The objectives of current research were evaluate the efficacy of commercially availableNewcastle disease vaccine and determine the best vaccination program. A total number of 150one-day-old unvaccinated chicks were divided equally into 5 groups. One vaccination programwere used for each group which differ from each other while group 5 was unvaccinated controlgroup. Serum were collected from all groups and five chickens from each group were sacrificed.Afterward immunization HI geometric mean titer (GMT) rates were observed that bothseroconverted birds in Group 1 to Group 4 have risen statistically significantly, with statisticalsignificant changes. (p < 0.05). However, the birds in group 4 which had the best HI titers(147). The levels of ChIFN-γ was measured by ELISA, there were also higher in the vaccinatedgroups (group 1, 2, 3 and 4) than in the non-vaccinated group. Group 4 also had the best ChIFN-γ level. The higher values of lymphoid organs (spleen, Bursa of Fabricius and thymus) indiceswere in vaccinated groups are compared to non-vaccinated groups, while between vaccinatedgroups there was no significant different (P < 0.05). Commercial ND vaccines are effective andvaccination scheme of group 4 (live ND vaccine at 7th day of age by eye drop as primaryvaccine followed by live ND vaccine at 21st day of age by drinking water as booster dose) hasmore protective effects in broiler chicken.

The efficacy of four infectious bursal disease virus (IBDV) vaccines including intermediate (D78) and intermediate plus (228E, IBD-Blen and Bursa-Vac+) were compared in priming vaccination of 10 days commercial old male layer chicks. There were different parameters were measured for testing these vaccines including; the immunogenic efficacy, the effect on performance, organ (bursa, spleen, and proventriculus) body weight index as well as histopathological examination of bursa, spleen, proventriculus and thymus. Chick was received a dose of 102 EID50 from one IBDV vaccine out of 228E, IBD-Blen or Bursa-Vac+, while D78 dose was 104 EID50. The results cleared out that all the tested vaccines passed through the maternal derived antibodies 2480.133 + 156.3. All vaccines stimulate antibody formation as measured by ELISA test. The used vaccines not affect markedly body weight and feed intake, as there were no significant differences between the control group and the vaccinated ones in the mean body weight and the feed conversion rate. Furthermore, the bursa: body weight index of vaccinated groups were generally less than those of control one at all intervals, while the spleen and proventriculus: spleen: body weight index of vaccinated groups was higher than control on at the end of the observation period. The used vaccines induced histopathological changes in bursa, spleen , proventriculus and thymus glands. These results indicated that all tested vaccine are of value in vaccination of commercial chicks from vaccinated breeders

Newcastle Disease virus (NDV) and Avian Influenza virus (AI) are represent a great negative significant causing severe economic losses and increased mortalities worldwide. Newcastle disease (ND) and Avian Influenza (AI) vaccination were targeting to lower the losses from mortality, reduce the viral load in the environment as well as eradication of positive cases. Many immunostimulants had been used to improve the immune response of vaccinated chickens. The current study was designed to compare the effect of different immunostimulants on chick's immune response to bivalent ND with AI-H5N1 oil vaccine. One hundred and ten, 1- day old Baladi chicks, At the 1st day of life (0 day) 10 birds were sacrificed to obtained individual blood samples for serum to determine maternal antibodies (MDAbs) to both AI and ND. Rest of birds (100 chicks) were divided into 5 equal groups (1-5); each 20 chicks. All chicken groups were vaccinated against ND with eye drop instillation of HB1 vaccine. While, at the 9th day birds of the groups 1-3 and 5 were given H5N1 vaccine by S.C injection, birds of group 4 were lifted as non AI vaccinated control. The used immune stimulants under test were given to groups 1, 2, and 3 as follows Lector, Superimmune and Imuvral; respectively. All the groups were subjected to daily observation with recording of feed intake, weekly body weight gain and total FCR, Weekly serum samples were collected, for serological examination, and the results showed high antibody titers, low mortality rates and better body performance in the groups treated with immunostimulants than the other groups which were not treated with the immunostimulants

OBJECTIVE To determine effects of in ovo administration of a probiotic on development of the intestinal microbiota of 2 genetic lineages (modern and heritage) of chickens. SAMPLE 10 newly hatched chicks and 40 fertile eggs to determine intestinal microbiota at hatch, 900 fertile eggs to determine effects of probiotic on hatchability, and 1,560 chicks from treated or control eggs. PROCEDURES A probiotic competitive-exclusion product derived from adult microbiota was administered in ovo to fertile eggs of both genetic lineages. Cecal contents and tissues were collected from embryos, newly hatched chicks, and chicks. A PCR assay was used to detect bacteria present within the cecum of newly hatched chicks. Fluorescence in situ hybridization and vitality staining were used to detect viable bacteria within intestines of embryos. The intestinal microbiota was assessed by use of 16S pyrosequencing. RESULTS Microscopic evaluation of embryonic cecal contents and tissues subjected to differential staining techniques revealed viable bacteria in low numbers. Development of the intestinal microbiota of broiler chicks of both genetic lineages was enhanced by in ovo administration of adult microbiota. Although the treatment increased diversity and affected composition of the microbiota of chicks, most bacterial species present in the probiotic were transient colonizers. However, the treatment decreased the abundance of undesirable bacterial species within heritage lineage chicks. CONCLUSIONS AND CLINICAL RELEVANCE In ovo inoculation of a probiotic competitive-exclusion product derived from adult microbiota may be a viable method of managing development of the microbiota and reducing the prevalence of pathogenic bacteria in chickens.

