This study investigated the effects of dietary supplementation with the prebiotics fructo-oligosaccharide (FOS) and mannan-oligosaccharide (MOS) on the performance, small intestinal microflora, and immune response of broilers. Two hundred forty 1-d-old Ross broiler chickens were randomly assigned to 6 dietary treatment groups: control, avilamycin (6 mg/kg), 0.25% FOS, 0.5% FOS, 0.025% MOS, and 0.05% MOS. Each treatment was fed to 4 replicates of 10 birds per diet for 4 wk. Except for the 0.5% FOS group, the overall BW gains of birds treated with avilamycin and prebiotics were significantly(P < 0.05) higher than those of the control group. No significant differences were found between the control and supplemented groups in overall feed intake, feed conversion, and mortality. The 0.05% MOS group was significantly (P< 0.05) lower than the control and 0.5% FOS groups in heterophil:lymphocyte ratio and basophil level. Concentrations of plasma IgA and IgG were not significantly different among the treatment groups. Quantitative real-time PCR indicated that supplementation of the diet with avilamycin or prebiotics caused significant (P < 0.05) changes in the small intestinal microbial community, as determined in samples obtained at the ileocecal junction. The populations of Clostridium perfringens and Escherichia coli decreased with 0.25% FOS, 0.05% MOS, or avilamycin, and lactobacilli increased in the 0.25% FOS and 0.25% MOS treatment groups. Total bacteria increased in the 0.25% FOS and 0.05% MOS treatments and decreased in the avilamycin treatment. Feeding 0.25% FOS and 0.05% MOS resulted in an increase in lactobacillus community diversity in the ileum. Our results showed that 0.25% FOS and 0.05% MOS were comparable with avilamycin in improving productivity in broilers raised in wire floor cages up to 28 d of age. Plasma immunoglobulins were not affected by prebiotics, but the heterophil:lymphocyte ratio, basophil level, and microbial population in the ileum were significantly affected.

Aims: To clone, characterize and compare the bile salt hydrolase (BSH) genes of Lactobacillus johnsonii PF01. Methods and Results: The BSH genes were amplified by polymerase chain reaction (PCR) using specific oligonucleotide primers, and the products were inserted into the pET21b expression vector. Escherichia coli BLR (DE3) cells were transformed with pET21b vectors containing the BSH genes and induced using 0Á1 mmol l À1 isopropylthiolgalactopyranoside. The overexpressed BSH enzymes were purified using a nickel-nitrilotriacetic acid (Ni 2+ -NTA) agarose column and their activities characterized. BSH A hydrolysed tauro-conjugated bile salts optimally at pH 5Á0 and 55°C, whereas BSH C hydrolysed glycoconjugated bile salts optimally at pH 5Á0 and 70°C. The enzymes had no preferential activities towards a specific cholyl moiety. Conclusions: BSH enzymes vary in their substrate specificities and characteristics to broaden its activity. Despite the lack of conservation in their putative substrate-binding sites, these remain functional through motif conservation. Significance and Impact of the Study: This is to our knowledge the first report of isolation of BSH enzymes from a single strain, showing hydrolase activity towards either glyco-conjugated or tauro-conjugated bile salts. Future structural homology studies and site-directed mutagenesis of sites associated with substrate specificity may elucidate specificities of BSH enzymes.

