Research Note: Effect of synbiotic supplementation on caecal Clostridium perfringens load in broiler chickens with different necrotic enteritis challenge models.

Studies were conducted to determine the efficacy of synbiotic applications to combat the negative effects of necrotic enteritis (NE). An in vitro study was conducted to test the effect of probiotics species supernatants to decrease Clostridium perfringens (CP) proliferation. Lactobacillus reuteri, Enterococcus faecium, Bifidobacterium animalis, and Pediococcus acidilactici culture supernatants decreased the proliferation of CP at 1:1 supernatant-to-pathogen dilution in vitro. Two in vivo studies were conducted to determine the in vivo response of synbiotic supplementation containing the aforementioned probiotic strains on broiler production performance and caecal CP load in broilers induced with NE infection. In experiment 1, 75 broiler chicks were randomly allotted to 3 treatment groups, control (basal diet), ionophore (Salinomycin), and synbiotic (PoultryStar me), from day of hatch, and NE was induced in all birds. There were no significant treatment effects on BW, feed consumption, and feed gain ratio. However, at 35 D, ionophore or synbiotic supplementation increased (P < 0.05) villi height and decreased interleukin (IL)-1 mRNA abundance, while synbiotic supplementation increased (P < 0.05) IL-10 mRNA abundance compared with the control group, respectively. In experiment 2, 360 broiler chicks were randomly allotted to 3 treatments, an unchallenged negative control (control; basal diet), challenged positive control (NE; basal diet), or NE + synbiotic group (synbiotic). At both 21 and 42 D of age, NE birds had decreased (P < 0.05) BW, feed conversion, and jejunal villi height compared with control, while NE + synbiotic birds were not different from control groups. At 42 D of age, NE birds had 2.2 log/g increased CP in the ceca contents compared with control, while synbiotic birds had CP load that was not different than that of the control group. NE + synbiotic birds had significantly greater amounts of bile anti-CP IgA than the control and NE groups. It can be concluded that synbiotic supplementation decreased CP proliferation in vitro and caecal CP load in vivo while improving production parameters during an NE infection in broilers.

Synbiotic supplementation to decrease Salmonella colonization in the intestine and carcass contamination in broiler birds.

In vitro and in vivo experiments were conducted to study the effects of synbiotic supplementation on Salmonella enterica ser. Enteritidis (SE) proliferation, cecal content load, and broiler carcass contamination. Lactobacillus reuteri, Enterococcus faecium, Bifidobacterium animalis, and Pediococcus acidilactici culture supernatants decreased (P < 0.05) the in vitro proliferation of SE at 1:1 supernatant: pathogen dilution. A total of 240 Cobb-500 broiler chicks were randomly allotted to three treatment groups (8 replicates/group with 10 birds/replicate): control (basal diet), antibiotic (Virginiamycin at 20 mg/kg feed), synbiotic (PoultryStar® ME at 0.5 g/kg feed containing L. reuteri, E. faecium, B. animalis, P. acidilactici and a Fructooligosaccharide) from day of hatch. At 21 d of age, all birds in experimental groups were orally inoculated with 250 µl of 1 X 109 CFU SE. Antibiotic supplementation increased (P < 0.05) body weight and feed consumption, compared to the control group. Birds in the synbiotic supplementation had intermediate body weight and feed consumption that were not significantly different from both the control and antibiotic group at 42 d of age in SE infected birds. No significant effects were observed in feed efficiency at 42 d of age among the groups. Antibiotic and synbiotic supplementation decreased (P < 0.05) SE load in cecal contents by 0.90 and 0.85 log units/ g and carcass SE load by 1.4 and 1.5 log units/mL of rinsate compared to the control group at 42 d of age (21 dpi). The relative abundance of IL-10, IL-1, TLR-4, and IFNγ mRNA was decreased (P < 0.05) in the antibiotic and synbiotic supplementation groups compared to the control birds at 42 d of age (21 dpi). It can be concluded that synbiotic supplementation decreased SE proliferation in vitro and decreased SE load in the cecal contents and broiler carcass.

Effects of hydroxychloride and sulfate form of zinc and manganese supplementation on superoxide dismutase activity and immune responses post lipopolysaccharide challenge in poultry fed marginally lower doses of zinc and manganese.

