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Salmonella enteritidis plays a significant role in zoonotic infections. This pathogen settles in the intestinal tract of poultry and contaminates meat and egg products during production for slaughter. Consequently, it can also be transmitted to humans along the food chain, posing a significant risk to public health. Bacteriophages offer a viable substitute for antibiotics in treating Salmonella enteritidis due to their specific bactericidal effect and safety. This study aimed to investigate the protective effect of bacteriophage against Salmonella enteritidis infection in chicken intestinal epithelial cells. Chicken intestinal epithelial cells were treated with various concentrations of bacterial suspension, and the impact on cell damage was assessed by measuring changes in cell viability and observing structural changes via transmission electron microscopy.In the phage protection experiment, the phages were co-incubated with Salmonella enteritidis for 2, 4, and 6 h. Thereafter, the adhesion rate and invasion rate of bacteria and gene transcription levels of Occludin, Claudin-1, ZO-1, NF-κB p65, TNF-α and IL-6 in cells were determined. The results indicated that the phage could significantly reduce both adhesion and invasion rates of Salmonella enteritidis at MOI = 10 (P < 0.05). Following phage treatment of the co-culture of chicken intestinal epithelial cells and Salmonella enteritidis (CICC10467), there was a significant reduction in the gene expression of pro-inflammatory cytokines NF-κB p65, TNF-α and IL-6, and a significant increase in the gene expression of anti-inflammatory cytokines Occludin, Claudin-1, and ZO-1. This indicates that the phage can inhibit the infection of chicken small intestinal epithelial cells by Salmonella enteritidis. Furthermore, phages were able to significantly alleviate inflammation and barrier integrity disruption caused by the bacteria in the co-culture. These observations suggest that phages are promising candidates for preventing and treating gastrointestinal bacterial infections., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Currently, phage biocontrol is increasingly used as a green and natural technology for treating Salmonella and other infections, but phages exhibit instability and activity loss during storage. Therefore, in this study, the effects of lyophilization on the activity and stability of phage cocktails for the control of multidrug-resistant Salmonella in broiler chickens were determined. Eight serotypes of Salmonella were isolated and identified from broiler chicken farms, and bacteriophages against multidrug-resistant Salmonella enterica subsp. enterica serovar Kentucky, Salmonella enterica subsp. enterica serovar Typhimrium and Salmonella enterica subsp. enterica serovar Enteritidis were isolated. The bacteriophage cocktail was prepared and lyophilized, and it was subjected to in vitro and in vivo examinations. A reconstituted lyophilized bacteriophage cocktail was used for the oral treatment of chicks before and after challenge with multidrug-resistant S. Kentucky. The colonization of cecum by S. Kentucky was detected by using real-time PCR, and the serum levels of IgM, IgA and IL-4 and pathological changes in the different groups were detected. Three Caudovirales phages families were identified including Autographiviridae, Straboviridae and Drexlerviridae against multidrug-resistant S. Kentucky, S. Typhimrium and S. Enteritidis. The groups treated with the bacteriophage cocktail showed no clinical signs, no postmortem lesions, and a mortality rate of 0%, which improved the growth performance parameters. Additionally, the estimated serum levels of IgM, IgA and IL-4 were significantly greater in the bacteriophage cocktail-treated groups. Lyophilization effectively preserves the long-term storage stability of phages. Therefore, lyophilized bacteriophage cocktail therapy is a valuable approach for controlling multidrug-resistant Salmonella infections in broiler chickens., (© 2024. The Author(s).)

Phage therapy is gaining momentum as an alternative to antibiotics in the treatment of salmonellosis caused by Salmonella. In this study, a novel Salmonella phage, vB&#95;SalS&#95;JNS02, was isolated successfully from poultry farms in Shandong, China. The biological characteristics of vB&#95;SalS&#95;JNS02 were analysed, which revealed a short latent period of approximately 10 min and a burst size of 110 PFU/cell. Moreover, vB&#95;SalS&#95;JNS02 exhibited remarkable stability across a wide pH range (pH 3-12) and temperatures ranging from 30 to 80°C. Genome sequencing analysis provided valuable insights into the genetic composition of vB&#95;SalS&#95;JNS02, which consists of a double-stranded DNA genome that spans 42,450 base pairs and has a G + C content of 49.4%. Of significant importance, the genomic sequence of vB&#95;SalS&#95;JNS02 did not contain any genes related to lysogenicity, virulence, or antibiotic resistance. The phage's efficacy was evaluated in a larval challenge study. Treatment with the phage resulted in increased survival of Galleria mellonella larvae (100, 70, and 85%) (MOI 0.1) in the prophylactic treatment, co-infection treatment, and remedial treatment experiments, respectively. Another in vivo experiment investigated the potential application of the phage in broiler chickens and revealed that a single oral dose of vB&#95;SalS&#95;JNS02 (10 8 PFU/mL, 100 µL/chick) administered 3 h after S. enteritidis oral administration provided effective protection. The introduction of bacteriophage not only enhances the production of secretory immunoglobulin A (sIgA), but also induces alterations in the composition of the gut microbial community. Phage therapy increases the relative abundance of beneficial bacteria, which helps to maintain intestinal barrier homeostasis. However, it is unable to fully restore the disrupted intestinal microbiome caused by S. enteritidis infection. Importantly, no significant adverse effects were observed in the animal subjects following oral administration of the phage, and our findings highlight vB&#95;SalS&#95;JNS02 is a hopeful candidate as a promising tool to target Salmonella infections in poultry., Competing Interests: DISCLOSURES The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Lulu Li reports financial support was provided by Ministry of Science and Technology of the People's Republic of China. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Feather pecking (FP) is a stress-induced neuropsychological disorder of birds. Intestinal dysbiosis and inflammation are common traits of these disorders. FP is, therefore, proposed to be a behavioral consequence of dysregulated communication between the gut and the brain. Probiotic bacteria are known to favorably modulate the gut microbiome and hence the neurochemical and immune components of the gut-brain axis. Consequently, probiotic supplementation represents a promising new therapeutic to mitigate widespread FP in domestic chickens. We monitored FP, gut microbiota composition, immune markers, and amino acids related to the production of neurochemicals in chickens supplemented with Lactobacillus rhamnosus or a placebo. Data demonstrate that, when stressed, the incidence of FP increased significantly; however, L. rhamnosus prevented this increase. L. rhamnosus supplementation showed a strong immunological effect by increasing the regulatory T cell population of the spleen and the cecal tonsils, in addition to limiting cecal microbiota dysbiosis. Despite minimal changes in aromatic amino acid levels, data suggest that catecholaminergic circuits may be an interesting target for further studies. Overall, our findings provide the first data supporting the use of a single-strain probiotic to reduce stress-induced FP in chickens and promise to improve domestic birds' welfare., (© 2021. The Author(s).)

Campylobacteriosis is the most commonly reported gastrointestinal disease in humans. Campybacter jejuni is the main cause of the infection, and bacterial colonization in broiler chickens is widespread and difficult to prevent, leading to high risk of occurrence in broiler meat. Phage therapy represents an alternative strategy to control Campylobacter in poultry. The aim of this work was to assess the efficacy of two field-isolated bacteriophages against experimental infections with an anti-microbial resistant (AMR) Campylobacter &nbsp; jejuni strain. A two-step phage application was tested according to a specific combination between chickens' rearing time and specific multiplicities of infections (MOIs), in order to reduce the Campylobacter load in the animals at slaughtering and to limit the development of phage-resistant mutants. In particular, 75 broilers were divided into three groups (A, B and C), and phages were administered to animals of groups B and C at day 38 (Φ 16-izsam) and 39 (Φ 7-izsam) at MOI 0.1 (group B) and 1 (group C). All broilers were euthanized at day 40, and Campylobacter &nbsp; jejuni was enumerated in cecal contents. Reductions in Campylobacter counts were statistically significant in both group B (1 log 10 colony forming units (cfu)/gram (gr)) and group C (2 log 10 cfu/gr), compared to the control group. Our findings provide evidence about the ability of phage therapy to reduce the Campylobacter load in poultry before slaughtering, also associated with anti-microbial resistance pattern.

