Effects of a probiotic, Enterococcus faecium, on growth performance, intestinal morphology, immune response, and cecal microflora in broiler chickens challenged with Escherichia coli K88

Assessing the Impact of Spraying an Enterococcus faecium-Based Probiotic on Day-Old Broiler Chicks at Hatch on the Incidence of Bacterial Chondronecrosis with Osteomyelitis Lameness Using a Staphylococcus Challenge Model

Bacterial chondronecrosis with osteomyelitis (BCO) lameness is a bone disease characterized by the translocation of bacteria from the gastrointestinal tract, which colonize microfractures in broiler leg bones caused by rapid animal growth rate and weight gain, resulting in lameness. As such, BCO lameness represents a significant challenge for the poultry industry. This study aims to evaluate the effect of spraying broiler chicks on d0 at hatch with an Enterococcus faecium probiotic on the incidence of BCO-induced lameness, utilizing a Staphylococcus aureus challenge model. There were four treatments: (1) negative control (no probiotic + no challenge, NC); (2) positive control (no probiotic + challenge, PC); (3) low dosage (4.0 × 108 CFU/chick + challenge, LOW); and (4) high dosage (2.0 × 109 CFU/chick + challenge, HIGH). On d5, groups two through four were challenged with Staphylococcus aureus through the drinking water at a concentration of 1.0 × 105 CFU/mL. Cumulative lameness incidence was determined through daily evaluations and necropsies conducted on lame birds starting from d22. Data were subjected to a binomial general regression analysis (significant p < 0.05). On d56, the PC group exhibited the highest cumulative lameness incidence (58.0%; p < 0.05), followed by LOW (36.0%), HIGH (28.7%), and NC groups (25.3%), respectively. These results suggest early probiotic application at day-of-hatch successfully reduced the incidence of lameness in challenged birds, thus contributing to understanding of efficient and sustainable broiler production.

Short-term supplementation with uncoated and encapsulated Enterococcus faecium affected growth performance, gut microbiome and intestinal barrier integrity in broiler chickens

Enterococcus faecium (E. faecium) is an alternative to antibiotics, while the probiotic effect of short-term application in mature broiler chickens remains unclear. In the current study, 48 Arbor Acres male broilers were chosen to investigate the effects of E. faecium on growth performance, the gut microbiome and intestinal health during the finishing period. Forty-eight birds were randomly allocated to 4 treatment groups that were fed a corn-soybean meal basal diet (Con), a basal diet supplemented with 1 g/kg amoxicillin (ABX), 5×106 CFU/g encapsulated E. faecium (cEF), or 5×106 CFU/g uncoated E. faecium (EF) from d 33 to 42. The results showed that 10 d of antibiotic treatment decreased the growth performance of the broilers (P < 0.05). The feed conversion ratio of the cEF and EF groups were lower than that of the Con group by 0.13 and 0.07, respectively (P > 0.05). The abundance of viable ileal and cecal E. faecium in the cEF group was greater than that in the EF group (P < 0.05), and both groups were markedly greater than those in the Con and ABX groups (P < 0.05). The ABX treatment decreased the Shannon and Chao1 indices of the cecal microbiota, while the dietary E. faecium treatment resulted in significant differences in the β diversity of the ileal and cecal microbiota (P < 0.05). Mantel correlation revealed that the ileal microbiota at the genus level was significantly correlated with the growth performance of broilers, with Lactobacillus, Bacillus and Escherichia-Shigella showing positive and strong correlations (P < 0.05). In the ileum, the crypt depth was lower in the cEF group than in the Con group, but the villi height-to-crypt depth ratio was greater in the cEF group than in the other groups (P = 0.037). However, the expression of the ZO-2 and Occludin genes was downregulated in the E. faecium-fed birds (P < 0.05). In the cecum, the acetate, butyrate and total SCFA levels were greater in the EF group (P < 0.05), while the propionate, isobutyrate and isovalerate levels were lower in the ABX group (P < 0.05). In summary, 10 d of dietary supplementation with E. faecium markedly increased colonization in mature broilers and potentially improved growth performance by modulating the ileal microbiota. Encapsulation techniques could enable a slow release of E. faecium in the intestine, thereby reducing the negative impacts of rapid expansion of E. faecium on the intestinal epithelium.

Evaluation of Natural Antimicrobial Substances Blend as a Replacement for Antibiotic Growth Promoters in Broiler Chickens: Enhancing Growth and Managing Intestinal Bacterial Diseases

In recent years, commercial use of antibiotic growth promoter (AGP) has restrictions due to drug resistance against intestinal pathogenic bacteria: Escherichia coli, Salmonella, and Clostridium perfringens. Currently there is no single non-antibiotic treatment approach that is effective against intestinal illnesses in broiler chicken. Hence, present study aimed to analyze efficacy of blend of natural antimicrobial substances (probiotics, prebiotics, organic acids, and essential oils blend named as AGPR) as replacers of AGPs (BMD and CTC) for promoting growth and controlling bacterial diseases in aforementioned three microbes challenged broiler chickens. Effects of treatments (5) and microbes (3) on growth and health performances in experimental birds were analyzed using two factorial ANOVA. Health performance like pathogen loads, morbidity and mortality was considerably reduced by AGPR. Similarly small intestine villi morphometry, nutrition utilization, serum immune response, and carcass yield, was improved significantly by AGPR equivalent to AGPs. Further, growth performance like body weight gain, feed efficiency was also improved by AGPR compared to control but, non-significantly. Among three microbes, E. coli infections had higher morbidity and mortality rates. It was concluded that AGPR blend could be used to improve growth and control the intestinal bacterial infections in broiler chickens as an alternative for AGPs.

Antibiotic resistance pattern and pathological features of avian pathogenic Escherichia coli O78:K80 in chickens

Abstract Avian pathogenic Escherichia coli (APEC) induces colibacillosis, an acute and systemic disease, resulting in substantial economic losses in the poultry sector. This study aimed to investigate the antibiotic resistance pattern associated with frequent virulence gene distribution in APEC O78:K80 that may cause pathological alterations in chickens. The antibiogram profile showed high resistance to erythromycin, chloramphenicol, tetracycline, ampicillin, and co-trimoxazole, followed by intermediate resistance to ciprofloxacin, levofloxacin, enrofloxacin, norfloxacin, nitrofurantoin, and doxycycline hydrochloride, and sensitive to amikacin, streptomycin, gentamicin, and colistin. Virulence gene distribution identifies eight (irp-2, iutA, ompT, iss, iucD, astA, hlyF, iroN) genes through a conventional polymerase chain reaction. APEC O78:K80 caused significantly high liver enzyme concentrations, serum interleukin-6 and tumor necrosis factor-alpha levels in experimental birds. Also, infected birds have hypoproteinemia, hypoalbuminemia, and hyperglobulinemia. Necropsy examination revealed fibrinous perihepatitis and pericarditis, congested lungs, intestinal ecchymotic hemorrhages and necrotizing granulomatosis of the spleen. Histopathological examination depicted hepatocellular degeneration, myocardial necrosis, interstitial nephritis, intestinal hemorrhages and lymphopenia in the spleen. This study is the first evidence to assess the antibiotic resistance profile linked with virulence genes and clinicopathological potential of APEC O78:K80 in chickens in Pakistan, which could be a useful and rapid approach to prevent and control the disease by developing the control strategies.

Compound bioengineering protein supplementation improves intestinal health and growth performance of broilers

Currently, antimicrobial peptides (AMPs) are of growing interest as potential substitutes for antibiotic growth promoters in animal production. The present study was conducted to evaluate the effects of dietary supplementation of bioengineering artificial Parasin I protein (API) and artificial plectasin protein (APL) (named as compound bioengineering protein, CBP) on growth performance and intestinal health of broilers. A total of 450 one-day-old Arbor Acres male healthy broilers were randomly allotted to 5 dietary groups with 10 replicates of 9 individuals in each replicate and supplemented with 0, 250, 500, 750, and 1,000 mg/kg CBP for 6 wk. Dietary CBP supplementation increased (P < 0.01) body weight (6 wk), average daily gain (0-6 wk), and average daily feed intake (3-6 wk and 0-6 wk). CBP addition enhanced antioxidant capacity, which was accompanied by the higher (P < 0.05) activity of serum total antioxidant capacity (T-AOC) (750 mg/kg), jejunal glutathione peroxidase (750 mg/kg), and T-AOC (500 and 1,000 mg/kg). Dietary CBP addition improved intestinal health, reflecting by the increased (P < 0.05) villus height to crypt depth ratio in the duodenum, the upregulated (P < 0.01) mRNA levels of claudin-1 (500 and 750 mg/kg) in the ileum, the downregulated (P < 0.01) mRNA expression of occludin (500 mg/kg) in the duodenum and claudin-1 (500 mg/kg) and occludin (500 and 750 mg/kg) in the jejunum, and the upregulated mRNA expression of (P < 0.01) mucin2 (MUC2) (1,000 mg/kg) in the duodenum. In addition, CBP upregulated (P < 0.01) IL-10 (1,000 mg/kg) in duodenum and ileum, and downregulated (P < 0.05) the mRNA expression of IL-6 (750 and 1,000 mg/kg), interferon-γ (1,000 mg/kg) in the jejunum and TNF-α (250 mg/kg) in the ileum. Furthermore, dietary CBP increased (P < 0.01) the abundance of total bacteria and Lactobacillus (500 and 750 mg/kg), and reduced (P < 0.05) the abundance of Escherichia coli (750 mg/kg) in the cecum. In conclusion, CBP supplementation enhances the antioxidant capacity, intestinal health, immune function, and ameliorates the gut microflora population, thus improving the growth performance of broilers. Dietary supplementation of 750 mg/kg CBP exhibits a better beneficial effect.

