Lisa Bielke

• University of Arkansas at Fayetteville

Three experiments were conducted to determine the appropriate dose level of E. gallopavonis for autogenous vaccine production to manage its highly virulent nature. In experiment 1, birds were divided into four groups: 0 (Non-inoculated Control, NIC), 30, 90, or 270 E. gallopavonis oocysts per poult (OPB); experiment 2 included NIC, 30, and 90 OPB,...

The present study used a PCR approach to characterize prevalence of coccidial species in fecal samples obtained from 40 individual Midwestern turkey flocks to characterize distribution of species in commercial flocks. Each sample was screened for six prominent Eimeria species using species-specific primers and were supplemented with a primary neste...

Early exposure to Enterobacteriaceae may result in inappropriate microbial colonization of the gastrointestinal (GI) tract, induce mild GI inflammation, alter immune system development, and predispose poultry to opportunistic infection. Four experiments were conducted to test Enterobacteriaceae isolates Escherichia coli LG strain (LG), E. coli Huff...

Inappropriate microbial colonization can induce gastrointestinal (GI) inflammation may predispose poultry to opportunistic infections and reduce growth performance. Four independent experiments were completed to test ability of select Enterobacteriaceae isolates to induce GI inflammation. Experiments 1 and 2 included a non-inoculated control (NC),...

This study examined the effects a synbiotic feed additive (PoultryStar meUS) on performance and intestinal health parameters in turkey poults administered a mixed Eimeria inoculation. The synbiotic feed additive consisted of Lactobacillus reuteri, Enterococcus faecium, Bifidobacterium animalis, Pediococcus acidilactici and a fructo-oligosaccharide...

Pioneer colonization of the gastrointestinal tract (GIT) by bacteria is thought to have major influence on neonatal tissue development. Previous studies have shown in ovo inoculation of embryos with saline (S), species of Citrobacter (C, C2), or lactic acid bacteria (L) resulted in an altered microbiome on day of the hatch (DOH). The present study...

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...

Proteomics has been used to investigate cross-talk between the intestinal microbiome and host biological processes. In this study, an in ovo technique and a proteomics approach was used to address how early bacterial colonization in the gastrointestinal tract (GIT) could modulate inflammatory and immune responses in young broilers. Embryos at 18 em...

Coccidiosis has been a pervasive disease within the poultry industry, with test parameters used to measure effectiveness of treatment strategies often being subjective or influenced by non-disease-related activity. Four experiments were completed, which examined several test parameters of coccidiosis, including body weight gain (BWG), lesion scores...

Necrotic enteritis (NE) is a pervasive enteric disease responsible for large scale economic losses within the global poultry industry. The etiologic agent of NE is Clostridium perfringens (CP), an opportunistic pathogen that utilizes numerous extracellular toxins and glycoside hydrolases (GH) as key virulence and nutrient acquisition factors. Notab...

Necrotic enteritis (NE) is a disease that has gained relevance in the poultry industry with both immediate and sustained effects on BW of broilers. The objective of the 3 experiments was to evaluate the impact of NE, induced by methods that reflect common broiler production systems, on the growth curve throughout the growth period. In addition, the...

Initial inoculation and colonization of the chicken gastrointestinal tract (GIT) by microbiota have been suggested to have a major influence on the growth performance and health of birds. Commercial practices in chicken production may alter or delay microbial colonization by pioneer colonizing bacteria that can have an impact on the development and...

A variety of necrotic enteritis (NE) research methodologies exist in the literature, many with components that do not represent standard industry practices. The models tested here aimed to investigate multiple NE methods that represent common broiler production systems. Two preliminary experiments compared Eimeria maxima (EM) plus NetB-negative Clo...

Aging, poor oxygenation, or improper storage temperature can lead to variable Eimeria oocyst viability, which is not readily assessed microscopically. Under fluorescent microscopy, some aged Eimeria maxima (EM) oocysts were strongly autofluorescent (AF) within the oocystoplasm and sporocysts, whereas others were distinctly non-fluorescent, leading...

Intestinal barrier leakage and/or altered gut microbial composition has been shown to markedly impact both osteoblast and osteoclast activities, systemically through circulation of gut immune cells and cytokines and locally by causing inflammation of extraintestinal organs such as the liver and bone marrow. Mild cases of heightened intestinal infla...

Most pathogens of poultry and other vertebrates enter the body via a mucosal portal of entry, and for the vast majority, this means either the respiratory or gastrointestinal tract (GIT). This chapter surveys the main bacterial pathogens found in the GIT of poultry, and examines the process of symbiosis between prokaryotes and the host in the gut....

Three experiments were conducted to evaluate the effect of in ovo administration of FloraMax®-B11 (FM) on Marek's disease (MD) herpesvirus of turkeys (HVT) vaccine protective efficacy, hatchability, microbiota composition, morphometric analysis, and Salmonella enteritidis (SE) infection in chickens. Experiment 1 consisted of 3 trials. In trials 1 a...

