Effects of Pediococcus acidilactici, mannan-oligosaccharide, butyric acid and their combination on growth performance and intestinal health in young broiler chickens challenged with Salmonella Typhimurium

Systematic review on microbiome-related nutritional interventions interfering with the colonization of foodborne pathogens in broiler gut to prevent contamination of poultry meat

This systematic review aimed to compile the available body of knowledge about microbiome-related nutritional interventions contributing to improve the chicken health and having an impact on the reduction of colonization by foodborne pathogens in the gut. Original research articles published between 2012 and 2022 were systematically searched in Scopus and PubMed. A total of 1,948 articles were retrieved and 140 fulfilled the inclusion criteria. Overall, 73 papers described 99 interventions against colonization by Escherichia coli and related organisms; 10 papers described 15 interventions against Campylobacter spp.; 36 papers described 54 interventions against Salmonella; 40 papers described 54 interventions against Clostridium perfringens. A total of 197 microbiome-related interventions were identified as effective against one or more of the listed pathogens and included probiotics (n = 80), prebiotics (n = 23), phytobiotics (n = 25), synbiotics (n = 12), organic acids (n = 12), enzymes (n = 4), essential oils (n = 14) and combination of these (n = 27). The identified interventions were mostly administered in the feed (173/197) or through oral gavage (11/197), in the drinking water (7/197), in ovo (2/197), intra amniotic (2/197), in fresh or reused litter (1/197) or both in the feed and water (1/197). The interventions enhanced the beneficial microbial communities in the broiler gut as Lactic acid bacteria, mostly Lactobacillus spp., or modulated multiple microbial populations. The mechanisms promoting the fighting against colonization by foodborne pathogens included competitive exclusion, production of short chain fatty acids, decrease of gut pH, restoration of the microbiome after dysbiosis events, promotion of a more stable microbial ecology, expression of genes improving the integrity of intestinal mucosa, enhancing of mucin production and improvement of host immune response. All the studies extracted from the literature described in vivo trials but performed on a limited number of animals under experimental settings. Moreover, they detailed the effect of the intervention on the chicken gut without details on further impact on poultry meat safety.

An investigation into the influence of fermented cottonseed meal on the productive performance, egg quality, and gut health in laying hens

The present study investigates the effects of replacing soybean meal (SBM) with either cottonseed meal (CSM) or fermented cottonseed meal (FCSM) on the productive performance, egg quality, blood biochemistry parameters, gut bacterial population, and small intestinal morphology of laying hens. A total of 648 Hy-Line W36 laying hens aged 40 weeks were randomly assigned to 9 treatments, with 6 replicates each and 12 birds per replicate. The feeding trial lasted 12 weeks. The treatments consisted of a control diet based on corn and SBM, as well as 8 experimental diets in which 7.5, 15, 22.5, and 30% of the SBM in the control diet was replaced with either CSM or FCSM. Laying hens fed diets with different levels of FCSM had higher egg production and egg mass than those fed with CSM diets at weeks 46 to 51 (P < 0.05). Diets containing FCSM also significantly improved the feed conversion ratio at weeks 40 to 45 and 46 to 51 (P < 0.05). Eggshell strength was significantly greater in birds fed diets containing FCSM than those fed other dietary treatments at 51 weeks of age (P < 0.05). Hens fed diets containing FCSM had higher calcium and lower cholesterol in serum than those on other diets (P < 0.05). Replacing SBM with FCSM decreased the egg yolk cholesterol content (P < 0.05). Additionally, feeding diets containing different levels of FCSM increased villus height and villus height to crypt depth in the jejunum (P < 0.05). Diets containing FCSM also reduced pH and coliform population in the ileum, and ceca and increased lactic acid bacteria count in the crop and ceca (P < 0.05). Overall, the present data showed that including FCSM in the diet of laying hens can positively affect productive performance compared to CSM. Moreover, substituting SBM with FCSM, can improve eggshell quality, promote gut health, and reduce egg yolk cholesterol concentration.

Butyric acid glycerides as substitutes for antibiotics as growth enhancers in the diet of nursery piglets

This study aimed to determine whether the addition of butyric acid glycerides as substitutes to conventional growth promoters can provide adequate zootechnical performance and intestinal health in healthy piglets in the nursery phase. We used 90 male piglets (average weight of 6.5 kg) subdivided into five treatments with six replicates per treatment. The treatments had the same basal diet: NC-negative control (without growth promoter), PC-positive control (with gentamicin, oral), PSB-protected sodium butyrate, FSB-free sodium butyrate, and TRI-tributyrin. In these animals, zootechnical performance was evaluated on days 1, 10, 20 and 39, microbiological analysis on days 14 and 39, hematocrit, blood biochemistry and intestinal histology, intestinal oxidation and antioxidation on day 39. The average daily weight gain was higher in the TRI group on days 21 to 39 in the nursery (P = 0.03), with more significant weight gain from 1 to 39 days (P = 0.05). There were higher leukocyte counts in the PC group than in the TRI group and higher lymphocyte counts in the PC treatment than in the NC or TRI groups. Escherichia coli counts were lower in the PC, followed by the PSB and TRI groups on day 39 (P = 0.01). Lower crypt depths were found in the TRI and FSB groups, followed by PC, than in the NC group (P = 0.01). Higher values for crypt villosity ratio were found in the FSB and TRI groups than in the NC group (P = 0.05). Lower lipid peroxidation was found in analyzes of serum oxidative status (LPO: P = 0.01), associated with greater activities of superoxide dismutase - SOD (P = 0.08), glutathione S-transferase - GST (P = 0.09) in PSB and TRI groups than in the NC group. In conclusion, the use of butyric acid in the form of tributyrin can be used as growth enhancers in piglets in the nursery phase.

Emerging trends and applications in health-boosting microorganisms-specific strains for enhancing animal health

Recent advancements in specific strain of probiotics have shown promising trends and applications in both ruminant and non-ruminant animal health. This study emphasizes the importance of tailored probiotics for these animal categories, discussing their potential benefits in improving nutrient utilization, growth performance, and disease management. The study also explores the different routes of probiotics administration, highlighting the various methods of delivery. Specifically, it highlights the benefits of probiotics in ruminant production performance, including enhanced rumen health, growth rates, milk production, and reduced digestive disorders. Additionally, it discusses the advantages of probiotics in non-ruminant farming, such as improved feed conversion efficiency, nutrient absorption, growth rates, immune responses, and reduced gastrointestinal issues, leading to increased productivity and profitability. In conclusion, recent advancements in specific strain of probiotics offer promising prospects for improving animal health. Tailored probiotics have shown potential in enhancing growth, nutrient utilization, and disease prevention, contributing to sustainable and effective animal husbandry practices.

Applications of Enteroendocrine Cells (EECs) Hormone: Applicability on Feed Intake and Nutrient Absorption in Chickens

This review focuses on the role of hormones derived from enteroendocrine cells (EECs) on appetite and nutrient absorption in chickens. In response to nutrient intake, EECs release hormones that act on many organs and body systems, including the brain, gallbladder, and pancreas. Gut hormones released from EECs play a critical role in the regulation of feed intake and the absorption of nutrients such as glucose, protein, and fat following feed ingestion. We could hypothesize that EECs are essential for the regulation of appetite and nutrient absorption because the malfunction of EECs causes severe diarrhea and digestion problems. The importance of EEC hormones has been recognized, and many studies have been carried out to elucidate their mechanisms for many years in other species. However, there is a lack of research on the regulation of appetite and nutrient absorption by EEC hormones in chickens. This review suggests the potential significance of EEC hormones on growth and health in chickens under stress conditions induced by diseases and high temperature, etc., by providing in-depth knowledge of EEC hormones and mechanisms on how these hormones regulate appetite and nutrient absorption in other species.

Soumeh E, Jazi V. Effects of black pepper and turmeric powder on growth performance, gut health, meat quality, and fatty acid profile of Japanese quail

In poultry production, the search for alternatives to in-feed antibiotics continues unabated. This study investigated the effects of dietary supplementation of black pepper and turmeric powder, separately or in combination, on the growth performance, gastrointestinal microbiota population, intestinal morphology, serum biochemical parameters, meat quality, and meat fatty acid profile in Japanese quails. Five hundred-day-old mixed-sex Japanese quail chicks were randomly assigned to one of five treatments: a control diet (CON); CON +0.2% antibiotic flavomycin as an antibiotic growth promoter (AGP); CON +0.5% turmeric powder (TUP); CON +0.5% black pepper powder (BPP); and CON +0.5% TUP, and 0.5% BPP (MIX). The findings showed that quail chicks fed AGP and TUP throughout the rearing period had better body weight gain (p = 0.007) and feed conversion ratio (p = 0.02) than the other treatments. The TUP, BPP, and MIX feeds reduced (p = 0.005) abdominal fat percentage. The MIX group had a better breast muscle water-holding capacity (p = 0.04) and lightness index (p = 0.02) and lower (p = 0.02) malondialdehyde concentration after 7 days of refrigerated storage. Feeding BPP, TUP, and MIX diets decreased (p = 0.001) serum cholesterol concentration. Quail chicks fed the CON diet showed significantly higher coliform counts in the crop and ileum (p < 0.001), whereas the lactic acid bacterial population was lower (p = 0.008) in the ileum. Birds that received the MIX diet exhibited a higher (p = 0.02) villus height to crypt depth ratio in the duodenum compared to the other groups. The tested feed additives increased (p < 0.001) villus height in the jejunum and ileum compared to other groups. Feeding the TUP, BPP, and MIX diets reduced (p < 0.001) total saturated fatty acid content and increased (p = 0.004) total polyunsaturated fatty acid concentration, where the MIX diet had the best results. Overall, the present data indicate that supplementing the basal diet with turmeric powder enhances the growth performance of Japanese quails. In some respects, such as gut health and meat quality, combining turmeric powder and black pepper powder was more effective than using them independently.