Mortality Causes in Captive Cantabrian capercaillie (Tetrao urogallus cantabricus) in Spain

The Cantabrian capercaillie (Tetrao urogallus cantabricus) is one of the most severely threatened subspecies of capercaillie. Its current population range is restricted to a small area of the Cantabrian Mountains (northwestern Spain), with only around 200 individuals remaining. As part of the national strategy for the conservation of the subspecies, the Cantabrian capercaillie Captive Breeding Center of Sobrescobio opened in 2009. Here, we use the information provided by the necropsies performed in this facility on 29 individuals (11 males, 13 females and 5 undetermined; 16 chicks and 13 adults) in order to describe the main mortality causes of captive-bred Cantabrian capercaillies. After necropsy, tissue samples were taken for evaluation using standard methods in histology and microbiology. The majority of the captive animals (18/29, 62.07%) died due to infectious diseases, mainly due to Escherichia coli, Clostridium perfringens, or Aspergillus fumigatus infection. The remaining 11 animals died due to stress-related processes (i.e., rupture of the heart apex and cardiomyopathy or neurogenic shock) (8/29, 27.59%), duodenal obstruction and coelomitis (1/29, 3.45%), perforation of the proventriculus and heart with a briar branch (1/29, 3.45%) or euthanasia due to a valgus leg deformity that prevented proper animal welfare (1/29, 3.45%). Young animals (i.e., younger than 2 months) died mainly due to infectious diseases (14/16, 87.5%), while stress-related causes were responsible for most adult deaths (7/13, 53.85%). We additionally report that two free-ranging adult males died due to exertional myopathy. This study provides relevant information for reducing mortality in captive capercaillies and improving both living conditions in captivity and the adaptation of these animals to the wild.

A systematic review on selection characterization and implementation of probiotics in human health

Probiotics are live bacteria found in food that assist the body's defence mechanisms against pathogens by reconciling the gut microbiota. Probiotics are believed to aid with gut health, the immune system, and brain function, among other factors. They've furthermore been shown to help with constipation, high blood pressure, and skin issues. The global probiotics market has been incrementally growing in recent years, as consumers' demand for healthy diets and wellness has continued to increase. This has prompted the food industry to develop new probiotic-containing food products, as well as researchers to explore their specific characteristics and impacts on human health. Although most probiotics are fastidious microorganisms that are nutritionally demanding and sensitive to environmental conditions, they become less viable as they are processed and stored. In this review we studied the current literature on the fundamental idea of probiotic bacteria, their medical benefits, and their selection, characterization, and implementations.

Graphical Abstract

Recent trends in the biotechnology of functional non-digestible oligosaccharides with prebiotic potential

Prebiotics as a part of dietary nutrition can play a crucial role in structuring the composition and metabolic function of intestinal microbiota and can thus help in managing a clinical scenario by preventing diseases and/or improving health. Among the different prebiotics, non-digestible carbohydrates are molecules that selectively enrich a typical class of bacteria with probiotic potential. This review summarizes the current knowledge about the different aspects of prebiotics, such as its production, characterization and purification by various techniques, and its link to novel product development at an industrial scale for wide-scale use in diverse range of health management applications. Furthermore, the path to effective valorization of agricultural residues in prebiotic production has been elucidated. This review also discusses the recent developments in application of genomic tools in the area of prebiotics for providing new insights into the taxonomic characterization of gut microorganisms, and exploring their functional metabolic pathways for enzyme synthesis. However, the information regarding the cumulative effect of prebiotics with beneficial bacteria, their colonization and its direct influence through altered metabolic profile is still getting established. The future of this area lies in the designing of clinical condition specific functional foods taking into consideration the host genotypes, thus facilitating the creation of balanced and required metabolome and enabling to maintain the healthy status of the host.

Temporal changes of genes associated with intestinal homeostasis in broiler chickens following a single infection with Eimeria acervulina

Infection with the protozoan parasite Eimeria can cause the economically devastating disease coccidiosis, which is characterized by gross tissue damage and inflammation resulting in blunted villi and altered intestinal homeostasis. Male broiler chickens at 21 d of age were given a single challenge with Eimeria acervulina. Temporal changes in intestinal morphology and gene expression were investigated at 0, 3, 5, 7, 10, and 14 d postinfection (dpi). There were increased crypt depths for chickens infected with E. acervulina starting at 3 dpi and continuing to 14 dpi. At 5 and 7 dpi, infected chickens had decreased Mucin2 (Muc2), and Avian beta defensin (AvBD) 6 mRNA at 5 and 7 dpi and decreased AvBD10 mRNA at 7 dpi compared to uninfected chickens. Liver-enriched antimicrobial peptide 2 (LEAP2) mRNA was decreased at 3, 5, 7, and 14 dpi compared to uninfected chickens. After 7 dpi, there was increased Collagen 3a1 and Notch 1 mRNA compared to uninfected chickens. Marker of proliferation Ki67 mRNA was increased in infected chickens from 3 to 10 dpi. In addition, the presence of E. acervulina was visualized by in situ hybridization (ISH) with an E. acervulina sporozoite surface antigen (Ea-SAG) probe. In E. acervulina infected chickens, Ea-SAG mRNA was only detectable on 5 and 7 dpi by both ISH and qPCR. To further investigate the site of E. acervulina infection, Ea-SAG and Muc2 probes were examined on serial sections. The Muc2 ISH signal was decreased in regions where the Ea-SAG ISH signal was present, suggesting that the decrease in Muc2 by qPCR may be caused by the loss of Muc2 in the localized regions where the E. acervulina had invaded the tissue. Eimeria acervulina appears to manipulate host cells by decreasing their defensive capabilities and thereby allows the infection to propagate freely. Following infection, the intestinal cells upregulate genes that may support regeneration of damaged intestinal tissue.

The Effects of Dietary Spirulina platensisis on Physiological Responses of Broiler Chickens Exposed to Endotoxin Stress

This study was proposed to highlight the impact of dietary Spirulina platensis (SP) supplementation in alleviating the deterioration effect of Escherichia coli (EC) on the growth performance, redox biomarkers, immune reaction, and hindgut microbial counts and acidosis in broiler chickens. Four hundred Cobb500, one-day-old, broiler chickens were deposited in battery cages (10 chicks per cage). The chicks were distributed into totally randomized 2 × 2 factorial treatments (10 replicate cages per treatment) from the day 22 to the day 42 of age. Birds of two of the groups were fed on a basal diet without SP supplementation (-SP groups), while birds of the other two groups were fed on a basal diet supplemented with 10 g/kg SP (+SP groups). At day 36th of age, birds in one of the -SP and +SP groups were challenged by an intraperitoneal (i.p.) injection with 10⁷ CFU/bird EC (O157:H7 strain) in 0.5 mL sterilized saline (+EC groups), whereas the other non-challenged groups were i.p. injected with 0.5 mL saline only (-EC groups). The current study results indicated that the boilers challenged with EC had a significant (p < 0.05) lower performance, poor antioxidant activity, immunosuppression, and higher numbers of pathogenic bacteria in the intestine when compared with the non-challenged birds. Dietary SP inclusion enhanced (p < 0.05) broiler growth, antioxidant activity, immune response, and intestinal beneficial bacteria and acidosis. Moreover, SP alleviated the reduction in all these parameters after exposure to EC infection. Therefore, diets containing 10 g/kg SP could be used as a promising approach to maximize broilers' production and support their health, particularly when challenged with EC infection.

Dynamic Changes in the Gut Microbiota and Metabolites during the Growth of Hainan Wenchang Chickens

Gut microbiota and their metabolites play important roles in animal growth by influencing the host's intake, storage, absorption, and utilization of nutrients. In addition to environmental factors, mainly diet, chicken breed and growth stage also affect changes in the gut microbiota. However, little research has been conducted on the development of gut microbiota and its metabolites in local chickens. In this study, the cecal microbiota and metabolites in different developmental stages of Hainan Wenchang chickens (a native breed of Bantam) were investigated using 16S rRNA sequencing and untargeted metabolomics. With aging, the structure of gut microbiota tended to be more stable. The relative proportions of dominant bacteria phyla Firmicutes, Bacteroidetes, and Proteobacteria showed stage changes with the development. With aging, gut microbiota and their metabolites may have structural and functional changes in response to nutrient metabolism and immune requirements in different physiological states. Several microbial and metabolic biomarkers with statistical differences were detected in different development stages. The bacteria that form networks with their significant related metabolites were different in various growth stages, including uncultured_bacterium_f_Ruminococcaceae, Ruminococcaceae_UCG-014, Faecalibacterium, uncultured_bacterium_o_Bacteroidales, and uncultured_bacterium_f_Lachnospiraceae. Partially differential bacteria were significantly correlated with short-chain fatty acids such as butyric acid. These findings may provide new insights into the physiological and molecular mechanisms of developmental changes of local chicken breeds, as well as resources for microbial and metabolic biomarker identification to improve growth efficiency.

Effects of dietary supplementation probiotic complex on growth performance, blood parameters, fecal harmful gas, and fecal microbiota in AA+ male broilers

In this study, Bacillus subtilis, Clostridium butyricum and Enterococcus faecalis were made into a probiotic complex (PC). The PC was supplemented in AA+ male broilers' diets to investigate the effects of PC on broiler growth performance, carcass traits, blood indicators, harmful gas emissions in feces and microbiota. Three hundred and sixty 1-day-old AA+ male broilers with an average initial body weight (data) were randomly divided into 3 dietary treatments of 6 replicates each, with 20 birds per replicate. The control group (T0) was fed a basal diet, while the test groups (T1 and T2) were supplemented with 0.025 and 0.05% PC in the basal diet, respectively. The trail was 42 days. The results showed that the supplementation of 0.05% PC significantly (p < 0.05) improved average daily gain (ADG) and average daily feed intake (ADFI) of broilers from 22 to 42 days and 1-42 days. Compared to the control group, the breast rate was significantly higher in T2, and the thymic index was significantly higher than that in T1 treatment (p < 0.05). The addition of PC had no significant effects on antibody potency in broiler serum (p > 0.05), but significantly increased albumin and total protein content in serum (p < 0.05). The addition of PC reduced H₂S and NH₃ emissions in the feces; the levels of Escherichia coli and Salmonella in the feces were significantly reduced and the levels of Lactobacillus were increased. And the most significant results were achieved when PC was added at 0.05%. Correlation analysis showed a significant positive correlation (p < 0.05) between the levels of E. coli and Salmonella and the emissions of H₂S and NH₃. Conclusion: Dietary supplementation with a 0.05% probiotic complex could improve the growth performance of broilers and also reduced fecal H₂S and NH₃ emissions, as well as fecal levels of E. coli and Salmonella, and increased levels of Lactobacillus. Thus, PC made by Bacillus subtilis, Clostridium butyricum and Enterococcus faecalis is expected to be an alternative to antibiotics. And based on the results of this trial, the recommended dose for use in on-farm production was 0.05%.

