INVESTIGATION OF THE PRESENCE OF ATOXOPLASMA SPP. IN BLUE-CROWNED LAUGHINGTHRUSH (DRYONASTES COURTOISI) ADULTS AND NEONATES.

Between 1996 and 2013, 71 blue-crowned laughingthrush (Dryonastes courtoisi) chicks, a small passerine bird endemic to China, were born at Mulhouse Zoo in northeast France. None of them survived past 1 yr, and 82% died between 0 and 6 days old of an unidentified cause and despite an attempt to establish an artificial breeding protocol. Atoxoplasma spp., causing a disease known as systemic isosporosis, is a coccidian parasite that can infect several species of birds. Mulhouse's adult birds were suspected to be infected with Atoxoplasma spp. and to transmit this parasite to their offspring. A treatment with toltrazuril (Baycox® 2.5%) was implemented in the four adult birds. Coprologic examinations were performed before, during, and after the treatment to quantify the parasite load in feces. Polymerase chain reaction (PCR) assays were used to test blood samples from the adult and liver, lung, gizzard, and kidney samples from 10 chicks to detect Atoxoplasma spp. Five of the 10 chicks had some tissue samples positive for Atoxoplasma spp. in at least one of the three repeats of the atoxoplasmosis PCR. An average of 181 Isospora spp. oocysts per gram of feces were found in the group of adults before treatment. This number was reduced to zero 1 wk after the beginning of the toltrazuril treatment. The PCR results suggest a transovarian transmission of Atoxoplasma spp., but further investigation is needed for confirmation. The treatment with toltrazuril appears to allow a significant reduction of the parasite excretion.

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.

Rotavirus and Cryptosporidium shedding in dairy calf feces and its relationship to colostrum immune transfer.

Twenty Holstein calves received 2 L of colostrum twice within 12 h after birth; the first feeding occurred within 2 h of parturition. The increase in adsorption efficiency was related to the gamma globulin provided in the first colostrum feeding. Absorption efficiency ranged from 2.4 to 46.1%. The number of sheddings of rotavirus and Cryptosporidium by the calves during their first 4 wk of life was associated with serum gamma globulin concentration 24 h after birth and absorption efficiency. Absorption efficiency and body weight combined accounted for 60.4% of the variation in the number of sheddings; heavier calves shed more than lighter calves. During the first 4 wk, calves that shed more frequently gained less weight; weight gain was also associated with serum gamma globulin levels 24 h after birth. Colostrum composition varied between quarters of the same cow. Total protein and gamma globulin content of colostrum from the rear quarters was higher than from the front quarters. The association between number of sheddings and absorption efficiency suggest that calves should not be fed colostrum containing less than 9 g/100 ml of total protein.