Recent Trends on Mitigative Effect of Probiotics on Oxidative-Stress-Induced Gut Dysfunction in Broilers under Necrotic Enteritis Challenge: A Review

Gut health includes normal intestinal physiology, complete intestinal epithelial barrier, efficient immune response, sustained inflammatory balance, healthy microbiota, high nutrient absorption efficiency, nutrient metabolism, and energy balance. One of the diseases that causes severe economic losses to farmers is necrotic enteritis, which occurs primarily in the gut and is associated with high mortality rate. Necrotic enteritis (NE) primarily damages the intestinal mucosa, thereby inducing intestinal inflammation and high immune response which diverts nutrients and energy needed for growth to response mediated effects. In the era of antibiotic ban, dietary interventions like microbial therapy (probiotics) to reduce inflammation, paracellular permeability, and promote gut homeostasis may be the best way to reduce broiler production losses. The current review highlights the severity effects of NE; intestinal inflammation, gut lesions, alteration of gut microbiota balance, cell apoptosis, reduced growth performance, and death. These negative effects are consequences of; disrupted intestinal barrier function and villi development, altered expression of tight junction proteins and protein structure, increased translocation of endotoxins and excessive stimulation of proinflammatory cytokines. We further explored the mechanisms by which probiotics mitigate NE challenge and restore the gut integrity of birds under disease stress; synthesis of metabolites and bacteriocins, competitive exclusion of pathogens, upregulation of tight junction proteins and adhesion molecules, increased secretion of intestinal secretory immunoglobulins and enzymes, reduction in pro-inflammatory cytokines and immune response and the increased production of anti-inflammatory cytokines and immune boost via the modulation of the TLR/NF-ĸ pathway. Furthermore, increased beneficial microbes in the gut microbiome improve nutrient utilization, host immunity, and energy metabolism. Probiotics along with biosecurity measures could mitigate the adverse effects of NE in broiler production.

Advances in enteropathogen control throughout the meat chicken production chain

Enteropathogens, namely Salmonella and Campylobacter, are a concern in global public health and have been attributed in numerous risk assessments to a poultry source. During the last decade, a large body of research addressing this problem has been published. The literature reviewed contains review articles on certain aspects of poultry production chain; however, in the past decade there has not been a review on the entire chain-farm to fork-of poultry production. For this review, a pool of 514 articles were selected for relevance via a systematic screening process (from >7500 original search articles). These studies identified a diversity of management and intervention strategies for the elimination or reduction of enteropathogens in poultry production. Many studies were laboratory or limited field trials with implementation in true commercial operations being problematic. Entities considering using commercial antienteropathogen products and interventions are advised to perform an internal validation and fit-for-purpose trial as Salmonella and Campylobacter serovars and biovars may have regional diversity. Future research should focus on nonchemical application within the processing plant and how a combination of synergisticinterventions through the production chain may contribute to reducing the overall carcass burden of enteropathogens, coupled with increased consumer education on safe handling and cooking of poultry.

Effects of nonantibiotic growth promoter combinations on growth performance, nutrient utilization, digestive enzymes, intestinal morphology, and cecal microflora of broilers

Given the ban on antibiotic growth promoters, the effects of nonantibiotic alternative growth promoter combinations (NAGPCs) on the growth performance, nutrient utilization, digestive enzyme activity, intestinal morphology, and cecal microflora of broilers were evaluated. All birds were fed pellets of two basal diets-starter (0-21 d) and grower (22-42 d)-with either enramycin (ENR) or NAGPC supplemented. 1) control + ENR; 2) control diet (CON, basal diet); 3) control + mannose oligosaccharide (MOS) + mannanase (MAN) + sodium butyrate (SB) (MMS); 4) control + MOS + MAN + Bacillus subtilis (BS) (MMB); 5) control + MOS + fruit oligosaccharide (FOS) + SB (MFS); 6) control + FOS + BS (MFB); 7) control + MOS + FOS + MAN (MFM); 8) control + MOS + BS + phytase (PT) (MBP). ENR, MOS, FOS, SB, MAN, PT, and BS were added at 100, 2,000, 9,000, 1,500, 300, 37, and 500 mg/kg, respectively. The experiment used a completely random block design with six replicates per group: 2400 Ross 308 broilers in the starter phase and 768 in the grower phase. All NAGPCs significantly improved body weight gain (P < 0.01), utilization of dry matter, organic matter, and crude protein (P < 0.05), villus height and villus height/crypt depth in the jejunum and ileum (P < 0.01), and decreased the feed conversion ratio (P < 0.01) at d 21 and 42. MMS, MMB, MFB, and MFM duodenum trypsin, lipase, and amylase activities increased significantly (P < 0.05) at d 21 and 42. On d 21 and 42, MMS, MMB, and MBP increased the abundance of Firmicutes and Bacteroides whereas MMB, MFB, and MBP decreased the abundance of Proteobacteria, compared to ENR and CON. Overall, the NAGPCs were found to have some beneficial effects and may be used as effective antibiotic replacements in broilers.

Dietary sodium butyrate improves female broiler breeder performance and offspring immune function by enhancing maternal intestinal barrier and microbiota

This study aimed to investigate the effects of dietary sodium butyrate (SB) supplementation on the reproductive performance of female broiler breeders under intensive rearing conditions and to analyze antioxidant capacity, immune function, and intestinal barrier function of the female breeders and their offspring. A total of 96,000 40-wk-old Ross308 female broiler breeders were divided into the control (CON) and SB groups, each with 6 replicates of 8,000 birds. Each house with similar production performance characteristics was considered a replicate. The experiment lasted for 20 wk, whereupon sampling took place. Results showed that SB improved the egg production performance, egg quality of broiler breeders, and hatchability (P < 0.05). Maternal supplementation with SB substantially increased serum immunoglobulin A levels in broiler breeders and offspring (both P = 0.04) and offspring immunoglobulin G (P < 0.001). The levels of interleukin-1β (P < 0.001) and interleukin-4 (P = 0.03) in the offspring were downregulated, while the total superoxide dismutase in the offspring and the eggs increased (P < 0.05). The serum biochemical components in breeders and offspring were altered by SB, as evidenced by the reduction in triglycerides, total cholesterol, and high- and low-density lipoproteins (P < 0.05). The intestinal morphology of broiler breeders and offspring also improved by the SB with the decreasing the jejunal crypt depth (P = 0.04) and increasing villus height in offspring (P = 0.03). Maternal jejunal and ileal intestinal barrier-related genes were also shown to be significantly affected by SB. Furthermore, SB altered the microbial diversity in maternal cecal contents, thus increasing the abundance of Lachnospiraceae (P = 0.004) and Ruminococcaceae (P = 0.03). Dietary SB enhanced the reproductive performance and egg quality of broiler breeders and improved the antioxidant capacity and immune function of broiler breeders and offspring, with the benefits potentially arising from the regulation of the maternal intestinal barrier and gut microbiota by SB.

Effect of dietary Saccharomyces-derived prebiotic refined functional carbohydrates as antibiotic alternative on growth performance and intestinal health of broiler chickens reared in a commercial farm

The search for effective in-feed antibiotic alternative is growing due to the global trend to reduce or ban the utilization of antibiotics as growth promotors in poultry diets. This study was processed to assess the effect of dietary refined functional carbohydrates (RFCs) replacing antibiotic growth promoters (AGP) on growth performance, intestinal morphologic structure and microbiota, as well as intestinal immune function and barrier function of broilers reared on a commercial broilers farm. Trials contained 3 treatments with 4 replicate broiler houses, with about 25,000 birds each room. The treatments were control group (CON), RFCs group (CON + 100 mg/kg RFCs), and AGP group (CON + 50 mg/kg bacitracin methylene disalicylate (BMD), respectively. Results showed that RFCs and AGP group significantly increased (P < 0.05) average daily gain (ADG) during d 22 to 45 in contrast to control. Compared with the control and AGP-treated groups, feeding RFCs increased (P < 0.05) jejunal villus height to crypt depth ratio. AGP addition reduced (P < 0.05) the jejunal villi surface area compared to broilers fed control and RFC supplemented diets. Supplementation of RFCs promoted (P < 0.05) the growth of Lactobacillus but inhibited Escherichia coli and Salmonella proliferation compared with the control group. Inclusion of RFCs and BMD enhanced (P < 0.05) antibody titers against avian influenza virus H9 compared with control. RFCs and AGP both down-regulated (P < 0.05) intestinal TLR4 mRNA levels, whereas RFCs tended to up-regulate (P = 0.05) IFN-γ gene expression compared to control. Expression of intestinal tight junction genes was not affected by either AGP or RFCs supplementation. Based on above observation, we suggested that RFCs could replace in-feed antibiotic BMD in broiler diets for reducing intestinal pathogenic bacteria and modulating immunity of broilers.

