Analysis of miRNA Expression in the Ileum of Broiler Chickens During Bacillus licheniformis H2 Supplementation Against Subclinical Necrotic Enteritis.

Subclinical necrotic enteritis (SNE) is one of the serious threats to the poultry industry. Probiotics have been proven to exert beneficial effects in controlling SNE. However, their exact mechanisms have not been fully elucidated. Moreover, few studies have focused on their impact on microRNAs (miRNAs). Therefore, the present study aimed to explore the miRNA expression profiles in the ileum of broiler chickens during probiotic supplementation for controlling SNE. A total of 180 newly hatched male broilers were randomly allocated into three groups, including a negative control group, an SNE infection group, and a Bacillus licheniformis H2 pretreatment group. Illumina high-throughput sequencing was conducted to identify the miRNA expression of the three groups. Results showed that 628 miRNAs, including 582 known miRNAs and 46 novel miRNAs, were detected in the miRNA libraries. The target genes of 57 significantly differentially expressed miRNAs were predicted and annotated. Moreover, they were found to be partly enriched in pathways related to immunity and inflammation such as tumor necrosis factor receptor binding, immune response-regulating signaling pathway, Toll-like receptor 2 signaling pathway, interleukin-15 production, activation of NF-κB-inducing kinase activity, and MAP kinase tyrosine/serine/threonine phosphatase activity. Some of the target genes of 57 miRNAs were related to the MAPK signaling pathway. Furthermore, the expression of several miRNAs, which may be involved in the MAPK signaling pathway, was significantly affected by SNE induction and showed no significant difference in the presence of H2. All these findings provide comprehensive miRNA expression profiles of three different treatment groups. They further suggest that H2 could exert beneficial effects in controlling SNE through immune and inflammatory response associated with altered miRNA expression, such as the MAPK signaling pathway.

Effects of glucose oxidase on growth performance, immune function, and intestinal barrier of ducks infected with Escherichia coli O88.

The negative effects of dietary antibiotics have become a widespread concern. It is imperative to search for a new type of green, safe, and efficient feed additive that can replace antibiotics. This study was to investigate the effects of glucose oxidase (GOD) on growth performance, immune function, and intestinal barrier in ducks infected with Escherichia coli O88. First, we established the E. coli challenge model of ducks through a preliminary experiment and then carried out the formal experiment by using 144 1-day-old male lean Peking ducklings (50 ± 2.75 g). All ducks were randomly assigned to 1 of 3 dietary treatment groups of basal diet (control), 30 mg/kg virginiamycin (antibiotic), and 200 U/kg GOD (1,000 U/g). Each group consisted of 6 replications with 8 birds per replicate. At day 7, all ducks were orally administered 0.2 mL E coli O88 (3 × 109 cfu/mL) twice, 8 h apart based on the preliminary experiment. The experiment lasted for 28 d. Dietary supplementation with GOD improved growth performance of ducks infected with E. coli. The GOD increased contents of Ig in plasma and secreted Ig A in jejunal mucosa. The GOD group had lower concentrations of inflammatory cytokines (tumor necrosis factor-α, IL-1ß, and IL-6) and their upstream regulator Toll-like receptor 4 in the jejunum of ducks than the control group. Supplementation with GOD increased villus height and decreased crypt depth in the jejunum. The gene expression of tight junction proteins (zonula occludens-1, claudin-1 and claudin-2) was enhanced by adding GOD. The GOD decreased intestinal permeability by reducing the concentrations of diamine oxidase and D-lactic in plasma of ducks. There were no significant differences in almost all the indices tested between the GOD and the antibiotic groups. In conclusion, supplementation of GOD improved growth performance, immune function, and intestinal barrier of ducks infected with E. coli O88. Glucose oxidase may serve as a promising alternative therapy to antibiotics to relieve or prevent colibacillosis in ducks.

Effects of methylsulfonylmethane and neutralizing anti-IL-10 antibody supplementation during a mild Eimeria challenge infection in broiler chickens.

