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.

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.

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 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.

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

Immunoreactivity for 28 kd vitamin D-dependent calcium-binding protein (calbindin-D28k) has been localized in the germinal epithelium and cells surrounding oogonia and oocytes (future granulosa cells) of developing and growing ovaries of chicken embryos. The protein first appeared prominently in the germinal epithelium of the developing left ovary in 8-day embryos. At the twelfth day of incubation, cells surrounding oogonia and oocytes reacted intensely for calbindin-D28k. The number and intensity of calbindin-D28k-containing cells increased in both types of cells as the embryos further developed. Calbindin-D28k remained in the germinal epithelium throughout the study period observed (up to 10 weeks). However, the protein was present transiently in the future granulosa cells. It gradually decreased after hatching, and was virtually absent from granulosa cells in a 10-week old chicken. Compared with the known process of onset of sexual development, these results indicated possible involvement of calbindin-D28k in the early phases of oogenesis in chicken ovaries.

Inclusion of lactose in the diets of chickens has been determined to reduce cecal colonization with Salmonella typhimurium. We hypothesized, therefore, that dietary lactose may be a practical means for reducing the prevalence of Salmonella contamination of chicken products. Because some strains of Salmonella are atypical and ferment lactose, we investigated the effects of dietary lactose on cecal colonization with lactose-fermenting S typhimurium. Broiler chicks were inoculated intracloacally with Lac+ S typhimurium selected for resistance to novobiocin and rifampicin. The chicks also were inoculated orally with certain anaerobes that do not effectively inhibit colonization by S typhimurium, but do appear essential for lactose mediated inhibition of cecal colonization. Control chicks were not given dietary lactose, and chicks in the experimental group were fed a diet containing 7% lactose. Enumeration of Lac+ S typhimurium in cecal contents revealed dietary lactose to be effective at controlling this organism. Control was correlated with changes in cecal pH and increases in undissociated volatile fatty acids, especially propionic acid.