Stimulating the regulation of pests by their natural enemies is a way to improve the sustainability of agriculture and respect for the environment. However, the presence of natural enemies does not guarantee the existence of a pest control service. To what extent are predatory mites commonly found in henhouses actually able to regulate a major egg industry pest mite, Dermanyssus gallinae? To answer this question, we have experimentally recreated portions of a poultry house ecosystem allowing the development of the pest over several generations in the presence of a chick and detritivorous mites (Astigmata) that are ubiquitous and abundant in layer farms. In these conditions, we compared the growth of D. gallinae populations in the presence and absence of native predatory arthropods. No effect of native predators on the growth of the D. gallinae population could be detected despite high initial predator-to-prey ratios and satisfactory growth of predator populations. Prey switching to the alternative prey Astigmata likely dilutes the effect of predation on the target prey. Further exploration is needed to see whether action could be taken to enhance the effect of top-down regulation., (© 2021 Wiley Periodicals LLC.)

The poultry farms need a safe and effective alternative for antibiotics that can counteract the negative impacts of necrotic enteritis (NE), which causes severe mortalities and economic losses. The current study was aimed to examine the influence of antibiotic (Flagymox) and the microbial-based administration on carcass traits in Clostridium (C.) perfringens-infected Cobb and Arbor Acres broilers. A total number of 360 Cobb and Arbor Acres broiler chicks (180 numbers per breed) were allocated to four groups; negative control group (without any treatments); positive control group (administration of C. perfringens at the rate of 1 × 10 9 cfu/bird via crop gavage twice daily from day 16 to 18 post-hatch); C. perfringens challenge plus antibiotic (Flagymox ® ) group, and Clostridium perfringens challenge plus microbial-based treatment (Big-lactoα ® ) group. The results indicated that the Flagymox and Big-lactoα treated Cobb breed group achieved a significant increase in their body weight (BW) than the positive control group at the third week post-infection. Also, the Arbor Acres breed gained significantly higher weight compared to the Cobb breed at the third week. Total weight gain (TWG) from 0 to the fifth week in the Cobb and Arbor Acres breeds were higher in the groups treated with Flagymox and Big-lactoα compared to the birds challenged with C. perfringens without any treatment, thus, increasing the total return (TR) in the treated groups. Economic efficiency showed no significant differences (p < .05) between the treatment groups of both the breeds. Although the treatment cost of Flagymox is higher than the microbial-based treatment (0.86 versus 0.35 LE), there were no mortalities reported in the microbial-based groups in both the breeds resulting in significantly low losses compared to the Flagymox treated groups. The groups treated with the microbial-based products in both breeds were superior in dressing percentage (75.16 and 77.06% for Cobb and Arbor Acres, respectively) compared to that of the other groups. In conclusion, microbial-based therapy improved the growth rate, carcass traits, survival rate, and economic efficiency in necrotic enteritis induced in Cobb and Arbor Acres broilers., (© 2021 The Authors. Veterinary Medicine and Science Published by John Wiley & Sons Ltd.)

The objective of this pilot study was to examine the histologic effects associated with three known sclerosing agents and their ability to induce fibrosis in the subcutaneous space between the cervicocephalic air sac and skin. In the future, these drugs may prove useful in treating birds experiencing cervicocephalic diverticula rupture. The agents used were 1% polidocanol, absolute ethanol, and doxycycline hyclate. Twelve healthy adult chickens ( Gallus gallus domesticus ) were used in this study. The chickens were randomly allocated into three groups denoting day of euthanasia (day 4, 7, or 14). On day 0, all agents were injected (0.2 ml) subcutaneously, in a four-point grid fashion, in both the cervical and pectoral region of each bird. After euthanasia, the skin and subcutaneous tissues corresponding to the injection sites were harvested for histologic assessment. Tissue sections were assessed for fibrosis and lymphocytic and histiocytic inflammation. A scoring system was established to rank sclerosing agents by fibrosing and inflammatory ability. In the cervical region of chickens, 1% polidocanol induced the greatest inflammatory changes by day 7. Data suggest that doxycycline hyclate may produce the greatest cutaneous and subcutaneous fibrosis overall among all groups of birds. No adverse reactions were associated with any injection. Sterile saline produced the least amount of inflammation when assessed with the scoring system. Further investigation is needed to determine the safety of injections of larger volume with these chemicals and whether these findings can be extrapolated to birds with disease.

Salmonella enteritidis can cause significant morbidity and mortality in humans and economic loss in the animal industry. Improving the innate immunity is an effective method to prevent S. enteritidis infection. Pediococcus pentosaceus is a Gram-positive coccus which had probiotics properties. Numerous previously published studies reported that probiotics were beneficial to gut microbiota by changing the intestinal flora structure and inhibiting the harmful microbial growth to enhance the innate immunity. We investigated the immunological effects of P. pentosaceus on Salmonella-infected chickens by the following experiment. A total of 120 broilers from AA line were fed and divided into 2 groups (treated and control groups) for the experiment from day 1. The control group was fed with the basic diet, while the treated group was fed with the basic diet adding P. pentosaceus microcapsule with the bacterial concentration of 1 g/kg in the feed and bacterial counts 2.5 × 10 9  CFU/g. All the birds were given with 0.5 ml of S. enteritidis bacterial suspension (10 9  CFU/ml) through oral cavity at day 9. The number of dead birds was recorded and used in the analysis. The bacterial culture method and quantitative real-time PCR analysis were used to evaluate the effects of P. pentosaceus on chickens infected with S. enteritidis and to ascertain the mechanism of the effect. The results showed that the P. pentosaceus could restrain the pathogenicity of S. enteritidis and reduce the death rate from 44.4% to 23.3%. The flora in the caecum exhibited "rising-declining" trends, and the gene ( TLR4 , MyD88 , TRAF6 NF-κB , IFN-β , TNF-a , IL6 , and IL8 ) expression pattern was different between the experimental and control group. P. pentosaceus as a probiotic may competitively inhibit the growth of S. enteritidis and control the inflammatory response through regulating the gene expression which involved in the toll-like receptor pathway and inflammation pathway., Competing Interests: The authors report no conflict of interest. The authors alone are responsible for the content and writing of the manuscript., (Copyright © 2020 Dan Lan et al.)

Phage therapy is considered an alternative modality in the treatment of different bacterial diseases. However, their therapeutic and preventive roles against infections caused by Salmonella Kentucky and Escherichia coli O119 were of little attention. In this study, two phages were isolated, characterized and assessed for their potential therapeutic and preventive roles against S. Kentucky and E. coli O119 infections in broilers. Commercial 1-day-old arboacres broiler chicks were assigned to seven groups: Group Ӏ was as a negative control, groups (П and Ш) were assigned as positive controls by the challenge of S. Kentucky and E. coli O119, respectively. The remaining four groups (IV, V, VI and VII) were administrated with five repeated phage doses to determine the effect of multiple doses. Phages were administrated in groups (IV and VI) after challenging with S. Kentucky and E. coli O119, respectively to assess their therapeutic role; moreover, their preventive role was evaluated through administration in groups (V and VII) before challenging with S. Kentucky and E. coli O119, respectively. Sampling was done from different organs at three time points and revealed that phage-treated groups had lower colony forming units of S. Kentucky and E. coli. Our results suggest that bacteriophages are efficient in the treatment and prevention of salmonellosis and colibacillosis in broiler farms., (© 2020 The Society for Applied Microbiology.)

