Haemolytic Complement Activity and Humoral Immune Responses to Sheep Red Blood Cells in Indigenous Chickens and in Eight German Dahlem Red Chicken Lines with Different Combinations of Major Genes (dwarf,naked neck and frizzled) of Tropical Interest

A total of 376 chickens from different ecotypes were immunized with the non-pathogenic multi-determinant antigen sheep red blood cells (SRBC). The ecotypes included indigenous chickens from various locations in Tanzania (n=102), India (n=86) and Bolivia (n=89). In addition, eight German Dahlem Red (GDR) chicken lines with different major genes (dwarf, naked neck and frizzled) of tropical interest were also immunized with SRBC. Immune competence of the breeds was assessed by measuring complement haemolytic activity, both from the classical calcium-dependent complement pathway (CPW) and alternative calcium-independent complement pathway (APW), alongside IgTotal, IgG and IgM antibody responses to SRBC at 7 days post immunization. Large variations in complement activity and antibody responses to SRBC were observed within and between the indigenous breeds. Many indigenous chickens, especially from Bolivia, showed decreased complement activity (APW) following immunization with SRBC. Breeds from India showed the highest CPW activity and humoral (especially IgM) responses to SRBC, suggesting high immune competence. In contrast, Bolivian chickens were characterized by low CPW activity, low APW activity and low antibody levels to SRBC suggesting an overall low immune competence. In the GDR chickens, characterized by high CPW activity and high IgG antibody responses to SRBC, the major genes for naked neck, frizzling and dwarfism had no significant effect on the antibody responses and complement activity to SRBC.     

Serum haemolytic complement activities in 11 different MHC (B) typed chicken lines

To study the relation between serum complement levels and the chicken MHC (B) complex, complement haemolytic activity was measured in sera from hens from seven pure-bred B-typed White and one Brown Leghorn lines, and three ISA-Warren lines that had been divergently selected for antibody responses to sheep red blood cells (SRBC). Significant differences occurred in the serum haemolytic complement activities, both belonging to the classic (CPW) and the alternative (APW) pathways, among the 11 different haplotyped chicken lines. Hens with high CPW and high APW titres predominantly displayed the B2 or B21 haplotypes. Chickens with low CPW and APW were found in B14 and B15 haplotypes. Haplotype B14 appears to be different in complement levels when present into the pure-bred lines or into the ISA-Warren line selected for low antibody responses to SRBC. Otherwise, the presence of B21 in ISA-Warren line selected for high antibody responses to SRBC does not differ with the B21 in the inbred lines (except in the NL-line for CPW values). In general the haplotypes B2 and B21 are found in chicken lines with enhanced disease resistance, and the B15 haplotype has been connected with enhanced disease susceptibility. Our results suggest that levels of haemolytic complement activity, either from the classical or from the alternative pathways, may underlie part of the immunocompetence ascribed to the MHC (B) complex in chickens.     

A Review of the Factors Affecting the Survival of Donkeys in Semi-arid Regions of Sub-Saharan Africa

German Dahlem Red chickens with three different major genes of tropical interest: Nana- (naked neck), Ff- (frizzled) and dw- (dwarf), respectively, were tested for serum haemolytic complement, which is essential in innate host defence against infectious agents. Eight different combinations of genes for body size and feather coverage were evaluated. Significant differences both for both the calcium-dependent (classical, CPW) and the calcium-independent (alternative, APW) complement titres were found between the phenotypes. Phenotype nanaffDw- showed the highest complement status. The frizzled (Ff-) gene had a negative influence on APW titres, whereas the dwarf (dw-) gene had a negative influence on CPW titres. The naked neck (Nana-) gene had various influences on the haemolytic complement status. All tested hens had MHC (B) 21 haplotypes, whereas the gene for dwarfism appeared to be linked with the B19 haplotype. It was concluded that introducing major genes (Nana-, dw-, Ff-) to conquer environmental stress in hot climates can have a negative impact on certain aspects of the innate immunity of poultry.     