Probiotics in Poultry Nutrition as a Natural Alternative for Antibiotics

Since the early 1950s, antibiotics have been used in poultry for improving feed efficiency and growth performance. Nevertheless, various side effects have appeared, such as antibiotic resistance, antibiotic residues in eggs and meat, and imbalance of beneficial intestinal bacteria. Consequently, it is essential to find other alternatives that include probiotics that improve poultry production. Probiotics are live microorganisms administered in adequate doses and improve host health. Probiotics are available to be used as feed additives, increasing the availability of the nutrients for enhanced growth by digesting the feed properly. Immunity and meat and egg quality can be improved by supplementation of probiotics in poultry feed. Furthermore, the major reason for using probiotics as feed additives is that they can compete with various infectious diseases causing pathogens in poultry's gastrointestinal tract. Hence, this chapter focuses on the types and mechanisms of action of probiotics and their benefits, by feed supplementation, for poultry health and production.

Modulatory effect of dietary probiotic and prebiotic supplementation on growth, immuno-biochemical alterations, DNA damage, and pathological changes in E. coli-infected broiler chicks

Avian pathogenic Escherichia coli is one of the principal causes of heavy economic losses to the poultry industry. Little is known about the underlying mechanisms, particularly the potential role of immunoglobulin A and the DNA damage, involving the beneficial effects of dietary supplementation of probiotics and prebiotics in avian colibacillosis. The current study investigated the potential effects of probiotic and prebiotic dietary supplementation on E. coli-infected broiler chicks. A total of 120 1-day-old unsexed Hubbard chicks were divided into six groups: Group 1 was considered as a negative control; Group 2 was supplemented with 1 g/kg feed of Lactobacillus plantarum; Group 3 was supplemented with amylase enzyme; Group 4 served as a positive control infected orally by E. coli O78; Group 5 was supplemented with L. plantarum from 1-day-old chicken and then infected orally with E. coli O78; and Group 6 was supplemented with amylase enzyme from 1-day old chicken and then infected orally with E. coli O78. For all examined groups, the experimental period lasted for 42 days. The E. coli-infected group revealed a decrease in body performance parameters with a significant increase in the liver enzymes and renal function tests. The same group recorded a significant decrease in serum total proteins, albumins, and globulins, and the alteration of immunological parameters, antioxidant enzymes, oxidative stress parameters, and comet assay revealed highly damaged DNA in the liver and the intestine. By histopathological examination, a series of histopathological changes in the liver, the kidney, and the intestine were observed. The infected chick pretreated with probiotics or prebiotics demonstrated an improvement in body performance parameters besides a significant decrease in the hepatic enzymes and renal function tests. We noticed that, in treated groups, there was a significant increase in serum total proteins in the serum albumin and globulin levels, immunological parameters, and antioxidant enzymes. Furthermore, DNA damage and histopathological changes within hepatic, renal, and intestinal tissues were markedly diminished in the treated groups compared with the infected group. We concluded that the adverse effects of E. coli could be modulated through the chemopreventive administration of probiotics and prebiotics.

Pretreatment with probiotics Enterococcus faecium NCIMB 11181 attenuated Salmonella Typhimurium-induced gut injury through modulating intestinal microbiome and immune responses with barrier function in broiler chickens

Background

Preventing Salmonella infection and colonization in young birds is key to improving poultry gut health and reducing Salmonella contamination of poultry products and decreasing salmonellosis for human consumption (poultry meat and eggs). Probiotics can improve poultry health. The present study was conducted to investigate the impact of a probiotics, Enterococcus faecium NCIMB 11181 (E. faecium NCIMB 11181) on the intestinal mucosal immune responses, microbiome and barrier function in the presence or absence of Salmonella Typhimurium (S. Typhimurium, ST) infection.

Methods

Two hundred and forty 1-day-old Salmonella-free male broiler chickens (Arbor Acres AA⁺) were randomly allocated to four groups with 6 replicate cages of 10 birds each. The four experimental groups were follows: (1) negative control (NC), (2) S. Typhimurium, challenged positive control (PC), (3) the E. faecium NCIMB 11181-treated group (EF), (4) the E. faecium NCIMB 11181-treated and S. Typhimurium-challenged group (PEF).

Results

Results indicated that, although continuous feeding E. faecium NCIMB 11181 did not obviously alleviate growth depression caused by S. Typhimurium challenge (P > 0.05), E. faecium NCIMB 11181 addition significantly blocked Salmonella intestinal colonization and translocation (P < 0.05). Moreover, supplemental E. faecium NCIMB 11181 to the infected chickens remarkably attenuated gut morphological structure damage and intestinal cell apoptosis induced by S. Typhimurium infection, as evidenced by increasing gut villous height and reducing intestinal TUNEL-positive cell numbers (P < 0.05). Also, E. faecium NCIMB 11181 administration notably promoting the production of anti-Salmonella antibodies in intestinal mucosa and serum of the infected birds (P < 0.05). Additionally, 16S rRNA sequencing analysis revealed that E. faecium NCIMB 11181 supplementation ameliorated S. Typhimurium infection-induced gut microbial dysbiosis by enriching Lachnospiracease and Alistipes levels, and suppressing Barnesiella abundance. Predicted function analysis indicated that the functional genes of cecal microbiome involved in C5-branched dibasic acid metabolism; valine, leucine and isoleucine biosynthesis; glycerolipid metabolism and lysine biosynthesis were enriched in the infected chickens given E. faecium NCIMB 11181. While alanine, asparate and glutamate metabolism; MAPK signal pathway-yeast; ubiquine and other terpenoid-quinore biosynthesis, protein processing in endoplasmic reticulum; as well as glutathione metabolism were suppressed by E. faecium NCIMB 11181 addition.

Conclusion

Collectively, our data suggested that dietary E. faecium NCIBM 11181 supplementation could ameliorate S. Typhimurium infection-induced gut injury in broiler chickens. Our findings also suggest that E. faecium NCIMB 11181 may serve as an effective non-antibiotic feed additive for improving gut health and controlling Salmonella infection in broiler chickens.

Effects of Compound Mycotoxin Detoxifier on Alleviating Aflatoxin B1-Induced Inflammatory Responses in Intestine, Liver and Kidney of Broilers

In order to alleviate the toxic effects of aflatoxins B1 (AFB1) on inflammatory responses in the intestine, liver, and kidney of broilers, the aflatoxin B1-degrading enzyme, montmorillonite, and compound probiotics were selected and combined to make a triple-action compound mycotoxin detoxifier (CMD). The feeding experiment was divided into two stages. In the early feeding stage (1−21 day), a total of 200 one-day-old Ross broilers were randomly divided into four groups; in the later feeding stage (22−42 day), 160 broilers aged at 22 days were assigned to four groups: Group A: basal diet (4.31 μg/kg AFB1); Group B: basal diet with 40 μg/kg AFB1; Group C: Group A plus 1.5 g/kg CMD; Group D: Group B plus 1.5 g/kg CMD. After the feeding experiment, the intestine, liver, and kidney tissues of the broilers were selected to investigate the molecular mechanism for CMD to alleviate the tissue damages. Analyses of mRNA abundances and western blotting (WB) of inflammatory factors, as well as immunohistochemical (IHC) staining of intestine, liver, and kidney tissues showed that AFB1 aggravated the inflammatory responses through NF-κB and TN-α signaling pathways via TLR pattern receptors, while the addition of CMD significantly inhibited the inflammatory responses. Phylogenetic investigation showed that AFB1 significantly increased interleukin-1 receptor-associated kinase (IRAK-1) and mitogen-activated protein kinase (MAPK) activities (p < 0.05), which were restored to normal levels by CMD addition, indicating that CMD could alleviate cell inflammatory damages induced by AFB1.

Salmonella Phages Affect the Intestinal Barrier in Chicks by Altering the Composition of Early Intestinal Flora: Association With Time of Phage Use

Phages show promise in replacing antibiotics to treat or prevent bacterial diseases in the chicken breeding industry. Chicks are easily affected by their environment during early growth. Thus, this study investigated whether oral phages could affect the intestinal barrier function of chicks with a focus on the cecal microbiome. In a two-week trial, forty one-day-old hens were randomly divided into four groups: (1) NC, negative control; (2) Phage 1, 10⁹ PFU phage/day (days 3–5); (3) Phage 2, 10⁹ PFU phage/day (days 8–10); and (4) AMX, 1 mg/mL amoxicillin/day (days 8–10). High-throughput sequencing results of cecal contents showed that oral administration of phages significantly affected microbial community structure and community composition, and increased the relative abundance of Enterococcus. The number of different species in the Phage 1 group was much higher than that in the Phage 2 group, and differences in alpha and beta diversity also indicated that the magnitude of changes in the composition of the cecal microbiota correlated with the time of phage use. Particularly in the first stage of cecal microbiota development, oral administration of bacteriophages targeting Salmonella may cause substantial changes in chicks, as evidenced by the results of the PICRUSt2 software function prediction, reminding us to be cautious about the time of phage use in chicks and to avoid high oral doses of phages during the first stage. Additionally, the Phage 2 samples not only showed a significant increase in the relative abundance of Bifidobacterium and Subdoligranulum, but also improved the intestinal morphology (jejunum) and increased the mRNA expression level of occludin and ZO-1. We concluded that phages do not directly interact with eukaryotic cells. The enhancement of intestinal barrier function by phages in chicks may be related to changes in the intestinal flora induced by phages. This implies that phages may affect intestinal health by regulating the intestinal flora. This study provides new ideas for phage prevention of intestinal bacterial infections and promotes large-scale application of phages in the poultry industry.