This study evaluated the effects of total sulfur amino acid (TSAA) levels on the performance and intestinal health of broilers challenged with Eimeria spp. A total of 432 one-day-old off-sex Cobb 500 male chicks were randomly assigned to a 3 × 2 factorial arrangement (6 replicates/12 birds), with diets and Eimeria challenge as the main factors. The diets were as follows: 70% (no methionine [Met] supplementation), 85, and 100% TSAA, supplemented with L-Met. At day 14, the challenged birds (n = 216) were orally gavaged with a pool of Eimeria acervulina, Eimeria maxima, and Eimeria tenella sporulated oocysts, and the unchallenged birds (n = 216) received water. At 6 and 12 D post inoculation (dpi), performance and intestinal health were evaluated. The challenge, regardless of diets, significantly impaired the performance, intestinal villi height, villus-to-crypt ratio, and ileal digestibility of dry matter, energy, and crude protein (CP) and modulated the tight junction protein (TJP) expression throughout the experiment. Moreover, the superoxide dismutase activity was increased, whereas the reduced glutathione (GSH)-to-oxidized glutathione (GSSG) ratio was decreased by the challenge at 6 dpi. Regardless of the challenge, the 70% TSAA diet reduced the body weight and feed intake in all phases, whereas the ileal digestibility of CP was higher in birds fed with the 70% TSAA diet than in those fed with the 100% TSAA diet at 6 dpi. No major differences were observed among the diets with regard to the intestinal histomorphology and TJP expression, and birds fed with the 100% TSAA diet had the highest GSH concentration at 12 dpi. Few interactions were observed, and the Met supplementation counteracted the negative effects of the Eimeria challenge on GSH concentration when 85 and 100% of TSAA levels were reached. Overall, the Eimeria challenge had a negative impact on growth and intestinal health. Moreover, the supplementation of L-Met until either 85 or 100% of TSAA levels were reached was enough to assure good performance and intestinal health in birds challenged or not challenged with Eimeria spp., (Copyright © 2020. Published by Elsevier Inc.)

The burden of enteric pathogens in poultry is growing after the ban of antibiotic use in animal production. Organic acids gained attention as a possible alternative to antibiotics due to their antimicrobial activities, improved nutrient metabolism and performance. The current study was conducted to evaluate the effectiveness of organic acid blend on broilers cecal microbiota, histomorphometric measurements, and short-chain fatty acid production in Salmonella enterica serovar Typhimurium challenge model. Birds were divided into four treatments, including a negative control, positive control challenged with S. Typhimurium, group supplemented with an organic acid blend, and birds supplemented with organic acid blend and Salmonella challenged. Results illustrate significant differences in feed conversion ratios and production efficiency factor between treatment groups, however, the influence of organic acid supplement was marginal. Organic acid blend significantly increased cecal acetic and butyric acids concentrations when compared to unsupplemented groups and resulted in minor alterations of intestinal bacterial communities., Competing Interests: The authors have declared that no competing interests exist.

Objective: Female reproductive tract disorders are common conditions of backyard poultry with an increasing demand for individual veterinary care. However, only limited case reports are available on diagnostic workup and outcomes of individual cases. This study aims at giving an overview of usually presented reproductive tract disorders, comparing diagnostic imaging findings with final diagnoses, and summarizing the outcome of the respective diseases., Material and Methods: The digital medical records archive of the University for Veterinary Medicine in Vienna was searched for chickens that were finally diagnosed with diseases of the reproductive tract, including all patients from May 1st, 2009 to May 31st, 2019. Information such as patient age, medical history, results of diagnostic imaging, final confirmed diagnosis, outcome, surgical protocol and necropsy findings was extracted., Results: Finally confirmed reproductive tract diseases were found in 57 of 315 female chickens. The most common conditions were egg-related coelomitis along with salpingitis or impacted salpinx (25/57), followed by ovarian or oviductal neoplasia (17/57). Clinical findings were unspecific in the majority of cases, but most conspicuous were chickens presented with a distended coelomic cavity and apathy. Coelomic ultrasonography as well as computed tomography proved to be valuable tools for distinguishing between the respective conditions. However, ultrasonography alone mainly failed (10/11) to differentiate between ovary or oviductal neoplasia and egg-related coelomitis with salpingitis or impacted salpinx, respectively. Computed tomography was perceived as a superior tool for final diagnosis. In total 6/6 CT-scans correctly made a definitive diagnosis. Nevertheless, accurate diagnosis was only possible after celiotomy with the necessity of consecutive surgery for most of the reported cases. As an overall outcome 34 of 57 patients were either euthanised or died, whereas only 23 chickens could be successfully treated and discharged. Several hens were reported to be doing well at home, according to regular check-up procedures within 4 years post-surgery., Conclusion and Clinical Relevance: Diagnostic work-up and treatment of hens with reproductive tract diseases can be challenging. Clinical presentation and diagnostic imaging provide important information, still celiotomy is often required for final diagnosis. The condition of the chickens is usually serious. Within our study, 40 % of the hens could be treated successfully. Therefore, a realistic assessment of each individual case and clarification for the owners are important., Competing Interests: The authors confirm that they do not have any conflict of interest., (© Georg Thieme Verlag KG Stuttgart · New York.)

Chitosan nanoparticles (CNPs) represent an efficient vaccination tool to deliver immunogenic antigens to the antigen-presenting cells (APCs), which subsequently stimulate protective immune responses against infectious diseases. Herein, we prepared CNPs encapsulating mRNA molecules followed by surface coating with conserved H9N2 HA2 and M2e influenza proteins. We demonstrated that CNPs efficiently delivered mRNA molecules into APCs and had effectively penetrated the mucosal barrier to reach to the immune initiation sites. To investigate the potential of CNPs delivering influenza antigens to stimulate protective immunity, we intranasally vaccinated chickens with empty CNPs, CNPs delivering HA2 and M2e in both mRNA and protein formats (CNPs + RNA + Pr) or CNPs delivering antigens in protein format only (CNPs + Pr). Our results demonstrated that chickens vaccinated with CNPs + RNA + Pr elicited significantly (p < 0.05) higher systemic IgG, mucosal IgA antibody responses and cellular immune responses compared to the CNPs + Pr vaccinated group. Consequently, upon challenge with either H7N9 or H9N2 avian influenza viruses (AIVs), efficient protection, in the context of viral load and lung pathology, was observed in chickens vaccinated with CNPs + RNA + Pr than CNPs + Pr vaccinated group. In conclusion, we show that HA2 and M2e antigens elicited a broad spectrum of protection against AIVs and incorporation of mRNAs in vaccine formulation is an effective strategy to induce superior immune responses.

This study investigated the effects of encapsulated cinnamaldehyde (CIN) and citral (CIT) alone or in combination (CIN + CIT) on the growth performance and cecal microbiota of nonvaccinated broilers and broilers vaccinated against coccidiosis. Vaccinated (1,600) and nonvaccinated (1,600) 0-day-old male Cobb500 broilers were randomly allocated to 5 treatments: basal diet (control) and basal diet supplemented with bacitracin (BAC, 55 ppm), CIN (100 ppm), CIT (100 ppm), and CIN (100 ppm) + CIT (100 ppm). In general, body weight (BW) and feed conversion ratio were significantly improved in birds treated with BAC, CIN, CIT, and CIN + CIT (P < 0.05) but were all decreased in vaccinated birds compared with nonvaccinated birds (P < 0.05). Significant interactions (P < 0.05) between vaccination and treatments for average daily gain during the periods of starter (day 0-9) and BW on day 10 were noted. Broilers receiving vaccines (P < 0.01) or feed supplemented with BAC, CIN, CIT, or CIN + CIT (P < 0.01) showed reductions in mortality rate from day 0 to 28. The incidences of minor coccidiosis were higher (P < 0.05) in vaccinated birds than in nonvaccinated birds. Diet supplementation with BAC or tested encapsulated essential oils showed comparable effects on the coccidiosis incidences. Similar to BAC, CIN and its combination with CIT reduced both incidence and severity of necrotic enteritis (P < 0.05). No treatment effects were observed on the cecal microbiota at the phyla level. At the genus level, significant differences between vaccination and treatment groups were observed for 5 (Lactobacillus, Ruminococcus, Faecalibacterium, Enterococcus, and Clostridium) of 40 detected genera (P < 0.05). The genus Lactobacillus was more abundant in broilers fed with CIT, while Clostridium and Enterococcus were less abundant in broilers fed with CIN, CIT, or CIN + CIT in both the vaccinated and nonvaccinated groups. Results from this study suggested that CIN alone or in combination with CIT in feed could improve chicken growth performance to the level comparable with BAC and alter cecal microbiota composition., (Copyright © 2019. Published by Elsevier Inc.)

