Pathology caused by three species of Eimeria that infect the turkey with a description of a scoring system for intestinal lesions.

Three-week-old turkey poults were infected with pure lines of three species of Eimeria (E. adenoeides, E. gallopavonis, and E. meleagrimitis) recently isolated from commercial turkey farms. The lines had been propagated from a single oocyst and identified by species-specific PCR amplification of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Five to six days after infection their intestines were removed and examined for the presence of intestinal lesions. A description and review of the pathology caused by these parasites is provided, and a scoring system developed by which the severity of the lesions can be evaluated. The system is similar to that described by Johnson, J. and Reid, W. M. [1970. Anticoccidial drugs: lesion scoring techniques in battery and floor-pen experiments with chickens. Experimental Parasitology, 28, 30-36] for chickens in which a score of zero to four is assigned to lesions of increasing severity. The intestinal lesions observed here, and their assigned scores, are supported by representative illustrations. It is hoped that they may prove a useful tool for evaluating the pathology caused by E. adenoeides, E. gallopavonis, and E. meleagrimitis in the turkey.RESEARCH HIGHLIGHTSA scoring system has been developed for intestinal lesions caused by three species of Eimeria that infect the turkey.The lesions attributable to these species are illustrated.

Growth-Promoting and Antioxidant Effects of Magnolia Bark Extract in Chickens Uninfected or Co-Infected with Clostridium perfringens and Eimeria maxima as an Experimental Model of Necrotic Enteritis.

BACKGROUND: Magnolia tree bark has been widely used in traditional Asian medicine. However, to our knowledge, no studies have been reported investigating the effects of dietary supplementation with magnolia bark extract in chickens. OBJECTIVE: We tested the hypothesis that dietary supplementation of chickens with a Magnolia officinalis bark extract would increase growth performance in uninfected and Eimeria maxima/Clostridium perfringens co-infected chickens. METHODS: A total of 168 chickens were fed from hatch either a standard diet or a diet supplemented with 0.33 mg or 0.56 mg M. officinalis bark extract/kg (M/H low or M/H high, respectively) from days 1 to 35. At day 14, half of the chickens were orally infected with E. maxima, followed by C. perfringens infection at day 18 to induce experimental avian necrotic enteritis. Daily feed intake, feed conversion ratio, body weight gain, and final body weight were measured as indicators of growth performance. Serum α1-acid glycoprotein (AGP) concentrations were measured as an indicator of systemic inflammation, and intestinal lesion scores were determined as a marker of disease progression. Transcript levels for catalase, heme oxygenase 1, and superoxide dismutase in the intestine, liver, spleen, and skeletal muscle were measured as indicators of antioxidant status. RESULTS: Growth performance increased between days 1 and 35 in uninfected and E. maxima/C. perfringens co-infected chickens fed M/H-low or M/H-high diets compared with unsupplemented controls. Gut lesion scores were decreased, whereas AGP concentrations were unchanged, in co-infected chickens fed magnolia-supplemented diets compared with unsupplemented controls. In general, transcripts for antioxidant enzymes increased in chickens fed magnolia-supplemented diets compared with unsupplemented controls, and significant interactions between dietary supplementation and co-infection were observed for all antioxidant enzyme transcript levels. CONCLUSION: Magnolia bark extract might be useful for future development of dietary strategies to improve poultry health, disease resistance, and productivity without the use of antibiotic growth promoters.

Effects of dietary Allium hookeri root on growth performance and antioxidant activity in young broiler chickens.

The objective of this experiment was to evaluate the antioxidant potential of Allium hookeri (AH) root in two forms, powdered AH root and fermented powdered AH root, to demonstrate its value as an antibiotic alternative feed additive for broiler chickens. A total of 125 male Ross-708 broiler chickens were randomly assigned to five groups (n = 25 birds/group) and fed standard diets supplemented with root or fermented root of AH at two different levels (1% or 5%). Control birds were provided with non-supplemented basal diets. Body weights was measured at days 14 and 21 of age. To monitor antioxidant activities, heme oxygenase (HMOX), aflatoxin B1 aldehyde reductase (AFAR), superoxide dismutase 1 (SOD1), and catalase (CAT) enzyme levels were quantified by real-time PCR in the jejunums 21-day-old birds. Also, serum levels of SOD, CAT, and malondialdehyde (MDA) were measured using commercial kits. The results showed greater body weight gains at day 14 in chickens fed diets supplemented with 1% AH root, as compared to the control group (p < 0.05). Up-regulated transcript levels of AFAR, HMOX1, and CAT were observed in the jejunum of chickens fed diets supplemented with AH. The serum levels SOD and CAT were significantly increased (p < 0.05) in groups treated with AH, whereas MDA levels were decreased in groups fed diets supplemented with AH, as compared to the control group. These results indicated that an optimum level of dietary AH supplementation to young broiler chickens influences growth and improves antioxidant activities.

Antibiotic growth promoters virginiamycin and bacitracin methylene disalicylate alter the chicken intestinal metabolome.