Effect of Dietary Zinc Methionine Supplementation on Growth Performance, Immune Function and Intestinal Health of Cherry Valley Ducks Challenged With Avian Pathogenic Escherichia coli

This study was carried out to evaluate the effects of supplemental zinc methionine (Zn-Met) on growth performance, immune function, and intestinal health of meat ducks challenged with avian pathogenic Escherichia coli (APEC). A total of 480 1-day-old Cherry Valley male ducks were randomly assigned to 8 treatments with 10 replicates, each replicate containing 10 ducks. A 4 × 2 factor design was used with four dietary zinc levels (0, 30, 60, 120 mg Zn/kg in the form Zn-Met was added to the corn-soybean basal diet) and challenged with or without APEC at 8-days-old ducks. The trial lasted for 14 days. The results showed that a dietary Zn-Met supplementation significantly increased body weight (BW) of 14 days and BW gain, and decreased mortality during 7-14-days-old ducks (p < 0.05). Furthermore, dietary 30, 60, 120 mg/kg Zn-Met supplementation noticeably increased the thymus index at 2 days post-infection (2 DPI) and 8 DPI (p < 0.05), and 120 mg/kg Zn-Met enhanced the serum IgA at 2 DPI and IgA, IgG, IgM, C3 at 8 DPI (p < 0.05). In addition, dietary 120 mg/kg Zn-Met supplementation dramatically increased villus height and villus height/crypt depth (V/C) of jejunum at 2 DPI and 8 DPI (p < 0.05). The TNF-α and IFN-γ mRNA expression were downregulated after supplemented with 120 mg/kg Zn-Met in jejunum at 8 DPI (p < 0.05). Moreover, dietary 120 mg/kg Zn-Met supplementation stimulated ZO-3, OCLN mRNA expression at 2 DPI and ZO-2 mRNA expression in jejunum at 8 DPI (p < 0.05), and improved the MUC2 concentration in jejunum at 2 DPI and 8 DPI (p < 0.05). At the same time, the cecal Bifidobacterium and Lactobacillus counts were increased (p < 0.05), and Escherichia coli counts were decreased (p < 0.05) after supplemented with Zn-Met. In conclusion, inclusion of 120 mg/kg Zn-Met minimizes the adverse effects of APEC challenge on meat ducks by improving growth performance and enhancing immune function and intestinal health.

Intestinal Mucosal Immunity-Mediated Modulation of the Gut Microbiome by Oral Delivery of Enterococcus faecium Against Salmonella Enteritidis Pathogenesis in a Laying Hen Model

Enterococcus faecium (E. faecium) is a protective role that has crucial beneficial functions on intestinal homeostasis. This study aimed to investigate the effects of E. faecium on the laying performance, egg quality, host metabolism, intestinal mucosal immunity, and gut microbiota of laying hens under the Salmonella Enteritidis (S. Enteritidis) challenge. A total of 400 45-week-old laying hens were randomly divided into four treatments (CON, EF, SCON, and SEF groups) with five replicates for each group and 20 hens per replicate and fed with a basal diet or a basal diet supplemented with E. faecium (2.5 × 10⁸ cfu/g feed). The experiment comprised two phases, consisting of the pre-salmonella challenged phase (from day 14 to day 21) and the post-salmonella challenged phase (from day 21 to day 42). At day 21 and day 22, the hens in SCON and SEF groups were orally challenged with 1.0 ml suspension of 10⁹ cfu/ml S. Enteritidis (CVCC3377) daily, whereas the hens in CON and EF groups received the same volume of sterile PBS. Herein, our results showed that E. faecium administration significantly improved egg production and shell thickness during salmonella infection. Also, E. faecium affected host lipid metabolism parameters via downregulating the concentration of serum triglycerides, inhibited oxidative stress, and enhanced immune functions by downregulating the level of serum malondialdehyde and upregulating the level of serum immunoglobulin G. Of note, E. faecium supplementation dramatically alleviated intestinal villi structure injury and crypt atrophy, and improved intestinal mucosal barrier injuries caused by S. Enteritidis challenge. Moreover, our data revealed that E. faecium supplementation ameliorated S. Enteritidis infection-induced gut microbial dysbiosis by altering the gut microbial composition (reducing Bacteroides, Desulfovibrio, Synergistes, and Sutterella, and increasing Barnesiella, Butyricimonas, Bilophila, and Candidatus_Soleaferrea), and modulating the gut microbial function, such as cysteine and methionine metabolism, pyruvate metabolism, fatty acid metabolism, tryptophan metabolism, salmonella infection, and the PI3K-Akt signaling pathway. Taken together, E. faecium has a strong capacity to inhibit the S. Enteritidis colonization of hens. The results highlight the potential of E. faecium supplementation as a dietary supplement to combat S. Enteritidis infection in animal production and to promote food safety.

Probiotics: Symbiotic Relationship with the Animal Host

Simple Summary

Intestinal health directly influences the profitability of animal production, and so growth-promoting antibiotics have been used in the feed or drinking water to reduce the impact of enteric diseases and improve production parameters. However, these have generated long-term bacterial resistance. In the search for natural alternatives to antibiotics, various probiotic strains have been developed to improve intestinal health and biological indicators in farm animals, which is important to provide the consumer with safe food. This review describes the main probiotic bacteria and yeasts, their in vitro properties and their impact on the antioxidant capacity and intestinal environment of animals. Furthermore, this review outlines the role of probiotics in apparently healthy ruminants, pigs and poultry, including animals with digestive diseases.

Abstract

Antibiotic growth-promoters in animal feeding are known to generate bacterial resistance on commercial farms and have proven deleterious effects on human health. This review addresses the effects of probiotics and their symbiotic relationship with the animal host as a viable alternative for producing healthy meat, eggs, and milk at present and in the future. Probiotics can tolerate the conditions of the gastrointestinal tract, such as the gastric acid, pH and bile salts, to exert beneficial effects on the host. They (probiotics) may also have a beneficial effect on productivity, health and wellbeing in different parameters of animal performance. Probiotics stimulate the native microbiota (microbes that are present in their place of origin) and production of short-chain fatty acids, with proven effects such as antimicrobial, hypocholesterolemic and immunomodulatory effects, resulting in better intestinal health, nutrient absorption capacity and productive responses in ruminant and non-ruminant animals. These beneficial effects of probiotics are specific to each microbial strain; therefore, the isolation and identification of beneficial microorganisms, as well as in vitro and in vivo testing in different categories of farm animals, will guarantee their efficacy, replicability and sustainability in the current production systems.

Progress in Alternative Strategies to Combat Antimicrobial Resistance: Focus on Antibiotics

Antibiotic resistance, and, in a broader perspective, antimicrobial resistance (AMR), continues to evolve and spread beyond all boundaries. As a result, infectious diseases have become more challenging or even impossible to treat, leading to an increase in morbidity and mortality. Despite the failure of conventional, traditional antimicrobial therapy, in the past two decades, no novel class of antibiotics has been introduced. Consequently, several novel alternative strategies to combat these (multi-) drug-resistant infectious microorganisms have been identified. The purpose of this review is to gather and consider the strategies that are being applied or proposed as potential alternatives to traditional antibiotics. These strategies include combination therapy, techniques that target the enzymes or proteins responsible for antimicrobial resistance, resistant bacteria, drug delivery systems, physicochemical methods, and unconventional techniques, including the CRISPR-Cas system. These alternative strategies may have the potential to change the treatment of multi-drug-resistant pathogens in human clinical settings.

Novel mono- and multi-strain probiotics supplementation modulates growth, intestinal microflora composition and haemato-biochemical parameters in broiler chickens

Background

The reduction of antimicrobial usage in food‐producing animals necessitates the intense search for novel alternatives, including new probiotic strains with more effective properties in improving growth performance and curtailing diseases in animals.

Objective

This study evaluated the effects of novel mono‐ and multi‐strain probiotics on the growth performance, intestinal microbiota and haemato‐biochemical parameters of broilers.

Methods

A total of 160 one‐day‐old Cobb 500 broilers were divided into eight treatment groups with two replicates consisting of (1) basal diet (negative control), (2) basal diet with antibiotic, colistin sulphate, (3) basal diet with commercial probiotic, PROMAX® (positive control), (4) basal diet with Pediococcus acidilactici I5, (5) basal diet with P. pentosaceus I13, (6) basal diet with Enterococcus faecium C14, (7) basal diet with Lactobacillus plantarum C16 and (8) basal diet with the combination of all the four probiotic strains. Birds were kept for 35 days and through oral gavage, 1 ml of 108 study probiotic strains administered on days 3–6, 14 and 18.

Results

Supplementation with P. pentosaceus I13, L. plantarum C16 or multi‐strain probiotics significantly (p < 0.05) improved the body weight gain and feed conversion ratio with decrease in feed intake and intestinal Enterobacteria counts. There was a significant (p < 0.05) increase in haemoglobin, mean corpuscular volume, total white blood cells, platelets counts and a lowered (p < 0.05) total cholesterol and glucose levels in multi‐strains probiotic supplemented birds.

Conclusion

The supplementation with novel multi‐strain probiotics improved growth, intestinal health and haemato‐biochemical parameters in broilers and could be used as suitable antibiotic alternatives.

Isolation and probiotic potential of lactic acid bacteria from swine feces for feed additive composition

Animal microbiota is becoming an object of interest as a source of beneficial bacteria for commercial use. Moreover, the escalating problem of bacterial resistance to antibiotics is threatening animals and humans; therefore, in the last decade intensive search for alternative antimicrobials has been observed. In this study, lactic acid bacteria (LAB) were isolated from suckling and weaned pigs feces (376) and characterized to determine their functional properties and usability as pigs additives. Selection of the most promising LAB was made after each stage of research. Isolates were tested for their antimicrobial activity (376) and susceptibility to antibiotics (71). Selected LAB isolates (41) were tested for the production of organic acids, enzymatic activity, cell surface hydrophobicity and survival in gastrointestinal tract. Isolates selected for feed additive (5) were identified by MALDI-TOF mass spectrometry and partial sequence analysis of 16S rRNA gene, represented by Lentilactobacillus, Lacticaseibacillus (both previously classified as Lactobacillus) and Pediococcus genus. Feed additive prototype demonstrated high viability after lyophilization and during storage at 4 °C and − 20 °C for 30 days. Finally, feed additive was tested for survival in simulated alimentary tract of pigs, showing viability at the sufficient level to colonize the host. Studies are focused on obtaining beneficial strains of LAB with probiotic properties for pigs feed additive.