Screening and Characterization of Pediococcus acidilactici LC-9-1 toward Selection as a Potential Probiotic for Poultry with Antibacterial and Antioxidative Properties

Growing interest has been focused on lactic acid bacteria as alternatives to antimicrobial growth promoters, which are characterized by the production of various functional metabolites, such as antimicrobial and antioxidants compounds. The present study was undertaken to evaluate a potential probiotic from the antioxidant perspective. LC-9-1, screened from the intestines of healthy animals, was revealed to be Pediococcus acidilactici on the basis of its morphological, biochemical, and molecular characteristics. The strain has excellent properties, including acid-production efficiency, antibacterial performance and antioxidant activity. The safety of the strain was also evaluated. Furthermore, the experiments in broiler chickens suggested that dietary LC-9-1 supplementation improved the growth performance and decreased the abdominal fat, and enhanced the antioxidant capability and intestinal innate immunity of broilers. Analysis of intestinal microbiota showed that a higher community diversity (Shannon index) was achieved. In addition to the significantly increased relative abundances of Pediococcus spp., beneficial genera such as Rothia spp. and Ruminococcus spp. were abundant, while opportunistic pathogens such as Escherichia-Shigella spp. were significantly reduced in LC-9-1-supplemented broilers. Collectively, such in-depth characterization and the available data will guide future efforts to develop next-generation probiotics, and LC-9-1 could be considered a potential strain for further utilization in direct-fed microbial or starter culture for fermentation.

A microencapsulated feed additive containing organic acids and botanicals has a distinct effect on proliferative and metabolic related signaling in the jejunum and ileum of broiler chickens

Well designed and formulated natural feed additives have the potential to provide many of the growth promoting and disease mitigating characteristics of in-feed antibiotics, particularly feed additives that elicit their effects on targeted areas of the gut. Here, we describe the mechanism of action of a microencapsulated feed additive containing organic acids and botanicals (AviPlus^®P) on the jejunum and ileum of 15-day-old broiler-type chickens. Day-of-hatch chicks were provided ad libitum access to feed containing either 0 or 500 g/MT of the feed additive for the duration of the study. Fifteen days post-hatch, birds were humanely euthanized and necropsied. Jejunum and ileum tissue samples were collected and either flash frozen or stored in RNA-later as appropriate for downstream applications. Chicken-specific kinome peptide array analysis was conducted on the jejunum and ileum tissues, comparing the tissues from the treated birds to those from their respective controls. Detailed analysis of peptides representing individual kinase target sites revealed that in the ileum there was a broad increase in the signal transduction pathways centering on activation of HIF-1α, AMPK, mTOR, PI3K-Akt and NFκB. These signaling responses were largely decreased in the jejunum relative to control birds. Gene expression analysis agrees with the kinome data showing strong immune gene expression in the ileum and reduced expression in the jejunum. The microencapsulated blend of organic acids and botanicals elicit a more anti-inflammatory phenotype and reduced signaling in the jejunum while resulting in enhanced immunometabolic responses in the ileum.

Applications of butyric acid in poultry production: the dynamics of gut health, performance, nutrient utilization, egg quality, and osteoporosis

Due to the increasing demand for antibiotic-free livestock products from the consumer side and the ban on the use of antibiotic growth promoters, the poultry feed industry is increasingly interested in developing more alternatives to cope with this problem. Organic acids (butyric acid) have many beneficial effects on poultry health, performance, and egg quality when used in their diet, thus they can be considered for the replacement of antibiotics in livestock production systems. Butyric acid is most efficacious against pathogenic bacteria such as Salmonella spp. and Escherichia coli, and stimulates the population of beneficial gut bacteria. It is a primary energy source for colonocytes and augments the differentiation and maturation of the intestinal cells. Collectively, butyric acid should be considered as an alternative to antibiotic growth promoters, because it reduces pathogenic bacteria and their toxins, enhancing gut health thereby increasing nutrient digestibility, thus leading to improved growth performance and immunity among birds. The possible pathways and mechanisms through which butyric acid enhances gut health and production performance are discussed in this review. Detailed information about the use of butyric acid in poultry and its possible benefits under different conditions are also provided, and the impacts of butyric acid on egg quality and osteoporosis are noted.

In Vitro Study to Evaluate the Efficacy of Ultrasonicated Ethanolic Extract of Rosmarinus officinalis and its Chitosan-Based Nanoparticles Against Eimeria tenella Oocysts of Chickens

In this study, chitosan nanoparticles (CsNPs) were used as nanocarrier for ultrasonicated ethanolic extract of Rosmarinus officinalis (UEERO) as a new nanoformulation against Eimeria tenella. Herein, CsNPs have been synthesized by ionic gelation method at pH 3 (CsNPs3) and pH 5 (CsNPs5), followed by characterization of morphology, size, polydispersity index (PDI), surface charge, and loading efficiency of UEERO. An in vitro sporulation inhibition assay (10, 5, 2.5, 1.25, 0.62, 0.31, 0.15, 0.07, 0.04, 0.02, and 0.01 mg/ml normal saline solution) against E. tenella was conducted. Results showed that free CsNPs and UEERO-CsNPs3/5 were cubic- and spherical-shaped with positive charge and average size of ~ 150.8 nm (314.4 nm) and 151.7 nm (321.1 nm), respectively. The total loading efficiency using UV–vis spectrophotometer, was 80.05 at pH 5 and 64.39% at pH 3. The in vitro sporulation inhibition assay revealed that UEERO, CsNPs3/5, and UEERO-CsNPs3/5 showed a potential inhibitory effect on sporulation (%), distortion in wall (%), and sporocyst abnormality (%) in a dose-dependent manner. Accordingly, the concentration (10 mg/ml) showed the best efficacy after 24 h in UEERO, free CsNPs, and UEERO-CsNPs. Moreover, UEERO-CsNPs3 and UEERO-CsNPs5 had stopped the sporulation (%) after 72 h. Taken all together, UEERO-CsNPs3 and UEERO-CsNPs5 are best effective against E. tenella in a dose-dependent manner in terms of sporulation (%), distortion in wall (%), and sporocysts abnormality.

An updated review on probiotics as an alternative of antibiotics in poultry - A review

Antibiotics used to be supplemented to animal feeds as growth promoter and as an effective strategy to reduce the burden of pathogenic bacteria present in the gastro-intestinal tract. However, in-feed antibiotics also kill bacteria that may be beneficial to the animal. Secondly, unrestricted use of antibiotics enhanced the antibiotic resistance in pathogenic bacteria. To overcome above problems, scientists are taking a great deal of measures to develop alternatives of antibiotics. There is convincing evidence that probiotics could replace in-feed antibiotics in poultry production. Because they have beneficial effects on growth performance, meat quality, bone health and eggshell quality in poultry. Better immune responses, healthier intestinal microflora and morphology which help the birds to resist against disease attack were also identified with the supplementation of probiotics. Probiotics establish cross-feeding between different bacterial strains of gut ecosystem and reduce the blood cholesterol level via bile salt hydrolase activity. The action mode of probiotics was also updated according to recently published literatures, i.e antimicrobial substances generation or toxin reduction. This comprehensive review of probiotics is aimed to highlight the beneficial effects of probiotics as a potential alternative strategy to replace the antibiotics in poultry.

