Effects of Vaccination Against Coccidiosis on Gut Microbiota and Immunity in Broiler Fed Bacitracin and Berry Pomace.

Feeding practices have been found to influence gut microbiota which play a major role in immunity of poultry. In the present study, changes in cecal microbiota and humoral responses resulting in the 55 ppm bacitracin (BACI), 1% each of cranberry (CP1) and wild blueberry (BP1) pomace alone or in combination (CP+BP) feeding in broiler Cobb 500 vaccinated or not against coccidiosis were investigated. In the non-vaccinated group, no significant treatment effects were observed on performance parameters. Vaccination significantly affected bird's performance parameters particularly during the growing phase from 10 to 20 days of age. In general, the prevalence of coccidiosis and necrotic enteritis (NE) was reduced by vaccination (P < 0.05). BACI-treated birds showed low intestinal lesion scores, and both CP1 and BP1 feed supplementations reduced Eimeria acervulina and Clostridium perfringens incidences similar to BACI. Vaccination induced change in serum enzymes, minerals, and lipid levels in 21-day old birds while, levels of triglyceride (TRIG) and non-esterified fatty acids (NEFA) were higher (P < 0.05) in CP1 treated non-vaccinated group than in the control. The levels of NEFA were lower in BACI- and CP1-fed birds than in the control in non-vaccinated day 28 old birds. The highest levels of all estimated three immunoglobulins (IgY, IgM, and IgA) were found in the vaccinated birds. Metagenomics analysis of the cecal bacterial community in 21-day old birds showed the presence of Firmicutes (90%), Proteobacteria (5%), Actinobacteria (2%), and Bacteroidetes (2%). In the vaccinated group, an effect of BACI was noted on Proteobacteria (P = 0.03). Vaccination and/or dietary treatments influenced the population of Lactobacillaceae, Enterobacteriaceae, Clostridiaceae, and Streptococcaceae which were among the most abundant families. Overall, this study revealed that besides their beneficial effects on performance, alike bacitracin, berry pomaces in poultry feed have profound impacts on the chicken cecal microbiota and blood metabolites that could be influenced by vaccination against coccidiosis.

Effect of yeast cell product supplementation on broiler cecal microflora species and immune responses during an experimental coccidial infection.

This experiment was conducted to study the effects of whole yeast (Pichia guilliermondii; CitriStim, ADM, Quincy, IL) cell product supplementation on cecal microflora population and intestinal immune parameters in broilers. In the first experiment, birds were fed 0, 0.1, or 0.2% yeast cell wall product for 42 d. Feeding yeast cell wall products decreased (P = 0.03) the proportion of Escherichia coli in the ceca by 31% compared with the control group. The group fed 0.2% yeast cell wall product had a 20% decrease (P = 0.23) in Salmonella population compared with the control group. In the second experiment, birds were fed yeast cell wall product for 21 d and challenged or not challenged with coccidial oocysts, thus resulting in a 2 (0 and 0.2% whole yeast product) × 2 (coccidial challenge and no coccidial challenge) factorial model. Supplementing whole yeast cell wall product prevented a coccidial infection-induced decrease in the Lactobacillus population (P = 0.09) at 12 d postchallenge. Supplementing yeast cell wall product prevented a coccidial infection-induced increase in the Salmonella population (P = 0.08) and E. coli (P = 0.12) at 12 d postchallenge. At 5 d (P < 0.01) and 12 d (P < 0.01) postcoccidial infection, yeast cell wall product supplementation or coccidial infection increased the regulatory T cell (Treg) percentage in the cecal tonsils, whereas yeast cell wall product supplementation in the coccidial-infected group decreased the increase in Treg percentage. At 5 d postcoccidial infection, coccidial infection increased (P = 0.01) the relative amounts of cecal interferon (IFN)γ mRNA. In addition, the yeast cell wall product supplementation in the coccidial-infected groups further increased (P = 0.15) the IFNγ mRNA. It could be concluded that yeast cell wall product supplementation decreased coccidial-infection-induced increase in E. coli and Salmonella colonization and improved IFNγ mRNA amounts after coccidial infection.

Effect of yeast cell product (CitriStim) supplementation on broiler performance and intestinal immune cell parameters during an experimental coccidial infection.

This experiment studied the effects of whole yeast cell product supplementation on broiler production parameters, fecal coccidial oocyst counts, and local and systemic immune parameters following an experimental coccidial infection. Birds were fed 0, 0.1, or 0.2% whole yeast cell product (CitriStim). At 21 d of age, birds were challenged with live coccidial oocysts. Supplementation with whole yeast cell product increased BW gain between 0 and 12 d (P = 0.01) postcoccidial challenge. Birds supplemented with 0.2% Citristim had better (P = 0.01) feed efficiency between 0 and 12 d postcoccidial infection. Supplementation with whole yeast cell product decreased (P = 0.01) the fecal coccidial oocyst count at 7 d postcoccidial challenge. Citristim supplementation at 0.2% increased (P < 0.01) macrophage nitric oxide production by 93 and 193% at 5 and 12 d postcoccidial challenge. Supplementation with whole yeast cell product at 0.2% increased cecal tonsil interleukin-1 mRNA amounts approximately 4.5- and 3.7-fold at 5 and 12 d postcoccidial challenge, respectively, over the group with no whole yeast cell product supplementation. Citristim supplementation downregulated cecal tonsil interleukin-10 mRNA amounts compared with the unsupplemented groups at both 5 (P = 0.01) and 12 d (P < 0.01) postcoccidial challenge. Supplementation with whole yeast cell product did not alter (P > 0.05) serum anticoccidial IgG contents or cecal tonsil CD4(+) and CD8(+) cell percentages at 5 and 12 d postcoccidial infection. It could be concluded that supplementing whole yeast cell product (CitriStim) to broiler diets can improve production parameters, decrease fecal oocyst count, and increase inflammatory cytokine production postcoccidial infection.

Effects of supplemental feeding on gastrointestinal parasite infection in elk (Cervus elaphus): preliminary observations.

The effects of management practices on the spread and impact of parasites and infectious diseases in wildlife and domestic animals are of increasing concern worldwide, particularly in cases where management of wild species can influence disease spill-over into domestic animals. In the Greater Yellowstone Ecosystem, USA, winter supplemental feeding of Rocky Mountain elk (Cervus elaphus) may enhance parasite and disease transmission by aggregating elk on feedgrounds. In this study, we tested the effect of supplemental feeding on gastrointestinal parasite infection in elk by comparing fecal egg/oocyst counts of fed and unfed elk. We collected fecal samples from fed and unfed elk at feedground and control sites from January to April 2006, and screened all samples for parasites. Six different parasite types were identified, and 48.7% of samples were infected with at least one parasite. Gastrointestinal (GI) nematodes (Nematoda: Strongylida), Trichuris spp., and coccidia were the most common parasites observed. For all three of these parasites, fecal egg/oocyst counts increased from January to April. Supplementally fed elk had significantly higher GI nematode egg counts than unfed elk in January and February, but significantly lower counts in April. These patterns suggest that supplemental feeding may both increase exposure and decrease susceptibility of elk to GI nematodes, resulting in differences in temporal patterns of egg shedding between fed and unfed elk.