Studies were conducted using a commercial Inovoject(TM) system to determine effects of in ovo feeding of dextrin and iodinated casein (IC) on hatch and posthatch growth in broilers. At ∼18.5 d embryonic development, eggs were treated with 0, 240, or 480 μg IC/mL in saline (Cont, IC240, and IC480) or dextrin (Dext, DextIC240 and DextIC480). The Dext...

Dextran sodium sulfate (DSS) has been shown to be effective at inducing enteric inflammation in broiler chickens, resulting in increased leakage of orally administered fluorescein isothiocyanate dextran to circulation. In a previous study, 2 doses of DSS (0.45 g/dose) administered as oral gavage resulted in increased mucosal permeability. The main...

The limits of physical and chemical methods to decrease aflatoxins in feed ingredients, stimulated the search on biological approaches of degradation. Recently, we identified three Bacillus spp. candidates that showed in vitro activity to biodegradate aflatoxin B1 (AFB1). The aim of this study was to evaluate the biodegradation potential of previou...

Antibiotic growth promoters (AGP) are well documented to play an important role in the feed efficiency of poultry. However, recent regulations and consumer demand are globally decreasing their use, resulting in a surge of research focused on the search for replacement compounds and probiotics in order to maintain current levels of performance in po...

1. The effects of the dietary inclusion of a Bacillus based direct-fed microbial (DFM) candidate on digesta viscosity, bacterial translocation, microbiota composition and bone mineralisation were evaluated in broilers consuming rye-based diets. 2. In the present study, control mash rye-based diets (CON) or Bacillus-DFM supplemented diets (TRT) were...

We have previously shown that intestinal barrier function can be adversely affected by poorly digested diets or feed restriction, resulting in increased intestinal inflammation-associated permeability. Three experiments were conducted in broilers to evaluate the effect of dexamethasone (DEX) treatment on systemic fluorescein isothiocyanate-dextran...

Gut inflammation is a cardinal event occurring in various gastrointestinal diseases regardless of etiology. A potential mechanism of action for antibiotic growth promoters and probiotics is alleviation or attenuation of such inflammation. In vivo inflammation models and markers to quantify changes in inflammation, such as paracellular leakage and t...

Traditionally, antibiotic growth promoters (AGP) have been used in foodstock animals to reduce enteric inflammation and maintain intestinal homeostasis, thus improving growth and performance. Due to increasing restrictions regarding the use of AGP however, precise and high throughput enteric inflammation models and markers to search for effective a...

Oral administration of dextran sodium sulfate (DSS) is commonly used as an inducer of enteric inflammation in rodents. However, there is a dearth of knowledge regarding appropriate dosage, timing, or ageresponses in broilers for this potential inducer of inflammation without necrosis. Two experiments were conducted in day-of-hatch chicks to analyze...

Vaccines targeting mucosal immunity are important for the control of infection by pathogens with mucosal portals of entry, such as avian influenza. However, reliable and effective methods for determining levels of mucosal IgA stimulated by vaccination are not well developed in poultry and are necessary for determining efficacy. The objective of the...

Unpublished data from our laboratory suggest that the respiratory tract may be a viable portal of entry for Salmonella infection. Further, field reports have indicated that tracheal sampling can be a sensitive tool for monitoring for Salmonella incidence in commercial flocks. In the present study we conducted a series of field trials in North and S...

Abstract Public concern with the incidence of antibiotic-resistant bacteria, particularly among foodborne pathogens such as Salmonella, has been challenging the poultry industry to find alternative means of control. The purposes of the present study were to evaluate in vitro and in vivo effects of chitosan on Salmonella enterica serovar Typhimurium...

The administration of nonpathogenic microflora in neonatal poultry has been employed to reduce or eliminate the colonization of enteric pathogens. This concept, also called Competitive Exclusion (CE), although effective against Salmonella, has not consistently worked against Campylobacter. Most CE cultures are developed by randomly collecting enter...

Conventionally, bacteriophages are considered viruses capable of amplification only in a narrow range of closely related bacteria. Presently, we selected bacteriophages with the ability to infect more than 1 bacterial genus. Initially, wild-type bacteriophages were selected for ability to form plaques in Salmonella enteritidis agar overlays. For de...

The ability of 2 probiotic cultures (P1 and P2) to reduce environmental Salmonella in commercial turkey flocks 2 wk prior to processing with or without the use of a commercial organic acid (OA) was evaluated. Salmonella-positive flocks were identified 3 to 4 wk before processing by using standard assembled drag swabs. Two weeks after treatment (pri...

The intestinal mucosa represents the most active defense barrier against the continuous challenge of food antigens and pathogenic microorganisms present in the intestinal lumen. Protection against harmful agents is conferred by factors such as gastric acid, peristalsis, mucus, intestinal proteolysis, and the intestinal biota. The establishment of b...