The susceptibility of the most common bacterial pathogens, namely E. coli, P. mirabilis and Ps. aeroginosa which were isolated from egg incubators and yolk sacs of randomly selected one day old Fayoumy chicks to three selected cephalosporins (cephradine, ceftiofur and cefquinome) were studied. The minimum inhibitory concentration (MIC), the minimum bactericidal concentration (MBC) of the tested drugs and the effect of these antibiotics on the body weight gain, mortality and immune response against Newcastle disease (ND) vaccine of the same bread of chicks were also estimated. The tested organisms were sensitive to ceftiofur and cefquinome whereas E.coli and ps. aeroginosa were found to be resistant to cephradine. The results showed that mortalities were higher in control and cephradine treated groups, while it was lower in the ceftiofur and cefquinome treated groups. On the other hand, the lowest mean body weight was recorded in control group (155.7±6.55 gm) followed by ceftiofur treated group (162.5±2.06 gm) and the highest mean body weight was recorded in cefquinome treated group (183.5±1.66 gm, p < 0.01) at 30 days of age. The study revealed that the tested antibiotics not exert any immune suppressive effect against (ND) vaccine.

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

Sunset Yellow FCF (SY), used frequently in ready-made foods, cosmetics, and the pharmaceutical industry, may cause many health problems. This study is intended to evaluate the morphological and cellular effects of SY on the embryonic chicken immune system throughout incubation. Babcock white leghorn eggs were randomly divided into four groups. Besides a control group, there were three treatment groups which received a single injection of 200, 1,000, or 2,000 ng of SY into the air sac just before incubation. The eggs were opened on the 10ᵗʰ, 13ᵗʰ, 16ᵗʰ, and 21ˢᵗ days of incubation. Samples of the bursa of Fabricius, thymus, and spleen were taken from embryos. Serial sections of 5 μm thickness were stained with histological methods and routine histological procedures were performed. An increase in the spleen volume was determined as the hatching time of the chicks approached. The highest eosinophil ratio was found in the SY₁,₀₀₀ and SY₂,₀₀₀ groups (P < 0.05), where the most significant change was developmental retardation in the thymus. In the bursa of Fabricius, there was less lymphocyte accumulation and eosinophilic cell infiltration with increasing doses. It was concluded that in ovo administered SY has undesired effects on embryonic development of the bursa of Fabricius, spleen, and thymus, and on spleen volume.

This study was undertaken to investigate the ameliorative effect of sodium selenite and nano-selenium on chicks exposed to heat stress. Ninety one day-old broiler chicks were divided into six groups each of 15 birds. Birds in group one and four were fed on basal diet and served as a control group, while birds in group two and five were fed on basal diet treated with 0.15 mg/Kg diet prepared selenium nanoparticles and birds in group three and six were fed on basal diet treated with 0.15 mg/Kg sodium selenite. On day 37 of experiment birds in 4th, 5th and 6th group were exposed to artificial heat stress at 40°C for 12 hours. Based on the results of total body weight gain and FCR lower parameters of body weight, body weight gain, feed conversion rate and higher feed intake ratio were observed in heat stressed chicks. Nano-selenium and Na selenite supplementation decreased the serum AST, ALT, urea, creatinine and MDA while the serum total protein, SOD, LZM, IgG, IgM and C3 were increased, also nano-selenium has ameliorative effect on hematological and histopathological findings. In conclusion, both nano-selenium and sodium selenite have an essential role in treatment of adverse effect of heat stress on chicks, with superiority of nano-selenium in improving anti- oxidative status and boosting immune response.