Commercial poultry farms are increasingly threatened by bacterial infections from avian pathogenic Escherichia coli (APEC) and broad-host Salmonella serovars. Recombinant attenuated Salmonella vaccines (RASV) elicit cross-reactive immune responses against APEC in chickens; however, assessment of broad protection is lacking. Probiotics boost chicken immunity and improve vaccination responses. The objective of this study was to determine whether the RASV, the probiotics, or their combination had protection against APEC and Salmonella. White Leghorn chicks were randomly placed into 4 groups: no treatment (CON), probiotics (PRO), RASV (VAX), or both prophylactics (P + V). Chicks in the PRO and P + V groups were fed probiotics daily, beginning at the age of 1-day-old. Chicks in the P + V and VAX groups were orally inoculated with RASV at the age of 4 D and boosted 2 wks later. Total and antigen-specific IgY responses to Salmonella (lipolysaccharide [LPS]) and E. coli (IroN and IutA) were measured in serum samples via ELISA. Bactericidal potential of both serum and blood against 42 APEC isolates comprising 25 serotypes was assessed in vitro. In vivo protection against APEC was evaluated by air sac challenge with APEC χ7122 (O78:K80), gross pathological lesions were scored, and bacterial loads were enumerated. In a second similar study, birds were orally challenged with S. Kentucky (CVM29188), and feces were enumerated for Salmonella at multiple time points. Vaccination elicited significant LPS-specific antibodies regardless of probiotics (P < 0.0001). Chicks in the P + V group demonstrated increased blood and serum bactericidal abilities against multiple APEC strains in vitro compared with the CON group. Following χ7122 challenge, P+V birds had less APEC in their blood (P < 0.001) and lower signs of airsacculitis (P < 0.01) and pericarditis/perihepatitis (P < 0.05) than CON birds. Finally, only P + V birds were negative for fecal Salmonella at all time points. This study shows this combination treatment may be a feasible method to reduce infection by APEC and Salmonella in chickens., (Copyright © 2019. Published by Elsevier Inc.)

A study with 884 Ross 308 male broilers, housed in 68 floor pens (0.75 m2) from 0 to 35 days of age was conducted to evaluate the effects of low crude protein (CP) diets, with partial replacement of soybean meal by free amino acids (AA), on performance, slaughter yields, litter quality and footpad lesions. During the first 11 d, all broilers received the same control starter diet (216 g/kg CP, 11.5 g/kg apparent fecal digestible (AFD) lysine, and 2900 kcal/kg AMEn). Thereafter, four experimental feeding programs with different levels of dietary CP (control and control with 1% (CP-1%), 2% (CP-2%) and 3% (CP-3%) less CP units) were provided in both the grower and finisher phase. In the control grower and finisher diet, the CP content was 208 and 198 g/kg, respectively. All diets were formulated to meet or exceed the recommendations concerning AFD AA, and to be iso-caloric within each feeding phase. Feed and water were provided for ad libitum intake during the entire experimental period. None of the low CP feeding programs affected body weight gain, feed intake or mortality from 0 to 35 d. However, CP conversion was improved with the reduction of CP content of the diet. Broilers fed the CP-2% or CP-3% feeding program had an improved feed conversion ratio. Broilers fed the low CP protein feeding programs had a better litter quality and less footpad lesions, compared to broilers fed the control feeding program. Broilers fed the CP-3% feeding program had a lower breast meat yield than broilers fed the control feeding program. Slaughter yields of broilers fed CP-1% or CP-2% feeding program did not differ from the control feeding program. This study demonstrated that the CP content of grower and finisher diets can be reduced by 2.2-2.3% units without adverse effects on growth performance of broilers, while CP reduction seems promising to reduce nitrogen excretion from broiler houses, improve bird welfare, and reduces dependence on vegetable protein sources., (© The Author(s) 2019. Published by Oxford University Press on behalf of Poultry Science Association.)

Mucosal vaccine delivery systems have paramount importance for the induction of mucosal antibody responses. Two studies were conducted to evaluate immunogenicity of inactivated AIV antigens encapsulated in poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs). In the first study, seven groups of specific pathogen free (SPF) layer-type chickens were immunized subcutaneously at 7-days of age with different vaccine formulations followed by booster vaccinations two weeks later. Immune responses were profiled by measuring antibody (Ab) responses in sera and lachrymal secretions of vaccinated chickens. The results indicated that inactivated AIV and CpG ODN co-encapsulated in PLGA NPs (2x NanoAI+CpG) produced higher amounts of hemagglutination inhibiting antibodies compared to a group vaccinated with non-adjuvanted AIV encapsulated in PLGA NPs (NanoAI). The tested adjuvanted NPs-based vaccine (2x NanoAI+CpG) resulted in higher IgG responses in the sera and lachrymal secretions at weeks 3, 4 and 5 post-vaccination when immunized subcutaneously. The incorporation of CpG ODN led to an increase in Ab-mediated responses and was found useful to be included both in the prime and booster vaccinations. In the second study, the ability of chitosan and mannan coated PLGA NPs that encapsulated AIV and CpG ODN was evaluated for inducing antibody responses when delivered via nasal and ocular routes in one-week-old SPF layer-type chickens. These PLGA NPs-based and surface modified formulations induced robust AIV-specific antibody responses in sera and lachrymal secretions. Chitosan coated PLGA NPs resulted in the production of large quantities of lachrymal IgA and IgG compared to mannan coated NPs, which also induced detectable amounts of IgA in addition to the induction of IgG in lachrymal secretions. In both mucosal and subcutaneous vaccination approaches, although NPs delivery enhanced Ab-mediated immunity, one booster vaccination was required to generate significant amount of Abs. These results highlight the potential of NPs-based AIV antigens for promoting the induction of both systemic and mucosal immune responses against respiratory pathogens., Competing Interests: The authors have declared that no competing interests exist.

A 1.5-year-old Polish hen was presented with a history of watery droppings and poor vent tone. Results of diagnostic tests revealed blood lead at levels considered to be toxic. Chelation therapy was started with calcium ethylenediaminetetraacetate. The hen was laying eggs before, during, and after chelation therapy. Eggs were tested for the presence of lead by combining yolk and albumen together. Before chelation therapy, the level of lead in the egg tested was 14 μg. Two days after the end of chelation therapy, results of a second blood lead test revealed a drop to nontoxic levels. No lead was detected in the combined yolks and albumen of eggs collected 7-11 days after the end of chelation therapy. Four weeks after the end of chelation therapy, no lead was identified in the shells of tested eggs.

Salmonella pullorum is the major pathogen that is harmful to the poultry industry in developing countries, and the treatment of chicken diarrhea caused by S. pullorum has become increasingly difficult. In this study, a virulent bacteriophage YSP2, which was able to specifically infect Salmonella, was isolated and characterized. Phage YSP2 was classified in the Siphoviridae family and had a short latent period of 10 min. No bacterial virulence- or lysogenesis-related ORF is present in the YSP2 genome, making it eligible for use in phage therapy. Experiments in vivo investigated the potential use of phages as a therapy against diarrhea in chickens caused by S. pullorum in a chicken diarrhea model, demonstrating that a single oral administration of YSP2 (1 × 10 10  PFU/mL, 80 μL/chicken) 2 h after S. pullorum oral administration at a double median lethal dose was sufficient to protect chickens against diarrhea. Gross inspection showed that YSP2 can effectively reduce organ damage and significantly relieve hemorrhage in the intestine and liver tissue. Moreover, YSP2 can maintain a high curative effect when diluted to 10 8 PFU/mL. In light of its therapeutic effect on chicken diarrhea, YSP2 may serve as an alternative treatment strategy for infections caused by S. pullorum.