A 28-day experiment was conducted in broilers to study the effects of feeding methylsulfonylmethane (MSM) and IL-10-neutralizing antibody from dried egg product (DEP) on the growth performance, immune responsivity, oxidative stress parameters, and gut health outcomes during a mild infection with mixed species of Eimeria. A total of 500 male Ross 308 chicks were allocated to five treatments: sham-inoculated (uninfected) chickens fed control diet (UCON), Eimeria-infected chickens fed control diet (ICON), and Eimeria-infected chickens fed control diet supplemented with 287 U/tonne of DEP (I-DEP), 0.4% MSM, or their combination (I-DEP-MSM), with 10 replicate cages of 10 birds per treatment. All infected groups received 1 mL of an oral inoculum containing Eimeria acervulina (10,000 oocysts), Eimeria maxima (5,000 oocysts), and Eimeria tenella (5,000 oocysts) on study days 7 and 14. Data were analyzed as a two-way ANOVA for all treatments including Eimeria-infected groups, in addition to a single degree of freedom contrast to compare uninfected and infected groups receiving the control diet. Mild Eimeria infection did not influence the growth performance in ICON compared with UCON at any time points. Overall (day 0-28) growth performance parameters were not influenced by either infection or dietary supplementation of MSM or DEP. However, birds in I-DEP-MSM showed improved ADG during study day 7 to 14 (i.e., 7 d after primary inoculation) indicating a beneficial effect immediately after Eimeria infection. Although MSM supplementation reduced thiobarbituric acid reactive substances (day 21 and 28), both MSM and DEP improved the total antioxidant capacity (day 21) in the plasma of infected birds. Histopathological outcomes were not influenced by treatments, and fecal oocyst output was higher in MSM- and DEP-supplemented groups than with ICON, indicating no beneficial effects. Similarly, expression of cecal inflammatory cytokines (IL-10, IL-1ß, and interferon-γ) was not affected by MSM, DEP, or their combination. Overall, the current results suggest that both MSM and DEP supplementation may benefit birds during a mild Eimeria infection as indicated by improvements in ADG and oxidative stress outcomes.

Reproductive tract diseases in female backyard chickens (Gallus gallus domesticus) - diagnostic imaging and final outcome during a decade.

OBJECTIVE: Female reproductive tract disorders are common conditions of backyard poultry with an increasing demand for individual veterinary care. However, only limited case reports are available on diagnostic workup and outcomes of individual cases. This study aims at giving an overview of usually presented reproductive tract disorders, comparing diagnostic imaging findings with final diagnoses, and summarizing the outcome of the respective diseases. MATERIAL AND METHODS: The digital medical records archive of the University for Veterinary Medicine in Vienna was searched for chickens that were finally diagnosed with diseases of the reproductive tract, including all patients from May 1st, 2009 to May 31st, 2019. Information such as patient age, medical history, results of diagnostic imaging, final confirmed diagnosis, outcome, surgical protocol and necropsy findings was extracted. RESULTS: Finally confirmed reproductive tract diseases were found in 57 of 315 female chickens. The most common conditions were egg-related coelomitis along with salpingitis or impacted salpinx (25/57), followed by ovarian or oviductal neoplasia (17/57). Clinical findings were unspecific in the majority of cases, but most conspicuous were chickens presented with a distended coelomic cavity and apathy. Coelomic ultrasonography as well as computed tomography proved to be valuable tools for distinguishing between the respective conditions. However, ultrasonography alone mainly failed (10/11) to differentiate between ovary or oviductal neoplasia and egg-related coelomitis with salpingitis or impacted salpinx, respectively. Computed tomography was perceived as a superior tool for final diagnosis. In total 6/6 CT-scans correctly made a definitive diagnosis. Nevertheless, accurate diagnosis was only possible after celiotomy with the necessity of consecutive surgery for most of the reported cases. As an overall outcome 34 of 57 patients were either euthanised or died, whereas only 23 chickens could be successfully treated and discharged. Several hens were reported to be doing well at home, according to regular check-up procedures within 4 years post-surgery. CONCLUSION AND CLINICAL RELEVANCE: Diagnostic work-up and treatment of hens with reproductive tract diseases can be challenging. Clinical presentation and diagnostic imaging provide important information, still celiotomy is often required for final diagnosis. The condition of the chickens is usually serious. Within our study, 40 % of the hens could be treated successfully. Therefore, a realistic assessment of each individual case and clarification for the owners are important.