Effects of Feeding Fermented Medicago sativa (Plus Soybean and DDGS) on Growth Performance, Blood Profiles, Gut Health, and Carcass Characteristics of Lande (Meat) Geese

The objective was to investigate the effects of alfalfa (Medicago sativa Linn)-mixed silage fermentation material (AMSFM) on various aspects of growth, function, and carcass characteristics of Lande (meat) geese. Based on a previous study, we used the following AMSFM: 80% Alfalfa +10% soybean meal +10% DDGS ensiled for 45 days. Lande geese, n = 264, 77 days of age, were randomly allocated into four groups with six replicates in each group. Control geese were fed a basal diet, whereas experimental groups were fed a basal diet supplemented with 6, 12, or 24% AMSFM. The experiment lasted 21 days. The AMSFM promoted some aspects of growth, with increase (p < 0.05) in leg muscle rate, lean meat rate, muscle protein content, and total energy content of leg muscle plus concurrent decreases (p < 0.05) in crude fat content and abdominal fat rate in chest muscle. In addition, AMSFM increased (p < 0.05) glutathione content in chest and leg muscles and serum superoxide dismutase activity, and it reduced (p < 0.05) muscle malondialdehyde content and serum concentrations of triglycerides, total cholesterol, urea, and aspartate aminotransferase, consistent with good liver and kidney function. Moreover, AMSFM improved (p < 0.05) ileum morphology. In conclusion, the optimal supplemented rate of AMSFM in the meat geese diet (12%) improved immunity and antioxidant status and enhanced growth performance and carcass characteristics of meat geese.

Effects of three probiotics and their interactions on the growth performance of and nutrient absorption in broilers

The purpose of this study was to investigate the effects of three probiotics and their interactions on growth performance, intestinal digestion and absorption, and nutrient transporters in broilers. A total of 350 one-day-old male Arbor Acres broilers were randomly divided into seven groups: the control group (broilers receiving normal drinking water), groups P1, P2 and P3 (broilers receiving drinking water with 1% Lactobacillus casei, Lactobacillus acidophilus and Bifidobacterium lactis , respectively) and groups CP1, CP2 and CP3 (broilers receiving drinking water with a 1% compound probiotic mixture in 2:1:1, 1:2:1, 1:1:2 ratios, respectively). The feeding period was divided into two experimental periods: 1∼21 days and 22∼42 days. Compared to those in the control group, the broiler slaughter indexes and average daily feed intakes in the probiotics groups were not significantly different (P > 0.05), but the villus height in the small intestine increased significantly, and the crypt depth decreased significantly (P < 0.05). In the 1- to 21-day, experimental period, the broiler average daily gains in groups CP2 and CP3 were significantly greater than that in the control group. Amylase, lipase, and trypsin activities in the jejunum in groups CP and P3 increased significantly. GLUT2 mRNA expression in the probiotics group was significantly incresaed compared with that in the control group (P < 0.05). In the 22- to 42-day period, the average daily gain in the CP group was significantly greater than that in the control group. Amylase activity in the CP2 group, and lipase and trypsin activities in the CP, P1 and P3 groups increased significantly. The GLUT2 mRNA expression in the CP group increased significantly (P < 0.05). In summary, three probiotics and their interactions improved the digestibility and absorption of nutrients by increasing the activities of digestive enzymes, improving the morphology of the digestive tract, and upregulating the expression of GLUT2 mRNA in the intestinalcell membrane to improve the production performance in broilers.

The control of poultry salmonellosis using organic agents: an updated overview

Salmonellosis is a severe problem that threatens the poultry sector worldwide right now. Salmonella gallinarium and Salmonella pullorum (Fowl typhoid) are the most pathogenic serovars in avian species leading to systemic infection resulting in severe economic losses in the poultry industry. Nontyphoidal serotypes of Salmonella (Paratyphoid disease) constitute a public health hazard for their involvement in food poisoning problems in addition to their zoonotic importance. Also, Salmonella species distribution is particularly extensive. They resisted environmental conditions that made it difficult to control their spread for a long time. Therefore, the current review aimed to through light on Salmonellosis in poultry with particular references to its pathogenesis, economic importance, immune response to Salmonella, Salmonella antibiotics resistance, possible methods for prevention and control of such problems using promising antibiotics alternatives including probiotics, prebiotics, symbiotics, organic acids, essential oils, cinnamaldehyde, chitosan, nanoparticles, and vaccines.

Long-chain glucomannan supplementation modulates immune responsiveness, as well as intestinal microbiota, and impacts infection of broiler chickens with Salmonella enterica serotype Enteritidis

The zoonotic pathogen Salmonella enterica serotype Enteritidis (SE) causes severe disease in young chickens. Restriction on antibiotic use requires alternative SE control strategies such as nutritional solutions to improve the resistance of chickens. In this study, chickens were fed long-chain glucomannan (GM) or standard diet and challenged with SE at seven days of age. During 21 days post-infection (dpi), we determined numbers and responsiveness of natural killer (NK) and T cells in ileum and spleen, and SE-specific antibody titers in serum. Microbiota compositions in ileum and caeca were determined, as well as correlations of these with numbers and function of immune cells. Some of the samples in the control group had numerically higher CFUs than the GM-treated group. In addition, the relative abundance of SE based on DNA assessment was significantly lower at 21 dpi upon GM supplementation. At 3 dpi, numbers of intraepithelial NK cells were significantly higher, while activation of intraepithelial NK cells (7 dpi), numbers of intraepithelial cytotoxic CD8⁺ T cells (14 dpi) and SE-specific antibodies (14 dpi) were numerically higher. Furthermore, relative abundance of the commensal lactic acid bacteria (LAB) significantly increased with GM supplementation post-infection. Higher relative abundance of streptococci was associated with reduced SE in ileal and caecal contents at 21 dpi. Relative abundance of streptococci negatively correlated with SE counts and positively correlated with NK cell activation and SE-specific antibodies, which suggests involvement of the commensal LAB in NK cell responsiveness. These results indicate that GM supplementation modulates the immune system, intestinal microbiota and impacts SE infection of young chickens.

Chemically Protected Sodium Butyrate Improves Growth Performance and Early Development and Function of Small Intestine in Broilers as One Effective Substitute for Antibiotics

The purpose of this study was to investigate the effects of chemically protected sodium butyrate (CSB) on growth performance and the early development and function of small intestine in broilers as one potential substitute for antibiotics. A total of 192 one-day-old Arbor Acres male broilers were randomly assigned into three dietary treatment groups (eight replicates per treatment): the control (CON) diet; ANT diet, CON diet supplemented with the antibiotics (enramycin, 8 mg/kg and aureomycin, 100 mg/kg); CSB diet, CON diet supplemented with 1000 mg/kg CSB, respectively. The results showed that dietary CSB and antibiotics addition significantly improved the growth performance of broilers by increasing the body weight gain (BWG) and feed conversion ratio (FCR) during different stages (p < 0.05). On day 21, the supplement of CSB in diet improved the structure of small intestine (duodenum, jejunum, and ileum) in broilers by increasing the ratio of villus height to crypt depth (VH/CD) (p < 0.05) and enhanced the butyric acid (BA) (p < 0.05) and total short chain fatty acids (SCFA) concentrations of small intestine (jejunum and ileum) compared with the CON and ANT diets. Besides that, the superoxide dismutase (SOD), total antioxidant capacity (TAC) and TAC to malondialdehyde (TAC/MDA) ratio of the ileal and jejunal mucosa were significantly higher (p < 0.05) in the CSB and ANT than in the CON. In addition, the supplement of CSB in diet markedly significantly enhanced α-amylase, lipase, and trypsin activities of the ileum (p < 0.05) as compared to the ANT diet. 16S rRNA gene sequencing indicated that CSB markedly increased the microbiota diversity of ileum in broilers at 21 days of age as compared to CON and ANT (p < 0.05). Furthermore, we found that Firmicutes was the predominant phyla and Lactobacillus was the major genus in the ileum of broilers. Compared with the ANT diet, the supplement of CSB in diet increased the relative abundance of some genera microbiota (e.g., Candidatus_Arthromitus, Romboutsia) by decreasing the relative abundance of Lactobacillus. Moreover, Akkermansia in the CSB was the highest in comparison to that in the CON and ANT. In addition, Kitasatospora that belongs to the phylum Actinobacteriota was only found in ileum of broilers fed the ANT diet. In summary, the supplement of 1000 mg/kg CSB in the diet improved the growth performance by promoting early development and function of the small intestine, which is associated with the regulation of intestinal flora and reestablishment of micro-ecological balance in broilers. Thus, CSB has great potential value as one of effective substitutes for in-feed antibiotics in the broiler industry.

Innovative Treatments Enhancing the Functionality of Gut Microbiota to Improve Quality and Microbiological Safety of Foods of Animal Origin

The gastrointestinal tract, or gut, microbiota is a microbial community containing a variety of microorganisms colonizing throughout the gut that plays a crucial role in animal health, growth performance, and welfare. The gut microbiota is closely associated with the quality and microbiological safety of foods and food products originating from animals. The gut microbiota of the host can be modulated and enhanced in ways that improve the quality and safety of foods of animal origin. Probiotics—also known as direct-fed microbials—competitive exclusion cultures, prebiotics, and synbiotics have been utilized to achieve this goal. Reducing foodborne pathogen colonization in the gut prior to slaughter and enhancing the chemical, nutritional, or sensory characteristics of foods (e.g., meat, milk, and eggs) are two of many positive outcomes derived from the use of these competitive enhancement–based treatments in food-producing animals.

Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Microencapsulation Improved Fumaric Acid and Thymol Effects on Broiler Chickens Challenged With a Short-Term Fasting Period

The first objective of this study was to demonstrate the usefulness of the microencapsulation technique to protect fumaric acid and thymol, avoiding their early absorption and ensuring their slow release throughout the gastrointestinal tract (GIT). For this purpose, the release of a lipid matrix microencapsulated brilliant blue (BB) was assessed in vitro, using a simulated broiler intestinal fluid, and in vivo. In vitro results showed that more than 60% of BB color reached the lower intestine, including 26.6 and 29.7% in the jejunum and ileum, respectively. The second objective was to determine the effects of microencapsulated fumaric acid, thymol, and their mixture on the performance and gut health of broilers challenged with a short-term fasting period (FP). One-day-old male ROSS 308 chickens (n = 280) were randomly distributed into seven treatments, with 10 replicates of four birds each. Dietary treatments consisted of a basal diet as negative control (NC), which was then supplemented by either non-microencapsulated fumaric acid (0.9 g/kg), thymol (0.6 g/kg), or a mixture of them. The same additive doses were also administered in a microencapsulated form (1.5 and 3 g/kg for the fumaric acid and thymol, respectively). At day 21, chickens were subjected to a 16.5-h short-term FP to induce an increase in intestinal permeability. Growth performance was assessed weekly. At day 35, ileal tissue and cecal content were collected from one bird per replicate to analyze intestinal histomorphology and microbiota, respectively. No treatment effect was observed on growth performance from day 1 to 21 (p > 0.05). Microencapsulated fumaric acid, thymol, or their mixture improved the overall FCR (feed conversion ratio) and increased ileal villi height-to-crypt depth ratio (VH:CD) (p < 0.001) on day 35 of the experiment. The microencapsulated mixture of fumaric acid and thymol increased cecal abundance of Bacteroidetes, Bacillaceae, and Rikenellaceae, while decreasing that of Pseudomonadaceae. These results indicate that the microencapsulation technique used in the current study can be useful to protect fumaric acid and thymol, avoiding early absorption, ensure their slow release throughout the GIT, and improve their effects on fasted broiler chickens.

Fermented Corn-Soybean Meal Mixed Feed Modulates Intestinal Morphology, Barrier Functions and Cecal Microbiota in Laying Hens

Simple Summary

Fermented feed has been of wide concern in livestock and poultry production because of its many advantages. In this study, the nutritional quality of the feed before and after fermentation was assessed, and four supplemental levels of fermented feed were used to replace unfermented feed to study the influence of fermented feed on the gut health of the laying hens during the laying peak period. The results suggest that fermented feed can improve the intestinal morphology and barrier functions of laying hens, possibly by altering the cecal microbiome.

Abstract

This study aimed to evaluate the effects of fermented corn–soybean meal mixed feed on intestinal barrier function and cecal microbiota in laying hens. A total of 360 Jingfen No.6 laying hens (22 wk-old) were assigned to 4 dietary treatments, which were offered basal diets (without antibiotics) containing 0, 4, 6 and 8% of fermented mixed feed respectively. The results showed that the pH value and anti-nutritional factor concentrations in fermented mixed feed were lower than those in unfermented feed (p < 0.05). Moreover, fermentation in the feed significantly increased the crude protein content (p < 0.05). Supplementation with fermented feed significantly reduced the crypt depth and increased the villi height:crypt depth ratio of duodenum and jejunum (p < 0.05). Meanwhile, fermented feed increased the secretory immunoglobulin A content and MUC2 mRNA expression of jejunum (p < 0.05). These beneficial effects were exhibited at the addition level ≥6% and microbial composition of caeca in the control, and so 6% fermented feed groups were analyzed. The structure of the gut microbiota was remarkably altered by additions, characterized by increased abundances of some health-promoting bacteria, such as Parasutterella, Butyricicoccus and Erysipelotrichaceae (p < 0.05). In summary, fermented mixed feed modulated cecal flora, subsequently contributing to improvements in intestinal morphology and barrier functions in laying hens.

Role of Yeast and Yeast-Derived Products as Feed Additives in Broiler Nutrition

Antibiotic resistance is looming problem in broiler production globally and there has been an increasing interest to look for sustainable alternatives to antibiotics. Yeast and its derived products are recognized as potential feed additives because of their beneficial impacts on poultry. Particularly, yeast exhibited positive effects on the humoral immunity by increasing serum immunoglobulin (Ig) A levels. Moreover, yeast and its products showed immune adjuvant-like properties that helped the broilers chicken to develop faster and stronger innate immune response under pathogenic challenges. Use of yeast and its products as prebiotic/probiotic improves the gut architecture mainly by improving the gut development and gut microbiome, reduction in colonization of pathogens through competitive exclusion, binding of toxins and enhancing digestion and absorption of nutrients. These unique properties of yeast and yeast products enhance animal welfare and productivity; warrant them to be used as a promising feed additive. This article, therefore, provides insights into the functional role of yeast and its products in the broiler diets and highlights its importance as a commercially viable alternative of synthetic antibiotic growth promoters in the broiler feed industry.

The effects of dietary supplementation of encapsulated thyme essential oil on growth, pro-inflammatory cytokines, and serum amino acid profiles of broiler chicks challenged with Salmonella typhimurium

Salmonella Typhimurium (S. Typhimurium) causes inflammation and has adverse effects on the growth of broiler chicks. Meanwhile, plant derivations improve the growth performance and decrease inflammation, but they do not have enough stability. Encapsulation of essential oils is a new strategy for decreasing their instability. This study was conducted to investigate the effects of dietary supplementation of encapsulated Thyme essential oil (ETEO) on growth, inflammatory cytokines, and amino acid profiles of broiler chicks challenged with S. Typhimurium. Three hundred one-d-old broiler chicks were assigned into 6 groups, and 5 replications per group. The broiler chicks (3 groups) were challenged with S. Typhimurium, on day 21 and birds received basal diet (positive control), encapsulated Thyme (P-ETEO), and non-capsulated Thyme (P-NETEO), while other groups received the same diets, but under normal as a negative control, encapsulated Thyme (N-ETEO) and non-capsulated Thyme (N-NETEO). Growth performance, pro-inflammatory cytokines, and serum amino acid profiles were assessed on day 42. The challenged birds in positive control showed lower growth performance, higher concentration for inflammatory cytokines, and disturbed blood serum concentrations for amino acid profiles compared to the negative control (P<0.05). The result showed that dietary supplementation of the ETEO could improve growth performance and amino acid profiles, and also decrease inflammatory responses (P<0.05). In sum, S. Typhimurium had negative effects on growth, immunity, and inflammation, but dietary inclusion of the ETEO could decrease its negative effects.

Metabolome and Microbiota Analysis Reveals the Conducive Effect of Pediococcus acidilactici BCC-1 and Xylan Oligosaccharides on Broiler Chickens

Xylan oligosaccharides (XOS) can promote proliferation of Pediococcus acidilactic BCC-1, which benefits gut health and growth performance of broilers. The study aimed to investigate the effect of Pediococcus acidilactic BCC-1 (referred to BBC) and XOS on the gut metabolome and microbiota of broilers. The feed conversion ratio of BBC group, XOS group and combined XOS and BBC groups was lower than the control group (P < 0.05). Combined XOS and BBC supplementation (MIX group) elevated butyrate content of the cecum (P < 0.05) and improved ileum morphology by enhancing the ratio of the villus to crypt depth (P < 0.05). The 16S rDNA results indicated that both XOS and BBC induced high abundance of butyric acid bacteria. XOS treatment elevated Clostridium XIVa and the BBC group enriched Anaerotruncus and Faecalibacterium. In contrast, MIX group induced higher relative abundance of Clostridiaceae XIVa, Clostridiaceae XIVb and Lachnospiraceae. Besides, MIX group showed lower abundance of pathogenic bacteria such as Campylobacter. Metabolome analysis showed that all the 3 treatment groups (XOS, BBC and MIX) showed lower concentrations of sorbitol and both XOS and BBC group had higher concentrations of pyridoxine levels than CT group. Besides, XOS and BBC groups enhanced the content of hydroxyphenyl derivatives 4-hydroxyphenylpyruvate 1 and 3-(3-hydroxyphenyl) propionic acid, respectively (P < 0.05). Notably, MIX group enhanced both 4-hydroxyphenylpyruvate 1 and 3-(3-hydroxyphenyl) propionic acid (P < 0.05). Thus, XOS and BBC may have a synergistic role to improve the performance of broilers by modulating gut microbiota and metabolome.