Avian Colibacillosis is among the major causes of economic loss in the poultry industry worldwide, with a more vivid impact on developing countries. The involvement of several bacteria has made it challenging to develop effective vaccines for this disease, particularly because it is notoriously difficult to make a vaccine that contains all the contributing pathogenic bacteria. Here, we report the design and fabrication of a bacterial ghost (BG) of E. coli O78:K80, which is among the major bacterial serotypes responsible for this disease. The generated ghost is then exploited as a homologous vaccine against Avian Colibacillosis. We demonstrate that hole formation in the cell wall of E. coli O78:K80 can happen properly in optical densities as high as 0.8 compared to the 0.3-0.4 standard for bacteria like E. coli TOP10. This is especially advantageous for mass production of this ghost which is a vital factor in development of any BG-based vaccine. Compared to E. coli TOP10, we faced a great challenge in transforming the wild type bacteria with the E-lysis plasmid which was probably due to higher thickness of the cell wall in O78:K80. This, however, was addressed by treating the cell wall with a different combination of ions.The vaccine was administered to Ross 308 broiler chickens via injection as well as through their respiratory system at a dose of 1010 BGs, repeated 3 times at weekly intervals. Chickens were then challenged with the wild type O78:K80 at a dose of 1011 bacteria together with Infectious Bronchitis H120 vaccine (as immunosuppressant) one week after the last immunization. Air sac lesions were significantly reduced in BG vaccinated groups in comparison with the control group. The levels of IFNγ, IgA and IgY were measured in the serum of immunized chickens as an indication of immune response and were compared with those of the chickens vaccinated with killed bacteria. The results show that O78:K80 BG can be used as an efficient homologous vaccine against Colibacillosis disease in poultry. We expect our findings can serve as the starting point for designing more sophisticated vaccines that contain all three major pathogenic bacteria involved in avian Colibacillosis.

1. Campylobacter jejuni is the most common bacterial cause of human food-borne gastroenteritis in the world. A major source of human infection is the consumption of contaminated meat, particularly poultry. New control measures to reduce or eliminate this pathogen from the animal gastrointestinal tract are urgently required, and the use of probiotics as competitive exclusion agents is a promising biocontrol measure to reduce C. jejuni in the food chain. 2. In this study, we assessed the potential of Lactobacillus johnsonii FI9785, which has shown efficacy against Clostridium perfringens, to combat C. jejuni. The effect of prophylactic administration of L. johnsonii on the ability of C. jejuni to colonise chickens was determined. 3. Two doses of L. johnsonii given a week apart led to a reduction in C. jejuni colonisation in the caecal contents, but this biocontrol seemed reliant upon a high level of initial colonisation by the probiotic. 4. The microbial composition in the chicken gut was significantly altered by the probiotic treatment, as shown by denaturing gradient gel electrophoresis of 16S rRNA gene amplicons. 5. Together these results demonstrate the potential of this probiotic strain to be tested further as a competitive exclusion agent in poultry against C. jejuni.

Several reports have shown that baculoviruses (BVs) have strong adjuvant properties on the mammalian immune system. Recent studies of our group demonstrated the ability of BV to stimulate the innate immunity in chickens. In this investigation, we aimed to assess the potential antiviral effect of BV given both, before and after infectious bursal disease virus (IBDV). In the first case, specific pathogen free chickens were intravenously inoculated with 5 × 10(7) pfu of Autographa californica nuclear polyhedrosis virus and 3 h later were orally administered 2.5 × 10(5) egg infectious doses 50 of IBDV. In the second case, chickens received IBDV 3 h before BV inoculation. Five days later, chickens were bled and euthanized. RNA from the bursa was analyzed for cytokine production. Also, bursae were used for virus recovery, and processed for lymphocyte isolation. The results showed that the administration of BV 3 h after the inoculation with IBDV produced important changes in the effect that IBDV causes in the bursa. BV reduced the infiltration of T lymphocytes, decreased the expression pattern of IL-6 and IFN-γ and inhibited IBDV replication. The results herein presented demonstrate that this Lepidopteran virus shows antiviral activity in chickens under experimental conditions. Investigations under field conditions have to be done to probe this strategy as a valuable sanitary tool for the treatment and prevention of chicken diseases., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Ascites syndrome is currently a serious disease issue for the global chicken industry. Ascites syndrome is a metabolic disorder frequently found in fast growing broilers including abdominal distention and standing fluid collection in chicken abdomen. It is one of the most common nutrition metabolic disorders., Materials and Methods: In this study, the clinical diagnosis technology of broiler ascites symptoms mainly included the trial inquiry of feeders and administrators, local observation, detection of farm gas and faeces and pathological autopsy., Results: The study investigated the case of broiler ascites syndrome of local commercial broiler chickens at the age of 4-5 weeks to reduce outburst of ascites syndrome in broiler chickens. Through the trial clinical diagnosis of broiler ascites symptoms and pathological autopsy and observation, it came to the definite diagnosis of broiler ascites. Subsequent investigation found that the rearing houses were closed and sealed with poor ventilation and a high breeding density and much ammonia gas., Conclusion: Under the comprehensive management and drug treatments, there were 800 chickens found ill and later came back to normal from illness after the treatments, except for the death of 38 sick chickens. The appetite and drink of broiler chicken came to normal gradually.

This study was conducted to investigate the effect of feeding a probiotic, Bacillus subtilis, on antibody titers against Newcastle and infectious bursal viruses in broiler chickens challenged with Salmonella enterica serotype Enteritidis. One hundred and sixty 1-day-old broiler chicks were randomly assigned to four treatments in a completely randomized design. The treatments were negative control, probiotic-treated group, challenged group, and challenged probiotic treated group. Salmonella challenging decreased (P < 0.05) the relative weights of spleen and bursa. Inclusion of probiotic to diet of challenged chickens increased the relative weight of spleen, but had no effect on the relative weight of bursa. There were no differences for the antibody titers of chickens between negative control and probiotic-treated group. Salmonella challenging decreased (P < 0.05) antibody titers against Newcastle and infectious bursal viruses. Improvements in the antibody titers were observed by the addition of probiotic to diet of these chickens. The results showed that dietary inclusion of probiotic had no significant effect on immune parameters of chickens at non-contaminated environment, display a greater efficacy at environment contaminated with pathogen and can improve immune responses of infected chickens.

The study was conducted to determine the anthelmintic efficacy of Aloe ferox, Agave sisalana, and Gunnera perpensa against Heterakis gallinarum in village chickens. The chickens naturally infected with H. gallinarum were randomly divided into 14 groups of eight chickens and orally administered distilled water (negative control), mebendazole (positive control), and graded levels (50-, 100-, 200-, and 400-mg/kg doses) of the three plant extracts. At days 0, 7, and 14, the floatation technique was used to determine fecal egg counts and H. gallinarum worms from chicken ceca were counted at days 0 and 14. Egg count reduction percentage (ECR%) was high at day 7 for all the test materials except for A. sisalana (100 mg/kg) that had 33%. At day 14, ECR% was high for all the other test materials save for A. ferox (200 mg/kg), mebendazole, and distilled water which was 50, 32, and 50%, respectively. A. ferox (200 mg/kg), G. perpensa (200 and 400 mg/kg), and A. sisalana (50 and 100 mg/kg) had the highest (85, 78, 74, 86, and 73%, respectively) worm count reduction percentage. The plants had anthelmintic properties. Advocacy and utilization of these plants in improving the health of village chickens could lead to increased productivity, boosting profits for the poultry industry thereby enabling it to meet the supply of animal protein and enhance livelihoods. It is imperative to determine compounds in the crude extracts of these medicinal plants which are responsible for the anthelmintic activities and their mechanism of action.

A Newcastle disease virus (NDV) isolate designated IBS002 was isolated from a commercial broiler farm in Malaysia. The virus was characterised as a virulent strain based on the multiple basic amino acid motif of the fusion (F) cleavage site (112)RRRKGF(117) and length of the C-terminus extension of the hemagglutinin-neuraminidase (HN) gene. Furthermore, IBS002 was classified as a velogenic NDV with mean death time (MDT) of 51.2 h and intracerebral pathogenicity index (ICPI) of 1.76. A genetic distance analysis based on the full-length F and HN genes showed that both velogenic viruses used in this study, genotype VII NDV isolate IBS002 and genotype VIII NDV isolate AF2240-I, had high genetic variations with genotype II LaSota vaccine. In this study, the protection efficacy of the recombinant genotype VII NDV inactivated vaccine was also evaluated when added to an existing commercial vaccination program against challenge with velogenic NDV IBS002 and NDV AF2240-I in commercial broilers. The results indicated that both LaSota and recombinant genotype VII vaccines offered full protection against challenge with AF2240-I. However, the LaSota vaccine only conferred partial protection against IBS002. In addition, significantly reduced viral shedding was observed in the recombinant genotype VII-vaccinated chickens compared to LaSota-vaccinated chickens.