Effects of hydroxychloride (OHCl) and sulfate form of zinc and manganese supplementation on immune responses of birds fed marginally lower levels of zinc and manganese during an experimental lipopolysaccharide (LPS) injection were studied. In experiment I, 30-week-old layer birds were fed 50 mg/kg Zn+45 mg/kg Mn or 100 mg/kg Zn+90 mg/kg Mn in sulfate or OHCl form and injected with 0 or 500 µg/kg LPS in a 2 (50 mg Zn+45 mg Mn and 100 mg Zn+90 mg Mn) X 2 (sulfate and OHCl) X 2 (0 and 500 µg LPS) factorial setup of treatments for 10 weeks. Among LPS-injected birds, those receiving 50 mg ZnOHCl+45 mg MnOHCl had comparable heterophil and monocyte superoxide dismutase (SOD) activity compared to the birds fed 100 mg Zn+90 mg Mn. Compared to the birds injected with PBS, LPS injection upregulated cathelicidin and IL-1 relative mRNA amounts in monocytes from birds fed 100 mg Zn+90 mg Mn, both in sulfate and OHCl form, and in birds fed 50 mg ZnOHCl+45 mg MnOHCl, but not in the birds fed 50 mg ZnSO4+45 mg MnSO4. In experiment II, one-day-old broiler birds were fed 50 mg ZnOHCl+45 mg MnOHCl, 50 mg ZnOHCl+90 mg MnOHCl, 100 mg ZnOHCL+45 mg MnOHCl, 100 mg ZnOHCl+90 mg MnOHCl, 50 mg ZnSO4+45 mg MnSO4, or 100 mg ZnSO4+90 mg MnSO4 for 21 and 42 days. Birds fed 100 mg ZnOHCl+45 mg MnOHCl form had a comparable heterophil and monocyte SOD activity and monocyte cathelicidin mRNA amounts compared to the group fed 100 mg Zn+90 mg Mn. Increasing the ZnOHCl content from 50 mg to 100 mg/kg Zn reversed (P > 0.05) the decrease in SOD activity and monocyte cathelicidin mRNA levels of the 50 mg ZnOHCl+45 mg MnOHCL fed group, and increasing the MnOHCl content from 45 mg to 90 mg/kg in the 100 mg ZnOHCl+45 mg MnOHCl group further increased SOD activity. In conclusion, birds fed diets with lower amounts of zinc and manganese in sulfate form decreased SOD activity and IL-1 and cathelicidin amounts during inflammation, and either increasing the dietary zinc and manganese content or feeding zinc and manganese in OHCl form synergistically increased the SOD activity and IL-1 and cathelicidin mRNA amounts in immune cells.

Effect of in vitro and in vivo 25-hydroxyvitamin D treatment on macrophages, T cells, and layer chickens during a coccidia challenge.

This article describes the in vitro and in vivo effects of a 25-hydroxycholecalciferol (25[OH]D) treatment in layer hens during a mixed coccidia challenge. HD11 cells (chicken macrophage cell line) were treated in vitro with a coccidia antigen or in a medium supplemented with either 1,25-dihydroxycholecalciferol (1,25[OH]2D) or 25(OH)D. HD11 cells treated in vitro with 200 nM of 1,25(OH)2D had increased nitrite production (P < 0.01) compared with HD11 cells treated with 0 or 200 nM of 25(OH)D. Treating HD11 cells with 25(OH)D decreased IL-10 mRNA by 1.7-fold, but 1,25(OH)2D treatment increased the amount of IL-10 mRNA by 2.7-fold (P < 0.01) compared with the group treated with 0 nM of 25(OH)D. Post-coccidial antigen stimulation, 25(OH)D or 1,25(OH)2D treatment decreased (P < 0.01) 1α-hydroxylase mRNA amounts in HD11 cells. Stimulating primary T cells in vitro with Concanavalin A (Con-A) decreased (P = 0.020) the 1α-hydroxylase mRNA amounts by 3-fold. ConA-B1-VICK cells (chicken T cell line) stimulated with 100 nM 1,25(OH)2D or with supernatants from HD11 cells treated with 25(OH)D plus lipopolysaccharide (LPS) had 1.3-fold less (P < 0.01) interferon (IFN)-γ mRNA compared with the group treated with 25(OH)D. Layer birds were fed a basal diet supplemented with 25(OH)D at 6.25, 25, 50, or 100 µg/kg, and at 21 d of age orally challenged with 1 × 10(5) live coccidia oocysts. Compared with birds fed similar levels of 25(OH)D and unchallenged with the coccidia oocyst, birds challenged with the coccidia oocyst had 15% reduced BW gain in the groups supplemented with either 6.25, 25, or 50 µg/kg of 25(OH)D, but only a 4% reduced BW gain in birds fed 100 µg/kg of 25(OH)D (P < 0.01). Birds fed 100 µg/kg 25(OH)D had decreased (P = 0.012) CD8+ cell percentages in cecal tonsils in both coccidial oocyst challenged and unchallenged birds, compared with birds fed 6.25 µg/kg 25(OH) and unchallenged with coccidial oocysts. At 15 d post-coccidia challenge, birds fed 100 µg/kg 25(OH)D and challenged with coccidial oocysts had 17% more CD4+CD25+ cells (P = 0.018) in the cecal tonsil compared with the birds fed 100 µg/kg 25(OH)D and unchallenged with coccidial oocysts. At d 6 post-coccidia challenge, birds fed 100 µg/kg 25(OH)D had a 3.5-fold increase (P < 0.01) in IL-10 mRNA amounts in the cecal tonsils compared with birds fed 6.25 µg/kg 25(OH)D. In conclusion, supplementing birds with 100 µg/kg 25(OH)D could be a nutritional strategy to reduce the production losses post-coccidia challenge.

