Chicken Spleen Research Articles

SteE enhances the colonization of Salmonella Pullorum in chickens

Salmonella pullorum (S. pullorum) is the causative agent of pullorum disease and results in severe economic losses in poultry, and can long-term survival by colonizing host organs. steE is an effector protein secreted by Salmonella pathogenicity island 2. It is not clear in vivo for the colonization of Salmonella. To investigate the role of steE on the colonization of S. Pullorum in the principal organs of chicken, we used S. pullorum and S. pullorum ΔsteE strains immunized chickens, respectively. The results of the virulence assay showed that the LD50 of S. pullorum ΔsteE was 22.8 times higher than that of S. pullorum in chickens. The colonization experiment of bacteria showed that the overall change trend of the number of S. pullorum and S. pullorum ΔsteE strains were similar in chicken liver, spleen, heart, bursa, and cecum, which increased first and then decreased. However, the deletion of steE caused significantly reduced colonization, pathological change, and virulence of S. pullorum in a chicken infection model. Our findings provide exciting insights into the pathogenic mechanism and live attenuated vaccine associated with steE in S. pullorum.

Genetic characterization and pathogenicity of H7N9 highly pathogenic avian influenza viruses isolated from South China in 2017.

Since 2017, the new H7N9 highly pathogenic avian influenza viruses (HPAIVs) have been responsible for more than 200,000 cases of chicken infection and more than 120,000 chicken deaths in China. Our previous study found that the Q26 was chicken-origin H7N9 HPAIV. In this study, we analyzed the genetic characterization of Q24, Q65, Q66, Q85, and Q102 H7N9 avian influenza viruses isolated from Guangdong, China in 2017. Our results showed that these viruses were highly pathogenic and belonged to two different genotypes, which suggested they occurred genetic reassortant. To investigate the pathogenicity, transmission, and host immune responses of H7N9 virus in chickens, we selected Q24 and Q26 viruses to inoculate chickens. The Q24 and Q26 viruses killed all inoculated chickens within 3 days and replicated effectively in all tested tissues. They were efficiently transmitted to contact chickens and killed them within 4 days through direct contact. Furthermore, we found that the expressions of several immune-related genes (e.g., TLR3, TLR7, MDA5, MAVS, IFN-β, IL-6, IL-8, OAS, Mx1, MHC I, and MHC II) were upregulated obviously in the lungs and spleen of chickens inoculated with the two H7N9 viruses at 24 h post-inoculation (HPI). Among these, IL-6 and IFN-β in lungs were the most upregulated (by 341.02-381.48-fold and 472.50-500.56-fold, respectively). These results suggest that the new H7N9 viruses isolated in 2017, can replicate and transmit effectively and trigger strong immune responses in chickens, which helps us understand the genetic and pathogenic variations of H7N9 HPAIVs in China.

MicroRNA expression in immune tissues of adult chickens after embryo stimulation with bioactive substances

The microbiota has a profound impact on the host organisms. The interaction between the host and its microbiota has an epigenetic mode of action. In poultry species, gastrointestinal microbiota might be stimulated before hatching. This stimulation with bioactive substances has a broad spectrum and long-term effects. This study aimed to examine the role of miRNA expression stimulated by host-microbiota interaction via administering a bioactive substance at the stage of embryonic development. This paper is a continuation of earlier research in the field of molecular analyzes in immune tissues after in ovo administration of bioactive substances. Eggs of Ross 308 broiler chicken and Polish native breed chicken (Green-legged Partridgelike) were incubated in the commercial hatchery. On day 12 of incubation, eggs were injected: the control group with saline (0.2 mM physiological saline), probiotic—Lactococcus lactis subsp. cremoris, prebiotic—galactooligosaccharides, and synbiotic—mentioned above prebiotic with probiotic. The birds were intended for rearing. miRNA expression analysis was performed using the miRCURY LNA miRNA PCR Assay in the spleen and tonsils of adult chickens. Six miRNAs differed significantly, at least between one pair of treatment groups. The most miRNA changes were observed in the cecal tonsils of Green-legged Partridgelike chickens. At the same time, only miR-1598 and miR-1652 showed significant differences between the treatment groups in the cecal tonsils and spleen of Ross broiler chickens. Only two miRNAs showed significant GeneOntology (GO)enrichment with the ClueGo plug-in. gga-miR-1652 target genes showed only 2 GOs significantly enriched: chondrocyte differentiation and early endosome. gga-miR-1612 target genes, the most significant GO was regulating the RNA metabolic process. The enriched functions were associated with gene expression or protein regulation, the nervous system, and the immune system. Results suggest that early microbiome stimulation in chicken might regulate the miRNA expression in different immune tissues in a genotype-dependent manner.