Selenium Yeast Alleviates Ochratoxin A-Induced Hepatotoxicity via Modulation of the PI3K/AKT and Nrf2/Keap1 Signaling Pathways in Chickens.

The aim of this study was to investigate the protective effects of selenium yeast (Se-Y) against hepatotoxicity induced by ochratoxin A (OTA). The OTA-induced liver injury model was established in chickens by daily oral gavage of 50 µg/kg OTA for 21 days. Serum biochemistry analysis, antioxidant analysis, as well as the qRT-PCR and Western blot (WB) analyses were then used to evaluate oxidative damage and apoptosis in chicken liver tissue. The results showed that Se-Y significantly increased liver coefficient induced by OTA (P < 0.05). OTA + Se-Y treated group revealed that Se-Y reduced the OTA-induced increase in glutamic pyruvic transaminase (ALT), glutamic oxaloacetic transaminase (AST) and malonaldehyde (MDA) content, and reversed the decrease in antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) (P < 0.05). In this study, we found that OTA is involved in the mRNA expression levels about Nrf2/Keap1 and PI3K/AKT signaling pathways, such as oxidative stress-related genes (Nrf2, GSH-Px, GLRX2 and Keap1) and apoptosis-related genes (Bax, Caspase3, P53, AKT, PI3K and Bcl-2). Besides, significant downregulations of protein expression of HO-1, MnSOD, Nrf2 and Bcl-2, as well as a significant upregulation of Caspase3 and Bax levels were observed after contaminated with OTA (P < 0.05). Notably, OTA-induced apoptosis and oxidative damage in the liver of chickens were reverted back to normal level in the OTA + Se-Y group. Our findings indicate that pretreatment with Se-Y effectively ameliorates OTA-induced hepatotoxicity.

Effects of encapsulated cinnamaldehyde and citral on the performance and cecal microbiota of broilers vaccinated or not vaccinated against coccidiosis.

This study investigated the effects of encapsulated cinnamaldehyde (CIN) and citral (CIT) alone or in combination (CIN + CIT) on the growth performance and cecal microbiota of nonvaccinated broilers and broilers vaccinated against coccidiosis. Vaccinated (1,600) and nonvaccinated (1,600) 0-day-old male Cobb500 broilers were randomly allocated to 5 treatments: basal diet (control) and basal diet supplemented with bacitracin (BAC, 55 ppm), CIN (100 ppm), CIT (100 ppm), and CIN (100 ppm) + CIT (100 ppm). In general, body weight (BW) and feed conversion ratio were significantly improved in birds treated with BAC, CIN, CIT, and CIN + CIT (P < 0.05) but were all decreased in vaccinated birds compared with nonvaccinated birds (P < 0.05). Significant interactions (P < 0.05) between vaccination and treatments for average daily gain during the periods of starter (day 0-9) and BW on day 10 were noted. Broilers receiving vaccines (P < 0.01) or feed supplemented with BAC, CIN, CIT, or CIN + CIT (P < 0.01) showed reductions in mortality rate from day 0 to 28. The incidences of minor coccidiosis were higher (P < 0.05) in vaccinated birds than in nonvaccinated birds. Diet supplementation with BAC or tested encapsulated essential oils showed comparable effects on the coccidiosis incidences. Similar to BAC, CIN and its combination with CIT reduced both incidence and severity of necrotic enteritis (P < 0.05). No treatment effects were observed on the cecal microbiota at the phyla level. At the genus level, significant differences between vaccination and treatment groups were observed for 5 (Lactobacillus, Ruminococcus, Faecalibacterium, Enterococcus, and Clostridium) of 40 detected genera (P < 0.05). The genus Lactobacillus was more abundant in broilers fed with CIT, while Clostridium and Enterococcus were less abundant in broilers fed with CIN, CIT, or CIN + CIT in both the vaccinated and nonvaccinated groups. Results from this study suggested that CIN alone or in combination with CIT in feed could improve chicken growth performance to the level comparable with BAC and alter cecal microbiota composition.

