Conventional Chickens Research Articles

The gut microbiota and its metabolite butyrate shape metabolism and antiviral immunity along the gut-lung axis in the chicken

The gut microbiota exerts profound influence on poultry immunity and metabolism through mechanisms that yet need to be elucidated. Here we used conventional and germ-free chickens to explore the influence of the gut microbiota on transcriptomic and metabolic signatures along the gut-lung axis in poultry. Our results demonstrated a differential regulation of certain metabolites and genes associated with innate immunity and metabolism in peripheral tissues of germ-free birds. Furthermore, we evidenced the gut microbiota’s capacity to regulate mucosal immunity in the chicken lung during avian influenza virus infection. Finally, by fine-analysing the antiviral pathways triggered by the short-chain fatty acid (SCFA) butyrate in chicken respiratory epithelial cells, we found that it regulates interferon-stimulated genes (ISGs), notably OASL, via the transcription factor Sp1. These findings emphasize the pivotal role of the gut microbiota and its metabolites in shaping homeostasis and immunity in poultry, offering crucial insights into the mechanisms governing the communication between the gut and lungs in birds.

Identification of Disease Case on Kampung Unggul Balitbangtan (KUB) Chicken on Farmers’ Henhouse in Central Java

The Indonesian Agency for Agricultural Research and Development developed the Kampung Unggul Balitbangtan (KUB) Chicken, a superior breed of native chicken. The KUB chicken exhibited resistance to diseases, boasted lower mortality rates, and yielded more eggs compared to conventional free-range chickens. However, the KUB chickens were not immune to certain prevalent avian diseases, leading to substantial mortality and subsequent economic losses in Indonesia. This study, conducted from October to December 2021 in Central Java, aimed to determine the prevalence of various diseases in KUB chickens housed in farmer’s henhouse. Data were collected from 30 KUB chicken farmers. The results indicated the following prevalence rates for various infections: Snot at 44%, Coccidiosis at 9%, Salmonellosis at 9%, Infectious Bursal Disease at 9%, Newcastle Disease at 4%, and Helminthiosis at 4% across all sampled coops. Snot infection was notably higher in KUB Chickens, largely attributed to inadequate management, followed by Coccidiosis, Salmonellosis, and Infectious Bursal Disease. Clearly, disease prevalence in KUB chickens within a farmer’s coop can be mitigated by improved management practices and appropriate vaccination.

Pharmacological validation of an attention bias test for conventional broiler chickens.

Fear and anxiety are considered concerns for animal welfare as they are associated with negative affective states. This study aimed to pharmacologically validate an attention bias test (ABT) for broiler chickens (Gallus gallus domesticus) as a cognitive bias test to determine anxiety. Two-hundred-and-four male Ross 708 broiler chickens were arbitrarily allocated to either the anxiogenic or control treatment at 25 days of age (n = 102/treatment). Birds from the anxiogenic group were administered with 2.5 mg of β-CCM (β-carboline-3-carboxylic acid-N-methylamide [FG 7142]) per kg of body weight through an intraperitoneal injection (0.1 ml/100 g of body weight). Birds from the control group were administered with 9 mg of a saline solution per kg of body weight. During ABT, birds were tested in groups of three (n = 34 groups of three birds/treatment) with commercial feed and mealworms as positive stimuli and a conspecific alarm call as a negative stimulus. Control birds were 45 s faster to begin feeding than anxiogenic birds. Birds from the control group vocalized 40 s later and stepped 57 s later than birds from the anxiogenic group. The occurrence of vigilance behaviors did not differ between treatments. This study was successful in pharmacologically validating an attention bias test for fast-growing broiler chickens, testing three birds simultaneously. Our findings showed that latencies to begin feeding, first vocalization, and first step were valid measures to quantify anxiety.