Aims: The aim of this study was to evaluate the effects of Bifidobacterium lactis HY8101 on insulin resistance induced using tumour necrosis factor-a (TNF-a) in rat L6 skeletal muscle cells and on the KK-A Y mouse noninsulindependent diabetes mellitus (NIDDM) model. Methods and Results: The treatment using HY8101 improved the insulinstimulated glucose uptake and translocation of GLUT4 via the insulin signalling pathways AKT and IRS-1(Tyr) in TNF-a-treated L6 cells. HY8101 increased the mRNA levels of GLUT4 and several insulin sensitivity-related genes (PPAR-c) in TNF-a-treated L6 cells. In KK-A Y mice, HY8101 decreased fasting insulin and blood glucose and significantly improved insulin tolerance. HY8101 improved diabetes-induced plasma total cholesterol and triglyceride (TG) levels and increased the muscle glycogen content. We observed concurrent transcriptional changes in the skeletal muscle tissue and the liver. In the skeletal muscle tissue, the glycogen synthesis-related gene pp-1 and GLUT4 were up-regulated in mice receiving HY8101 treatment. In the liver, the hepatic gluconeogenesis-regulated genes (PCK1 and G6PC) were down-regulated in mice receiving HY8101 treatment. Conclusions: Bifidobacterium lactis HY8101 can be used to moderate glucose metabolism, lipid metabolism and insulin sensitivity in mice and in cells. Significance and Impact of the Study: Bifidobacterium lactis HY8101 might have potential as a probiotic candidate for alleviating metabolic syndromes such as diabetes.

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The objective of this experiment was to investigate the effect of dietary supplementation of Lactobacillus-fermented Artemisia princeps (LFA) on growth performance, meat lipid peroxidation, and intestinal microflora in Hy-line Brown male chickens. A total of six hundred twenty-four 1-d-old Hy-Line Brown male chicks were randomly allotted to 3 dietary treatments with 4 replicated pens consisting of 52 chicks. The control diet was formulated to be adequate in energy and nutrients. Two additional diets were prepared by adding 2.5 or 5.0 g/kg of LFA to the control diet. The experimental diets were fed on an ad libitum basis to the birds during 7 wk. Body weight gain and feed intake were recorded at 2 and 7 wk. At the end of the experiment, 2 birds from each treatment were killed by cervical dislocation and the samples for ileal content, breast, and thigh meat were collected for the determination of meat lipid peroxidation and microbial population. Results indicated that increasing inclusion level of LFA in diets improved BW gain (linear and quadratic, P < 0.05) and tended to improve feed efficiency (linear and quadratic, P < 0.10) of birds during 0 to 7 wk. Feeding the diets containing increasing amounts of LFA to birds reduced (quadratic, P < 0.05) thiobarbituric acid-reactive substance (TBARS) values in breast and thigh meat during 15 d of storage. The concentrations of Lactobacillus spp. in the ileal content of birds increased (linear and quadratic, P < 0.05), but those of Salmonella spp. tended to be decreased (quadratic, P < 0.10) as inclusion level of LFA in diets increased. These results suggest that dietary LFA may be used as a functional ingredient to improve growth performance, meat lipid stability, and intestinal health of birds.

1. Bacteriophages (BP) have gained increasing attention as a treatment of bacterial infection for animals. However, the data pertaining to dietary application of BP for laying hens have been limited. 2. This study aimed to investigate the effect of dietary BP on laying performance, egg quality and caecal bacterial populations in laying hens. 3. The dietary BP used in this experiment was a mixture of individual BP targeting Salmonella gallinarum, Salmonella pullorum, Salmonella typhimurium, Salmonella enteritidis, Salmonella derby and Staphylococcus aureus. 4. A total of 360 Hy-Line Brown laying hens of 32 weeks of age were allotted to one of three dietary treatments with 6 replicates in a completely randomised design. The basal diet was prepared, and 0.4 or 0.8 g/kg BP mixture was supplemented to the basal diet. Diets were fed to hens for 8 weeks. 5. Laying performance and egg quality were not affected by dietary treatments. As inclusion levels of BP mixture in diets were increased, the DNA copy numbers for Salmonella spp. in the caecal contents decreased linearly, whereas the DNA copy numbers for Escherichia coli in the caecal contents increased linearly. 6. Results indicate that dietary supplementation of BP mixture decreases the target Salmonella spp. populations but increases Escherichia coli populations in the gastrointestinal tract of laying hens with little impact on laying performance and egg quality.