Lead Levels in the Eggs of a Chicken With Lead Toxicosis.

A 1.5-year-old Polish hen was presented with a history of watery droppings and poor vent tone. Results of diagnostic tests revealed blood lead at levels considered to be toxic. Chelation therapy was started with calcium ethylenediaminetetraacetate. The hen was laying eggs before, during, and after chelation therapy. Eggs were tested for the presence of lead by combining yolk and albumen together. Before chelation therapy, the level of lead in the egg tested was 14 µg. Two days after the end of chelation therapy, results of a second blood lead test revealed a drop to nontoxic levels. No lead was detected in the combined yolks and albumen of eggs collected 7-11 days after the end of chelation therapy. Four weeks after the end of chelation therapy, no lead was identified in the shells of tested eggs.

Examination of the effects of virus inactivation methods on the induction of antibody- and cell-mediated immune responses against whole inactivated H9N2 avian influenza virus vaccines in chickens.

Several types of avian influenza virus (AIV) vaccines exist, including live-attenuated, vectored, and whole inactivated virus (WIV) vaccines. Inactivated vaccines offer some advantages compared to other types of vaccines, including ease of production and lack of ability to revert to a virulent state. However, WIV are poorly immunogenic, especially when these vaccines are delivered to mucosal surfaces. There are several factors that contribute to the immunogenicity of vaccines, one of which is the method used to inactivate viruses. Several methods exist for producing influenza WIVs, including formaldehyde, a chemical that affects protein structures leading to virus inactivation. Other methods include treatment with beta-propiolactone (BPL) and the application of gamma radiation, both of which have less effects on protein structures compared to formaldehyde, and instead alter nucleic acids in the virion. Here, we sought to determine the effect of the above inactivation methods on immunogenicity of AIV vaccines. To this end, chickens were vaccinated with three different H9N2 WIVs using formaldehyde, BPL, and gamma radiation for inactivation. In addition to administering these three WIVs alone as vaccines, we also included CpG ODN 2007, a synthetic ligand recognized by Toll-like receptor (TLR)21 in chickens, as an adjuvant for each WIV. Subsequently, antibody- and cell-mediated immune responses were measured following vaccination. Antibody-mediated immune responses were increased in chickens that received the BPL and Gamma WIVs compared to the formaldehyde WIV. CpG ODN 2007 was found to significantly increase antibody responses for each WIV compared to WIV alone. Furthermore, we observed the presence of cell-mediated immune responses in chickens that received the BPL WIV combined with CpG ODN 2007. Based on these results, the BPL WIV + CpG ODN 2007 combination was the most effective vaccine at inducing adaptive immune responses against H9N2 AIV. Future studies should characterize mucosal adaptive immune responses to these vaccines.

Diabetes Mellitus With Concurrent Cerebellar Degeneration and Necrosis in a Domestic Goose ( Anser anser domesticus).

A 5-year-old sexually intact male Toulouse goose ( Anser anser domesticus) was presented for ataxia, polyuria, and polydipsia. The goose was cachectic and exhibited head tremors. Results of plasma biochemical analysis and point-of-care glucometry revealed persistent hyperglycemia. Despite supportive care and oral glipizide, the goose died within 48 hours of presentation. Necropsy revealed severe pancreatic atrophy and fibrosis with regionally extensive cerebellar encephalomalacia and generalized Purkinje cell degeneration and necrosis. On a wet basis, hepatic zinc concentration was determined to be twice the reference interval by atomic absorption spectroscopy. Based on these findings, the pancreatic insufficiency with secondary diabetes mellitus was attributed to chronic zinc toxicosis. Despite birds' relative resistance to high blood glucose concentrations, prolonged hyperglycemia is suspected to have caused selective Purkinje cell degeneration and necrosis by glial activation, mitochondrial dysfunction, and glutamate toxicity, which resulted in the clinically observed motor deficits. This is consistent with experimental diabetic rat models. This case highlights the need for further investigation of the complex pathophysiology of diabetes mellitus in birds.