Effect of recycled litter on immune cells in the cecal tonsils of chickens.

This experiment was conducted to study selected aspects of the gut immune response in broiler chicks reared on fresh or recycled litter that were fed diets with and without subtherapeutic antibiotic supplementation. All of the chicks were reared in pens that contained either fresh pine shavings (fresh litter) or litter that was recycled for 3 consecutive flocks (recycled litter). The experiment was a 2 × 2 factorial arrangement of treatments with 4 replicate pens (n = 4) per treatment. At 10 and 35 d of age, the cecal tonsils were analyzed for intestinal immune measurements. The cecal tonsils of birds reared on recycled litter had increased IL-1 mRNA (P < 0.01) and a lower percentage of CD4(+)CD25(+) cells at 10 and 35 d of age when compared with those of chicks reared on fresh litter. Birds fed diets supplemented with bacitracin had a reduction in CD4(+) cells (P = 0.01) at 10 d of age when compared with that of chicks that were not fed the antibiotic. The combination of bacitracin supplementation and fresh litter resulted in an approximate 10-fold increase in IL-10 mRNA (P = 0.01) at 10 d of age when compared with that of the unsupplemented chicks in fresh litter. Among those chicks that were not supplemented with bacitracin, the recycled-litter treatment resulted in 25-fold (P = 0.01) and 39-fold (P = 0.02) higher IL-4 mRNA levels at 10 and 35 d of age, respectively, when compared with those of the chicks reared on fresh litter. In conclusion, the intestinal immune response of birds reared on recycled litter is skewed toward an inflammatory response, whereas the fresh litter treatment was skewed toward an anti-inflammatory response. Bacitracin supplementation did not interact with the litter type to alter IL-1 mRNA levels in cecal tonsils, suggesting the low efficiency of bacitracin in alleviating the inflammatory response induced by recycled litter.

Effect of killed whole yeast cell prebiotic supplementation on broiler performance and intestinal immune cell parameters.

Two experiments were conducted to study the effect of CitriStim, a commercial killed whole yeast cell prebiotic, on broiler performance, regulatory T cells, CD4(+) and CD8(+) percentages, and IL-10 and IL-1 mRNA contents of the spleen and cecal tonsils. No immune challenges were imposed in either of the 2 experiments. One-day-old broiler chicks were fed a corn- and soybean meal-based diet supplemented with 0, 0.1, or 0.2% CitriStim (ADM, Decatur, IL) for 35 d. At 21 (P = 0.03) and 35 d (P = 0.02) of age, CitriStim supplementation at 0.2% increased regulatory T cell percentage in the cecal tonsil compared with that of the 0% CitriStim-supplemented group. At 21 (P = 0.08) and 35 d (P = 0.01) of age, CitriStim supplementation at 0.2% increased IL-10 mRNA content of the cecal tonsil compared with that of the 0% CitriStim-supplemented group. At 21 (P = 0.13) and 35 d (P < 0.01) of age, CitriStim supplementation at 0.2% decreased IL-1 mRNA content compared with that of the 0% CitriStim supplemented group. CitriStim supplementation did not (P > 0.05) alter the IL-10 and IL-1 mRNA contents in the spleen. CitriStim supplementation did not (P > 0.05) alter the CD4(+) and CD8(+) cell percentages in the spleen and cecal tonsil at 21 and 35 d of the experiment. CitriStim supplementation increased regulatory T cell percentage and IL-10 mRNA content and decreased IL-1 mRNA content in the cecal tonsil to produce a net antiinflammatory milieu. The immunomodulatory effect of CitriStim supplementation was a local effect rather than a systemic effect.