The innate immune system is a critical component directing the overall response of the immune system early in the inflammatory process. Evaluation of the innate immune system could offer a screening method for the selection of breeding stock from commercial chicken operations to improve flock health and prevent the loss of genes crucial to disease resistance. Three commercial broiler chicken lines (designated Lines A, B and C) were profiled for efficiency of their innate immunologic response. Oxidative burst and bactericidal functions of heterophils and monocytes, as well as heterophil degranulation, were analyzed. The birds were tested 1, 4, 8 and 15 days post-hatch. Individual lines differed in their ability to perform innate immunological responses during the first 15 days post-hatch. Although bactericidal capabilities were similar, oxidative burst responses by monocytes were low in comparison to that generated by heterophils. The fact that monocytes are not particularly adept at producing an oxidative burst at this age suggests that this is not a major avenue of innate defense by monocytes. Heterophil oxidative burst response was stronger in Line C than Line A during the first four days post-hatch. Line B showed no difference from Line C in heterophil oxidative burst response at 1 d, but produced a stronger response than Line C on 4 and 8 d post-hatch. Degranulation by heterophils showed significant differences in responses of Lines A and C depending on the day post-hatch, and stronger response in Line C vs Line B in the first four days post hatch. The first week post-hatch is an important time as chicks are particularly susceptible to infection as neonates. Mortality data of the commercial lines indicates that Line A is the most susceptible to demise, followed by Line C and then Line B. These results suggest that oxidative burst production efficiency is an important defensive function to monitor for immunoprofiling.

Virulence of three Canadian poultry strains of Salmonella enteritidis, namely phagetypes (PT) 4, 8 and 13, and one Salmonella heidelberg strain was assessed in orally and intraperitoneally inoculated one-day old chickens and compared to the virulence of a human S. enteritidis PT 4 strain from the United Kingdom (UK). The two PT 4 strains were also compared in orally inoculated adult laying hens. In addition, orally inoculated Balb/c mice were used to evaluate virulence of the above strains and two strains of Salmonella typhimurium containing different plasmids. In orally inoculated one-day old chickens, the UK S. enteritidis PT 4 strain was more virulent than the Canadian PT 4 strain. The UK PT 4 strain was also more virulent and invasive in adult laying hens than the Canadian PT 4 strain. The S. enteritidis PT 8 strain and one S. typhimurium strain isolated from a chicken hatchery were the most virulent for orally inoculated Balb/c mice. This strain of S. typhimurium contained the 60 megadalton plasmid associated with virulence for Balb/c mice which was not present in the S. typhimurium strain isolated from a pig with septicemic disease.

The B1 strain of Newcastle disease virus (NDV-B1), which is nonpathogenic for newly hatched chickens, killed embryos when it was used to inoculate chicken eggs at embryonation day 18. Treatment of NDV-B1 with an alkylating agent, ethylmethane sulfonate (EMS) markedly reduced the pathogenicity of the virus for 18-day-old chicken embryos. Eggs inoculated with the modified virus (NDV-B1-EMS) hatched, and the virus was isolated from lungs and spleen of 1-day-old chickens. The hatched chickens developed antibody to NDV and were protected against challenge exposure (at 4 weeks of age) with a highly virulent GB-Texas strain of NDV. Presence of maternal antibody to NDV in embryonating eggs did not influence the protective ability of NDV-B1-EMS, which also induced protective immunity when administered to 4-week-old chickens. The 50% protective dose of NDV-B1-EMS in maternal antibody-negative and -positive embryos was calculated to be 10.77 and 17.70 embryo 50% lethal doses, respectively. Results of the study indicated that NDV-B1-EMS may be used as an embryo vaccine to protect chickens against Newcastle disease.

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.

Pseudomonas aerusinosa infection was diagnosed in broiler chicks, and was submitted to the National Veterinary Research and Quarantine Service in Korea. The total mortality rate was about 1,500 birds out of 22,000 broilers. Clinically, affected birds showed clinical signs including depression and anorexia with lameness and trembling of the leg. At necropsy, the dead broilers appeared to have omphalitis, yolk sac infection, fibrinous epicarditis, and fibrinous exudates in liver with swollen hock joint. Microscopically, there were multiple necrotic foci in the liver, fibrinous exudates in the heart, and infiltration of heterophils into the joint spaces of the hock joint.