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Broilers often suffer from subclinical intestinal health problems of ill-defined etiology, which have a negative impact on performance. Macroscopic and microscopic evaluations can be used to monitor intestinal health, but because these are subjective and time-consuming, respectively, objective and easy-to-measure biomarkers are urgently needed. Fecal biomarkers can potentially be used as noninvasive, objective measures to evaluate gut health in broilers. The aim of the current study was to evaluate ovotransferrin (OVT) as a biomarker in fecal/colonic samples derived from broilers from 27 industrial farms by investigating associations between OVT, broiler performance and gut histology parameters. Eight chickens per farm were randomly selected, weighed and euthanized on d 28 of the production round. A duodenal section was collected to measure the intestinal villus structure (villus length, crypt depth) and the inflammatory status of the gut (CD3+ T-lymphocytes area percentage). The coefficient of variation for the OVT (between farms; 83.45%, within farms; 95.13%) was high compared to the villus length (between farms; 10.91%, within farms; 15.48%), crypt depth (between farms; 15.91%, within farms; 14.10%), villus-to-crypt ratio (between farms; 22.08%, within farms; 20.53%), and CD3+ (between farms; 36.38%, within farms; 26.13%). At farm level, colonic OVT was significantly associated with the average slaughter weight (P = 0.005), daily weight gain (P = 0.007) and the European production index (EPI) (P = 0.009). At broiler level, significant associations were found between colonic OVT and the villus length (P = 0.044) and between the colonic OVT and villus-to-crypt ratio (P = 0.050). These results thus show that quantifying OVT in colon can have merit for evaluation of intestinal health in broilers under field conditions. [ABSTRACT FROM AUTHOR]

The grains that form the basis of most commercial chicken diets are rich in cellulose, an unbranched β-1,4-linked D-glucopyranose polymer, used as a structural molecule in plants. Although it is a predominant polysaccharide in cereal hulls, it is considered an inert non-fermentable fiber. The aim of the current study was to analyze the effect of in-feed supplementation of cellulose on the gut microbiota composition of broilers. Administration of cellulose to chickens, on top of a wheat-based diet, changed the caecal microbiota composition, as determined using pyrosequencing of the 16S rRNA gene. At day 26, a significantly (P < 0.01) higher relative abundance of the Alistipes genus was observed in the caeca of broilers fed the cellulose-supplemented diet, compared to animals fed the control diet. An in vitro batch fermentation assay showed a significant (P < 0.01) growth stimulation of Alistipes finegoldii in the presence of cellulose. In conclusion, in-feed supplementation of cellulose alters the microbiota composition at the level of the phylum Bacteroidetes , specifically the Alistipes genus. This suggests that cellulose is not essentially inert but can alter the gut micro-environment. [ABSTRACT FROM AUTHOR]

Galactomannans are abundant nonstarch polysaccharides in broiler feed ingredients. In broilers, diets with high levels of galactomannans have been associated with innate immune response stimulation, poor zootechnical performance, nutrient and lipid absorption, and excessive digesta viscosity. However, data about its effects on the gut microbiome are scarce. β-Mannanases are enzymes that can hydrolyze β-mannans, resulting in better nutrient utilization. In the current study, we have evaluated the effect of guar gum, a source of galactomannans, supplemented to broiler diets, either with or without β-mannanase supplementation, on the microbiota composition, in an attempt to describe the potential role of the intestinal microbiota in β-mannanase-induced gut health and performance improvements. One-day-old broiler chickens (n = 756) were randomly divided into 3 treatments: control diet, guar gum-supplemented diet (1.7%), or guar gum-supplemented diet + β-mannanase (Hemicell 330 g/ton). The zootechnical performance, gut morphometry, ileal and cecal microbiome, and short-chain fatty acid concentrations were evaluated at different time points. The guar gum supplementation decreased the zootechnical performance, and the β-mannanase supplementation restored performance to control levels. The mannan-rich diet-induced dysbiosis, with marked effects on the cecal microbiota composition. The guar gum-supplemented diet increased the cecal abundance of the genera Lactobacillus, Roseburia, Clostridium sensu stricto 1 , and Escherichia-Shigella , and decreased Intestinimonas, Alistipes, Butyricicoccus , and Faecalibacterium. In general, dietary β-mannanase supplementation restored the main microbial shifts induced by guar gum to levels of the control group. In addition, the β-mannanase supplementation reduced cecal isobutyric, isovaleric, valeric acid, and branched-chain fatty acid concentrations as compared to the guar gum-supplemented diet group, suggesting improved protein digestion and reduced cecal protein fermentation. In conclusion, a galactomannan-rich diet impairs zootechnical performance in broilers and results in a diet-induced dysbiosis. β-Mannanase supplementation restored the gut microbiota composition and zootechnical performance to control levels. [ABSTRACT FROM AUTHOR]