Haemolytic complement activity,C3 and Factor B consumption in serum from chickens divergently selected for antibody responses to sheep red blood cells

Antibody responses, serum complement haemolytic activity, and complement component C3 and Factor B consumption were studied in chickens divergently selected for high and low antibody responses to sheep red blood cells, and in a randombred control line. Significantly higher total and IgG antibody responses to SRBC were found after intramuscular immunisation in the high antibody responder (H) line versus the low antibody responder (L) line and the control (C) line. Also significantly higher antibody titres were found in the C line as compared to the L line. Ca-dependent (classical) and Ca-independent (alternative) complement haemolytic activity was significantly higher in the H line than in the L line. Also initial complement haemolytic activity and C3 levels prior to immunisation with SRBC were significantly higher in the H than in the L line. The L line, on the other hand, showed numerically higher Factor B levels. Immunisation with SRBC was followed by a different consumption of C3 in serum of the H line than the L line.The results indicated that divergent selection of chickens for specific antibody responses to SRBC affected complement levels and C3 consumption in these chickens. This suggests a genetic linkage between these two immune traits.     

Comparison of parasite-specific immunoglobulin levels in two chicken lines during sustained infection with Ascaridia galli

Increasingly large numbers of poultry are held in production systems with access to outdoor areas. In these systems intestinal helminths are found with flock prevalences of up to 100%. Helminth infections influence chicken health negatively, which is why the following investigation has been performed.In the present experiment, 20 chickens of two inbred chicken lines containing the major histocompatibility complex (MHC) haplotypes, B14 and R5, were inoculated with 500 embryonated Ascaridia galli eggs. The A. galli-specific IgG titres of serum samples and the excretion of A. galli eggs in chicken faeces were measured for a period of 81 weeks.The level of excreted A. galli eggs measured as eggs per gram chicken faeces (EPG) varied greatly between chickens in each line. Significant differences were found between the two lines and with the R5 chickens reaching the highest levels. Likewise, the A. galli-specific IgG titres in serum differed significantly between the two lines, and an inverse relationship between infection level (EPG) and antibody titres was found. Although this inverse relationship suggests that humoral immunity may be involved in protection against A. galli infection, the high antibody titres did not prevent continued infection.     

Classical and alternative pathway haemolytic activities of ovine complement: variations with age and sex

The classical (CH50) and alternative (ACH50) pathway haemolytic activities of sheep complement were measured with microtechniques. Storage of blood at room temperature (instead of 4 degrees C) before centrifugation and usage of sera stored at -70 degrees C were compatible with complement titration. The effects of age and sex were tested in 303 sera obtained from animals aged between 2 weeks and 3.5 years old. ACH50 titres were low during the first 1.5 months of life then increased to reach the level found in adults at the age of 3 months. Conversely, CH50 titres were very high in suckling lambs, decreased up until the age of 3 months and then increased to reach the adult level at 1 year old. In lambs, the haemolytic complement activity was significantly higher in females than in males.     

Phenotypes Including Immunocompetence in Scavenging Local Chicken Ecotypes in Tanzania

A study was conducted to determine the variations in physical characters and immunocompetence among scavenging local chicken ecotypes in Tanzania. Eighty-four adult scavenging local chickens from four eco-climatic regions of Tanzania were studied. Measurements of adult body weight, body length, shank length and egg weight and observations of plumage colour and pattern, earlobe colour, skin colour and the shape of the comb were conducted. The antibody response to sheep red blood cells, serum haemolytic complement and the cutaneous response to phytohaemagglutinin-P were assessed. Five ecotypes were identified and named Mbeya, Morogoro-medium, Ching'wekwe, Kuchi and Singamagazi. Singamagazi and Kuchi were significantly heavier, with longer shanks and heavier eggs than the other ecotypes. The average adult body weight for males ranged from 1621 g (Mbeya) to 2915 g (Singamagazi). Average female weights ranged from 1108 g (Morogoro-medium) to 2020 g (Singamagazi). Mean egg weights ranged from 37.65 g (Ching'wekwe) to 45.61 (Singamagazi). The Kuchi had mostly rose and walnut combs, while the other ecotypes were mostly single combed. In each ecotype there were chickens with a high or low antibody response to red blood cells, but there was a significant difference between the ecotypes.     

