The decrease in subtherapeutic antibiotic administration in poultry has increased the need to address production challenges caused by pathogens, such as E. coli. One potential way to improve bird health and reduce bacterial infection is through the addition of litter amendments that absorb moisture. Biochar (BC) has previously been shown to increase water holding capacity in poultry litter, but its effects on E. coli mitigation are unknown. The objectives of this research were to 1) evaluate water activity of poultry litter amended with pine and miscanthus BC, and 2) determine the effects of different BC inclusion rates on litter E. coli populations. The studies found that BC increased water activity when mixed with broiler litter, and pine BC resulted in lower E. coli counts over time than miscanthus BC. An inclusion rate of 30% by weight of pine BC was most effective at reducing E. coli populations in broiler litter.

Modern broiler houses are expensive to build, maintain, and insure. Protecting them from extreme weather events is a major concern to producers, integrators, and insurance companies. Lightning strikes can cause catastrophic fires and electrical damage and can lead to costly bird losses. A greater understanding of the impact of lightning on the commercial broiler industries of MS and AL is needed. The objectives of this research were collection of baseline resistance data for broiler houses and equipment in both states, and mapping lightning strike densities across MS and AL, evaluating annual, monthly, seasonal, and diurnal patterns. 63.5% of surveyed broiler houses were at or below the recommended 25 Ω (ohms). Ufer grounding resulted in lower resistance ratings than grounding rods. Lightning strike density was elevated in counties near the Gulf Coast, highest during the summer months. Producers should inspect their grounding systems annually to mitigate lightning-induced damage.

Avian Pathogenic E. coli can lead to infections in laying hens and wide-spread economic problems in the table egg industry. A vaccine widely used to combat APEC is the Poulvac E. coli vaccine, which is normally applied via spray vaccination. Application of this vaccine via in ovo injection has not been examined. The purpose of this series of studies was to determine the effects of injecting 50 μL of different dosages of the PECV into Hy-Line W-36 layer hatching eggs on the hatchability and characteristics of the hatchlings, and on the livability and characteristics of the chicks through 21 d growout. Administration of the PECV at 18 d of incubation yielded unsatisfactory results in terms of hatchability and the characteristics of the chicks at hatch and through 21 d of age. Commercial use of the PECV via in ovo injection in Hy-Line W-36 layer hatching eggs is not recommended.

Salmonella Enteritidis (SE) infections in laying hens is a significant cause of foodborne illness linked to the consumption of contaminated eggs. This dissertation encompasses novel strategies aimed to explore appropriate in-vitro and in-vivo models to evaluate the effects of these novel strategies to reduce SE in laying hens. Firstly, we investigated the potential probiotics, prebiotics, and essential oil combinations to reduce SE in-vitro. The results showed that probiotics and prebiotics are equally effective to reduce SE. In subsequent studies, we evaluated the role of vaccination history on cecal microbiota and SE infections with various doses of oral SE challenge. Our findings showed a dose-dependent response on fecal SE shedding in vaccinated and unvaccinated laying hens. Concurrently, we found an increased abundance of phylum Synergistota in the cecal microbiota following an SE infection, as well as a surge in the relative abundance of fatty-acid producing bacteria. The emphasizing the necessity to understand microbiota changes during SE infection for developing an effective intervention. We further researched the efficacy of a Bacillus-based probiotic and a glycan-based product to reduce SE infections in laying hens. These products were effective in reducing SE in the fecal and cecal content of laying hens. However, our research also underscored the necessity of developing a precise enumerate method to accurately measure the concentration of Salmonella in fecal and tissue samples. Overall, we expect this dissertation to contribute valuable insights into developing effective strategies to reduce SE infections in laying hens. These findings, while promising, underscore the ongoing challenge to develop a robust and effective solution to address the problem of SE in laying hens.

Cercarial dermatitis (CD) is manifested as a strong itchy rash that usually occurs after bathing in the natural water bodies where it makes recreation uncomfortable. As a consequence, the natural swimming areas and be closed because of inconvenient water quality, what subsequently leads to the financial losses. The infection can also affect people working in the natural water bodies as lifeguards (at the natural swimming areas), people monitoring water organisms or water quality etc.). Nowadays, CD in Czech Republic occurs more frequently than in the past. For this reason, the topic of avian schistosomes and CD is very attractive not only for scientists, but newly also for employees of hygienic stations and health institutes. Based on the Act No. 258/2000 Coll. on protection of public health and related executive Decree No. 238/2011 Coll. approved this year their duty will be regular monitoring of official natural swimming areas for causative agents of CD. For the comprehensive overview about the occurrence of the avian schistosomes and CD, up to now, at the localities in the Czech Republic the specialized overview map with the marked catches of avian schistosomes and CD was created in the program ArcGIS Online. This map was made with use the records obtained from the scientific articles, final...