Salmonella is an important zoonotic agent, and poultry products remain one of the main sources of infection for humans. Salmonella Infantis is an emerging serotype in poultry worldwide, reflected by an increased prevalence in poultry flocks, on broiler meat and in human foodborne illness cases. In the current study, the efficacy of oral administration of a live monovalent Salmonella Enteritidis and a live bivalent Salmonella Enteritidis/Typhimurium vaccine, against a Salmonella Enteritidis and Infantis infection, was determined. Oral administration of the live vaccines to day-old chickens caused a decrease in caecal colonization by Salmonella Enteritidis, but not Infantis, at day 7, when challenged at day 2. Vaccination with the bivalent vaccine at day 1 resulted in a decreased spleen colonization by both Salmonella Infantis and Enteritidis. Twice (at day 1 and week 6) and thrice vaccination (at day 1, week 6 and 16) of laying hens with the bivalent vaccine resulted in a decreased caecal colonization by Salmonella Enteritidis and Infantis, and significantly lower oviduct colonization levels by Salmonella Enteritidis. These data show cross-protection against Salmonella Infantis by oral administration of live vaccine strains belonging to other serogroups. [ABSTRACT FROM AUTHOR]

Intestinal integrity losses have been identified as a main driver for poor performance in broilers. The oral administration of markers such as iohexol is a major asset for measuring intestinal permeability (IP) alterations. The aim of the current study was to evaluate oral iohexol administration and serum levels as a quantitative measure for IP in Ross 308 broilers and to identify possible associations with histologic measurements. A total of 40, day-old broiler chickens were randomly divided into 4 groups of 10 broilers and a coccidiosis model was used to induce IP. Three challenge groups received a mixture of different field strains and concentrations of Eimeria acervulina and Eimeria maxima at d 16, and 1 group operated as an uninfected control group. On d 20, 5 birds per group were orally administered the permeability marker iohexol at a dose of 64.7 mg/kg body weight and blood was taken 60 min after the oral gavage. On d 21 these 5 birds per group were euthanized. On d 21, 5 other birds per group were given iohexol where after blood was taken. These birds were euthanized on d 22. During necropsy, birds were scored for coccidiosis lesions and a duodenal segment was taken for histology. The Eimeria challenge had a significant impact on the villus length, crypt depth, villus-to-crypt ratio and CD3+ T-lymphocytes area percentage. Challenged birds had a significant higher concentration of serum iohexol on both sampling days, as compared to the uninfected controls. A significant correlation could be found between the serum iohexol concentration and the histologic parameters (villus length, crypt depth and villus-to-crypt ratio) on the first sampling day. This suggests that iohexol may be used as a gut permeability marker in broilers under Eimeria challenge. [ABSTRACT FROM AUTHOR]

Inflammatory bowel disease (IBD) is a chronic inflammation of the digestive tract, characterized by dysbiosis of the intestinal microbiota. Probiotics have been suggested as a strategy to reduce active disease or extend remission. We isolated and characterized the butyrate-producing strain Butyricicoccus pullicaecorum 25-3 T and identified it as a potential probiotic for patients with IBD. To evaluate the safety of 25-3 T for use in humans, we conducted a standard acute oral toxicity test and a 28-day repeated oral dose toxicity test. The complete genome of B. pullicaecorum 25-3 T was sequenced to search for virulence factors and antibiotic resistance determinants. The minimum inhibitory concentration (MIC) of 21 antimicrobials was determined. Results showed no adverse effects in the oral toxicity tests. B. pullicaecorum 25-3 T is resistant against aminoglycosides and trimethoprim. The genome of 25-3 T contains no virulence factors, one gene related to harmful metabolites and 52 sequences with high similarity to antimicrobial and toxic compound resistance genes, that did not correspond with a resistant phenotype. This first report of a safety assessment of a butyrate-producing strain from Clostridium cluster IV shows that B. pullicaecorum 25-3 T is a non-pathogenic strain, but carries antibiotic resistance genes with the risk of transfer, that need further investigation. [ABSTRACT FROM AUTHOR]