A molecular analysis of the patterns of genetic diversity in local chickens from western Algeria in comparison with commercial lines and wild jungle fowls

The objectives of this study were to characterize the genetic variability of village chickens from three agro‐ecological regions of western Algeria: coastal (CT), inland plains (IP) and highlands (HL), to reveal any underlying population structure, and to evaluate potential genetic introgression from commercial lines into local populations. A set of 233 chickens was genotyped with a panel of 23 microsatellite markers. Geographical coordinates were individually recorded. Eight reference populations were included in the study to investigate potential gene flow: four highly selected commercial pure lines and four lines of French slow‐growing chickens. Two populations of wild red jungle fowls were also genotyped to compare the range of diversity between domestic and wild fowls. A genetic diversity analysis was conducted both within and between populations. Multivariate redundancy analyses were performed to assess the relative influence of geographical location among Algerian ecotypes. The results showed a high genetic variability within the Algerian population, with 184 alleles and a mean number of 8.09 alleles per locus. The values of heterozygosity (He and Ho) ranged from 0.55 to 0.62 in Algerian ecotypes and were smaller than values found in Jungle fowl populations and higher than values found in commercial populations. Although the structuring analysis of genotypes did not reveal clear subpopulations within Algerian ecotypes, the supervised approach using geographical data showed a significant (p < 0.01) differentiation between the three ecotypes which was mainly due to altitude. Thus, the genetic diversity of Algerian ecotypes may be under the influence of two factors with contradictory effects: the geographical location and climatic conditions may induce some differentiation, whereas the high level of exchanges and gene flow may suppress it. Evidence of gene flow between commercial and Algerian local populations was observed, which may be due to unrecorded crossing with commercial chickens. Chicken ecotypes from western Algeria are characterized by a high genetic diversity and must be safeguarded as an important reservoir of genetic diversity.     

Demonstration of Alternative and Classical Complement Pathway Activity in Colostrum from Buffalo (Bubalus bubalis)

Buffalo colostrum caused lysis of unsensitized red blood cells (RBC) from sheep, goats, rabbits and chickens. RBC from cattle and buffalo were resistant to lysis. That lysis was due to the presence of natural antibodies to these RBC was ruled out since there was no reduction in haemolytic titres even after adsorption with the respective RBC. The addition of EGTA to the diluent had no effect on the haemolytic activity. These findings indicate the presence of alternative complement pathway (ACP) activity in buffalo colostrum. The haemolytic activity of buffalo complement for unsensitized rabbit RBC was reduced to very low levels by heating at 50°C for 45 min. Treatment with zymosan also inhibited the haemolytic activity, while inulin had no effect. The maximum activity of ACP occurred in the presence of 4 mmol/L Mg²⁺ in the diluent. The range of ACP activities in colostrum from buffaloes varied from 4.06 to 8.48 CH₅₀ units/ml. Using a standard system for titrating the classical complement pathway and rabbit red blood cells sensitized with goat haemolysin, the range of complement activity in buffalo colostrum was 4.81–6.77 CH₅₀/ml.     