Preparation of single-chain antibody against VP3 protein of duck hepatitis virus type 1 by phage display technology.

To construct phage antibody library for VP3 protein of duck hepatitis virus type 1(DHAV-1) and pan the specific single-chain variable fragment antibody (scFv), total RNA was extracted from the protein VP3- immunized mice spleen., vp3 gene encoding VP3 protein was amplified from the genome of DHAV-1 by RT-PCR method for the following recombinant pET-VP3 construction, immunogenic VP3 expression and purification, and combined with SOE-PCR method to complete the assembly of scFv. The scFv gene was cloned into pCANTAB5E vector for phage antibody library construction. Finally, the library for anti-VP3 scFv was screened by four rounds of adsorption-elution-enrichment with the purified VP3 protein. The characters of binding ability, specificity and neutralization of soluble antibodies expressed were evaluated by ELISA. The results showed 7 VP3-specific scFvs have been screened and identified with high both sensitivity and specificity for binding DHAV-1. To our knowledge, this is the first report for VP3-specific scFv of DHAV-1 and potentially promising application used in prevention and treatment of duck viral hepatitis.

Immunomodulatory effect of baculovirus in chickens: How it modifies the immune response against infectious bursal disease virus.

Several reports have shown that baculoviruses (BVs) have strong adjuvant properties on the mammalian immune system. Recent studies of our group demonstrated the ability of BV to stimulate the innate immunity in chickens. In this investigation, we aimed to assess the potential antiviral effect of BV given both, before and after infectious bursal disease virus (IBDV). In the first case, specific pathogen free chickens were intravenously inoculated with 5 × 10(7) pfu of Autographa californica nuclear polyhedrosis virus and 3 h later were orally administered 2.5 × 10(5) egg infectious doses 50 of IBDV. In the second case, chickens received IBDV 3 h before BV inoculation. Five days later, chickens were bled and euthanized. RNA from the bursa was analyzed for cytokine production. Also, bursae were used for virus recovery, and processed for lymphocyte isolation. The results showed that the administration of BV 3 h after the inoculation with IBDV produced important changes in the effect that IBDV causes in the bursa. BV reduced the infiltration of T lymphocytes, decreased the expression pattern of IL-6 and IFN-γ and inhibited IBDV replication. The results herein presented demonstrate that this Lepidopteran virus shows antiviral activity in chickens under experimental conditions. Investigations under field conditions have to be done to probe this strategy as a valuable sanitary tool for the treatment and prevention of chicken diseases.

Inhibition of infectious bursal disease virus by vector delivered SiRNA in cell culture.

Infectious Bursal Disease (IBD) is major threat to poultry industry. It causes severe immunosuppression and mortality in chicken generally at 3 to 6 weeks of age. RNA intereference (RNAi) emerges as a potent gene regulatory tool in last few years. The present study was conducted to evaluate the efficiency of RNAi to inhibit the IBD virus (IDBV) replication in-vitro. VP2 gene of virus encodes protein involved in capsid formation, cell entry and induction of protective immune responses against it. Thus, VP2 gene of IBDV is the candidate target for the molecular techniques applied for IBDV detection and inhibition assay. In this study, IBDV was isolated from field cases and confirmed by RT-PCR. The virus was then adapted on chicken embryo fibroblast cells (CEF) in which it showed severe cytopathic effects (CPE). The short hairpin RNA (shRNAs) constructs homologous to the VP2 gene were designed and one, having maximum score and fulfilling maximum Reynolds criteria, was selected for evaluation of effective inhibition. Selected shRNA construct (i.e., VP2-shRNA) was observed to be the most effective for inhibiting VP2 gene expression. Real time PCR analysis was performed to measure the relative expression of VP2 gene in different experimental groups. The VP2 gene was less expressed in virus infected cells co-transfected with VP2-shRNA as compared to mock transfected cells and IBDV+ cells (control) at dose 1.6 µ g. The result showed ∼95% efficient down regulation of VP2 gene mRNA in VP2-shRNA treated cells. These findings suggested that designed shRNA construct achieved high level of inhibition of VP2 gene expression in-vitro.