Integrated analysis of methylation profiles and transcriptome of Marek's disease virus-infected chicken spleens reveal hypomethylation of CD4 and HMGB1 genes might promote Marek's disease tumorigenesis

Marek's disease (MD) is a lymphoproliferative neoplastic disease caused by Marek's disease virus (MDV). Previous studies have showed that DNA methylation was involved in MD development, but systematic studies are still lacking. Herein, we performed whole genome bisulfite sequencing (WGBS) and RNA-seq in MDV-infected tumorous spleens (IN), noninfected spleens (NoIN), and survivor (SUR) spleens of chickens to identify the genes playing important roles in MD tumor transformation. We generated the first genome-wide DNA methylation profile of MDV-infected, noninfected, and survivor chickens. Combined the WGBS and RNA-Seq, we found that the expression of 25% differential expression genes (DEGs) were significantly correlated with methylation of CpG sites in their gene bodies or promoters. Further, we focused on the DEGs with differentially methylated regions (DMRs) on genes' body and promoter, and it showed the expression of 60% DEGs were significantly correlated with methylation of CpG sites in DMRs. Finally, we identified 8 genes, including CD4, CTLA4, DTL, HMGB1, LGMN, NUP210, RAD52, and ZAP70, and their expression was negatively correlated with methylation of DMRs in their promoters in both IN vs. NoIN and IN vs. SUR. These 8 genes showed specifically high expression in IN groups and clustered in module turquoise analyzed by WGCNA. Out of 8 genes, CD4 and HMGB1 were drop in QTLs associated with MD resistance. Thus, we overexpressed the 2 genes to simulate their high expression in the IN group and found they significantly promoted MDCC-MSB-1 cell proliferation, which revealed they might play promoting roles in MD tumorigenesis in IN due to their high expression induced by hypomethylation.

Regulation of the MyD88 gene in chicken spleen inflammation induced by stress.

In order to investigate the regulatory role of the myeloid differentiation factor 88 (MyD88) gene in the stress inflammatory response to chicken spleen, the chicken stress model and macrophage (HD11) inflammation model were constructed in this study. Enzyme-linked immunosorbent assay and quantitative real-time PCR were used to investigate the effects of MyD88 on immune and inflammatory indicators. The results demonstrated that the levels of IgG, CD3+ and CD4+ in the serum of chickens in the beak trimming stress and heat stress groups decreased significantly compared to the control group without stress (P < 0.05), and the inflammation-related indices IL-1β, TNF-α, IL-6 and NF-κB increased significantly (P < 0.05). Stress up-regulated the expression levels of MyD88, IL-1β, NF-κB and TLR4 in the spleen, stimulated the release of inflammatory factors. Overexpression of MyD88 significantly up-regulated the expression levels of the inflammatory factors IL-1β, TNF-α, IL-8, NF-κB and TLR4 in HD11 cells (P < 0.05). Co-treatment with lipopolysaccharide (LPS) further promoted the expression levels of the inflammatory cytokines in HD11 cells. Interference with the expression of MyD88 significantly reduced the expression level of inflammatory factors in HD11 cells (P < 0.05) and had an antagonistic effect with LPS to alleviate the inflammatory reaction. In conclusion, the MyD88 gene has a pro-inflammatory effect and is highly expressed in the beak trimming and heat stress models in chicks, regulating the inflammatory response in poultry. It was involved in regulating the expression of immune-related genes in HD11 cells and had a synergistic effect with LPS.

