition was evaluated in broilers. The results showed that adding both chlortetracycline (50 g/1,000 kg) and tylosin (50 g/1,000 kg) significantly increased abdominal fat weight, abdominal fat percentage (p < .05), and triglyceride and cholesterol levels (p < .05) in blood. Also, both products synchronously stimulated intestinal absorption and synthesis of liver fat. The expression levels of the peroxisome proliferator-activated receptor γ (PPARγ), diacylgycerol acyltransferase 2 (DGAT2), lipoprotein lipase (LPL), and fatty acid-binding protein (FABP4) genes in abdominal fat tissue significantly increased (p < .05 or 0.01) when antibiotics were added to the feed. However, no significant difference was found in expression of the fatty acid synthesis (FAS) or acetyl CoA carboxylase (ACC) genes. Further in vitro study results revealed that antibiotics had no effect on fat content or the related gene expression levels in preadipocytes. In summary, the antibiotics induced fat deposition in adipose tissues by activating extracellular absorption of fatty acids from intestinal absorption and synthesis of liver fat. However, it shows no direct regulation by adipose tissue.

Microstructure of the small intestine in broiler chickens fed a diet with probiotic or synbiotic supplementation

The aim of the study was to determine the effect of dietary supplementation of a probiotic and a synbiotic on the morphometric parameters of the small intestine of broiler chickens. The experiment was conducted on three hundred sixty, one-day-old female Ross 308 chicks, which were randomly selected from 20,000 birds and divided into three treatment groups (n = 120) with ten replicates per treatment. The control group (C) was fed a commercial diet, the probiotic group (PRO) was fed the same diet with an added 1% of the probiotic Lavipan® (Lactococcus lactis, Carnobacterium divergens, Lactobacillus casei, Lactobacillus plantarum and Saccharomyces cerevisiae), and the synbiotic group (SYN) was fed the commercial diet with an added synbiotic: 0.8% of the prebiotic RFO (extracted from lupin seeds) and 1% Lavipan®. According to the manufacturer's data, apart from the typical probiotic action,microorganisms contained in the preparation release anti-bacterial substances (hydrogen peroxide and bacteriocins) and, therefore, are antagonistic towards pathogenic bacteria present in the gut of animals. Supplementation took place in the first seven days of rearing, and all birds had ad libitum access to water and feed during the 42 days of the experiment. On the last day, all birds were slaughtered and samples from three segments of the small intestine were taken. Villi area, height, width and crypt depth ratios were read using Multiscan software. Synbiotic supplementation increased the BWG of broilers from first to tenth day of rearing, compared to the control group. The PRO group had improved villi morphometric parameters of the duodenum. In the jejunum and ileum, both bioactive substances improved villus width and villus surface area. Crypts were deeper in the small intestine of birds supplemented with bioactive substances, which allows greater renewal of the villi. As expected, the intestinal morphometric parameters of broiler chickens benefited from bioactive substance supplementation.

Dose-dependent response to phytobiotic supplementation in feed on growth, hematology, intestinal pH, and gut bacterial load in broiler chicken

Objective:

The present study was aimed to evaluate dose-dependent effects of phytobiotic (Galibiotic) supplements in feed on growth performance, hematological parameters, intestinal pH, and gut bacterial population in broiler chick.

Materials and Methods:

A total of 50 ten day old broiler chicks were divided into five groups, namely, Group A as control (without galibiotic), Group B (galibiotic at 1 gm/kg feed), Group C (galibiotic at 2 gm/kg feed), Group D (galibiotic at 5 gm/kg feed), and Group E (galibiotic at 10 gm/kg feed). All the birds were reared for 42 days and samples were collected before and after sacrifice.

Results:

Live body weights showed no significant differences between the groups but overall feed conversion ratios (FCRs) of treatment groups were significantly low in Group E having the lowest. Blood samples collected for hematology differed significantly (p < 0.01) among the different groups. Intestinal pH was lower in treatment groups with Group E having the lowest. Cecal total viable count was highest in Group A and lowest in Group E. The cecal coliform count was low in all the treatment groups.

Conclusion:

Along with previously published report, it may conclude that the phytobiotic could be used as an alternative to antibiotics due to positive growth performance, lower FCR, carcass quality, and improved gut health of broiler chicks.