Avian pathogenic Escherichia coli (APEC) causes colibacillosis in poultry, leading to important economic losses worldwide. To cure APEC-infected chickens, a cocktail of four different APEC-specific bacteriophages (phages) was composed and tested. Specific phages were selected from a collection of phages isolated in Belgium. The selection was based on their obligate lytic infection cycle, a broad host range, low cross-resistance and low frequency of development of resistant APEC mutants. Genome analysis of the phages indicated they were close relatives of T4 and N4, considered to be safe in vivo. Chickens were intratracheally infected with APEC strain CH2 (serogroup O78), causing a mortality of about 50% during the seven days following the infection. The phage cocktail was administered 2h after the infection, via three different ways: intratracheally, intra-esophageally or via the drinking water. Treated groups did not show a significant decrease in mortality, lesion scores or weight loss compared to untreated groups, although the APEC-specific phages could be re-isolated from the lung and heart of chickens that were euthanized. Moreover, the re-isolated bacteria from infected chickens had remained sensitive to the phage cocktail. Our results indicate that the efficiency of the phage cocktail used in treating CH2-infected chickens in vivo is negligible, even though in vitro, the phages in the cocktail were able to efficiently lyse the APEC strain CH2. Our results emphasize that the 'traditional' pathway of isolation, followed by phenotypical and genotypical characterization of phages composing the cocktail, does not lead to success in phage therapy in all cases., (Copyright © 2013 Elsevier B.V. All rights reserved.)

This study analyzed the effects of different broiler production systems on health care costs in the Netherlands. In addition to the conventional production system, the analysis also included 5 alternative animal welfare systems representative of the Netherlands. The study was limited to the most prevalent and economically relevant endemic diseases in the broiler farms. Health care costs consisted of losses and expenditures. The study investigated whether higher animal welfare standards increased health care costs, in both absolute and relative terms, and also examined which cost components (losses or expenditures) were affected and, if so, to what extent. The results show that health care costs represent only a small proportion of total production costs in each production system. Losses account for the major part of health care costs, which makes it difficult to detect the actual effect of diseases on total health care costs. We conclude that, although differences in health care costs exist across production systems, health care costs only make a minor contribution to the total production costs relative to other costs, such as feed costs and purchase of 1-d-old chicks., (Poultry Science Association Inc.)

This article describes some of the milestones in research concerned with protozoan parasites of the genus Eimeria that infect birds and cause the disease coccidiosis. The time period covered is from 1891, when oocysts were first found in the ceca of diseased chickens, to the present. Progress in our understanding has lagged behind that of other protozoan parasites such as Toxoplasma and Plasmodium despite the enormous importance of Eimeria to animal livestock production. Nevertheless, applied research by universities, government agencies, and private industry has resulted in the successful development of methods of control, research that continues today. The topics covered and the references provided are selective and include life cycles and biology, pathology, ultrastructure, biochemistry, immunity, genetics, host cell invasion, species identification, taxonomy, chemotherapy, vaccination, and literature concerned with avian coccidiosis. This review is primarily concerned with the avian species of Eimeria that infect poultry, but some important advances, principally in immunology, have been made using species that infect rodents and rabbits. These are included where appropriate.

Avian intestinal spirochaetosis (AIS) results from the colonization of the caeca and colon of poultry by pathogenic Brachyspira, notably Brachyspira pilosicoli. Following the ban on the use of antibiotic growth promoters in the European Union in 2006, the number of cases of AIS has increased, which, alongside emerging antimicrobial resistance in Brachyspira, has driven renewed interest in alternative intervention strategies. Lactobacillus-based probiotics have been shown to protect against infection with common enteric pathogens in livestock. Our previous studies have shown that Lactobacillus reuteri LM1 antagonizes aspects of the pathobiology of Brachyspira in vitro. Here, we showed that L. reuteri LM1 mitigates the clinical symptoms of AIS in chickens experimentally challenged with B. pilosicoli. Two groups of 15 commercial laying hens were challenged experimentally by oral gavage with B. pilosicoli B2904 at 18 weeks of age; one group received unsupplemented drinking water and the other received L. reuteri LM1 in drinking water from 1 week prior to challenge with Brachyspira and thereafter for the duration of the study. This treatment regime was protective. Specifically, B. pilosicoli was detected by culture in fewer birds, bird weights were higher, faecal moisture contents were significantly lower (P<0.05) and egg production as assessed by egg weight and faecal staining score was improved (P<0.05). Also, at post-mortem examination, significantly fewer B. pilosicoli were recovered from treated birds (P<0.05), with only mild-moderate histopathological changes observed. These data suggest that L. reuteri LM1 may be a useful tool in the control of AIS.

There has been a resurgent interest in the use of bacteriophages or their gene products to control bacterial pathogens as alternatives to currently used antibiotics. Clostridium perfringens is a gram-positive, spore-forming anaerobic bacterium that plays a significant role in human foodborne disease as well as non-foodborne human, animal, and avian diseases. Countries that have complied with the ban on antimicrobial growth promoters in feeds have reported increased incidences of C. perfringens-associated diseases in poultry. To address these issues, new antimicrobial agents, putative lysins encoded by the genomes of bacteriophages, are being identified in our laboratory. Poultry intestinal material, soil, sewage, and poultry processing drainage water were screened for virulent bacteriophages that could lyse C. perfringens and produce clear plaques in spot assays. Bacteriophages were isolated that had long noncontractile tails, members of the family Siphoviridae, and with short noncontractile tails, members of the family Podoviridae. Several bacteriophage genes were identified that encoded N-acetylmuramoyl-l-alanine amidases, lysozyme-endopeptidases, and a zinc carboxypeptidase domain that has not been previously reported in viral genomes. Putative phage lysin genes (ply) were cloned and expressed in Escherichia coli. The recombinant lysins were amidases capable of lysing both parental phage host strains of C. perfringens as well as other strains of the bacterium in spot and turbidity reduction assays, but did not lyse any clostridia beyond the species. Consequently, bacteriophage gene products could eventually be used to target bacterial pathogens, such as C. perfringens via a species-specific strategy, to control animal and human diseases without having deleterious effects on beneficial probiotic bacteria.

In total, 432 thirty-six-week-old laying hens were fed a basal diet supplemented with mannan-oligosaccharide (MOS) or an essential oil mixture (EOM) from 36 to 51 wk of age. Hens were divided into 3 equal groups replicated 6 times with 24 hens per replicate. No significant difference was observed among the dietary treatments in terms of performance indices. Different from the dietary manipulation, high environmental temperatures negatively influenced all of the laying performance traits except the feed conversion ratio in association with the diminished feed consumption. The MOS, and particularly the EOM, tended to alleviate the deleterious effect of heat stress on BW gain. Mortality was higher in MOS-fed hens than with other treatments. A supplementation diet with MOS or EOM provided increments in eggshell weight (P < 0.01). Relative albumen weight was significantly decreased (P < 0.05) in response to EOM or MOS supplementation; however, this was not the case in the yolk weight rate. The MOS decreased albumen height and Haugh unit (P < 0.05). High environmental temperatures hampered entire egg quality characteristics except for the eggshell breaking strength and egg yolk weight. These results indicated that heat stress adversely affected both productive performance and egg quality. As for the results of this study, neither MOS nor EOM was efficacious in improving efficiency of egg production and stimulating humoral immune response in laying hens reared under moderate and hot climatic conditions. However, the ameliorative effect exerted by MOS and EOM on eggshell characteristics is conclusive.

Necrotic enteritis caused by Clostridium perfringens leads to serious economical losses to the poultry industry. There is a growing need to find effective, nontoxic, antibiotic alternatives to prevent and cure the disease. In our study, the efficacy of protected sodium butyrate at 1.5 g/kg (BP70), a Bacillus amyloliquefaciens spore suspension with 10(9) cfu/g (BAL; Ecobiol), a protected blend of essential oils (1%) at 1.5 g/kg (EO), and a combination of sodium butyrate with essential oils (1%) protected with vegetable fat at 1.5 g/kg (BP70+EO; Natesse) was investigated in an artifical C. perfringens-infection model. Body weight gain, gross pathological and histopathological lesion scores, villus lengths, and villus length:crypt depth ratio was determined and compared with the control group. Broilers infected with C. perfringens and treated with essential oils or the combination of sodium butyrate and essential oils showed significantly better BW gain (P < 0.05), increased villus length and villus length:crypt depth ratio (P < 0.001), and decreased gross pathological and histopathological lesion scores (P < 0.05) compared with the control. Sodium butyrate alone and B. amyloliquefaciens spore suspension had no beneficial effects on the course of the disease in this study. According to our results, the protected combination of sodium butyrate and essential oils, as well as the protected essential oils, can be potential candidates for the prevention and treatment of necrotic enteritis in broiler chickens.