The effects of vitamin E on T cell subsets and immunoglobulin-containing plasma cells in the spleen of heat-stressed broiler chickens

iven a bird’s underdeveloped lymph vessels and lymph nodes, the spleen is of the utmost importance in the avian immune system. Broiler chickens can be subjected to heat stress (HS), which causes an increase in mortality, a decrease in feed intake, body weight gain, and hatchability. Vitamin E is an important antioxidant for cells, but there is limited information about how heat stress affects spleen tissue in chickens and how vitamin E can change this effect. Therefore, the aim of this study was to investigate the effects of vitamin E based on the location of subpopulations of T cells and immunoglobulin-producing plasma cells in the spleens of broiler chickens subjected to HS. The results indicated that vitamin E supplementation in the broiler chicken diet could increase the population of immune system cells in heat-stressed chickens. The findings of this study could be used as a reference for the development of management strategies for broiler chickens, especially in countries with a hot climate.

Molecular analysis of chicken interferon-alpha inducible protein 6 gene and transcriptional regulation.

Interferon-alpha inducible protein 6 (IFI6) is an interferon-stimulated gene (ISG), belonging to the FAM14 family of proteins and is localized in the mitochondrial membrane, where it plays a role in apoptosis. Transcriptional regulation of this gene is poorly understood in the context of inflammation by intracellular nucleic acid-sensing receptors and pathological conditions caused by viral infection. In this study, chicken IFI6 (chIFI6) was identified and studied for its molecular features and transcriptional regulation in chicken cells and tissues, i.e., lungs, spleens, and tracheas from highly pathogenic avian influenza virus (HPAIV)-infected chickens. The chIFI6-coding sequences contained 1638 nucleotides encoding 107 amino acids in three exons, whereas the duck IFI6-coding sequences contained 495 nucleotides encoding 107 amino acids. IFI6 proteins from chickens, ducks, and quail contain an IF6/IF27-like superfamily domain. Expression of chIFI6 was higher in HPAIV-infected White Leghorn chicken lungs, spleens, and tracheas than in mock-infected controls. TLR3 signals regulate the transcription of chIFI6 in chicken DF-1 cells via the NF-κB and JNK signaling pathways, indicating that multiple signaling pathways differentially contribute to the transcription of chIFI6. Further research is needed to unravel the molecular mechanisms underlying IFI6 transcription, as well as the involvement of chIFI6 in the pathogenesis of HPAIV in chickens.

Cyto- and histoarchitectonics of the chicken spleen in the post-vaccination period

One of the main functions of the spleen is participation in many immunological processes, protecting the body from various harmful agents. It is a secondary organ of lymphopoiesis and the only organ of immunogenesis, which provides immune control of blood and detects genetically foreign agents in it, and performs the role of a biological filter. Therefore, the Study of its histo-architectonics has theoretical and practical significance. The histostructure of the spleen of chickens has significant differences, particularly the absence of trabeculae, a small amount of connective tissue based around large vessels. The structure of the spleen of one-day-old vaccinated and non-vaccinated chickens is not formed, as there is no differentiation of the white pulp from the red pulp, which is related to the biological features of the chickens' body. According to our research, the presence of lymphoid nodules is observed for the first time in the 25-day age of the vaccinated group chickens. According to morphometric studies, it was established that their number was 2.33 ± 0.42 pcs. Comprehensive farm vaccination programs include ten vaccinations of chickens up to 100 days of age. Under the influence of multiple antigenic stimulations in the following age periods of a 50-day-old bird (after six vaccinations: twice against infectious bronchitis and infectious bursal disease, once against Marek's disease and Newcastle disease), the 75-day (after nine times vaccination), 100-day (after ten times vaccination) number and sizes of lymphoid nodules, as well as periarterial lymphoid sheaths and periellipsoid lymphoid sheaths increased concerning chickens of the control group. Our research established that the histostructure of the spleen of one-day-old chickens of the experimental and control groups is incomplete. The bird's spleen, a peripheral organ of immune protection, is formed at 25 days. However, chickens are vaccinated twice (against Marek's disease and infectious bronchitis) in the incubator when they are less than one day old, and 90% of the planned vaccinations are completed by the age of 75 days. Therefore, studying morphological changes in the spleen of birds of different ages can be an essential tool for re-evaluating preventive treatment protocols in modern poultry farming.