Lactobacillus reuteri and Enterococcus faecium from Poultry Gut Reduce Mucin Adhesion and Biofilm Formation of Cephalosporin and Fluoroquinolone-Resistant Salmonella enterica

Non-typhoidal Salmonella (NTS) can cause infection in poultry, livestock, and humans. Although the use of antimicrobials as feed additives is prohibited, the previous indiscriminate use and poor regulatory oversight in some parts of the world have resulted in increased bacterial resistance to antimicrobials, including cephalosporins and fluoroquinolones, which are among the limited treatment options available against NTS. This study aimed to isolate potential probiotic lactic acid bacteria (LAB) strains from the poultry gut to inhibit fluoroquinolone and cephalosporin resistant MDR Salmonella Typhimurium and S. Enteritidis. The safety profile of the LAB isolates was evaluated for the hemolytic activity, DNase activity, and antibiotic resistance. Based on the safety results, three possible probiotic LAB candidates for in vitro Salmonella control were chosen. Candidate LAB isolates were identified by 16S rDNA sequencing as Lactobacillus reuteri PFS4, Enterococcus faecium PFS13, and Enterococcus faecium PFS14. These strains demonstrated a good tolerance to gastrointestinal-related stresses, including gastric acid, bile, lysozyme, and phenol. In addition, the isolates that were able to auto aggregate had the ability to co-aggregate with MDR S. Typhimurium and S. Enteritidis. Furthermore, LAB strains competitively reduced the adhesion of pathogens to porcine mucin Type III in co-culture studies. The probiotic combination of the selected LAB isolates inhibited the biofilm formation of S. Typhimurium FML15 and S. Enteritidis FML18 by 90% and 92%, respectively. In addition, the cell-free supernatant (CFS) of the LAB culture significantly reduced the growth of Salmonella in vitro. Thus, L. reuteri PFS4, E. faecium PFS13, and E. faecium PFS 14 are potential probiotics that could be used to control MDR S. Typhimurium and S. Enteritidis in poultry. Future investigations are required to elucidate the in vivo potential of these probiotic candidates as Salmonella control agents in poultry and animal feed.

Dietary supplementation of Bacillus-based probiotics on the growth performance, gut morphology, intestinal microbiota and immune response in low biosecurity broiler chickens

A feeding trial was conducted to evaluate the effects of Bacillus-based probiotics on growth performance, intestinal histo-morphology, gut microbial population and immune response in broilers. A total of 2000 Hubbard Classic day-old chicks were randomly enrolled in four experimental groups and 4 replicates of 500 birds in each group, and reared for 35 days under a low- level of biosecurity measures. The trial groups were assigned treatment-1 (T1): basal diet(control), treatment-2 (T2): basal diet plus Bacillus licheniformis (DSM17236), treatment-3 (T3): basal diet plus Bacillus subtilis (PB6), and treatment-4 (T4) basal diet plus 4% Flavomycin. All four groups were fed with maize-soybean based prepared feeds (starter, grower and finisher). Dietary inclusion of B. licheniformis significantly improved body weight gain and lessened FCR in T2 compared to other groups (p < 0.05). Probiotics increased the population of Bacillus spp. and decreased the population of Clostrium perfringens, Salmonella spp. and Escherichia coli in the jejunum and ileum in broiler birds on day 21 and 35 (p < 0.05). The highest antibody production was observed in B. licheniformis treated group (T2) compared to other probiotic treated group (T1). Taken together, the study findings suggest that B. licheniformis probiotics could be used as a feasible alternative to antimicrobials in the broiler production considering beneficial impacts at low biosecurity broiler farms.

Lactose Glycation of the Maillard-Type Impairs the Benefits of Caseinate Digest to the Weaned Rats for Intestinal Morphology and Serum Biochemistry

The Maillard reaction between the lactose and milk proteins unavoidably occurs during the thermal treatment of milk. Although the impact of this reaction on protein nutrition and safety has been well-studied, whether a lactose glycation of milk proteins of the Maillard-type might affect the rats in their growth and intestinal morphology needs an investigation. In this study, caseinate and lactose-glycated caseinate were digested using pepsin and trypsin. Afterward, the resultant caseinate digest and glycated caseinate digest (lactose content of 13.5 g/kg of protein) at 100, 200, and 400 mg/kg body weight (BW)/d were assessed for their effects on the female weaned Wistar rats in terms of daily body weight gain, intestinal morphology, digestive and brush-border enzyme activities, as well as serum chemical indices. The results showed that glycated caseinate digest always showed a weaker effect on rat than caseinate digest either at the 0-7 or 0-28 d feeding stage, and more importantly, at the highest dose of 400 mg/kg BW/d, it caused obvious adverse effect on the rats, reflected by lower values of these indices. Compared with caseinate digest, glycated caseinate digest in the rats caused 0.9-15.4% and 10.6-49.7% decreases in average daily gain of BW and small intestinal length, 1.1-21.5% and 2.3-33.3% decreases in villus height and the ratio of villus height to crypt depth of the small intestine, or 0.3-57.6% and 0.2-55.7% decreases in digestive and critical brush-border enzyme activities, respectively. In addition, when the rats were fed with glycated caseinate digest, some serum indices related to oxidative stress status were enhanced dose-dependently. Lactose glycation of the Maillard-type is thus considered as a negative event of the Maillard reaction on milk proteins because this reaction might impair protein benefits to the body.

Effect of a Potential Probiotic Candidate Enterococcus faecalis-1 on Growth Performance, Intestinal Microbiota, and Immune Response of Commercial Broiler Chickens

The probiotic effect of Enterococcus faecalis-1 (isolated from healthy chickens) on growth performance, immune response, and modulation of the intestinal microbiota of broilers was assessed with a total of 100-day-old commercial Cobb chicks. The chicks were randomly divided into two equal groups. The control group received a basal diet, while the test group received a basal diet and was orally supplied with E. faecalis at a dose of 10⁸ CFU/bird/day. Results showed that E. faecalis-1 supplement significantly (P < 0.05) improved the body weight and feed conversion ratio of treated broilers compared with the control ones. The mortality percentage was reduced in E. faecalis-1-supplemented group. The total IgY serum level was significantly (P < 0.05) increased in broilers receiving E. faecalis-1 supplement (7.1 ± 0.39) compared with the control group (5.8 ± 0.3), while the serum avidin level was significantly (P < 0.05) decreased in E. faecalis-1-supplemented broilers (76 ± 11.1). There was no significant change in the immune response towards avian influenza and Newcastle vaccines in both groups. The total Lactobacillus and Enterococcus counts were significantly (P < 0.05) higher in the cecal contents of broilers given E. faecalis-1 than those that received the control treatment. E. faecalis-1 supplement enhanced the enzyme activities, antioxidant system, and liver functions of treated broilers compared with those in the control group. Collectively, these results showed that E. faecalis-1 could promote growth performance and immunological status and convey beneficial modulation of the cecal microbiota in broilers.

Effects of the Probiotic Candidate E. faecalis-1, the Poulvac E. coli Vaccine, and their Combination on Growth Performance, Caecal Microbial Composition, Immune Response, and Protection against E. coli O78 Challenge in Broiler Chickens

The present study was performed on 180-day-old commercial Cobb chicks to assess the effects of the probiotic candidate Enterococcus faecalis-1, the Poulvac Escherichia coli vaccine, and their combination on growth parameters, intestinal microbial composition, immune response, and protection against challenge with the avian pathogen E. coli O78. The experimental groups were as follows: G1, basal diet; G2, basal diet and challenge with O78 at 28 days of growth; G3, basal diet, vaccination with Poulvac (1 and 15 days), and challenge with O78 at 28 days of growth; G4, basal diet, E. faecalis-1 supplementation for the first 3 days of growth, and challenge with O78 at 28 days of growth; G5, basal diet, E. faecalis-1 supplementation for the first 3 days of growth, vaccination with Poulvac (1 and 15 days), and challenge with O78 at 28 days of growth; G6, basal diet and E. faecalis-1 supplementation for the first 3 days of growth. The results showed that E. faecalis-1 in drinking water significantly improved the growth performance and immune response, increased the total Enterococcus counts, reduced the mortality, and decreased the visceral invasion by O78 in challenged broilers. While the effect of the Poulvac vaccine alone or with E. faecalis-1 was not significant compared with that of the E. faecalis-1 supplement, the vaccine improved the growth rate and decreased the mortality and visceral invasion by APEC O78 in challenged broilers. These results showed that E. faecalis-1 supplementation and routine vaccination with the Poulvac vaccine could improve the growth performance and immune response of broiler chickens and protect against challenge with APEC O78.

Probiotics-Live Biotherapeutics: a Story of Success, Limitations, and Future Prospects-Not Only for Humans

In livestock production, lactic acid bacteria (LAB) represent the most widespread microorganisms used as probiotics. For such critical use, these bacteria must be correctly identified and characterized to ensure their safety and efficiency. Recently, probiotics have become highly recognized as supplements for humans and in particular for animals because of their beneficial outcome on health improvement and well-being maintenance. Various factors, encompassing dietary and management constraints, have been demonstrated to tremendously influence the structure, composition, and activities of gut microbial communities in farm animals. Previous investigations reported the potential of probiotics in animal diets and nutrition. But a high rate of inconsistency in the efficiency of probiotics has been reported. This may be due, in a major part, to the dynamics of the gastrointestinal microbial communities. Under stressing surroundings, the direct-fed microbials may play a key role as the salient limiting factor of the severity of the dysbiosis caused by disruption of the normal intestinal balance. Probiotics are live microorganisms, which confer health benefits on the host by positively modifying the intestinal microflora. Thus, the aim of this review is to summarize and to highlight the positive influence of probiotics and potential probiotic microbe supplementation in animal feed with mention of several limitations.