This study was carried out to determine the immunomodulating effect of β-glucans and mannan oligosaccharide (MOS) on the immune response of chickens to Newcastle disease vaccine. The results showed that birds received β-glucans and MOS having higher average body weights values and significantly higher ND HI antibody titer than the other non medicated groups. Thymus, spleen and bursal indices of control negative showed significantly lower values than vaccinated medicated and non-medicated groups. Both total and differential leukocytic and lymphocytic counts showed significantly higher in medicated group than other groups. Liver function test showed lower AST and ALT in medicated group than other groups. Results of challenge test with NDV confirmed that MOS and B glucans immunostimulant improved protection rate by 15% in medicated than non- medicated ones. In conclusion MOS and B glucans can be given to chicken to improve both body weight and protection against VV NDV challenge that predominated in Egypt.

The haematochemical, histopathological and immunological studies were carried out on chicks experimentally infected with the low pathogenic avian influenza virus (LPAIV) (A/Turkey/CA/209092/02) H5N2. Eighty SPF one day old chicks were serologically negative for specific antibodies against avian influenza virus. The birds were devided into 2 groups, birds in the 1st group were inoculated with the virus via the intraocular and intranasal routs, while the other group was kept as non-infected control. Five birds were sacrificed from both groups at 5, 7, 10, 15, and 21 days post inoculation. Sera and heparinized blood as well as tissue specimens from lung, liver, spleen, trachea, small intestine and bursa of Fabricius were collected. Estimation of haemagglutination inhibition antibodies response against AI, liver and kidney function tests, rate of proliferation of T-lymphocyte were conducted. The experimentally infected birds showed general signs of illness with 80% morbidity and 6 % mortality. There was an increase in aniline aminotransferase (ALT) and asparate aminotransferase (AST) enzymes which reflected liver damage. High urea and creatinine values were also detected in sera of infected birds which proved kidney dysfunction. There was no significant proliferation of T-lymphocyte among examined groups. Very low haemagglutinating inhibiting (HI) antibodies was detected in infected birds. Histopathological examination displayed conspicuous depletion and necrosis of the lymphocytic aggregation in the organs of the haemobiotic system (Bursa of Fabricius, spleen and thymus). Such finding may decipher the low sero-conversion as well as the unproliferation of T-lymphocyte. The necrobiotic changes in liver and kidney sections in addition to congestion and edema elucidate the increased parameters in their functions. Also, the epithelial hyperplasia of the tracheal mucosa and the sloughing in the lining mucosal epithelium are indicative for the epithelio-tropism of the AI virus.

The objective of this study was to compare the effects of 3 diet formulations containing different protein sources (animal, plant, and a combination of animal and plant) on the colonization of Campylobacter jejuni in the gastrointestinal tract of broiler chickens. A freshly isolated strain of C. jejuni (biotype IV, serotype HS O:21, O:29, HL untypable) from a broiler chicken was used to infect 3-day-old chicks that had been free of C. jejuni; 0.5 mL of an inoculum containing 108 colony-forming units was administered orally. Shedding of the organism was studied, and C. jejuni in the ceca, jejuni, and crop were enumerated by quantitative culture. The isolates recovered from the birds during the study period of 35 d were characterized and confirmed as C. jejuni by the use of standard methods and underwent biotyping, serotyping, antimicrobial susceptibility testing by disk diffusion and the E-test, and flagellin gene typing. A cyclical pattern of shedding of C. jejuni was observed in all the birds. Colonization was highest in the ceca. The ceca of birds receiving plant-protein-based feed had significantly less colonization then the ceca of birds receiving the other types of feed, whereas the differences in colonization of the jejuni and crops were not significant. Characterization by biotyping, serotyping, and flagellin gene typing showed that 95% of the recovered isolates were identical to the strain used for infecting the chicks. However, with the Lior-HL typing scheme, 74% of the recovered isolates were HL untypable. Antimicrobial resistance testing did not reveal significant differences between the infecting strain and the recovered isolates among the different feed groups.

Newly hatched chickens were treated with the trichothecene mycotoxin, T-2 toxin, during the first day of life. Control chickens were treated with other agents known to cause immunosuppression-cyclosporine, cyclophosphamide, and aflatoxin. Chickens were infected on day 6 (5 days after treatment with T-2 toxin) by intraperitoneal inoculation with Salmonella typhimurium. Blood samples were collected from treated chickens (noninfected) and used to assess the responsiveness of blood lymphocytes to T-cell or B-cell mitogens, phytohemagglutinin, or lipopolysaccharide, respectively. The T-2 toxin had a profound negative effect on the ability of the chickens to resist salmonellosis, as measured by survival. However, the toxin effect in reducing phytohemagglutinin- and lipopolysaccharide-stimulated mitogenesis, though significant (P > 0.05), was not severe. Our data indicate a direct effect of T-2 toxin on native resistance to systemic salmonellosis, which was not accompanied by marked alteration in T- or B-cell responses to mitogenic stimulation.

Effects of immunosuppression were compared in newly hatched chickens given cyclophosphamide (CY) after inoculation with avian nephritis virus (ANV). All CY-treated infected chickens died within 13 days after inoculation of the virus and had heavy urate deposits throughout the body. However, non-CY-treated infected, CY-treated noninfected, and non-CY-treated noninfected control chickens survived through the observation period. In a chronologic study, the value of serum uric acid in CY-treated infected chickens was more than 3 times higher than that in non-CY-treated infected chickens, and more than 9 times higher than in noninfected chickens. Serum uric acid values were coincident with the positive degree of ANV antigen in the tubular epithelial cells in the kidneys and with the severity of renal degeneration. Serologic and immunohistologic examinations did not reveal detectable antibody and IgG- and IgM-containing cells in the spleen and kidneys of CY-treated infected chickens. However, non-CY-treated infected chickens had an increased number of IgM- and IgG-containing cells and antibody against ANV on postinoculation day 6. These findings demonstrated that CY treatment enhanced the susceptibility of chickens to ANV infection.