Beta-glucan enhanced immune response to Newcastle disease vaccine and changed mRNA expression of spleen in chickens

The present study was performed to investigate the effect of oral administration of β-glucan (G70), a product obtained from the cell wall of yeast, on Newcastle disease virus (NDV)-specific hemagglutination inhibition (HI) titers, lymphocyte proliferation, and the role of T lymphocyte subpopulations in chickens treated with live NDV vaccine. In addition, the influence of β-glucan on splenic gene expression was investigated by transcriptome sequencing. The results revealed that the supplementation of β-glucan boosted the titer of serum NDV HI increased the NDV stimulation index of lymphocytes in peripheral blood and intestinal tract, and promoted the differentiation of T lymphocytes into CD4+ T cells. The RNA sequencing (RNA-seq) analysis demonstrated that G70 upregulated the mRNA expressions related to G-protein coupled receptor and MHC class I polypeptide, and downregulated the mRNA expressions related to cathelicidin and beta-defensin. The immunomodulatory effect of G70 might function through mitogen-activated protein kinase signaling pathway. To sum up, G70 could boost the immunological efficacy of live NDV vaccine in chickens and could be applied as a potential adjuvant candidate in the poultry industry.

Application of ORF3 Subunit Vaccine for Avian Hepatitis E Virus.

Avian hepatitis E virus (HEV) is the main etiologic pathogen of chicken big liver and spleen disease which is widely prevalent in China in recent years. However, due to the lack of a highly effective culture system in vitro, a genetically engineered subunit vaccine is the main direction of vaccine development. In this study, ORF3 genes of VaHEV strain from laying hens and YT-aHEV strain from broilers were amplified, respectively, and ORF3 protein was successfully expressed by Escherichia coli prokaryotic expression system. The serum samples were collected periodically to detect avian HEV antibodies by indirect immunofluorescence after specific pathogen free chickens immunized with the two proteins and their mixed proteins, the results showed that all serum samples were positive for antibodies to avian HEV. The antibody-positive chickens were artificially challenged with the cell-adapted strain YT-aHEV strain. The chickens from the immunized control group were infected successfully; no fecal detoxification was detected in the immunized group. In this study, two representative strains of ORF3 subunit vaccines of laying hens and broilers were prepared by prokaryotic expression, the immune effects of different proteins of these were evaluated through immunization and challenge studies in vivo, which provided a new technical possibility for prevention and control of avian HEV.

Spleen-based proteogenomics reveals that Escherichia coli infection induces activation of phagosome maturation pathway in chicken

ABSTRACT Avian pathogenic Escherichia coli (APEC) leads to economic losses in poultry industry and is also a threat to human health. Various strategies were used for searching virulence factors, while little is known about the mechanism by which APEC survives in host or is eliminated by host. Thus, chicken colibacillosis model was constructed by intraperitoneally injecting E. coli O78 in this study, then the protein dynamic expression of spleen was characterized at different post-infection times by quantitative proteome. Comparative analysis showed that E. coli induced significant dysregulation at 72 h post infection in spleen tissue. Transcriptomic method was further used to assess the changes of dysregulated proteins at 72 h post infection at the mRNA level. Total 278 protein groups (5.7%) and 2,443 genes (24.4%) were dysregulated, respectively. The upregulated proteins and genes were consistently enriched in phagosome and lysosome pathways, indicating E. coli infection activates phagosome maturation pathway. The matured phagolysosome might kill the invasive E. coli. This study illuminated the genetic dysregulation in chicken spleen at the protein and mRNA levels after E. coli infecting and identified candidate genes for host response to APEC infection.