Influence of space availability on measures of fear in conventional broiler chickens

Many of the fear tests used in the welfare assessments of broiler chickens assume that birds will withdraw from a given stimulus if they are fearful. However, fear test responses may also depend on the amount of space available in the broilers’ environment. As broiler chickens grow, the available space decreases, which, together with a decline in walking ability, may bias the results of fear tests. In the present study, we aimed to examine the relationship between space availability and measures of fear in broiler chickens. We hypothesized that broilers kept in pens with lower space availability would show reduced withdrawal in two movement-dependent fear tests, the stationary person test (SPT) and the novel object test (NOT), as space restrictions would limit the birds’ ability to move away. Fast-growing broilers (Ross 708) were housed at similar target stocking densities (34 kg/m2) until 27 days of age, after which an experimental intervention was introduced in which half of the pens were provided with additional space, reducing the target stocking density to 16 kg/m2. The fear tests were conducted when the birds were 21, 27 (before the change in space availability), 29, and 37 days old. Statistical analyses were performed in R using Generalized Additive Models. We found no effect of space availability on the measures of the SPT (P = 0.32). Space availability seemingly had a temporary effect on the measures of the NOT, as birds housed in the larger pens (16 kg/m2) showed increased withdrawal compared to the birds housed in the smaller pens (34 kg/m2) at 29 days of age (P = 0.04). However, no difference was found at 37 days of age (P = 0.63), and, therefore, we speculate whether the temporary effect at 29 days of age was due to the novelty of the environment rather than due to increase in space availability per se. We conclude that space availability had no effect on the outcome of the SPT and that it, overall, had no lasting effect on the outcome of the NOT. We speculate whether our findings might be explained by our chosen levels of stocking density for the smaller pens, as these may not have been sufficiently high to limit the birds’ ability to respond to the fear tests used, i.e. the birds, although space restricted, still had the option of being outside of proximity of the presented stimuli.

Microbiota promotes recruitment and pro-inflammatory response of caecal macrophages during E. tenella infection

BackgroundEimeria genus belongs to the apicomplexan parasite phylum and is responsible for coccidiosis, an intestinal disease with a major economic impact on poultry production. Eimeria tenella is one of the most virulent species in chickens. In a previous study, we showed a negative impact of caecal microbiota on the physiopathology of this infection. However, the mechanism by which microbiota leads to the physiopathology remained undetermined. Macrophages play a key role in inflammatory processes and their interaction with the microbiota during E. tenella infection have never been investigated. We therefore examined the impact of microbiota on macrophages during E. tenella infection. Macrophages were monitored in caecal tissues by immunofluorescence staining with KUL01 antibody in non-infected and infected germ-free and conventional chickens. Caecal cells were isolated, stained, analyzed and sorted to examine their gene expression using high-throughput qPCR.ResultsWe demonstrated that microbiota was essential for caecal macrophage recruitment in E. tenella infection. Furthermore, microbiota promoted a pro-inflammatory transcriptomic profile of macrophages characterized by increased gene expression of NOS2, ACOD1, PTGS2, TNFα, IL1β, IL6, IL8L1, IL8L2 and CCL20 in infected chickens. Administration of caecal microbiota from conventional chickens to germ-free infected chickens partially restored macrophage recruitment and response.ConclusionsTaken together, these results suggest that the microbiota enhances the physiopathology of this infection through macrophage recruitment and activation. Consequently, strategies involving modulation of the gut microbiota may lead to attenuation of the macrophage-mediated inflammatory response, thereby limiting the negative clinical outcome of the disease.

Microbiome Analysis of Organic and Conventional Chickens Processed Using Whole Carcass Enrichment and Rinse Methods

Investigating the chicken microbiome is important to establish control measures for pathogens to protect consumers. This study aimed at evaluating the comparative efficiency of human pathogen detection through 16S rRNA sequencing of organic and conventional chickens processed using whole carcass enrichment (WCE) and rinse (WCR) methods. Organic and conventional whole broiler carcasses (n = 31) were vigorously shaken with 500 mL buffered peptone water (BPW). For the rinse method, a 30 mL aliquot was mixed with 30 mL of BPW. The rest of the sample, including the carcass, was used for the enrichment method. All samples were incubated at 37°C for 24 h. The samples were divided into five groups [Negative Control: only BPW without chicken (n = 5), Organic-Rinsed (n = 7), -Enriched (n = 8), Conventional-Rinsed (n = 7), and -Enriched (n = 9)]. Fifty milliliters of each sample were subjected to DNA extraction followed by 16S rRNA sequencing. Proteobacteria and Firmicutes predominated the microbiota of both conventional and organic chickens, followed by low abundances of Bacteroidetes and Fusobacterium. While the abundance of Proteobacteria and Firmicutes remained unchanged in organic chicken irrespective of the methods used, a noticeable shift in the Proteobacteria and Firmicutes ratio (59%:39% in rinsed to 38%:60% in enriched) was observed in conventional chicken. Furthermore, the choice of method did not yield any differences in Abundance-Based Coverage Estimator, and Jackknife, among conventional and organic chickens but resulted in a statistically significant difference in the Shannon, Simpson, Chao1, and phylogenetic diversity indices (p < 0.05). The relative abundance of Salmonella and Campylobacter was less than 0.1%. The results suggested the WCE method provides a broad range of information on the chicken microbiome.