Intestinal Escherichia coli caused diarrhea in chicken makes serious damage directly to the chicken culture industry. Bacteriophage therapy is able to control the diarrhea in chickens effectively. In this study, the biosafety of bacteriophages was evaluated for treating intestinal pathogenic E. coli, which induced diarrhea in chickens. Ten bacteriophages were isolated from feces of chickens with diarrhea using the ill-chicken intestinal pathogenic E. coli 3-2 as target organism. Three bacteriophages propagated on E. coli 3-2 with relative big and clear plaques were selected and used together for toxicity experiment and evaluating the effect of therapy on chicken weight gain. In 3 weeks of trial, no mice given with or without mixed bacteriophages died, and the weight of mice of the experimental group did not show significant difference to the control group after 3 weeks infection. Besides remarkable decreasing the death rate of chickens with diarrhea, treatment of mixed bacteriophages also promoted the weight gain and saved the diet consumption as the utilize rate of diet increased 11% compared with the control group. These observations indicated that a mixture of three bacteriophages would be biosafe for rapid and effective preventing pathogenic E. coli infections.

Effect of dietary supplementation of astaxanthin (Ax) from Phaffia rhodozyma on lipopolysaccharide-induced inflammatory responses was investigated in male broiler chickens fed a corn-based diet. Birds (1 week of age) were fed a corn-enriched diet containing either 0 or 100 ppm Ax for 2 weeks and were intraperitoneally injected with lipopolysaccharide (LPS, 1 mg/kg body weight). Inflammatory responses were evaluated by determining changes in expression of messenger RNA (mRNA) in cytokines and mediators related to inflammatory responses (interleukin (IL)-1 beta and -6, inducible nitrite synthase (iNOS), interferon (IFN)- γ and cyclooxygenase (Cox)-2 in the liver and spleen after 2 h of LPS injection and plasma ceruloplasmin concentration as an acute phase protein. Birds fed Ax showed significantly higher iNOS mRNA expression in the liver and spleen compared to that of control birds. Ax-fed birds also showed greater increase in mRNA expression in the liver of IL-1, IL-6 and IFN-γ compared to that of control birds. The enhancing effect of Ax was further progressed when LPS was injected. No difference was found in plasma ceruloplasmin concentration between the Ax-fed group and control group. The results suggest that feeding supplementation of Ax (100 ppm) to a corn-enriched diet possibly does not have anti-inflammatory effect in male broiler chickens., (© 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.)

A Salmonella Gallinarum (SG)-specific bacteriophage isolated from sewage effluent was used to prevent horizontal transmission of SG in commercial layer chickens. Six-week-old chickens, each challenged with 5 x 10(8) colony-forming units of SG, cohabited with contact chickens treated with 10(6) plaque-forming units/kg of bacteriophage, prepared in feed additives, for 7 days before, and 21 days after challenge with SG. Mortality was observed for 3 wk after challenge and SG was periodically reisolated from the liver, spleen, and cecum of chickens. SG re-isolation from organs was decreased and a significant (P < 0.05) reduction in mortality was observed in contact chickens treated with the bacteriophage, as compared to untreated contact chickens, indicating that bacteriophage administration in feed additives significantly prevented the horizontal transmission of SG. These results provide important insights into prevention and control strategies against SG infection and suggest that the use of bacteriophages may be a novel, safe, and effectively plausible alternative to antibiotics for the prevention of SG infection in poultry.

The efficacy of bacteriophage EC1, a lytic bacteriophage, against Escherichia coli O78:K80, which causes colibacillosis in poultry, was determined in the present study. A total of 480 one-day-old birds were randomly assigned to 4 treatments groups, each with 4 pens of 30 birds. Birds from the control groups (groups I and II) received PBS (pH 7.4) or 10(10) pfu of bacteriophage EC1, respectively. Group III consisted of birds challenged with 10(8) cfu of E. coli O78:K80 and treated with 10(10) pfu of bacteriophage EC1 at 2 h postinfection, whereas birds from group IV were challenged with 10(8) cfu of E. coli O78:K80 only. All the materials were introduced into the birds by intratracheal inoculation. Based on the results of the present study, the infection was found to be less severe in the treated E. coli-challenged group. Mean total viable cell counts of E. coli identified on eosin methylene blue agar (designated EMB + E. coli) in the lungs were significantly lower in treated, E. coli-challenged birds than in untreated, E. coli-challenged birds on d 1 and 2 postinfection. The EMB + E. coli isolation frequency was also lower in treated birds; no E. coli was detectable in blood samples on any sampling day, and E. coli were isolated only in the liver, heart, and spleen of treated chickens at a ratio of 2/6, 1/6, and 3/6, respectively, at d 1 postinfection. The BW of birds from the E. coli-challenged group treated with bacteriophage EC1 were not significantly different from those of birds from both control groups but were 15.4% higher than those of the untreated, E. coli-challenged group on d 21 postinfection. The total mortality rate of birds during the 3-wk experimental period decreased from 83.3% in the untreated, E. coli-challenged birds (group IV) to 13.3% in birds treated with bacteriophage EC1 (group III). These results suggest that bacteriophage EC1 is effective in vivo and could be used to treat colibacillosis in chickens.

1. Bacteriophage (phage) crude lysate of Gram-negative bacteria often contains bacterial debris, including lipopolysaccharides found in the outer membrane of the cell wall, which are potentially toxic. 2. In this study, an in vivo evaluation of the toxicity of a suspension of three phages to control pathogenic Escherichia coli strains in poultry was performed. 3. Eighteen commercial layers, 7 weeks old, were intramuscularly injected with phage lysate (8.21 x 10(4) Endotoxin Units/dose). The control group was injected with sterile Luria Bertani (LB) broth. 4. Bird prostration and decrease in body weight gain and water intake per gram of body weight were observed only on the day of the inoculation in the challenged group. Over the following 6 d, no differences were observed in the chickens' activity. 5. These results support the view that phage crude lysate carrying endotoxins are not toxic for chickens.

Three experiments were performed to assess the ability of a Lactobacillus plantarum probiotic combined with a xylanase to reduce the effects of Salmonella Typhimurium infection in broiler chickens from 1 to 30 or 42 d of age. Chicks were challenged at 3 d of age with 10(8) or 10(5) cfu Salmonella Typhimurium/chick. Four diets were studied: a wheat-based diet (C+) supplemented with 0.1 g/kg of xylanase (E) or 10(6) cfu/g of L. plantarum (P), or both (PE). Uninfected chicks fed the C diet were used as negative control (C-). Six or 8 chicks were housed per cage with 9 cages/treatment. Growth performance and feed conversion ratio (FCR) were recorded weekly. In experiment 1, bacterial enumeration in ceca was achieved using the fluorescent in situ hybridization technique. Salmonella enumeration was realized in excreta by microbiological cultures (experiments 2 and 3). Nutrient digestibilities and AME(n) were determined in experiment 3 from d 35 to 39. Infection with Salmonella Typhimurium led to a significant decrease in the daily weight gain (DWG) by 23.6 to 32.8%, whereas FCR was increased by 1.0 to 19.7%. Chickens fed the PE diet showed significantly improved performance in comparison with C+ birds (DWG: +12.5% in experiment 1; FCR: -2.1 to 8.6%), and in comparison with the P and E treatments (DWG: +6.3 to 8.3% in experiment 1; FCR: -2.7 to 6.4%). In experiment 3, the FCR was significantly improved by 3% with the PE diet in comparison with C- chickens. The PE combination tended to restore a microflora similar to that of uninfected broilers, whereas the P and E diets had less of an effect on the profile of bacterial communities. At slaughter age, Salmonella contamination was reduced by 2.00 and 1.85 log colony-forming units for the E and PE treatment, respectively. The PE diet significantly reduced the crude fat digestibility by 9.2%, in comparison with the C+ chickens. These results suggest that the combination between L. plantarum and a xylanase as feed additive could be effective for reduction of the detrimental effect after Salmonella Typhimurium infection of broilers.