Biological influence of nanotechnological j, se, s citrates in broiler chickens in the second period of rearing

The research was carried out on two groups of broilers ROOS-308, divided into control (1) and experimental (2) groups, in the conditions of industrial cultivation and daily addition to water of nanotechnological citrates J, Se, S for 24-48 days of fattening. The research was aimed to identify the complex combined biological action of nanotechnological citrates J, Se, S in broiler chickens under conditions of their use for 2-3 growing periods. The 7-day changes dynamics in body weight, survival and death rate of chickens, the mass of internal organs and its correlation to chicken body mass at the day 48, the technological slaughter period, were defined as study periods. Blood and internal organs samples were taken to determine biochemical parameters and study its development by mass and mass coefficients at the slaughter period. The corrective effect of nanotechnological J, Se, S citrates on the protein indicators and mineral metabolism, growth and development of the liver, stomach, spleen and thyroid gland of chicken was identified. There was an increase in body weight gain of broiler chickens by 4-4,5 % during growth periods with the use of J, Se, S citrates and 5,2 % for day 48 of life while the mortality decreased by 0,62 % during the study period (Group 1 – 1,64 %; Group 2 – 1,02 %). The average daily gain during 48 days in the control Group 1 was 59,6 g with a body weight of 2859 g and the experimental Group 2 – 62,72 % with body weight of 3009 g respectively.

Molecular and pathological investigations of Marek's disease outbreaks in vaccinated poultry farms in Plateau State, North Central-Nigeria.

Marek's disease (MD) is a devastating neoplastic disease of poultry caused by MD virus (MDV). MD is one of the several diseases limiting the thriving Nigerian poultry industry. MD is mostly diagnosed in Nigeria based on history and gross lesions without laboratory investigations leading to underreporting of the disease. This study investigated MD outbreaks in poultry farms using polymerase chain reaction (PCR) and histopathology. Tumourous visceral organs were collected from dead chickens presented to veterinary clinics from 110 farms in Plateau State, North Central Nigeria from April 2013 to August 2014. Clinical signs observed in affected chickens were paralysis, stunting and uneven growth. Whilst the gross lesions observed were hepatomegaly, splenomegaly with lymphoma, prominent peripheral nerves and cachexia. The meq gene of MDV‑1 was detected by PCR in 55.0% (n = 11/20) of broilers and 71.1% (n = 64/90) of vaccinated layer chicken samples collected. Microscopy revealed severe diffuse lymphocytic infiltrations in the heart, spleen and liver of chickens with tumourous gross lesions. Based on history, gross lesions, detection of meq gene of MDV‑1 by PCR and histopathology results, MD was confirmed in the affected farms. Despite vaccination, outbreaks of MD still occurs in poultry farms in Nigeria. This study represents the first confirmatory diagnosis of MD in vaccinated poultry in Nigeria.

The effect of vaccination on the live weight of chickens and the absolute weight of the spleen and gland

Choosing optimal chicken immunization programs is an urgent problem in poultry farming. Studying the morphology of the organs of the chickens' immune system allows you to objectively assess the effectiveness of prevention methods. The article provides data on the effect of multiple vaccinations on the live weight of chickens and the absolute weight of immune defense organs: the spleen and gland of chickens aged 1, 15, 25, 50, 75, 100, and 120 days. One of the leading indicators of the growth of young birds is the dynamics of live weight under the influence of external factors. Identical technological conditions at the beginning of the experiment and the selection of livestock according to the principle of analogs in groups made it possible to assess the effect of vaccination on the chickens' bodies based on live weight indicators. According to our research results, it was established that in chickens of 100- and 120-day-old age, with multiple vaccinations, there is a probable increase in live weight indicators compared to the control group of animals. Our research showed that by 25 days in chickens (vaccinated six times), the hands of the absolute mass of the spleen practically did not change. At the same time, in 25-, 100-, and 120-day-old chickens, there is an increase in the absolute mass of the spleen and the gland at 15- and 50-day-old compared to the indicators of non-vaccinated animals. This indicates the implementation of immune reactions in the studied organs of immune protection due to increased migration of T- and B-lymphocytes to them. In addition, if age periods are compared, a decrease in the absolute mass of the Garder gland was found in 75-day-old chickens compared to 50-day-old chickens, which indicated the involutional processes of this gland. The maximum parameters of the gland's absolute mass were found at 50 days in chickens of both the vaccinated and non-vaccinated groups. Thus, in vaccinated chickens, this indicator of the gland was 0.095 g. Organometric changes in the spleen and gland of vaccinated chickens can be one of the criteria for diagnosing poultry immunodeficiencies.

Effect of splenic transfer factor on the development of intestinal mucosal barrier in laying hens.