The caecal microbiota promotes the acute inflammatory response and the loss of the intestinal barrier integrity during severe Eimeria tenella infection.

Coccidiosis, a disease caused by intestinal apicomplexan parasites Eimeria, is a threat to poultry production. Eimeria tenella is one of the most pathogenic species, frequently causing a high prevalence of opportunistic infections. The objective of this study is to investigate the role of the microbiota in the pathogenesis of severe Eimeria tenella infection. We have previously shown that microbiota can promote parasite development. To study the effect of the microbiota on the pathogenesis of this infection, we used an experimental condition (inoculum of 10 000 oocysts E. tenella INRAE) in which the parasite load is similar between germ-free and conventional broilers at 7 days post-infection (pi). Thirteen conventional and 24 germ-free chickens were infected. Among this latter group, 12 remained germ-free and 12 received a microbiota from conventional healthy chickens at 4 days pi. Caeca and spleens were collected at 7 days pi. Our results demonstrated caecal lesions and epithelium damage in conventional chickens at 7 days pi but not in germ-free infected chickens. Administration of conventional microbiota to germ-free chickens partially restored these deleterious effects. At day 7 pi, both infected conventional and germ-free chickens exhibited increased gene expression of inflammatory mediators, including IL15, IFNγ, TNFα and the anti-inflammatory mediator SOCS1, whereas the inflammatory mediators CXCLi2, CCL20, IL18, CSF1, NOS2, PTGS2, IL1β, IL6, the receptor CCR2, and the anti-inflammatory mediators TGFβ1 and IL10 were upregulated only in infected conventional chickens. Notably, the IL18, PTGS2 gene expression was significantly higher in the infected conventional group. Overall, the inflammatory response enhanced by the microbiota might be in part responsible for higher lesion scores. Epithelial tight junction protein gene expression analysis revealed a significant upregulation of CLDN1 with the infection and microbiota, indicating a potential loss of the intestinal barrier integrity. These observations imply that, during E. tenella infection, the caecal microbiota could trigger an acute inflammatory response, resulting in a loss of intestinal integrity. Increase in bacterial translocation can then lead to the likelihood of opportunistic infections. Hence, modulating the microbiota may offer a promising strategy for improving poultry gut health and limiting caecal coccidiosis.

Characterizing the gut microbiome of broilers raised under conventional and no antibiotics ever practices

Meat from broilers raised without the use of antibiotics is becoming increasingly popular among consumers. Consequently, interest in the microbial profiling of chickens produced under nonconventional practices is growing, however, research on this topic is lacking. The current study was designed to characterize the dynamics of gut microbial populations of broilers raised under conventional and no antibiotics ever (NAE) practices. Four commercial farms (2 conventional and 2 NAE) were included in this study. On each farm, cecal (n=224) and ileal (n=224) contents were collected from birds at different stages during the grow out of a single flock and following transportation to the processing facility. Cecal microbiota was dominated by the genera Escherichia and Enterococcus upon hatching in both conventional and NAE flocks, shifting with time toward predominantly Faecalibacterium and Bacteroides. The composition of cecal microbial communities of NAE broilers was different than that of conventional chickens (P ≤ 0.05). Conventional broilers harbored a rich, but less diverse cecal microbiota than NAE, while the ileal microbiota was primarily populated with genera previously named Lactobacillus, which exhibited a higher abundance in NAE broilers (P ≤ 0.05). In both production systems, the microbiota followed a similar temporal succession that was more evident in the ceca. Transportation to the processing plant impacted the microbial composition of the ileum (P ≤ 0.05), characterized by an increase in the relative abundance of Psychrobacter. Finally, differential abundance analysis showed a positive correlation between Campylobacter and Enorma within the cecum microbiota, and a negative correlation with Salmonella.