Lutein supplementation alters inflammatory cytokine production and antioxidant status in F-line turkeys.

Effect of dietary lutein supplementation on turkey production parameters, cytokine production, and oxidative status during an acute phase response following lipopolysaccharide (LPS) injection was studied. One-day-old chicks were fed a basal diet supplemented with 3 levels (0, 25, or 50 mg/kg of feed) of lutein. At 50 d of dietary lutein supplementation, turkeys were injected or not injected with LPS. Increasing dietary lutein increased the liver and plasma lutein content in both LPS injected and uninjected groups. In the groups fed 50 mg of lutein, LPS treatment decreased the lutein content of both the liver and the plasma at 48 h post-LPS injection. In the groups fed 0 mg of lutein, LPS treatment decreased the BW gain and feed consumption at 24 and 48 h post-LPS injection. The feed intake and BW gain of the group fed 50 mg of lutein in the LPS injected groups were comparable to those of the group with no LPS injection at both 24 and 48 h post-LPS injection. Treatment with LPS increased IL-1ß mRNA content (P = 0.01) in the group fed 0 mg of lutein. In the LPS injected groups, increasing dietary lutein to 50 mg decreased the IL-1ß mRNA amount compared with the group fed 0 mg of lutein. In the LPS injected groups, increasing dietary lutein to 50 mg increased IL-10 mRNA content compared with the group fed 0 mg of lutein. Injection of LPS increased the thiobarbituric reactive substances content of the liver in the group fed 0 mg of lutein. Increasing dietary lutein to 50 mg decreased the thiobarbituric reactive substances content of the liver in the LPS injected groups. Dietary lutein supplementation decreased oxidative damage and inflammatory responses post-LPS injection by decreasing IL-1ß production and increasing IL-10 production in turkeys.

Dietary lutein and fish oil interact to alter atherosclerotic lesions in a Japanese quail model of atherosclerosis.

Interactions between concentration of dietary lutein and fish oil in diets on atherosclerosis incidences were studied in a cholesterol-induced-atherosclerosis (CIA) model. CIA Japanese quail were fed a basal diet with three amounts of lutein (0, 25 and 50 mg/kg diet) and two amounts of fish oil (3% and 6%) in a 3 × 2 factorial in five replications. Samples were collected at 24 and 27 weeks of age. Atherosclerosis lesions in the dorsal aorta were measured by histochemistry sectioning. At 27 weeks of age, increasing dietary fish oil content to 6% decreased (p < 0.01) the atherosclerotic lesions only in the 0 mg lutein supplemented groups. At 27 weeks of age, increasing dietary fish oil content to 6% increased the atherosclerotic lesion score when lutein was supplemented at either 25 or 50 mg/kg feed. Aorta and liver lutein content increased (p < 0.01) with increasing dietary lutein content at 27 weeks of age. Increasing dietary fish oil content to 6% increased (p < 0.01) the aorta fat content by twofold and decreased (p < 0.01) the liver fat by 26% at 27 weeks of age. Increasing the dietary fish oil content to 6% increased (p = 0.01) the total PUFA and decreased (p = 0.03) the total mono unsaturated fatty acids content of the aorta at 27 weeks of age. At 27 weeks of age, increasing dietary fish oil content to 6% decreased the amount of TBARS (p = 0.01) and IL-1 mRNA (p < 0.01) only in the 0 mg lutein supplemented groups. Increasing dietary fish oil content to 6% increased the amount of TBARS and IL-1 mRNA of the aorta when lutein was supplemented at either 25 or 50 mg/kg diet. Dietary lutein supplementation decreased atherosclerosis lesions only at low levels of dietary polyunsaturated fatty acids.