The aim of this study was to investigate the effects of different doses of chicken spleen transfer factor (TF) on the structure of intestinal epithelial cells in different age groups. One-day-old White Leghorns laying hens were randomly divided into four groups: three groups were administered TF at different dosages (0.10, 0.25 or 1.00 mL) and a fourth group was set as control (administered saline, 1.00 mL). Using hematoxylin and eosin staining, high-throughput sequencing, microbiota analysis, quantitative polymerase reaction and western blotting. We measured the effects of different doses of TF on the following: intestinal mucosal epithelial tissue morphology, intestinal mucosal epithelial barrier-related gene expression profiles, and intestinal epithelial tight junction gene protein levels. The collected data show that TF can improve the absorption of nutrients by increasing villus height and crypt depth, and regulate intestinal flora disorders. Furthermore, we verified that the expression of the claudin and occludin tight junctions between intestinal epithelial cells was increased with TF. this research is very important for focusing on the structure and gene expression of intestinal tissues. The results provide a scientific rationale for feeding and nutrition programs for green and healthy farming, as well as technical support to improve the production efficiency of the livestock and poultry breeding industry. © 2022 Society of Chemical Industry.

Identification of suitable reference genes for normalization of quantitative real-time PCR-based gene expression in chicken (Gallus gallus).

The recent availability of genome information greatly facilitates the fundamental research on chicken. In different organs, gene expression patterns can provide clues to understanding the biological functions. For rapid and accurate quantification of gene expression, quantitative real-time PCR (qPCR) has become one of the most widely used methods. However, the success of qPCR data normalization depends on the use of a suitable reference gene and a single reference gene is not universally suitable for all the experiments. Therefore, reference gene validation is a crucial step for different organ tissues of chicken where suitable reference genes for qPCR analysis in varieties of tissues have not been investigated exhaustively so far. In this study, we have selected 30 Gallus gallus candidate reference genes from NCBI, amplified and studied their expression profiles by qPCR in different organ tissues (breast muscle, thigh muscle, heart, liver, spleen, gizzard, and bursa) of chicken. The result showed that, for breast muscle HSP10 and RPL23, thigh muscle RPL14 and RPL13, liver ALB and HSP70, spleen ALB and GAPDH, heart CYCS and TUBA8B, gizzard RPL5 and 18S rRNA, and bursa EEF1A1 and PGK2 are most stable genes respectively. The results also showed that for different organ tissues, individual or a combination of reference genes should be selected for data normalization. In this study, we have identified and validated 30 reference genes in seven different organ tissues to provide accurate transcript normalization and quantification, which can be useful for gene expression studies in other avian species.

Generation of bioluminescent enzyme immunoassay for ferritin by single-chain variable fragment and its NanoLuc luciferase fusion.

Ferritin, widely present in liver and spleen tissue, is considered as a serological biomarker for liver diseases and cancers. The detection of ferritin may be an important tool in health diagnosis. In this study, 14 non-immunized chicken spleens were utilized to construct a single-chain fragment (scFv) phage library. After 4 rounds of panning, 7 unique clones were obtained. The optimal clone was further screened and combined with NanoLuc luciferase (Nluc) as a dual functional immunoprobe to bioluminescent enzyme immunoassay (BLEIA), which was twice as sensitive as its parental scFv-based double-sandwich enzyme-linked immunoassay (ds-ELISA). The cross-reactivity analysis revealed that the proposed methods were highly selective and suitable for clinical detection. To further verify the performance of the immunoassays, serum samples were tested by the proposed methods and a commercial ELISA kit, and there was a good correlation between the results. These results suggested that scFv fused with Nluc might be a powerful dual functional tool for rapid, practically reliable, and highly sensitive ferritin detection.