TEKNOLOGI PEMBUATAN RANSUM DAN INTRODUKSI AYAM KUB BAGI MASYARAKAT DI KELURAHAN KOTO LUA KECAMATAN PAUH KOTA PADANG

Balitbangtan Superior Kampung Chicken (KUB) is a superior native chicken due to selection from native chicken families for six generations conducted by the Indonesian Agency for Agricultural Research and Development. KUB chickens have faster growth compared to ordinary native chickens. This training program was conducted for the Koto Lua community, Pauh District, Padang City, West Sumatra. This activity aims to help the community by conducting training on making poultry rations using conventional feed ingredients. In addition, this activity also aims to introduce one of the potential local chickens producing meat and eggs, namely: KUB chicken. The methods used in this activity were counseling and discussion (conventional feed and KUB chickens), training (traditional preparation of ration), mentoring (KUB chicken rearing), and evaluation at the end of the activity. 100 KUB chickens are raised by the service team from 1-28 days (4 weeks); after that, the KUB chickens are given to 10 heads of families (10 chickens per head of family), provided they have raised chickens and have a chicken coop. This activity results in the community gaining knowledge about feed ingredients that can be used as poultry rations. Community-rearing chickens until 16 weeks of age achieve an average body weight of 1000–150 g/head. The conclusion from this activity is that the community is skilled in making rations and raising KUB chickens, with a survival rate of around 90%.

Detection and Antimicrobial Resistance Profile of Enteropathogenic (EPEC) and Shigatoxigenic Escherichia coli (STEC) in Conventional and Organic Broiler Chickens

Detection and Antimicrobial Resistance Profile of Enteropathogenic (EPEC) and Shigatoxigenic Escherichia coli (STEC) in Conventional and Organic Broiler Chickens

Uncovering the core principles of the gut-lung axis to enhance innate immunity in the chicken.

Research in mammals has evidenced that proper colonization of the gut by a complex commensal microbial community, the gut microbiota (GM), is critical for animal health and wellbeing. It greatly contributes to the control of infectious processes through competition in the microbial environment while supporting proper immune system development and modulating defence mechanisms at distant organ sites such as the lung: a concept named ‘gut-lung axis’. While recent studies point to a role of the GM in boosting immunity and pathogen resilience also in poultry, the mechanisms underlying this role are largely unknown. In spite of this knowledge gap, GM modulation approaches are today considered as one of the most promising strategies to improve animal health and welfare in commercial poultry production, while coping with the societal demand for responsible, sustainable and profitable farming systems. The majority of pathogens causing economically important infectious diseases in poultry are targeting the respiratory and/or gastrointestinal tract. Therefore, a better understanding of the role of the GM in the development and function of the mucosal immune system is crucial for implementing measures to promote animal robustness in commercial poultry production. The importance of early gut colonization in the chicken has been overlooked or neglected in industrial poultry production systems, where chicks are hampered from acquiring a complex GM from the hen. Here we discuss the concept of strengthening mucosal immunity in the chicken through GM modulation approaches favouring immune system development and functioning along the gut-lung axis, which could be put into practice through improved farming systems, early-life GM transfer, feeding strategies and pre-/probiotics. We also provide original data from experiments with germ-free and conventional chickens demonstrating that the gut-lung axis appears to be functional in chickens. These key principles of mucosal immunity are likely to be relevant for a variety of avian diseases and are thus of far-reaching importance for the poultry sector worldwide.

Parasitas gastrintestinais em galinhas de raças ornamentais de um criatório particular na cidade Juiz de Fora, Brasil

To evaluate the occurrence of gastrointestinal parasites in chickens of ornamental breeds from a private farm located in Juiz de Fora, Minas Gerais. Fecal samples were collected from the animals individually, collecting the feces right after defecation. The collections were carried out in September 2018. The samples were packed in sterile plastic containers, identified and sent to the Laboratory of Parasitology and Parasitic Diseases of the Centro Universitário de Valença (UNIFAA), for analysis by the simple centrifuge-float technique. Two genera of helminths, Capillaria spp. and Ascaridia spp., and the protozoan Eimeria spp. It can be concluded that the gastrointestinal parasites found in the ornamental chickens studied did not differ from the endoparasites found in conventional free-range chickens. Coproparasitological exams are an excellent, fast and cheap way to verify/identify parasitic forms, which, once diagnosed, must be fought so that they do not compromise the health of the animals, especially in cases of ornamental birds that, because they are less rustic, may be more sensitive to parasites.