Impact of Fermented or Enzymatically Fermented Dried Olive Pomace on Growth, Expression of Digestive Enzyme and Glucose Transporter Genes, Oxidative Stability of Frozen Meat, and Economic Efficiency of Broiler Chickens

The use of dried olive pomace as complementary energy sources in poultry feed is still limited due to its low protein and high fiber contents. Bioconversion of olive pomace through solid-state fermentation with or without exogenous enzymes is considered as a trial for improving its nutritional value. This study aimed to evaluate the effects of fermented olive pomace with or without enzymatic treatment on the growth, modulations of genes encoding digestive enzymes and glucose transporters, meat oxidative stability, and economic efficiency of broiler chickens. A total of 1400 day-old broiler chicks (Ross 308) were randomly allocated to seven dietary treatments with 10 replicates of 20 birds/replicate. Treatments included control (basal corn-soybean diet) and other six treatments in which basal diet was replaced by three levels (7.5, 15, and 30%) of fermented olive pomace (FOPI) or enzymatically fermented olive pomace (FOPII) for 42 days. The highest body weight gain was observed in groups fed 7.5 and 15% FOPII (increased by 6.6 and 12.5%, respectively, when compared with the control group). Also, feeding on 7.5 and 15% FOPII yielded a better feed conversion ratio and improved the digestibility of crude protein, fat, and crude fiber. The expression of the SGLT-1 gene was upregulated in groups fed FOPI and FOPII when compared with the control group. Moreover, the expression of the GLUT2 gene was elevated in groups fed 7.5 and 15% FOPII. By increasing the levels of FOPI and FOPII in diets, the expression of genes encoding pancreatic AMY2A, PNLIP, and CCK was upregulated (p < 0.05) when compared with the control. Fat percentage and cholesterol content in breast meat were significantly reduced (p < 0.05) by nearly 13.7 and 16.7% in groups fed FOPI and FOPII at the levels of 15 and 30%. Total phenolic and flavonoid contents in breast meat were significantly increased in groups fed 15 and 30% FOPI and FOPII when compared with the control group and even after a long period of frozen storage. After 180 days of frozen storage, the inclusion of high levels of FOP significantly increased (p < 0.05) the levels of glutathione peroxide and total superoxide dismutase and meat ability to scavenge free radical 1,1-diphenyl-2-picrylhydrazyl. Furthermore, the highest net profit and profitability ratio and the lowest cost feed/kg body gain were achieved in groups fed 7.5 and 15% of FOPII, respectively. The results of this study indicated that dietary inclusion of 15% FOPII could enhance the growth performance and economic efficiency of broiler chickens. Moreover, a higher inclusion level of FOPI or FOPII could enhance the quality and increase the oxidative stability of frozen meat and extend the storage time.

Influence of Anacardium occidentale leaf supplementation in broiler chicken diet on performance, caecal microbiota, blood chemistry, immune status, carcass, and meat quality

1. This study investigated the growth performance, caecal microbiota, blood chemistry, splenic cytokines, serum immunoglobulins, carcase, meat quality and oxidative status of broiler chickens fed diets supplemented with Anacardium occidentale leaf powder (AOLP) in comparison with antibiotic and synthetic antioxidant.2. Three hundred and twenty, one-day old Arbor Acre broiler chicks were randomly allotted into four treatment groups consisting of eight pen replicates with 10 birds per pen. The treatment groups were T0, basal diet only; T1, basal diet + 0.4 g/kg oxytetracycline + 0.12 g/kg butylated hydroxyanisole (BHA); T2, basal diet + 2 g/kg AOLP and T3, basal diet + 4 g/kg AOLP. The birds were fed for 42 d when performance was assessed, and then euthanised.3. During 0-42 d, feed conversion ratio was higher (P = 0.033) in T0 birds compared with birds fed other diets. Diet did not affect carcase traits, organ weights, serum biochemical indices, and meat composition, pH, cook loss or meat colour. Supplemented birds had higher erythrocyte (P = 0.042) and haemoglobin (P = 0.025), and lower leukocytes (P = 0.012) compared with the T0 birds.4. Diet T3 upregulated (P = 0.020) splenic interleukin-10 compared with other diets. The T0 birds had higher (P < 0.05) interleukin-6 and serum IgG and IgM compared with the supplemented birds. Caecal E. coli and Salmonella spp. counts were higher (P < 0.05) in T0 birds than in the supplemented groups. Lactobacillus spp. counts were higher (P = 0.001) in T3 birds than in those fed other diets. Breast and thigh meat from the T0 birds had higher (P < 0.05) TBARS value, and carbonyl content compared to the supplemented birds. The T0 breast meat had higher drip loss (P = 0.001) than meat from the supplemented birds.5. The results suggested that AOLP exhibited antimicrobial and antioxidant properties that were comparable to the responses to oxytetracycline and BHA (T1) in broiler diets. Nonetheless, the efficacy of AOLP needs to be verified under disease challenge or compromised health condition.

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.

Evaluation of transfer of maternal immunity to the offspring of broiler breeders vaccinated with a candidate recombinant vaccine against Salmonella Enteritidis

Salmonella Enteritidis (SE) is a major cause of foodborne diseases in humans being frequently related to the consumption of poultry products. Therefore, guaranteeing early immunity to chicks is an important tool to prevent the colonization and infection by this pathogen. The present study evaluated the effectiveness of a candidate recombinant vaccine against SE. Thirty female and five male broiler breeders that were ten weeks-old were divided into 3 groups: unvaccinated (UV), vaccinated with recombinant vaccine candidate (VAC) and vaccinated with commercial bacterin (BAC). Samples of serum and embryonated egg were collected at seven and twelve weeks after the booster dose to quantify the transfer rate of IgY to egg yolks and offspring. Subsequently, forty day-old offspring were divided into two groups (UV and VAC) and challenged on the following day with 10⁷ CFU/chick of SE. Samples of serum, intestine, liver, and cecal content were harvested. Throughout the experiment period, significantly higher levels of IgY were observed in the egg yolk and also in the serum of broiler breeders and offspring of the VAC group in comparison to the UV group. In addition, increased transfer rates of IgY were observed in the VAC group when compared to the BAC group. Furthermore, higher villus-crypt ratios were found out in duodenum, jejunum and ileum at four days post-infection in the offspring from the VAC group. A high challenge dose of SE (10⁷ CFU per chick) was used and despite the stronger humoral immune response provoked by the candidate vaccine, there were no statistical differences in the recovery of viable SE cells from the offspring cecal contents. Therefore, the effect of vaccination to improve intestinal quality may affect the development of the chickens and consequently increase the resistance to lower SE challenge doses.

Dietary Supplementation of Potential Probiotics Bacillus subtilis, Bacillus licheniformis, and Saccharomyces cerevisiae and Synbiotic Improves Growth Performance and Immune Responses by Modulation in Intestinal System in Broiler Chicks Challenged with Salmonella Typhimurium

This study evaluates the effects of probiotics and synbiotics on the performance, immune responses, and intestinal morphology, and the expression of immunity-related genes of broiler chicks challenged with Salmonella typhimurium. Three hundred and sixty broiler chicks were divided into six groups, including broiler chicks challenged and non-challenged with S. typhimurium and fed with probiotic, synbiotic, and basal diet without additive. Growth performance (food intake, daily gain, feed conversion ratio, and mortality), immune responses (antibody titer against sheep red blood cells, immunoglobulins G and M), intestinal morphology, lactic acid bacteria population, and the expression of immunity-related genes (interferon-γ, interleukins 6 and 12, and tumor necrosis factor-α) were investigated. The administration of S. typhimurium decreased growth performance (P = 0.0001), immune responses (P = 0.0001), intestinal morphology (P = 0.0001), lactic acid bacteria population (P = 0.0001), and the expression of immunity-related genes (P = 0.0001) of broiler chickens. However, broiler chicks fed with probiotic (P = 0.001) and synbiotic (P = 0.0001) showed better growth performance, immune responses, intestinal morphology, lactic acid bacteria population, and the expression of immunity-related genes in comparison with infected broiler chicks fed with basal diet lack of probiotic and synbiotic. Feeding probiotics (P = 0.001) and synbiotics (P = 0.0001) showed positive effects for challenged and non-challenged broiler chicks. In sum, feeding synbiotic and probiotic alleviated the negative effects of S. typhimurium on growth and immunity of broiler chicks. It can be suggested to apply synbiotic and probiotics as benefit additive against infectious challenges, such as S. typhimurium.