Influence of bacteriophage P22 on the inflammatory mediator gene expression in chicken macrophage HD11 cells infected with Salmonella Typhimurium.

This study was designed to evaluate the effects of bacteriophage on the intracellular survival and immune mediator gene expression in chicken macrophage-like HD11 cells. The invasive ability and intracellular survival of Salmonella Typhimurium (ST(P22-) ) and lysogenic S. Typhimurium (ST(P22+) ) in HD11 cells were evaluated at 37 °C for 24 h postinfection (hpi). The expression of inflammatory mediator genes was determined in ST(P22-) - and ST(P22+) -infected HD11 cells treated with and without bacteriophage P22 at 1 and 24 hpi using quantitative RT-PCR. The ability of ST(P22-) and ST(P22+) to invade HD11 cells was significantly decreased by bacteriophage P22 at 1 hpi. The numbers of intracellular ST(P22-) and ST(P22+) were significantly decreased from 2.39 to 1.62 CFU cm(-2) and from 3.40 to 1.72 CFU cm(-2) in HD11 cells treated with bacteriophage P22, respectively, at 24 hpi. The enhanced expression of inflammatory mediators was observed in ST(P22-) - and ST(P22+) -infected HD11 cells treated with and without bacteriophage P22. These results suggest that the application of bacteriophage could be an effective way to control the intracellular infection.

Inhibition of avian leukosis virus subgroup J replication by miRNA targeted against env.

No effective vaccine has been developed against the subgroup J avian leukosis virus (ALV-J). The genetic diversity of ALV-J might be related to the env gene, therefore, we selected conserved sequences of the env gene and designed interference sequence. In this study, microRNAs (miRNAs) were designed and synthesized, corresponding to conserved regions of the env gene. These miRNAs were cloned into the linearized eukaryotic expression vector. The recombinant plasmids were transfected into DF-1 cells. After transfection, the cells were inoculated with ALV-J. In reporter assays, the transfection efficiency is 80% by indirect immunofluorescence (IFA). Expression of the virus envelope glycoprotein was measured by IFA and western blotting assays. The relative expression of env gene was determined using quantitative PCR. Our results show that the mi-env 231 and mi-env 1384 could effectively suppress the replication of ALV-J with an efficiency of 68.7-75.2%. These data suggest that the miRNAs targeting the env can inhibit replication of ALV-J efficiently. This finding provides evidence that miRNAs could be used as a potential tool against ALV infection.

Reduction of infectious bursal disease virus replication by shRNAs targeting the VP1 and VP2 genes driven by chicken U6 promoter.

Infectious bursal disease virus (IBDV) causes a highly contagious and immunosuppressive disease in young chickens and results in considerable economic losses for the poultry industry. To suppress the replication of IBDV, two short hairpin RNAs (shRNAs) were designed for targeting the VP1 and VP2 genes of IBDV. Recombinant plasmids carrying each shRNA or two shRNAs were constructed based on vector pSilencer2.1-U6 in which the human U6 promoter was replaced with chicken U6 promoter. In chicken embryo fibroblasts, transfection with these shRNA plasmids 24h before infection with IBDV B87 reduced 50% tissue culture infectious doses (TCID(50)) from 10(8.75) TCID(50)/0.1 mL to 10(3.75)-10(1.0) TCID(50)/0.1 mL. In 10-day old specific pathogen-free (SPF) chicken embryos, incubation with a mixture of IBDV B87 and a shRNA plasmid via the allantoic cavity resulted in 100% mortality and high IBDV virus titer in the control group but 25-0% mortality and near normal embryo development in the specific shRNA groups; additionally, IBDV VP1 and VP2 mRNA levels were reduced by 72-95% in the shRNA groups as compared with the control groups. When challenged with a virulent strain IBDV GX8/99, 14-day-old chickens pre-treated with the single shRNA plasmids or the dual shRNA plasmid showed approximately 70% or 90% survival at 5 days post-challenge while those pre-treated with control plasmid or saline had less than 5% survival. The current study suggests that two IBDV shRNAs expressed by a plasmid under chicken U6 promoter could effectively and synergistically reduce IBDV replication in vitro and in vivo.

