In consequence of the withdrawal of products that assisted animal production, such as antimicrobial growth promoters, once-controlled enteric diseases have returned and new multifactorial diseases causing gut disorders of unknown origin have emerged in broilers. One of these widespread syndromes causing intestinal health problems in broilers is in the field referred to as "dysbacteriosis". During the present study, the histopathology of the intestinal tract of broilers affected with dysbacteriosis was analysed. Commercial broilers were given a macroscopic dysbacteriosis score by experienced veterinarians during necropsy. Samples from the duodenum and caecum were taken from each broiler for histopathological analysis. An increase in the macroscopic dysbacteriosis score coincided with increased villus atrophy, a decrease in the thickness of the tunica muscularis and an increase in T-lymphocyte infiltration in the gut mucosa. Also more and larger goblet cells were observed in the animals with high macroscopic dysbacteriosis scores. Although the exact aetiology still remains to be identified, dysbacteriosis in broiler chickens thus coincides with an inflammatory reaction in the gut mucosa.

In broiler chickens, a diet where the major cereal types are wheat, rye and/or barley has a lower digestibility compared with a diet in which maize is the major cereal type. In the present study, the effects of two different dietary cereal types, maize v. wheat/rye, on host factors (inflammation and gut integrity) and gut microbiota composition were studied. In addition, the effects of low-dose Zn-bacitracin supplementation were examined. Broilers given a wheat/rye-based diet showed more villus fusion, a thinner tunica muscularis, more T-lymphocyte infiltration, higher amount of immune cell aggregates in the mucosa, more and larger goblet cells and more apoptosis of epithelial cells in the mucosa than those given a maize-based diet. Adding Zn-bacitracin generally reversed these alterations. The microbiota composition was analysed by the use of terminalrestriction fragment length polymorphism, showing changes in the microbiota composition depending on the cereal type used in the diets. The effect of the change of cereal type on the gut microbiota composition was larger than that of Zn-bacitracin supplementation. In conclusion, a wheat/rye-based diet evoked mucosal damage, an alteration in the composition of the microbiota and an inflammatory bowel type of condition.

Butyricicoccus pullicaecorum gen. nov., sp. nov., an anaerobic, butyrate-producing bacterium isolated from the caecal content of a broiler chicken Five isolates that produced large amounts of butyrate were obtained in the course of a study on the butyrate-producing microbiota from the caecal content of a 4-week-old broiler chicken. The five isolates were virtually indistinguishable in biochemical and genetic terms, suggesting that they were derived from a single bacterial clone colonizing this habitat. A phylogenetic analysis based on 16S rRNA gene sequences demonstrated that the five isolates represented a unique lineage within the Clostridium leptum subgroup of the clostridia, with Eubacterium desmolans as the closest phylogenetic neighbour (about 93 % similarity). These data indicate that the five novel isolates represent a single novel species within a novel genus, for which we propose the name Butyricicoccus pullicaecorum gen. nov., sp. nov. The type strain of Butyricicoccus pullicaecorum is 25-3 T (5LMG 24109 T 5CCUG 55265 T ). The DNA G+C content of strain 25-3 T was 54.5 mol% .

A study was conducted to analyze the effect of the cereal type in the diet on the susceptibility for Salmonella Enteritidis in broilers. In the first experiment, 40 newly hatched broiler chicks were randomly assigned to 4 different experimental treatment groups. Two treatment groups were fed a maize-soybean-based diet, of which one contained 100 mg/kg of the antibiotic growth promoter zinc bacitracin. The 2 other treatment groups were fed a wheat/rye-soybean-based diet, of which one was supplemented with 100 mg/kg of zinc bacitracin. The broilers were inoculated with Salmonella Enteritidis at d 11 and killed at d 15. When the nonantibiotic- and the antibiotic-treated birds were pooled, the Salmonella colonization in the spleen and ceca of the birds fed a maize-based diet was significantly lower in comparison to colonization of spleen and ceca in the wheat/rye groups. Zinc bacitracin did not affect Salmonella colonization. In a second experiment, which was a modified repetition of the first experiment, 120 newly hatched broiler chicks were randomly assigned to 2 experimental treatments. They were fed a maize-soybean or a wheat/rye-soybean based diet, inoculated with Salmonella Enteritidis at d 11, and killed at d 15. A significantly lower Salmonella colonization was observed in the spleen, liver, and ceca of broilers given a maize-based diet in comparison to those given a wheat/rye-based diet. These data show that the cereal type in broiler feed can affect Salmonella colonization probably due to changes in intestinal health of the birds. Hence, altering the diet composition can be regarded as a simple tool to supplement other control measures against Salmonella in broilers.