Influence of dietary supplementation of Crassocephalum crepidioides leaf on growth, immune status, caecal microbiota, and meat quality in broiler chickens

The effect of dietary supplementation of Crassocephalum crepidioides leaf powder (CCLP) in comparison with oxytetracycline and butylated hydroxyanisole (BHA) on growth, caecal microbiota, immune status, blood chemistry, carcass traits, meat quality, and oxidative stability in broiler chickens was evaluated. Two hundred and eighty 1-day-old Arbor acre chicks were randomly assigned to a basal diet containing either no additive (control, CON), 400 ppm oxytetracycline + 150 ppm BHA (ANTIBIOX), 1000 ppm CCLP (CCLP-1), or 2000 ppm CCLP (CCLP-2) for 42 days. Each dietary group had seven replicates with ten birds per replicate. Supplemented birds had higher (P < 0.05) feed efficiency, hemoglobin, and hematocrit compared with the CON birds. Diet did not affect feed intake, body weight gain, splenic interleukin-1β, interleukin-6, interleukin-10, and serum IgM. The CCLP-2 birds had lower (P < 0.05) serum total and LDL cholesterol than did birds fed other treatments. Salmonella spp. and Escherichia coli counts and serum IgG were higher in the CON birds than in the supplemented birds. The ANTIBIOX birds had lower (P < 0.05) Lactobacillus spp. count, and higher (P < 0.05) E. coli count compared with the CCLP-supplemented birds. Carcass, muscle pH, and cook loss were not affected by diet. The CON breast meat had higher drip loss and lower redness than did the breast meat of the supplemented birds. Carbonyl content and TBARS value in the thigh and breast meat of the supplemented birds were lower (P < 0.05) than those of the CON birds. These results infer that CCLP exhibited antioxidant and antimicrobial properties that were comparable to those of BHA and oxytetracycline in the diet of broiler chickens.

The effects of dietary supplementation with lotus leaf extract on the immune response and intestinal microbiota composition of broiler chickens

This study aimed to assess the effect of lotus leaf extract (LLE) on the immune response and intestinal microbiota composition of broiler chickens. One-day-old birds were assigned to 7 treatments. Two maize-based control diets were each given with or without 50 mg/kg chlortetracycline (antibiotics and blank control groups, respectively). Five experimental diets were each given with 1.0, 2.5, 5.0, 7.5, or 10.0 g/kg LLE. Average daily weight gain (ADG) was assessed, and the immune organ index was calculated. Serum cytokine and immunoglobulin levels were determined, and intestinal microbiota composition was analyzed via high-throughput sequencing of the 16S rRNA gene. Results showed that in the LLE5 group, ADG was higher than that of the antibiotics and blank control groups (P < 0.05) from d 7 to 21, the thymus index at d14, spleen index at d 21, and bursa index at d 14 and 21 were increased markedly (P < 0.05). In the LLE5 and LLE7.5 groups, serum total IgG and sIgA concentrations were higher than those of the antibiotics and blank control groups (P < 0.05) at d 7 and higher than those of the antibiotics group (P < 0.05) at d 14. No significant effect was observed for interferon-gamma concentrations between the antibiotics and LLE5 or LLE7.5 groups; compared with the antibiotics group, IL2 concentrations were increased in the LLE5 group at d 7 and in the LLE7.5 group at d 21 (P < 0.05). 16s rRNA sequencing analysis revealed that there were 1,704, 232, and 4,814 operational taxonomic unit in the blank control group, antibiotics group, and LLE groups, respectively. The intestinal microbiota consisted mainly of Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes (>95%) at the phylum level; at the family level, the abundance of Clostridiaceae and Bacteroidales S24-7 was increased, whereas that of Peptostreptococcaceae was reduced in LLE5 group (P < 0.05). These findings suggest that LLE may be a good source of prebiotics, helping to modulate the immune response and boost the levels of beneficial bacteria.

Productive parameters, cecal microflora, nutrient digestibility, antioxidant status, and thigh muscle fatty acid profile in broiler chickens fed with Eucalyptus globulus essential oil

This study was conducted to evaluate the effects of different dietary inclusion of eucalyptus essential oil (EEO) on growth performance, relative organ weight, cecal microflora, nutrient digestibility, serum biochemical parameters, and thigh muscle fatty acid profile in broiler chickens. A total of six hundred 1-day-old male broiler chickens were randomly allocated into 5 treatment groups with 8 replicate pens, and each pen contained 15 birds. The experiment lasted for 42 d. Dietary treatments included corn–soybean meal-based diet supplemented with 0, 250, 500, 750, and 1,000 mg/kg EEO. The results indicated that dietary treatments had no effect on growth performance parameters in the 1 to 10 d period. From day 11 to 24, dietary supplementation of EEO showed a linear decrease in feed conversion ratio (FCR, P < 0.05). From day 25 to 42 and the overall period (1–42 d), broilers fed with different levels of EEO showed a linear increase in body weight gain (BWG) and reduction in feed conversion ratio (linear, P < 0.05). The relative organ weight were unaffected by any of the dietary treatments. With increasing levels of EEO, the cecal Escherichia coli (linear, P = 0.085) count showed a trend in reduction, and the cecal lactic acid bacteria population tended to increase (linear, P = 0.063). The apparent ileal digestibility of ether extract and organic matter were linearly and quadratically increased in response to increasing dietary EEO supplementation (P < 0.05). A trend of linear decrease in total cholesterol in the serum of birds fed with different levels of EEO was recorded (P = 0.074). Eucalyptus essential oil's inclusion increased serum superoxide dismutase linearly but reduced serum malondialdehyde linearly (P < 0.05). Dietary supplementation of EEO affected the fatty acid profile of thigh muscle so that increased the concentrations of total polyunsaturated fatty acids (linear, P < 0.05) and reduced total saturated fatty acid contents (linear, P < 0.05). Taken together, the inclusion of EEO increased BWG and decreased FCR during day 25 to 42 and day 1 to 42, and partially improved cecal microflora balance, nutrient digestibility, antioxidant activity, and thigh muscle fatty acid profile in broiler chickens.

Prebiotic mannooligosaccharides: Synthesis, characterization and bioactive properties

Functional oligosaccharides are non-digestible food ingredients that confer numerous health benefits. Among these, mannooligosaccharides (MOS) are emerging prebiotics that have characteristic potential bio-active properties. Microbial mannanases can be used to break down mannan rich agro-residues to yield MOS. Various applications of MOS as health promoting functional food ingredient may open up newer opportunities in food and feed industry. Enzymatic hydrolysis is the widely preferred method over chemical hydrolysis for MOS production. Presently, commercial MOS is being derived from yeast cell wall mannan and is widely used as prebiotic in feed supplements for poultry and aquaculture. Apart from stimulating the growth of probiotic microflora, MOS impart anticancer and immunomodulatory effects by inducing different gene markers in colon cells. This review summarizes recent developments and future prospects of enzymatic synthesis of MOS from various mannans, their structural characteristics and their potential health benefits.

Reduction of Salmonella Typhimurium Cecal Colonisation and Improvement of Intestinal Health in Broilers Supplemented with Fermented Defatted 'Alperujo', an Olive Oil By-Product

Salmonella spp. contaminates egg and poultry meat leading to foodborne infections in humans. The emergence of antimicrobial-resistant strains has limited the use of antimicrobials. We aimed to determine the effects of the food supplement, fermented defatted 'alperujo' (FDA), a modified olive oil by-product, on Salmonella Typhimurium colonisation in broilers. One hundred and twenty 1-day-old broilers were divided into four experimental groups-two control groups and two treated groups, and challenged with S. Typhimurium at day 7 or 21. On days 7, 14, 21, 28, 35, and 42 of life, duodenum and cecum tissue samples were collected for histopathological and histomorphometric studies. Additionally, cecum content was collected for Salmonella spp. detection by culture and qPCR, and for metagenomic analysis. Our results showed a significant reduction of Salmonella spp. in the cecum of 42-day-old broilers, suggesting that fermented defatted 'alperujo' limits Salmonella Typhimurium colonization in that cecum and may contribute to diminishing the risk of carcass contamination at the time of slaughter. The improvement of the mucosal integrity, observed histologically and morphometrically, may contribute to enhancing intestinal health and to limiting Salmonella spp. colonisation in the host, mitigating production losses. These results could provide evidence that FDA would contribute to prophylactic and therapeutic measures to reduce salmonellosis prevalence in poultry farms.

Probiotics (Direct-Fed Microbials) in Poultry Nutrition and Their Effects on Nutrient Utilization, Growth and Laying Performance, and Gut Health: A Systematic Review

Simple Summary

Probiotics are live bacteria, fungi, or yeasts that supplement the gastrointestinal flora and help to maintain a healthy digestive system, thereby promoting the growth performance and overall health of poultry. Probiotics are increasingly being included in poultry diets as an alternative to antibiotics. This systematic review provides a summary of the use of probiotics in poultry production and the potential role of probiotics in the nutrient utilization, growth and laying performance, and gut health of poultry.