Effect of the use of probiotic Bacillus subtilis (QST 713) as a growth promoter in broilers: an alternative to bacitracin methylene disalicylate

The global poultry trend toward the more responsible use of antibiotics is becoming recurrent and has demanded the need to generate new natural alternatives. Probiotics have gained importance as an option to use as growth promoters. This study aimed to evaluate Bacillus subtillis QST713 as a substitute for an antibiotic growth promoter (BMD). A total of 150 male broilers were assigned to three dietary treatments: 1) control diet (CO), 2) control diet + 500 g/t of BMD (AGP), and 3) control diet + 100 g/t of B. subtilis QST713 (PB), respectively. Each treatment was monitored for 5 wk for the productive variables: body weight, accumulated feed consumption, food conversion, and European efficiency factor. At the end of each week, fresh fecal samples were cultured and quantified for E. coli, Enterococcus spp., and Lactobacillus spp. At the end of the trial, blood samples were analyzed for hemogram and intestinal samples (anterior portion) for histomorphometry. The data were statistically analyzed with an analysis of variance and subjected to a least significant difference test (Tukey). The zootechnical yields were similar in the AGP and PB groups (P ˃ 0.05); both superior to the control group. In the hematological profiles, no difference was observed between the experimental groups. E. coli and Enterococcus counts were significantly lower (P ˂ 0.05), and Lactobacillus counts were significantly (P ˂ 0.05) higher in the PB group, relative to CO and AGP groups. No differences (P ˃ 0.05) were found in bacterial counts between the CO and AGP groups. The intestinal mucosa and villi in the PB group were significantly (P ˂ 0.05) longer and with less deeper crypts than CO and AGP groups. We conclude that B. subtillis QST713, used at the suggested commercial dose (100 g/ton), is an effective growth-promoting alternative to BMD that modulates the microbiota and intestinal architecture, thus producing zootechnical yields consistent with BMD.

Probiotics and gut health: linking gut homeostasis and poultry productivity

The use of probiotics in poultry production has increased rapidly, and this movement has been promoted by global events, such as the prohibition or decline in the use of antibiotic growth promotants in poultry feeds. There has been a persistent search for alternative feed additives, and probiotics have shown that they can restore the composition of the gut microbiota, and produce health benefits to the host, including improvements in performance. Probiotics have shown potential to increase productivity in poultry, especially in flocks challenged by stressors. However, the outcomes of probiotic use have not always been consistent. There is an increasing demand for well defined products that can be applied strategically, and currently, probiotic research is focusing on delineating their mechanisms of action in the gut that contribute to an improved efficacy. In particular, mechanisms involved in the maintenance and protection of intestinal barrier integrity and the role of the gut microbiota are being extensively investigated. It has been shown that probiotics modulate intestinal immune pathways both directly and through interactions with the gut microbiota. These interactions are key to maintaining gut homeostasis and function, and improving feed efficiency. Research has demonstrated that probiotics execute their effects through multiple mechanisms. The present review describes recent advances in probiotic use in poultry. It focuses on the current understanding of gut homeostasis and gut health in chickens, and how it can be assessed and improved through supplementation of poultry diets with probiotics in poultry diets. In particular, cellular and molecular mechanisms involved in the maintenance and protection of gut barrier structure and function are described. It also highlights important factors that influence probiotic efficacy and bird performance.

Effects of Enterococcus faecalis administration on the community structure of airborne bacteria in weanling piglet and layer hen houses

Probiotics have been shown to improve microbial compositions in animal intestine and feces, but the effects of probiotic administration on airborne microbial composition in animal houses remain unclear. In this study, we investigated the effects of dietary Enterococcus faecalis on the bacterial community structure in the air of piglet and layer hen houses. Indoor air and feces from piglet and layer hen houses were sampled after supplementing E. faecalis in feed for 60 days, and bacterial community structures were analyzed using Illumina high-throughput sequencing technology. Results showed that Chao1, ACE, Shannon, and Simpson indices of bacterial diversity did not significantly change in feces or indoor air of piglet or layer hen after supplementation with E. faecalis (P > 0.05). However, E. faecalis administration resulted in a decrease in the relative abundance of Proteobacteria (P < 0.05). In addition, E. faecalis significantly reduced the relative abundance of opportunistic pathogens such as Acinetobacter, Escherichia, and Shigella (P < 0.05), and beneficial bacterial genus such as Lactobacillus was significantly enriched in both feces and indoor air (P < 0.05). These changes should be of benefit to livestock, farm workers, and the surrounding environment.

Effects of Dietary Supplementation of Recombinant Plectasin on Growth Performance, Intestinal Health and Innate Immunity Response in Broilers

The present study was conducted to evaluate the effects of dietary supplementation of recombinant plectasin (Ple) on the growth performance, intestinal health, and serum immune parameters in broilers. A total of 288 1-day-old male broilers (Arbor Acres) were randomly allotted to four dietary treatments including the basal diet (NC) and basal diet supplemented with 10 mg enramycin/kg (PC), 100 mg Ple/kg (LPle), and 200 mg Ple/kg (HPle) diets. The results indicated Ple increased (P < 0.01) average daily gain and decreased (P ≤ 0.02) feed to gain ratio of broilers. In addition, the supplementation of Ple in the diets increased (P ≤ 0.01) duodenal lipase (day 21) and trypsin (day 42) activities compared with the NC group. Similar as the supplementation of enramycin, Ple also increased villus height and decreased crypt depth in jejunum (day 21), and thus the villus height to crypt depth ratio (P < 0.01) was increased compared to the NC group on day 42. The serum immunoglobulin M (days 21 and 42), immunoglobulin G (day 42), complement 3 (day 21), and complement 4 (days 21 and 42) were significantly increased (P ≤ 0.02) due to the supplementation of Ple and enramycin, while the concentration of malondialdehyde in jejunum was decreased (P < 0.01) in PC, LPle, and HPle groups on day 21 compared with those in the NC group. Furthermore, Ple reduced (P < 0.01) Escherichia coli and total aerobic bacteria population in ileum and cecum of birds on days 21 and 42. These results indicate that the recombinant plectasin has beneficial effects on growth performance, intestinal health, and innate immunity in broilers.

Mandated restrictions on the use of medically important antibiotics in broiler chicken production in Canada: implications, emerging challenges, and opportunities for bolstering gastrointestinal function and health– A review

Chicken Farmers of Canada has been progressively phasing out prophylactic use of antibiotics in broiler chicken production. Consequently, hatcheries, veterinarians, and nutritionists have been mandated to contend with less reliance on use of preventive antibiotics. A topical concern is the increased risk of proliferation of enteric pathogens leading to poor performance, increased mortality and compromised welfare. Moreover, the gut harbors several taxa such as Campylobacter and Salmonella capable of causing significant illnesses in humans via contaminated poultry products. This has created opportunity for research and development of dietary strategies designed to modulate gastrointestinal environment for enhanced performance and food safety. Albeit with inconsistent responses, literature data suggests that dietary strategies such as feed enzymes, probiotics/prebiotics and phytogenic feed additives can bolster gut health and function in broiler chickens. However, much of the efficacy data was generated at controlled research settings that vary significantly with the complex commercial broiler production operations due to variation in dietary, health and environmental conditions. This review will summarize implications of mandated restrictions on the preventative use of antibiotics and emerging Canadian broiler production programs to meet processor specifications. Challenges and opportunities for integrating alternative dietary strategies in commercial broiler production settings will be highlighted.

Novel multi-strain probiotics reduces Pasteurella multocida induced fowl cholera mortality in broilers

Pasteurella multocida causes fowl cholera, a highly contagious poultry disease of global concern, causing significant ecological and economic challenges to the poultry industry each year. This study evaluated the effects of novel multi-strain probiotics consisting of Lactobacillus plantarum, L. fermentum, Pediococcus acidilactici, Enterococcus faecium and Saccharomyces cerevisiae on growth performance, intestinal microbiota, haemato-biochemical parameters and anti-inflammatory properties on broilers experimentally challenged with P. multocida. A total of 120 birds were fed with a basal diet supplemented with probiotics (10⁸ CFU/kg) and then orally challenged with 10⁸ CFU/mL of P. multocida. Probiotics supplementation significantly (P < 0.05) improved growth performance and feed efficiency as well as reducing (P < 0.05) the population of intestinal P. multocida, enterobacteria, and mortality. Haemato-biochemical parameters including total cholesterol, white blood cells (WBC), proteins, glucose, packed cell volume (PCV) and lymphocytes improved (P < 0.05) among probiotic fed birds when compared with the controls. Transcriptional profiles of anti-inflammatory genes including hypoxia inducible factor 1 alpha (HIF1A), tumor necrosis factor- (TNF) stimulated gene-6 (TSG-6) and prostaglandin E receptor 2 (PTGER2) in the intestinal mucosa were upregulated (P < 0.05) in probiotics fed birds. The dietary inclusion of the novel multi-strain probiotics improves growth performance, feed efficiency and intestinal health while attenuating inflammatory reaction, clinical signs and mortality associated with P. multocida infection in broilers.

Effect of Lactobacillus Species Probiotics on Growth Performance of Dual-Purpose Chicken

Introduction

In-feed probiotics are becoming attractive alternatives to antibiotics in the poultry industry due to the ever-growing strict prohibitions on antibiotic growth promoters (AGP) in animal production.

Methods

The study was conducted to investigate the effects of Lactobacillus paracaseis sparacasei and Lactobacillus rhamnosus on the growth performance of 120 day-olds randomly selected Sasso dual-purpose chicken. They were divided into four groups with two replicates per group and 15 chicks per replicate. The treatments were T₁ (control), T₂ (supplement diet with 4g probiotic), T₃ (supplement diet with 2g probiotic), T₄ (supplement diet with 1g probiotic). The experimental feeding trials were conducted after two weeks adaptation period.

Results

The present findings revealed that the chickens supplemented with Lactobacillus species probiotics during the first week of age have shown higher body weight than control (p < 0.05). The feed intake of week one of T₂ and T₃ were significantly higher (p< 0.05) than the T₁ (control). However, there was no significant difference (p> 0.05) in feed intake in the 2^nd, 3^rd, 4^th, and 5^{t h} weeks of all treatment groups. The present result showed that there was a significant body weight gain (p< 0.05) in all probiotic fed groups than the control group. The highest body weight gain was observed in chickens found in the T4 treatment group. Whereas the body weight gains significantly higher and improved the feed conversion (p<0.05) in the T₂ and T₄ than the T₁ (control). However, the feed conversion ratio was significantly influenced by probiotic inclusion in T₃ as compared to the control group.