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Arginine transport is primarily mediated by the cationic amino acid transporters (CATs) in mammalian cells, but in aves the y+, b0,+ and B0,+ transport systems have also been observed. Arginine is the limiting catabolic substrate required for the production of nitric oxide (NO), a highly reactive compound that acts as a signaling molecule or killing compound. NO is synthesized by inducible nitric oxide synthase (iNOS) by macrophages for pathogen clearance. In mammals, CAT-2B is responsible for ARG import in the macrophage for NO synthesis, but the chicken CAT-2B isoform does not transport ARG. Therefore the objective of these studies was to identify the CAT(s) involved in mediating ARG uptake during a NO response in the chicken macrophage. Experiments were performed to measure: 1) ARG transporter mRNA and NO production from three sources of macrophages (HD11 cell line, n=6; primary 32d Cobb 500, n=8; Hyline W36, n=7) in response to Escherichia coli lipopolysaccharide (LPS); 2) the effect of CAT over-expression on NO production in response to LPS (HD11 cell line; n=8). In response to LPS iNOS mRNA abundance increased (P<0.05) 8.5-fold in the HD11 macrophages, 3.22-fold in broiler macrophages and 2.79-fold in layer macrophages. In all cells, CAT-1 was induced and CAT-2A increased (P<0.05) between 1.28 and 1.68-fold. CAT-2B was not detected at any time point or treatment condition. In the virally transformed chicken macrophage cell line (HD11) CAT-3 mRNA was induced, but in primary cells CAT-3 increased (P<0.05) 1.27-fold in broilers and 1.23-fold in layers. Transiently transfected chicken macrophages produce NO independent of LPS treatment by 6h, mock transfected controls did not respond by 6h. In the presence of LPS, CAT-1 transfected macrophages produced 50.0% more NO than mock transfected cells (P<0.05). CAT-2A and CAT-3 transfected macrophages produced only 17.6% and 72.1% of the total NO produced by controls (P<0.05). These results indicate that CAT-1 and CAT-3 are both sufficient to sustain ARG import for NO production in the chicken macrophage, but that CAT-1 produces a maximal response. These results also show that iNOS, despite its name, is constitutively present and can be activated by induction of CATs to import ARG.

Research has shown Spirulina to be a viable feedstuff in poultry production. Other species of microalgae are being studied to determine their effects on poultry production. This project compared four microalgaes: Hydrodictyon, Vaucheria, Uronema, and Spirulina and was broken down into three trials. The first experiment investigated the digestibility of an algae species, Spirulina, in broiler chicken diets. Eighty, 25-day-old Ross 708 broiler chicks were sorted into 20 metabolism cages and received one of two diets: Control Diet or Test Diet (75% basal diet + 25% Spirulina). The apparent ileal amino acid digestibility (AIAAD) of lysine, methionine, cysteine, threonine, isoleucine, valine and arginine in Spirulina was 94.5%, 91.3%, 56.1%, 71.4%, 76.8%, 69.8% and 90.4% respectively. Apparent metabolizable energy (AME) of Spirulina was 2279 kcal/kg. The second experiment focused on digestibility of Spirulina and novel algae species in laying hens. Sixty, 80-week-old Lohman LSL-Lite laying hens were randomly assigned to Control Diet, Hydrodictyon Test Diet (87.5% basal diet + 12.5% hydrodictyon), 12.5% or one of three other test diets (75% basal diet + 25% Spirulina, Uronema, and Vaucheria). Spirulina diets contained the highest crude protein (25.5%) and methionine levels (0.68%). Uronema had the highest gross energy content of 3880.5 kcal/kg and lysine levels (1.12%). Hydrodictyon diet was the most nutritionally similar to the control. Crude protein was at 15.3% and 16.6% for control and Hydrodictyon respectively. Gross energy was 3429.6 kcal/g in control versus 3316.1 kcal/kg in Hydrodictyon. Lastly, crude fat was 2.7% compared to Hydrodictyon at 2.4%. The last trial was to determine the effects of the addition of microalgae in the diet on laying hen production. Seventy-eight, 23-month-old laying hens were assigned to 1 of 3 of the following experimental diets: control, control + 1% microalgae, or control + 2% microalgae. Microalgae, regardless of inclusion level, had no significant effect on egg weight in this study. Increasing level of inclusion of Spirulina, Hydrodictyon, and Uronema from 0 to 2 % significantly increased yolk color. Vaucheria influenced yolk color at the 2% level. No significance differences shown from any of the algae species regardless of inclusion level for egg weight, egg mass, shell thickness, shell strength, shell weight, albumen weight, yolk weight, and albumen height. In addition, there was no significant difference in feed conversion ratio, feed intake, body weight, or tibial strength between the treatments. However, as these are novel algaes, further studies are required to determine the true usability in poultry production.

While in no way passing judgments on the quality of the investigations which have been published, there is one conclusion that must be reached and this is that there is room for further investigations. The studies which form the basis of this paper were undertaken to widen the general range of information on the avian kidney and its associated osseous cradle. In addition to the discussion, numerous photographs and diagrams are submitted to clarify and support the text. The present paper deals with with kidney and pelvic girdle of two species of sparrow: Zonotrichia leucophrys and Passer domesticus.

The H9N2 subtype of avian influenza A virus (aIAV) is circulating among birds worldwide, leading to severe economic losses. H9N2 cocirculation with other highly pathogenic aIAVs has the potential to contribute to the rise of new strains with pandemic potential. Therefore, rapid detection of H9 aIAVs infection is crucial to control virus spread. A qualitative reverse transcription recombinase polymerase amplification (RT-RPA) assay for the detection of aIAV subtype H9N2 was developed. All results were compared to the gold standard (real-time reverse transcription polymerase chain reaction (RT-PCR)). The RT-RPA assay was designed to detect the hemagglutinin (HA) gene of H9N2 by testing three pairs of primers and a probe. A serial concentration between 106 and 100 EID50 (50% embryo infective dose)/mL was applied to calculate the analytical sensitivity. The H9 RT-RPA assay was highly sensitive as the lowest concentration point of a standard range at one EID50/mL was detected after 5 to 8 min. The H9N2 RT-RPA assay was highly specific as nucleic acid extracted from H9 negative samples and from other avian pathogens were not cross detected. The diagnostic sensitivity when testing clinical samples was 100% for RT-RPA and RT-PCR. In conclusion, H9N2 RT-RPA is a rapid sensitive and specific assay that easily operable in a portable device for field diagnosis of aIAV H9N2.