Performance, egg quality, and immune response of laying hens fed diets supplemented with mannan-oligosaccharide or an essential oil mixture under moderate and hot environmental conditions.

In total, 432 thirty-six-week-old laying hens were fed a basal diet supplemented with mannan-oligosaccharide (MOS) or an essential oil mixture (EOM) from 36 to 51 wk of age. Hens were divided into 3 equal groups replicated 6 times with 24 hens per replicate. No significant difference was observed among the dietary treatments in terms of performance indices. Different from the dietary manipulation, high environmental temperatures negatively influenced all of the laying performance traits except the feed conversion ratio in association with the diminished feed consumption. The MOS, and particularly the EOM, tended to alleviate the deleterious effect of heat stress on BW gain. Mortality was higher in MOS-fed hens than with other treatments. A supplementation diet with MOS or EOM provided increments in eggshell weight (P < 0.01). Relative albumen weight was significantly decreased (P < 0.05) in response to EOM or MOS supplementation; however, this was not the case in the yolk weight rate. The MOS decreased albumen height and Haugh unit (P < 0.05). High environmental temperatures hampered entire egg quality characteristics except for the eggshell breaking strength and egg yolk weight. These results indicated that heat stress adversely affected both productive performance and egg quality. As for the results of this study, neither MOS nor EOM was efficacious in improving efficiency of egg production and stimulating humoral immune response in laying hens reared under moderate and hot climatic conditions. However, the ameliorative effect exerted by MOS and EOM on eggshell characteristics is conclusive.

Vitamin A deficiency in turkey poults.

Vitamin A deficiency was diagnosed in a commercial flock of 13,000 4-6-week-old turkey poults in the summer of 2004. The birds were initially submitted for examination because of a 3% increase in the reported daily mortality of the flock. Clinically, affected birds had stunted growth and ruffled feathers, showed signs of incoordination, and were depressed. At necropsy, pale white pseudomembranous to mucoid material was observed on the mucosal surface of the tongue, oral cavity, portions of the esophagus, and the crop of some birds. Histologically, there was squamous metaplasia of the mucosal epithelium of the oral mucosa, esophagus, sinuses, nasal glands, bronchi, proventriculus, and the bursa of Fabricius. Vitamin A was not detected in the feed sample at a detection limit of 0.5 mg/kg. Serum vitamin A concentrations in 7 birds were very low and ranged from 0.05 to 0.1 mg/L. Vitamin A concentrations in livers were extremely low (0.1 mg/kg wet weight, 1/7 poults) or undetectable (< 0.1 mg/kg wet weight, 6/7 poults). A diagnosis of vitamin A deficiency was made based on gross and microscopic lesions and vitamin A concentrations in serum, liver, and feed. To the authors' knowledge, this is the first documented case of vitamin A deficiency in poults submitted from a commercial meat turkey producer comparatively depicting the gross and microscopic lesions with those found in other species of birds and mammals.

Activated vitronectin as a target for anticancer therapy with human antibodies.

The formation of a provisional extracellular matrix represents an important step during tumor growth and angiogenesis. Proteins that participate in this process become activated and undergo conformational changes that expose biologically active cryptic sites. Activated matrix proteins express epitopes not found on their native counterparts. We hypothesized that these epitopes may have a restricted tissue distribution, rendering them suitable targets for therapeutic human monoclonal antibodies (huMabs). In this study, we exploited phage antibody display technology and subtractive phage selection to generate human monoclonal antibody fragments that discriminate between the activated and native conformation of the extracellular matrix protein vitronectin. One of the selected antibody fragments, scFv VN18, was used to construct a fully human IgG/kappa monoclonal antibody with an affinity of 9.3 nM. In immunohistochemical analysis, scFv and huMab VN18 recognized activated vitronectin in tumor tissues, whereas hardly any activated vitronectin was detectable in normal tissues. Iodine 123-radiolabeled huMabVN18 was shown to target to Rous sarcoma virus-induced tumors in chickens, an animal model in which the epitope for huMab VN18 is exposed during tumor development. Our results establish activated vitronectin as a potential target for tumor therapy in humans.