Differences in carcass composition and meat quality of conventional and slow-growing broiler chickens raised at 2 stocking densities

The fast growth rate of broiler chickens is a welfare concern that has increased consumer interest in chicken from slower growing (SG) broilers. Replacing conventional (CONV) broilers with SG broilers will reduce chicken supply and SG broilers require different management practices than CONV. This study evaluated the effects of 2 stocking densities on the carcass composition and meat quality of CONV broilers that reach market weight at 42 d and SG broilers that reach market weight at 63 d. Male broilers from each strain were exclusively stocked into 16 pens at a density of either 29 kg/m2 or 37 kg/m2. Live body, carcass without giblets (WOG), and part weights were recorded and used to calculate yield. Initial and 24-hour pH, color (L*, a*, and b*), cooking loss, and Warner Bratzler shear force of the breast and thigh muscles were measured. Birds from both strains reached similar live body and carcass WOG weights. CONV had 3.4%, 13.0%, and 2.8% greater (P ≤ 0.002), carcass WOG, breast, and tenderloin yields, while SG had 2.7%, 5.0%, 7.5%, and 1.2% greater (P < 0.0001) wings, leg quarters, frame, and skin yields, respectively. CONV breast 24-h pH and cooking loss were greater (P ≤ 0.04) than SG. While SG thigh shear force was greater than CONV (P = 0.008), breast shear force was the lowest for CONV stocked at 29 kg/m2 and the greatest for SG stocked at 37 kg/m2 (P = 0.04). SG had a paler breast than CONV, while CONV had a yellower breast than SG (P < 0.0001). While SG had a redder thigh than CONV (P = 0.002), SG stocked at 29 kg/m2 had a redder breast than SG stocked at 37 kg/m2, with both CONV groups intermediate (P = 0.04). These results indicate that differences in male broiler meat quality were affected more by strain than by stocking density. Compared with CONV, SG broiler meat quality was more affected by stocking density in this study.

Differences in Genotype and Antimicrobial Resistance between Campylobacter spp. Isolated from Organic and Conventionally Produced Chickens in Sweden.

Antibiotic resistance is a major challenge worldwide and increased resistance to quinolones in Campylobacter is being reported. Analysis of antibiotic resistance was performed on 157 Campylobacter strains (123 C. jejuni and 34 C. coli) from conventional and organic chickens produced in Sweden. Susceptibility for tetracycline, ciprofloxacin, erythromycin, nalidixic acid, streptomycin, and gentamycin was determined by microdilution. All 77 isolates from organic chickens were sensitive to all antibiotics, except two C. jejuni that were resistant to tetracycline. Of the 80 isolates from conventional chickens, 22.5% of C. jejuni and 11.1% of C. coli were resistant to quinolones and 5.6% of C. jejuni were resistant to tetracycline. Whole-genome sequencing resulted in 50 different sequence types of C. jejuni and six of C. coli. Nine sequence types were found in both organic and conventional chickens. Two of these (ST-19 and ST-257) included isolates from conventional broilers with different resistance phenotypes to the remaining isolates from conventional and organic broilers. There are management differences between the production systems, such as feed, breed, use of coccidiostats, and access to outdoor area. It is unlikely that quinolone resistance has arisen due to use of antimicrobials, since fluoroquinolones are not permitted in Swedish broiler production.

Susceptibility of Commensal E. coli Isolated from Conventional, Antibiotic-Free, and Organic Meat Chickens on Farms and at Slaughter toward Antimicrobials with Public Health Relevance.