SteE Enhances the Virulence of Salmonella Pullorum in Chickens by Regulating the Inflammation Response

Salmonella enterica serovar Pullorum (S. Pullorum) is a host-specific pathogen, which causes acute gastroenteritis with high mortality in poultry. However, the association between steE, encoded by type III secretion system 2, and Salmonella virulence is not well-understood. To elucidate the functions of steE in S. Pullorum, ΔsteE strain was constructed using the λ-Red recombination technology. Compared to that in the wild-type, the deletion of steE in S. Pullorum reduced bacterial invasion, proliferation, and late apoptosis in the infected HD-11 cells. In addition, we analyzed the mRNA expression levels of effector genes and cytokines by qRT-PCR. SteE was associated with the regulation of various effector genes and inflammatory cytokines in HD-11 cells during S. Pullorum infection. The wild-type effector steE promoted the expression of anti-inflammatory cytokines (IL-4 and IL-10) and reduced that of pro-inflammatory cytokines (IL-1β, IL-6, and IL-12) compared to that in the ΔsteE-infected HD-11 cells and chicken spleens. Results from the chicken infection model showed that the deletion of steE resulted in significantly decreased colonization and long-term survival of the bacteria and alleviated pathological lesions compared to those in the wild-type. Further, steE increased the virulence of S. Pullorum in chickens by regulating the expression of inflammatory cytokines. Our findings provide insights into the persistent infection and autoimmunity associated with steE in S. Pullorum.

Effects of humic acid and organic acids supplements on performance, meat quality, leukocyte count, and histopathological changes in spleen and liver of broiler chickens

The aim of the present study is to evaluate the effect of Humic Acid (HA), Organic Acids (OA), and their combination (HAOA) on the growth performance, meat quality, leukocyte count, and histopathological changes in the liver and spleen of broiler chickens. A total of 2100 one-day-old mix-sexed broiler chickens were randomly divided into 4 groups with 5 replicates per treatment using 105 birds per pen (pen is used as an experimental unit). Treatments were: 1) Control (basal diet without additives), 2) Basal diet +0.1% HA, 3) Basel diet +0.1% HA+ 0.02% OA, 4) Basel diet +0.02% OA. Growth performance was not significantly affected by all dietary treatments during the experiment period. Sensory evaluation of breast meat indicated a significant positive response for color and smell corresponding to treatment 2) Basal diet +0.1% HA and treatment 3) Basel diet +0.1% HA+ 0.02% OA (P < 0.05). Birds receiving HA and HAOA developed fewer hepatic lesions compared to the control group (P < 0.05) and showed normal spleen structure with the extension of the white pulp area. Supplementation of HAOA corresponds to a lower heterophil to lymphocyte (H/L) ratio. The combination of HA and OA improves sensory attributes of cooked breast meat, H/L ratio, and preserves the histological structure of the spleen and liver of broiler chickens. HAOA can be recommended as a combined feed additive to improve broiler chickens' health.

Effect of Different Water Quality with and Without Vitamin C on Some Physiological Parameters of Broiler Chickens

The current study was designed to investigate the effect of different water quality with and without vitamin C on some blood parameters and the relative weight of the heart, liver, gizzard, spleen and bursa gland of broiler chickens. A total of 252 one day old, unsexed chicks of broiler chicken (ROSS 308), average body weight 42 g were used in this study. The birds were randomly distributed into seven treatment groups (each group 36 birds), with three replicates per each (12 birds per replicate) based on completely randomized design for 35 days. The first group drank reverse osmosis (R.O) without any addition containing 28.16 total dissolved solids mg.l-1 (TDS), whereas the second, third and fourth groups drank water containing 1849.6, 1452.8 and 1356.8 TDS mg.l-l respectively. The fifth, sixth and seventh group drank water containing 1849.6, 1452.8 and 1356.8 TDS mg.l-1 with 100 mg.l-1 vitamin C respectively. The birds fed ad libitum a starter diet for 21 days and thereafter, on a grower diet. Increasing water TDS resulted in a significant increase in AST and ALT enzymes. On the other hand, increasing water TDS causing a decrease in the total protein and globulin. Addition vitamin C to different water quality causing a significant decrease in AST and ALT enzymes and increase in the total protein and globulin. Different water quality with or without vitamin C had no effect on albumin in serum and relative weight of heart, liver, gizzard and spleen. Increasing water TDS resulted in a significant increase in the relative weight of bursa gland. On the other hand, addition vitamin C to different water quality causing a significant decrease in the relative weight of bursa gland. It can be concluded that an increasing the level total dissolved solids (TDS) in broiler chickens drinking water caused stress for birds. The addition of vitamin C by 100 mg per liter led to a reduction in the stress of birds.