Conclusion

Overall, the results suggest that Lactobacillus paracaseis sparacasei and Lactobacillus rhamnosus have a positive effect on the growth performance of broilers.

The use of probiotics in animal feeding for safe production and as potential alternatives to antibiotics

Although the production of safe food for human consumption is the primary purpose for animal rearing, the environment and well-being of the animals must also be taken into consideration. Based on microbiological point of view, the production of healthy food from animals involves considering foodborne pathogens, on the one hand and on the other hand, the methods used to fight against germs during breeding. The conventional method to control or prevent bacterial infections in farming is the use antibiotics. However, the banning of these compounds as growth promoters caused many changes in animal breeding and their use has since been limited to the treatment and prevention of bacterial infections. In this function, their importance no longer needs to be demonstrated, but unfortunately, their excessive and abusive use have led to a double problem which can have harmful consequences on consumer health: Resistance to antibiotics and the presence of antibiotic residues in food. The use of probiotics appears to be a suitable alternative to overcome these problems because of their ability to modulate the immune system and intestinal microflora, and further considering their antagonistic role against certain pathogenic bacteria and their ability to play the role of growth factor (sometimes associated with prebiotics) when used as feed additives. This review aims to highlight some of the negative effects of the use of antibiotics in animal rearing as well as emphasize the current knowledge on the use of probiotics as a feed additive, their influence on animal production and their potential utility as an alternative to conventional antibiotics, particularly in poultry, pig, and fish farming.

The Protective Effect of E. faecium on S. typhimurium Infection Induced Damage to Intestinal Mucosa

Intensive farming is prone to induce large-scale outbreaks of infectious diseases, with increasing use of antibiotics, which deviate from the demand of organic farming. The high mortality rate of chickens infected with Salmonella caused huge economic losses; therefore, the promising safe prevention and treatment measures of Salmonella are in urgent need, such as probiotics. Probiotics are becoming an ideal alternative treatment option besides antibiotics, but the effective chicken probiotic strains with clear protective mechanism against Salmonella remain unclear. In this study, we found Enterococcus faecium YQH2 was effective in preventing Salmonella typhimurium infection in chickens. Salmonella typhimurium induced the loss of body weight, and liver and intestinal morphology damage. The inflammatory factor levels increased and intestinal proliferation inhibited. However, after treatment with Enterococcus faecium YQH2, broilers grew normally, the pathological changes of liver and intestine were reduced, and the colonization of Salmonella in the intestine was improved. Not only that, the length of villi and the depth of crypts were relatively normal, and the levels of inflammatory factors such as IL-1β, TNF-α, and IL-8 were reduced. The number of PCNA cells of Enterococcus faecium YQH2 returned to normal under the action of Salmonella typhimurium infection, which was conducive to the normal proliferation of intestinal epithelial cells. The protective effect of Enterococcus faecium YQH2 may be due to the attribution to the activation of hypoxia and then induced the proliferation of intestinal stem cells to repair the damage of intestinal mucosa under Salmonella typhimurium infection. This study demonstrated that Enterococcus faecium YQH2 was effective in preventing Salmonella typhimurium infection, which could be further used in the chicken health breeding.

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.

Bacillus subtilis delivery route: effect on growth performance, intestinal morphology, cecal short-chain fatty acid concentration, and cecal microbiota in broiler chickens

As the poultry industry recedes from the use of antibiotic growth promoters, the need to evaluate the efficacy of possible alternatives and the delivery method that maximizes their effectiveness arises. This study aimed at expounding knowledge on the effect of the delivery method of a probiotic product (Bacillus subtilis fermentation extract) on performance and gut parameters in broiler chickens. A total of 450 fertile eggs sourced from Cobb 500 broiler breeders were randomly allotted to 3 groups: in ovo probiotic (n = 66), in ovo saline (n = 66), and noninjection (n = 200) and incubated for 21 d. On day 18.5 of incubation, 200 μL of either probiotic (10 × 10⁶ cfu) or saline was injected into the amnion. At hatch, chicks were reallotted to 6 new treatment groups: in ovo probiotic, in ovo saline, in-feed antibiotics, in-water probiotic, in-feed probiotics, and control (corn-wheat-soybean diet) in 6 replicate cages and raised for 28 d. Of all hatch parameters evaluated, only percentage pipped eggs was found significant (P < 0.05) with the noninjection group having higher percentage pipped eggs than the other groups. Treatments did not affect the incidence of necrotic enteritis on day 28 (P > 0.05). Irrespective of the delivery method, the probiotic treatments had no significant effect on growth performance. The ileum villus width of the in ovo probiotic treatment was 18% higher than the in ovo saline group (P = 0.05) but not statistically higher than other groups. The jejunum villus height was 23% higher (P = 0.000) in the in ovo probiotic group than in the control group. There was no effect of treatment on total cecal short-chain fatty acid concentration and cecal gut microbiota composition and diversity (P > 0.05), although few unique bacteria differential abundance were recorded per treatment. Conclusively, although probiotic treatments (irrespective of the delivery route) did not affect growth performance, in ovo delivery of the probiotic product enhanced intestinal morphology, without compromising hatch performance and gut homeostasis.

In ovo inoculation of an Enterococcus faecium-based product to enhance broiler hatchability, live performance, and intestinal morphology

Previous studies have suggested the use of probiotics, as alternative to antibiotics, to enhance broiler performance. The administration of probiotics in feed has been widely explored; however, few studies have evaluated the in ovo inoculation of probiotics. Therefore, the objective was to evaluate the impact of in ovo inoculation of different concentrations of GalliPro Hatch (GH), an Enterococcus faecium-based probiotic, on hatchability, live performance, and gastrointestinal parameters. Ross x Ross 708 fertile eggs were incubated, and on day 18, injected with the following treatments: 1) 50 μL of Marek's vaccine (MV), 2) MV and 1.4 × 105 cfu GH/50 μL, 3) MV and 1.4 × 106 cfu GH/50 μL, 4) MV and 1.4 × 107 cfu GH/50 μL. On the day of hatch, chicks were weighed, feather sexed, and hatch residue was analyzed. Male birds (640) were randomly assigned to 40 floor pens. On day 0, 7, 14, and 21 of the grow-out phase, performance data were collected. One bird from each pen was used to obtain yolk weight and intestinal segment weight and length. Hatchability was not impacted by any GH treatment (P = 0.58). On day 0, yolk weight was lower for all treatments than for MV alone. On day 0 to 7, feed intake was lower for 105 and 107 GH; the feed conversion ratio (FCR) was lower for all treatments than for MV alone (P = 0.05; P = 0.01, respectively). From day 14 to 21, the 107 GH treatment had higher BW gain (P = 0.05). For day 0 to 21, 107 GH had a lower FCR than MV alone (P = 0.03). On day 0, all GH treatments resulted in heavier tissues and longer jejunum, ileum, and ceca lengths than MV alone (P < 0.05). Spleen weight was higher for 105 and 107 GH than for MV alone. In conclusion, GH does not impact hatchability, and some concentrations improved live performance through the first 21 d of the grow-out phase. These improvements could result from the increased yolk absorption and improved intestinal and spleen morphology seen in this study.

Immediate and transgenerational effects of thymol supplementation, inactivated Salmonella and chronic heat stress on representative immune variables of Japanese quail

Environmental challenges are integrated in the inmunoneuroendocrine interplay, impacting the immune system of the challenged individuals, and potentially implying transgenerational effects on their offspring. This study addressed whether dietary supplementation with thymol can modulate the immune response of adult Japanese quail when simultaneously exposed to an inoculum of inactivated Salmonella Enteritidis and a chronic heat stress (CHS). We also evaluated whether the experienced situations by adults can affect the immune response of their undisturbed offspring. In the parental generation, supplemented quail exposed to CHS had a higher inflammatory response and similar values of the heterophil/lymphocyte (H/L) ratio than those that were not supplemented. In their offspring, those chicks whose parents were exposed to CHS showed higher inflammatory response and lower antibody production. Regarding the H/L ratio, chicks whose parents were supplemented showed lower H/L ratio values. Dietary supplementation with thymol partially and positively modulated the inflammatory response and avoided H/L ratio alteration in the parental generation exposed to high environmental temperatures, suggesting these adults were better at dealing with the challenge. The lower H/L ratio values in the offspring suggests that chicks are more capable to deal with potential stressful situations associated with conventional breeding conditions.

The Current Status of the Alternative Use to Antibiotics in Poultry Production: An African Perspective

Over the years the growth and health of food-producing animals have been enhanced by the use of antibiotics. These have helped reduce on-farm mortalities, lower incidences of diseases and more importantly improve productivity. Generally, the utilization of antibiotics in feed has been reevaluated since bacterial pathogens have established and shared a variety of antibiotic resistance mechanisms that can easily be spread within microbial communities. Multiple countries have introduced bans or severe restrictions on the non-therapeutic use of antibiotics. This has therefore warranted the urgent need for alternatives. Africa is facing its own challenges as it has been reported to be one of the continents with the highest number of foodborne diseases with approximately 91 million related diseases and 137,000 death per annum. Stakeholder and policy direction has been put in place to curb this escalation; however, the problem persists. The use of alternatives has been recommended and some successfully used in other countries as well as Africa, including pro- and prebiotics and phytochemicals. This then leads to the core aim of this review which is to (1) determine the extent to which antimicrobial-resistant pathogens have affected Africa, (2) assess the current measures put in place by Africa to reduces antimicrobial resistance and finally (3) explore the alternative use of antibiotics in poultry production. Improved sanitary conditions and farm biosecurity are important alternatives that could be adopted by farmers instead of depending on antibiotic drugs for disease control and prevention.