The spread of resistant bacteria from livestock to the food industry promoted an increase of alternative poultry production systems, such as organic and antibiotic-free ones, based on the lack of antimicrobial use, except in cases in which welfare is compromised. We aimed to investigate the antibiotic susceptibility of commensal Escherichia coli isolated from organic, antibiotic-free, and conventional broiler farms and slaughterhouses toward several antimicrobials critically important for human health. To assess antimicrobial susceptibility, all E. coli isolates and extended spectrum beta-lactamase (ESBL) E. coli were analysed by the microdilution method. The prevalence of tigecycline, azithromycin and gentamicin E. coli-resistant strains was highest in organic samplings. Conversely, the lowest prevalence of resistant E. coli strains was observed for cefotaxime, ceftazidime and ciprofloxacin in organic systems, representing a significant protective factor compared to conventional systems. All E. coli strains were colistin-susceptible. Contamination of the external environment by drug-resistant bacteria could play a role in the presence of resistant strains detected in organic systems. Of interest is the highest prevalence of cephalosporin resistance of E. coli in conventional samplings, since they are not permitted in poultry. Our results suggest that monitoring of antibiotic resistance of the production chain may be helpful to detect “risks” inherent to different rearing systems.

Upregulation of gut cathepsin L during Eimeria tenella infection

Coccidiosis is a disease caused by Eimeria, which represents the first parasitic disease in poultry farming. Among them, E. tenella is a virulent species which specifically colonizes the caecum. The inflammatory response to infection is associated to numerous host proteases including cysteine cathepsins that can be deleterious for tissue and innate immunity integrity. Here, germ-free and conventional chickens were used as models to find out whether the microbiota could modify the intestinal expression of host cysteine cathepsins during coccidiosis. The basal caecal peptidase activity primarily relies on host proteases rather than proteases from the commensal flora. While mRNA levels of E. tenella cathepsins B and L remained unchanged in germ-free and conventional broilers, an overall increase in endopeptidase activity of cysteine cathepsins was found in E. tenella-infected caeca in both experimental models (P < 0.005). A significant decrease in avian cystatin C transcription was also observed in infected conventional, but not in infected germ-free broilers. Despite an unchanged mRNA level of avian cathepsin L (CatL), its protein expression raised following infection, in parallel with an increased transcription of antimicrobial β-defensins (AvBD1, AvBD2, AvBD4, AvBD6, and AvBD7). Taken together, data support that host CatL is post-translationally upregulated during E. tenella infection, and thus may be involved in the alteration of the gut proteolytic balance. Furthermore, CatL may participate to inflammation occurring during coccidiosis through its known ability to proteolytically inactivates up-regulated avian β-defensins that are key molecules of innate immunity.

The Influence of Vaccination of Broiler Chickens and Turkeys with Live E. coli Attenuated Vaccine on E. coli Population Properties and TRT Vaccination Efficacy.

Simple SummaryEscherichia coli infections are considered one of the major causes of economic loss in the poultry industry. The reasons for the magnitude of the problem are the numerous sources of infection with these bacteria for birds and the need for an effective prevention method. Vaccination is one of the strategies for minimizing the consequences of E. coli infection. In this study, we performed three independent experiments at farm level using a live vaccine against E. coli. Antibiotic-free broiler chickens, conventional broiler chickens and broiler turkeys were examined in different experiments. The most meaningful results and conclusions of these experiments are that vaccination against colibacillosis decreases the population count of E. coli, increases the antibiotic susceptibility of field E. coli isolates and has no impact on the efficacy of vaccination against another significant poultry upper respiratory tract disease—TRT. We believe that the vaccination of broiler chickens and turkeys against E. coli can improve bird health and should be considered in terms of routine immunoprophylaxis.Colibacillosis is one of the major causes of economic losses in the poultry industry. Vaccination against E. coli is attracting increasing interest. The aim of the study was to evaluate the influence of vaccination with live, aroA gene-deleted vaccine on the structure and properties of field E. coli population and its potential impact on TRT vaccination efficacy in broiler chickens and turkeys. We performed three independent experiments on farms: (1) with antibiotic-free broiler chickens, (2) with conventional broiler chickens and (3) with broiler turkeys. In experiment 1, we have recorded an approx. 0–15% prevalence of multi-susceptible E. coli strains in the first production cycle. Starting from production cycle number two, after vaccination introduction, successive significant increases in E. coli susceptibility emerged, reaching 100% of strains at the end of production cycle 3. Increased E. coli susceptibility remained for three production cycles after vaccination withdrawal. In experiments 2 (2 production cycles) and 3 (1 production cycle), we recorded similar tendencies of E. coli susceptibility profile change. In experiments 1 and 2, the E. coli population count was lower after vaccination. In experiments 2 and 3, no negative influence of E. coli vaccination on the level of specific antibodies against TRT was recorded.