Abstract

Probiotics are live microorganisms which, when administered in adequate amounts, confer health benefits to the host. The use of probiotics in poultry has increased steadily over the years due to higher demand for antibiotic-free poultry. The objective of this systematic review is to present and evaluate the effects of probiotics on the nutrient utilization, growth and laying performance, gut histomorphology, immunity, and gut microbiota of poultry. An electronic search was conducted using relevant keywords to include papers pertinent to the topic. Seventeen commonly used probiotic species were critically assessed for their roles in the performance and gut health of poultry under existing commercial production conditions. The results showed that probiotic supplementation could have the following effects: (1) modification of the intestinal microbiota, (2) stimulation of the immune system, (3) reduction in inflammatory reactions, (4) prevention of pathogen colonization, (5) enhancement of growth performance, (6) alteration of the ileal digestibility and total tract apparent digestibility coefficient, and (7) decrease in ammonia and urea excretion. Thus, probiotics can serve as a potential alternative to antibiotic growth promoters in poultry production. However, factors such as the intestinal health condition of birds, the probiotic inclusion level; and the incubation conditions, feedstuff, and water quality offered to birds may affect the outcome. This systematic review provides a summary of the use of probiotics in poultry production, as well as the potential role of probiotics in the nutrient utilization, growth and laying performance, and gut health of poultry.

Prospects of yeast based feed additives in poultry nutrition: Potential effects and applications

Yeast and its derivatives are extensively utilized as feed additives in poultry industry owing to their desirable health and growth promoting effects. Exhaustive number of studies had reported positive effects of yeast based additives on growth, meat quality, immunity, antioxidant status, and gastrointestinal functions in poultry birds. Owing to their prebiotic/probiotic properties, they also play significant role in gut development and modulation of gut microbiome by favouring beneficial microbes while reducing colonization of pathogenic microbes by competitive exclusion. They also possess effective potential for binding of dietary toxins in addition to improving digestion and utilization of nutrients. Moreover, yeast based additives have exhibited desirable effects on humoral immunity by increasing serum immunoglobulin (Ig) A levels. These additives have been also used as immune adjuvants to boost innate immune response under any pathogenic challenges in birds. Due to their diverse biological activities, yeast products are potentially capable for immune hemostasis by mediating balance between pro- and anti-inflammatory activities. These unique properties of yeast based products make them promising feed additive to promote health and productivity leading to efficient poultry production. Yeast can be supplemented in poultry diets @ 5.0–10.0 g/kg of feed. Numerous studies had reported significant improvement in body weight gain (3 to 8%) and FCR (1.6 to 12%) in broilers in response to supplementation of yeast based additives. Moreover, yeast supplementation also improved hemoglobin (Hb g/dl) levels up to 2.59 to 6.62%, total protein (>0.69%) while reducing serum cholesterol (mg/dl) up to 3.68 to 13.38%. Despite the potential properties and beneficial effects, use of yeast and its derivatives as feed additives in poultry industry is not matching its inherent potential due to many reasons. This review aims to highlight the importance and potential role of yeast and its products as natural growth promoter to replace in feed antibiotics to address the issues of antibiotic residues and microbial resistance. This article provides insights on functional role of yeast based additives in poultry diets and their importance as commercially viable alternatives of antibiotic growth promoters in poultry feed industry.

Protective effects of dietary mannan oligosaccharide on heat stress-induced hepatic damage in broilers

Heat stress is a major concern in broiler's production, which can damage liver of broilers. This study investigated the protective effects of mannan oligosaccharide (MOS) on heat stress-induced hepatic injury in broilers. A total of 144 day-old male chicks were allocated into three treatment groups. Broilers raised under normal ambient temperature were fed a basal diet (control group), and broilers under heat stress (32-33 °C for 8 h daily) were given the basal diet supplemented without MOS (heat stress group) or with 1 g/kg MOS (MOS group) for 42 days. Compared with the control group, heat stress reduced liver weight, whereas increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities in the serum. It also reduced glutathione peroxidase (GSH-Px) activity in the serum and liver, GSH content, and superoxide dismutase (SOD) activity in the liver, but increased malondialdehyde (MDA) concentration in the serum and liver. Dietary MOS decreased serum ALT activity in heat-stressed broilers. MOS inclusion also decreased serum MDA content, but elevated hepatic GSH-Px and SOD activities, with MDA content and GSH-Px activity still being different from the control group, and SOD activity being similar to the control group. Heat stress increased concentrations of tumor necrosis factor α (TNF-α) in the serum and liver, interleukin-1β (IL-1β) in the liver, and mRNA abundances of HSP70, TLR4, MyD88, TNF-α, and IL-1β in the liver of broilers. Serum TNF-α content and mRNA abundances of hepatic TLR4 and TNF-α in MOS group were lower than the heat stress group, whereas these indexes were still higher than the control group. Our results indicated that dietary MOS ameliorated hepatic damage in heat-stressed broilers through alleviation of oxidative stress and inflammation.

A microencapsulated feed additive containing organic acids, thymol, and vanillin increases in vitro functional activity of peripheral blood leukocytes from broiler chicks

During the first week after hatch, young chicks are vulnerable to pathogens as the immune system is not fully developed. The objectives of this study were to determine if supplementing the starter diet with a microencapsulated feed additive containing citric and sorbic acids, thymol, and vanillin affects in vitro functional activity of peripheral blood leukocytes (PBLs). Day-old chicks (n = 800) were assigned to either a control diet (0 g/metric ton [MT]) or a diet supplemented with 500 g/MT of the microencapsulated additive. At 4 D of age, peripheral blood was collected (100 birds per treatment), and heterophils and monocytes isolated (n = 4). Heterophils were assayed for the ability to undergo degranulation and production of an oxidative burst response while nitric oxide production was measured in monocytes. Select cytokine and chemokine mRNA expression levels were also determined. Statistical analysis was performed using Student t test comparing the supplemented diet to the control (P ≤ 0.05). Heterophils isolated from chicks fed the microencapsulated citric and sorbic acids, thymol, and vanillin had higher (P ≤ 0.05) levels of degranulation and oxidative burst responses than those isolated from chicks on the control diet. Heterophils from the supplemented chicks also had greater (P ≤ 0.05) expression of IL10, IL1β, and CXCL8 mRNA than those from control-fed chicks. Similarly, nitric oxide production was significantly (P ≤ 0.05) higher in monocytes isolated from birds fed the supplement. The cytokine and chemokine profile in monocytes from the supplement-fed chicks showed a significant (P ≤ 0.05) drop in IL10 mRNA expression while IL1β, IL4, and CXCL8 were unchanged. In conclusion, 4 D of supplementation with a microencapsulated blend made up of citric and sorbic acids, thymol, and vanillin enhanced the in vitro PBL functions of degranulation, oxidative burst, and nitric oxide production compared with the control diet. Collectively, the data suggest feeding broiler chicks a diet supplemented with a microencapsulated blend of citric and sorbic acids, thymol, and vanillin may prime key immune cells making them more functionally efficient and acts as an immune-modulator to boost the inefficient and undeveloped immune system of young chicks.

Dietary l-arginine supplementation ameliorates inflammatory response and alters gut microbiota composition in broiler chickens infected with Salmonella enterica serovar Typhimurium

This study was conducted to investigate the effects of dietary arginine (Arg) supplementation on the inflammatory response and gut microbiota of broiler chickens subjected to Salmonella enterica serovar Typhimurium. One hundred and forty 1-day-old Arbor Acres male birds were randomly assigned to a 2 × 2 factorial arrangement including diet treatment (with or without 0.3% Arg supplementation) and immunological stress (with or without S. typhimurium challenge). Samples were obtained at 7 D after infection (day 23). Results showed that S. typhimurium challenge caused histopathological and morphological damages, but Arg addition greatly reduced these intestinal injuries. S. typhimurium challenge elevated the levels of serum inflammatory parameters, including diamine oxidase, C-reactive protein, procalcitonin, IL-1β, IL-8, and lipopolysaccharide-induced tumor necrosis factor-alpha factor (LITNF) homolog. However, Arg supplementation decreased the serum procalcitonin, IL-1β, IL-8, and LITNF concentration. S. typhimurium challenge significantly increased jejunal IL-1β, IL-8, IL-10, and IL-17 mRNA expression and tended to upregulate IL-22 mRNA expression, but Arg supplementation remarkably reduced IL-8 mRNA expression, tended to downregulate IL-22 mRNA expression, and dramatically elevated IFN-γ and IL-10 mRNA expression. In addition, sequencing data of 16S rDNA indicated that the population of Proteobacteria phylum; Enterobacteriaceae family; Escherichia–Shigella, and Nitrosomonas genera; and Escherichia coli and Ochrobactrum intermedium species were more abundant, but the population of Rhodocyclaceae and Clostridiaceae_1 families and Candidatus Arthromitus genus were less abundant in the ileal digesta of birds with only S. typhimurium infection when compared with the controls. Treatment with Arg in birds subjected to S. typhimurium challenge increased the abundances of Firmicutes phylum, Clostridiaceae_1 family, Methylobacterium and Candidatus Arthromitus genera but decreased the abundance of Nitrosomonas genus and Rhizobium cellulosilyticum and Rubrobacter xylanophilus species as compared with the only S. typhimurium–challenged birds. In conclusion, Arg supplementation can alleviate intestinal mucosal impairment by ameliorating inflammatory response and modulating gut microbiota in broiler chickens challenged with S. typhimurium.