Although dietary antibiotic growth promoters have long been used to increase growth performance in commercial food animal production, the biochemical details associated with these effects remain poorly defined. A metabolomics approach was used to characterize and identify the biochemical compounds present in the intestine of broiler chickens fed a standard, unsupplemented diet or a diet supplemented with the antibiotic growth promoters, virginiamycin or bacitracin methylene disalicylate. Compared with unsupplemented controls, the levels of 218 biochemicals were altered (156 increased, 62 decreased) in chickens given the virginiamycin-supplemented diet, while 119 were altered (96 increased, 23 decreased) with the bacitracin-supplemented diet. When compared between antibiotic-supplemented groups, 79 chemicals were altered (43 increased, 36 decreased) in virginiamycin- vs. bacitracin-supplemented chickens. The changes in the levels of intestinal biochemicals provided a distinctive biochemical signature unique to each antibiotic-supplemented group. These biochemical signatures were characterized by increases in the levels of metabolites of amino acids (e.g. 5-hydroxylysine, 2-aminoadipate, 5-hydroxyindoleaceate, 7-hydroxyindole sulfate), fatty acids (e.g. oleate/vaccenate, eicosapentaenoate, 16-hydroxypalmitate, stearate), nucleosides (e.g. inosine, N6-methyladenosine), and vitamins (e.g. nicotinamide). These results provide the framework for future studies to identify natural chemical compounds to improve poultry growth performance without the use of in-feed antibiotics.

Characterization of Clostridium perfringens Strains Isolated from Healthy and Necrotic Enteritis-Afflicted Broiler Chickens.

Necrotic enteritis (NE) is an important enteric disease in poultry, and Clostridium perfringens (CP) type A strains are the primary etiology. NE is responsible for annual losses of US $6 billion to the poultry industry in the United States. An increase in the incidence of NE has been also associated with withdrawal of antibiotic growth promoters from poultry feed. In this study, CP strains isolated from healthy and NE-afflicted birds were characterized microbiologically and molecularly, and their virulence was experimentally tested in chickens. All strains were hemolytic, lecithinase positive, and identified as CP by biochemical tests. Three distinct colony morphologies were seen in brain-heart infusion media with 0.3% agarose, FeSO4, and ZnCl2. The CP strains responded differently to iron chelation with 2,2'-bidypinol. PCR toxinotyping showed that all tested strains were alpha toxin-positive, seven (N11, N10, CP1, CP5, CP13, JGS, and Del1) were beta2-toxin-positive, and only one (Del1) was necrotic enteritis toxin B-like-positive. In vivo studies indicated that most isolates, including strain N11 isolated from the normal chicken gut, were sufficiently virulent to produce NE disease in the Eimeria/CP dual infection model. The Del1 and N11 strains merit further investigation to identify their virulence factors and immune-protective antigens.

Dietary Bacillus subtilis-based direct-fed microbials alleviate LPS-induced intestinal immunological stress and improve intestinal barrier gene expression in commercial broiler chickens.

This study investigated the effects of Bacillus subtilis-based probiotics on the performance, modulation of host inflammatory responses and intestinal barrier gene expression of broilers subjected to LPS challenge. Chickens were randomly allocated to one of the 3 dietary treatment groups - control, antibiotic, or probiotic. At 14days, half of the chickens in each treatment were injected with LPS (1mg/kg body weight), and the other half injected with sterile PBS. Chickens fed probiotics weighed significantly more than controls at 15days of age, irrespective of immune challenge. LPS challenge significantly reduced weight gain at 24h post-injection, and the probiotics did not alleviate the LPS-induced reduction of weight gain. Serum α-1-AGP levels were significantly higher in LPS-injected chickens, and probiotic supplementation significantly reduced their levels. The percentages of CD4+ lymphocytes were significantly increased in probiotic groups in the absence of immunological challenge but were reduced during LPS challenge compared to controls. CD8+ lymphocytes were significantly reduced in probiotic-fed birds. The LPS-induced increase in the expression of cytokines IL8 and TNFSF15 was reduced by probiotic supplementation, and IL17F, iNOS expression was found to be significantly elevated in probiotic-fed birds subjected to LPS challenge. The reduced gene expression of tight junction proteins (JAM2, occludin and ZO1) and MUC2 induced by LPS challenge was reversed by probiotic supplementation. The results indicate that B. subtilis-based probiotics differentially regulate intestinal immune and tight junction protein mRNA expression during states of LPS-mediated immunological challenge.

Dietary Allium hookeri reduces inflammatory response and increases expression of intestinal tight junction proteins in LPS-induced young broiler chicken.

We undertook a study to assess the effects of Allium hookeri (AH) root and fermented root on inflammation and intestinal integrity of lipopolysaccharide (LPS)-challenged broiler chickens. Birds were assigned to six groups (n = 25 birds/treatment) and fed with basal diets (CON) or basal diets supplemented with AH root or fermented root at two concentrations (1 or 5%). At 7 d of age, five groups (n= 125) in each dietary treatment were injected with LPS (1 mg/kg body weight), and the remaining 25 birds were injected with sterile phosphate-buffered saline (PBS) as a negative control. LPS challenge significantly reduced average body weight gain at 24 h post-injection compared with PBS control. Fermented root supplementation increased average body weight gain by 1% compared with the LPS-challenged control. Serum α- 1-AGP levels, interleukin (IL)-1ß, IL-8, tumor necrosis factor superfamily member 15 (TNFSF15), and LPS-induced tumor necrosis factor-α factor (LITAF) transcript levels were significantly higher in the small intestine in LPS-injected chickens. However α-1-AGP levels were reduced by AH root or fermented root (1 and 5%) supplementation and IL-1ß, IL-8, and LITAF were also down-regulated by root and fermented root (1 and 5%) supplementation. The reduced expression of tight junction proteins (junctional adhesion molecule 2 (JAM2) and occludin) and intestinal mucin 2 (MUC2) by LPS challenge was reversed by root or fermented root (1 and 5%) supplementation. These findings demonstrate that dietary AH root and fermented root influence antiinflammatory activity and tight junction protein expression in LPS-induced chickens.