Enterococcus faecium Modulates the Gut Microbiota of Broilers and Enhances Phosphorus Absorption and Utilization

Modern broiler chickens have ongoing bone health problems. Phosphorus (P) plays an important role in bone development and increased understanding of P metabolism should improve the skeletal health of broilers. Enterococcus faecium has been widely used as a probiotic in broiler production and is shown to improve skeletal health of rats, but its effect on the bones of broilers remains unclear. This study investigated the effect of E. faecium on P absorption and utilization in broilers and the associated changes in the gut microbiota using 16S rDNA sequencing. Dietary supplementation with E. faecium improved P absorption through upregulation of the expression of intestinal NaP-IIb mRNA and increased the concentration of serum alkaline phosphatase. These actions increased P retention and bone mineralization in E. faecium-treated broilers. The positive effects of E. faecium on P metabolism were associated with changes in the populations of the intestinal microbiota. There was increased relative abundance of the following genera, Alistipes, Eubacterium, Rikenella and Ruminococcaceae and a decrease in the relative abundance of Faecalibacterium and Escherichia-Shigella. Dietary supplementation with E. faecium changed gut microbiota populations of broilers, increased the relative abundance of SCFA (short-chain fatty acid)-producing bacteria, improved intestinal P absorption and bone forming metabolic activities, and decreased P excretion. E. faecium facilitates increased utilisation of P in broilers.

Analysis of the effects of nanosilver on bacterial community in the intestinal fluid of silkworms using high-throughput sequencing

Nanosilver is an environment-friendly, harmless alternative of traditional disinfectants which can be potentially applied in the sericulture industry. However, the effects of nanosilver on the intestinal bacterial community of the silkworms (Bombyx mori L.) are unclear. In this study, Illumina MiSeq high-throughput sequencing technology was used to assess the intestinal bacterial community in both male and female silkworms while treated with different concentrations of nanosilver. We found that nanosilver significantly influenced the composition of silkworm intestinal bacterial community on the different taxonomic levels. Most conspicuously, the abundance of Firmicutes was increased by the treatment of 20 mg L-1 nanosilver but decreased by that of 100 mg L-1 nanosilver at the phylum level. The same trend was observed in Bacilli at the class level and in Enterococcus at the genus level. In some extreme cases, application of nanosilver eliminated the bacterium, e.g., Brevibacillus, but increased the population of several other bacteria in the host intestine, such as Blautia, Terrisporobacter, Faecalibacterium, and some bacteria could only be found in nanosilver treatment groups, e.g., Dialister. In addition, although nanosilver generally showed negative effects on the cocooning rate in a dose-dependent manner, we found that 20 mg L-1 nanosilver treatment significantly increased the body weight of silkworms and did not show negative effects on the survival rate. These results indicated that the intestinal bacteria community of silkworm larvae was significantly changed after nanosilver treatment which might consequently influence host growth and development.

Supplementing neonatal Jersey calves with a blend of probiotic bacteria improves the pathophysiological response to an oral Salmonella enterica serotype Typhimurium challenge

The objectives of the current study were to determine the effects of supplementing a blend of probiotic bacteria (Provida Calf, MB Nutritional Sciences, Lubbock, TX) on the pathophysiological response to an oral Salmonella enterica serotype Typhimurium challenge in neonatal Jersey calves. Twenty-four Jersey bull calves within 24 h of birth were acquired from a local calf ranch, blocked by total serum protein and initial body weight, and randomly assigned to 1 of 3 treatments (n = 8). Calves were assigned to either (1) Control (CON); base milk replacer, (2) Control + Salmonella Typhimurium (CON+ST); base milk replacer and challenged with Salmonella Typhimurium on d 7; or (3) Provida Calf probiotics + Salmonella Typhimurium (PRO+ST); same milk replacer supplemented with a proprietary blend of Lactobacillus casei and Enterococcus faecium strains and challenged with Salmonella Typhimurium on d 7. The PRO+ST calves were supplemented for the first 3 d with 2 × 10¹⁰ cfu/d and then with 2 × 10⁹ cfu/d for the remainder of the study. The CON+ST and PRO+ST calves were each challenged with approximately 5 × 10⁶ cfu of Salmonella Typhimurium (ATCC# 14028), which was a mild challenge that did not cause scours in the calves. Peripheral blood samples were collected on d 0, 7, 10, 14, and 21 and analyzed for hematology; serum was collected and analyzed for haptoglobin, glucose, and urea N. Rectal temperatures were collected daily from d 6 to 21, when all calves were killed, so that persistent colonization of Salmonella Typhimurium and histomorphology of both the duodenum and ileum could be determined. Serum haptoglobin and urea N concentrations were increased among CON+ST on d 10. In contrast, the peak rectal temperature on d 10 in PRO+ST calves was 40.4°C, which was greater than that for CON and CON-ST (38.9°C and 39.7°C, respectively). The neutrophil percentage in peripheral circulation in PRO+ST calves was 55.4%, which was greater than that for CON and CON+ST (34.8 and 41.8%, respectively). Seven of the 8 PRO+ST calves had elevated neutrophil percentages on d 10 compared with d 7, whereas 4 of the 8 CON+ST calves had reduced neutrophil percentages on d 10 compared with d 7. Villus height-to-crypt depth ratios in the duodenum were greater among CON and PRO+ST calves, being 1.38, 0.84, and 1.43 for CON, CON+ST, and PRO+ST, respectively. In the ileum, the PRO+ST calves had greater villus height-to-crypt depth ratios than both the CON and CON+ST calves (1.64, 1.53, and 2.43 for CON, CON+ST, and PRO+ST, respectively). These data indicate that supplementing neonatal calves with the blend of probiotic bacteria used in the current study can influence the pathophysiological response to a mild enteric Salmonella Typhimurium challenge.

Effects of GABA Supplementation on Intestinal SIgA Secretion and Gut Microbiota in the Healthy and ETEC-Infected Weanling Piglets

Pathogenic enterotoxigenic Escherichia coli (ETEC) has been considered a major cause of diarrhea which is a serious public health problem in humans and animals. This study was aimed at examining the effect of γ-aminobutyric acid (GABA) supplementation on intestinal secretory immunoglobulin A (SIgA) secretion and gut microbiota profile in healthy and ETEC-infected weaning piglets. A total of thirty-seven weaning piglets were randomly distributed into two groups fed with the basal diet or supplemented with 40 mg·kg-1 of GABA for three weeks, and some piglets were infected with ETEC at the last week. According to whether ETEC was inoculated or not, the experiment was divided into two stages (referred as CON1 and CON2 and GABA1 and GABA2). The growth performance, organ indices, amino acid levels, and biochemical parameters of serum, intestinal SIgA concentration, gut microbiota composition, and intestinal metabolites were analyzed at the end of each stage. We found that, in both the normal and ETEC-infected piglets, jejunal SIgA secretion and expression of some cytokines, such as IL-4, IL-13, and IL-17, were increased by GABA supplementation. Meanwhile, we observed that some low-abundance microbes, like Enterococcus and Bacteroidetes, were markedly increased in GABA-supplemented groups. KEGG enrichment analysis revealed that the nitrogen metabolism, sphingolipid signaling pathway, sphingolipid metabolism, and microbial metabolism in diverse environments were enriched in the GABA1 group. Further analysis revealed that alterations in microbial metabolism were closely correlated to changes in the abundances of Enterococcus and Bacteroidetes. In conclusion, GABA supplementation can enhance intestinal mucosal immunity by promoting jejunal SIgA secretion, which might be related with the T-cell-dependent pathway and altered gut microbiota structure and metabolism.

Post hatch recovery of a probiotic Enterococcus faecium strain in the yolk sac and intestinal tract of broiler chickens after in ovo injection

Concerns about antibiotic-resistant bacteria and their presence in animal products grow and thus alternatives to use of antibiotics in animal production are being investigated. Probiotics have gained increased focus due to improvements in performance, immune health and pathogen reduction when provided to poultry through feed. These traits may be further improved if probiotics can be provided to the embryo before hatch, before meeting environmental pathogens. The objective was to determine the faith of a probiotic Enterococcus faecium (M74) strain in the yolk sac and intestinal tract of broiler chickens after injection into hatching eggs. E. faecium M74 (1.4 × 107 CFU/egg) was applied in ovo at day 18 of incubation. From 1- and 7-day-old chickens, 20 samples from yolk sac, caecal tonsils and rest of the intestinal tract were subjected to CFU counting. Isolates from a sample subset were typed by pulsed-field gel electrophoresis (PFGE). Enterococci were found in varying numbers: 1.0 × 104-2.2 × 1010 CFU/g. The prevalence of M74 PFGE profiles was high in 1-day-old (88%) and 7-day-old chickens (67%). This demonstrates that the embryos ingested M74 before hatching, that M74 is viable for intestinal colonization through in ovo administration, and that the strain multiplies in the chickens gastrointestinal tract post hatching.

Bioprospecting of probiotics with antimicrobial activities against Salmonella Heidelberg and that produce B-complex vitamins as potential supplements in poultry nutrition

The demand for animal protein for human consumption has been risen exponentially. Modern animal production practices are associated with the regular use of antibiotics, potentially increasing the emerging multi-resistant bacteria, which may have a negative impact on public health. In poultry production, substances capable of maximizing the animals’ performance and displaying an antimicrobial activity against pathogens are very well desirable features. Probiotic can be an efficient solution for such a task. In the present work, lactic acid bacteria (LAB) were isolated from chicken cecum and screened for their antagonistic effect towards many pathogens. Their capacity of producing the B-complex vitamins folate and riboflavin were also evaluated. From 314 isolates, three (C43, C175 and C195) produced Bacteriocin-Like Inhibitory Substances (BLIS) against Staphylococcus aureus (inhibition zones of 18.9, 21.5, 19.5 mm, respectively) and also inhibited the growth of Salmonella Heidelberg. The isolate C43 was identified as Enterococcus faecium, while C173 and C195 were both identified as Lactococcus lactis subsp. lactis. Moreover, the isolates L. lactis subsp. lactis strains C173 and C195 demonstrated high potential to be used as probiotic in poultry feed, in addition to their advantage of producing folate (58.0 and 595.5 ng/mL, respectively) and riboflavin (223.3 and 175.0 ng/mL, respectively).