Antimicrobial resistance in Escherichia coli between conventional and organic broiler flocks

Antimicrobial resistance ( AMR ) is a growing concern for human and animal health. Public awareness of these issues has contributed to increased demand for organic food. In poultry production, there are 3 major production types: no antibiotic ever, organic, and conventional. Organics have been considered safer alternatives that carry fewer antibiotic-resistant bacteria and have less incidence of stable resistance. In this study, we examined the impact of organic and conventional production practices on the resistance patterns of the intestinal microbiome of chickens. Culture and sensitivity analysis performed on the cecal contents were compared between organic and conventionally grown chickens from identical parent stock collected in July and September. The results demonstrated that Escherichia coli isolated from conventionally produced chickens were significantly more resistant to neomycin ( P -value <0.0002) and tetracycline ( P -value = 0.0000) when compared with organically produced chickens in the July collection samples. However, there was no significant difference observed between groups in the September samples. These data demonstrate that AMR patterns of E. coli can differ significantly between organic and conventional chickens in the samples, but AMR pattern among E. coli isolates may not be consistent.

Nuclear Magnetic Resonance (NMR)-Based Quantification on Flavor-Active and Bioactive Compounds and Application for Distinguishment of Chicken Breeds.

The purpose of this study was to use 1H nuclear magnetic resonance (1H NMR) to quantify taste-active and bioactive compounds in chicken breasts and thighs from Korean native chicken (KNC) [newly developed KNCs (KNC-A, -C, and -D) and commercial KNC-H] and white-semi broiler (WSB) used in Samgye. Further, each breed was differentiated using multivariate analyses, including a machine learning algorithm designed to use metabolic information from each type of chicken obtained using 1H-13C heteronuclear single quantum coherence (2D NMR). Breast meat from KNC-D chickens were superior to those of conventional KNC-H and WSB chickens in terms of both taste-active and bioactive compounds. In the multivariate analysis, meat portions (breast and thigh) and chicken breeds (KNCs and WSB) could be clearly distinguished based on the outcomes of the principal component analysis and partial least square-discriminant analysis (R2=0.945; Q2=0.901). Based on this, we determined the receiver operating characteristic (ROC) curve for each of these components. AUC analysis identified 10 features which could be consistently applied to distinguish between all KNCs and WSB chickens in both breast (0.988) and thigh (1.000) meat without error. Here, both 1H NMR and 2D NMR could successfully quantify various target metabolites which could be used to distinguish between different chicken breeds based on their metabolic profile.

The Absence of Gut Microbiota Alters the Development of the Apicomplexan Parasite Eimeria tenella

Coccidiosis is a widespread intestinal disease of poultry caused by a parasite of the genus Eimeria. Eimeria tenella, is one of the most virulent species that specifically colonizes the caeca, an organ which harbors a rich and complex microbiota. Our objective was to study the impact of the intestinal microbiota on parasite infection and development using an original model of germ-free broilers. We observed that germ-free chickens presented significantly much lower load of oocysts in caecal contents than conventional chickens. This decrease in parasite load was measurable in caecal tissue by RT-qPCR at early time points. Histological analysis revealed the presence of much less first (day 2pi) and second generation schizonts (day 3.5pi) in germ-free chickens than conventional chickens. Indeed, at day 3.5pi, second generation schizonts were respectively immature only in germ-free chickens suggesting a lengthening of the asexual phase of the parasite in the absence of microbiota. Accordingly to the consequence of this lengthening, a delay in specific gamete gene expressions, and a reduction of gamete detection by histological analysis in caeca of germ-free chickens were observed. These differences in parasite load might result from an initial reduction of the excystation efficiency of the parasite in the gut of germ-free chickens. However, as bile salts involved in the excystation step led to an even higher excystation efficiency in germ-free compared to conventional chickens, this result could not explain the difference in parasite load. Interestingly, when we shunted the excystation step in vivo by infecting chickens with sporozoites using the cloacal route of inoculation, parasite invasion was similar in germ-free and in conventional chickens but still resulted in significantly lower parasite load in germ-free chickens at day 7pi. Overall, these data highlighted that the absence of intestinal microbiota alters E. tenella replication. Strategies to modulate the microbiota and/or its metabolites could therefore be an alternative approach to limit the negative impact of coccidiosis in poultry.