The effect of a Lactobacillus spp.-based probiotic (FM-B11) on Salmonella enterica serovar Enteritidis (SE) recovery was evaluated in liquid (Expt. 1) and lyophilized (Expt. 2) forms in two separate experiments with two trials each. For each trial, 80 broiler chicks were randomly allocated into two treatments: control and probiotic culture. All chicks were challenged with SE (approximately 10(4) colony-forming units [cfu]) upon arrival at our laboratory. In both experiments, probiotic culture was administered in the drinking water for 3 consecutive days at a final concentration of approximately 10(6) cfu/ml, beginning 1 hr after SE challenge. Cecal tonsils were aseptically removed at 24 and 72 hr postchallenge, followed by enrichment and plating on xylose lactose deoxycholate (XLD) agar for the presence or absence of Salmonella-typical colonies. In Expt. 1, a significant reduction (P < 0.05) in SE-positive samples was observed in both trials at 24 and 72 hr postchallenge. Additionally, in Expt. 2, the lyophilized probiotic decreased (P < 0.05) SE recovery at both 24 and 72 hr postchallenge compared with the control group in trial 1. In trial 2, SE evaluation was performed only at 72 hr after challenge and fewer (P < 0.001) treated samples were positive for SE. Results showed that application of either liquid or lyophilized probiotic culture in the drinking water for 3 consecutive days can help to reduce SE recovery from young birds, although further research is needed to elucidate the mechanism of this response.

We evaluated the effect of a Lactobacillus-based probiotic culture (FM-B11) for reduction of Salmonella Enteritidis in neonatal broiler chicks. In all experiments, chicks were challenged with approximately 10(4) cfu of Salmonella Enteritidis upon arrival at our laboratory, and the treatments were administered 1 h postchallenge. Cecal tonsil samples were obtained 24 h posttreatment and enriched for Salmonella Enteritidis recovery. The first experiment compared the effects of oral administration of doses of 10(4), 10(6), and 10(8) cfu/chick. In this experiment, doses of 10(6) and 10(8) both significantly reduced Salmonella Enteritidis recovery compared with controls (15 vs. 85% Salmonella Enteritidis positive), but 10(4) cfu did not significantly reduce Salmonella Enteritidis recovery. The second experiment compared the efficacy of oral administration of the live probiotic culture, with or without supernatant removed, to inactivated cultures or supernatant alone. Live probiotic organisms, with or without supernatant, significantly reduced Salmonella Enteritidis in this experiment, but inactivated or cell-free treatments did not reduce Salmonella Enteritidis. In the final 2 experiments, differing doses of probiotic culture were administered on the vent lips, where the treatment was taken into the lower gastrointestinal tract via cloacal drinking. Concentrations of probiotic culture from 10(2) to 10(7) cfu/chick significantly reduced Salmonella Enteritidis, and there was no difference in Salmonella Enteritidis recovery between treatment concentrations. These data suggest that this Lactobacillus-based probiotic culture may be efficacious for reduction of Salmonella Enteritidis in neonatal chicks.

Disease prevalence and veterinary treatments in organic animal production differ from those in conventional systems. In order to gather information about current practices in organic layer husbandry, 33 organic egg producers of 16 small, 12 medium-sized, and 5 large farms were asked to complete a questionnaire on disease prevalence and treatments. On these farms, the mean mortality was 9% and the mean laying percentage was 79%. In contrast with the regulations for organic farming, the use of chemotherapeutics was not recorded on 30% of the farms. One third of the farmers were not aware of the type of vaccination given to their hens, and on the other farms hens had been vaccinated as pullets against nine or more viral and bacterial diseases. Several health problems were mentioned, such as feather pecking, red mites, helminths, infectious bronchitis, colibacillosis, and coccidiosis. On 19 farms, diseases were treated with homeopathic, phytotherapeutic, or other alternative medicines; on 10 of these farms chemotherapeutics were also used. On 4 farms only chemotherapeutics were used, on 10 farms no products were used, and on some farms up to seven products were used. Although quite a large number of organic layer farmers in the Netherlands used homeopathic, phytotherapeutic, or other alternative medicines, the use of chemotherapeutics is currently inevitable to prevent animal suffering or distress in organic husbandry.

Eggs are a major source of human infections with Salmonella. Therefore controlling egg contamination in laying hen flocks is one of the main targets for control programmes. A study was carried out to assess the effect of oral vaccination with TAD Salmonella vac E, TAD Salmonella vac T and with both vaccines TAD Salmonella vac E and TAD Salmonella vac T, on colonization of the reproductive tract and internal egg contamination of laying hens with Salmonella Enteritidis. Three groups of 30 laying hens were vaccinated at 1 day, 6 weeks and 16 weeks of age with either one of the vaccine strains, or a combination of both vaccine strains, while a fourth group was left unvaccinated. At 24 weeks of age, the birds were intravenously challenged with 0.5 ml containing 5 x 10(7)cfu Salmonella Enteritidis PT4 S1400/94. The number of oviducts from which Salmonella was isolated, was significantly lower in the vaccinated than in the non-vaccinated hens at 3 weeks post-challenge. Significantly less egg contents were Salmonella positive in the birds vaccinated with TAD Salmonella vac E or TAD Salmonella vac T (12/105 batches of eggs in both groups) than in the unvaccinated birds (28/105 batches of eggs). Internal egg contamination in the hens vaccinated with both TAD Salmonella vac E and TAD Salmonella vac T was even more reduced, as over the whole experiment, only one batch of eggs was positive. In conclusion, these data indicate that vaccination of laying hens with these live vaccines could be considered as a valuable tool in controlling internal egg contamination.

Infectious bursal disease (IBD) is an acute and highly contagious disease of young chickens caused by Birnavirus. Mortality of infected birds can be best prevented if injected with antibodies. The present study was an attempt to raise specific hyper-immune polyclonal antibodies against IBD virus in Pakistan. Commercial layers divided into four groups were injected with IBD vaccine subcutaneously according to four different treatment regimens. Eggs were collected daily and antibodies were purified from yolk with dextran sulphate. Titers of antibodies in serum and yolk were evaluated with enzyme linked immunosorbant assay and agar gel precipitation test. Antibody titers were significantly higher in yolk than serum. Eggs collected at 28 days post-vaccination had maximum antibody titers. Of treatment regimens, T3 was found to be most effective for hyperimmunization. Lyophilized antibodies stored at 4 degrees C did not lose their activity till the end of experiment. IBD virus infected birds were injected with purified antibodies which induced 92% recovery as compared to control birds. The study implicates that the purified antibodies may be useful as a therapeutic agent to cure IBD infected birds.

Colonization of broiler chickens by the enteric pathogen Campylobacter jejuni is widespread and difficult to prevent. Bacteriophage therapy is one possible means by which this colonization could be controlled, thus limiting the entry of campylobacters into the human food chain. Prior to evaluating the efficacy of phage therapy, experimental models of Campylobacter colonization of broiler chickens were established by using low-passage C. jejuni isolates HPC5 and GIIC8 from United Kingdom broiler flocks. The screening of 53 lytic bacteriophage isolates against a panel of 50 Campylobacter isolates from broiler chickens and 80 strains isolated after human infection identified two phage candidates with broad host lysis. These phages, CP8 and CP34, were orally administered in antacid suspension, at different dosages, to 25-day-old broiler chickens experimentally colonized with the C. jejuni broiler isolates. Phage treatment of C. jejuni-colonized birds resulted in Campylobacter counts falling between 0.5 and 5 log10 CFU/g of cecal contents compared to untreated controls over a 5-day period postadministration. These reductions were dependent on the phage-Campylobacter combination, the dose of phage applied, and the time elapsed after administration. Campylobacters resistant to bacteriophage infection were recovered from phage-treated chickens at a frequency of <4%. These resistant types were compromised in their ability to colonize experimental chickens and rapidly reverted to a phage-sensitive phenotype in vivo. The selection of appropriate phage and their dose optimization are key elements for the success of phage therapy to reduce campylobacters in broiler chickens.