Reciprocal Antibody and Complement Responses of Two Chicken Breeds to Vaccine Strains of Newcastle Disease Virus, Infectious Bursal Disease Virus and Infectious Bronchitis Virus

Serum antibody responses and haemolytic complement activity were evaluated in White Leghorn (WLH) and Rhode Island Red (RIR) chickens that were vaccinated with live-attenuated vaccines of Newcastle disease virus, or infectious bronchitis virus, or infectious bursal disease virus by means of ocular challenge at 10 times the normal vaccination dose. Complement titres in non-vaccinated birds were significantly higher in WLH birds compared to RIR birds. The lentogenic viral infection resulted in an immediate stimulation of complement activity, followed by a decrease to initial complement levels within 2 weeks post vaccination, when the antibody response took over immune defence. As compared to WLH chickens, RIR birds mounted a faster and significantly higher antibody response to the vaccine viruses used. In WLH hens, significantly higher haemolytic complement activity post vaccination was found as compared to RIR hens. Possible consequences of the observed differences in immune responsiveness of the two breeds to viral vaccines are discussed.     

京海黄鸡杂交组合亲本鸡球虫抗性指标的比较

为研究京海黄鸡杂交组合亲本BB鸡与FF鸡鸡球虫病抗性的差异,试验选取BB和FF公鸡各30只,饲养至9日龄时,每个群体随机分为免疫组(n=15)和非免疫对照组(n=15),分组当天免疫组京海黄鸡杂交组合亲本按正典鸡球虫病四价活疫苗说明书要求接种鸡球虫疫苗,疫苗免疫后第8天采用生物素双抗体酶联免疫吸附法(ELISA)测定免疫组和非免疫对照组8个血浆球虫抗性指标,并进行差异显著性检验.结果显示,BB鸡免疫组过氧化氢酶(CAT)、超氧化物歧化酶(SOD)和白介素17(IL-17)的含量显著高于FF鸡免疫组(P <0.05);BB杂交组合亲本免疫组CAT含量极显著高于对照组(P <0.01),SOD含量显著高于对照组(P <0.05);FF杂交组合亲本免疫组CAT和谷胱甘肽过氧化物酶(GSH-Px)含量均显著高于对照组(P <0.05).综合分析结果表明,BB鸡免疫效果优于FF鸡群体,BB鸡球虫病抗性优于FF鸡群体.     

BF, HP, DQB and DRB are associated with haemolytic complement activity, acute phase protein reaction and antibody response in the pig

In order to examine the loci factor B (BF), C3, corticotropin releasing hormone (CRH), DQB, DRB, haptoglobin (HP) and transforming growth factor beta 1 (TGFB1) for association with traits of humoral, specific and unspecific defence F2-animals of a porcine resource family were genotyped at single nucleotide polymorphisms within these loci. Haemolytic complement activity in the alternative and classical pathway, C3c and haptoglobin serum concentration and antibody titres were determined immediately prior and at days 4 and 10 after vaccinations against Mycoplasma hyopneumoniae (Mh), Aujeszky's disease virus, and porcine reproductive and respiratory syndrome virus at 6, 14 and 16 weeks of age, respectively. Analysis of variance revealed association of BF, HP and DRB with C3c serum concentration. The trend of haemolytic complement activity and C3c serum concentration during the experiment was affected by the interaction of DQB genotype and time of measurement. Association with antibody titres were found for BF, DQB and DRB. Results of the mixed model analyses were confirmed by quantitative transmission disequilibrium test that showed linkage and association with antibody titres, complement activity and acute phase reaction at certain times of measurement. The findings promote the importance of the candidate genes for humoral mechanisms of unspecific and specific defence that provide natural resistance against many pathogens.     

THE SEROLOGICAL RESPONSE OF CHICKENS TO AUSTRALIAN LENTOGENIC STRAINS OF NEWCASTLE DISEASE VIRUS

SUMMARY: Australian lentogenic Newcastle disease viruses were evaluated as uninactivated vaccines in Australian chickens, the response being evaluated by the production of haemagglutination-inhibition (HI) antibodies. Two viruses, V4 and PM9, induced high levels of antibody and were readily transmissible between chickens by contact exposure. Three other viruses were poorly immunogenic and poorly transmissible. Chickens vaccinated intramuscularly with the V4 strain produced higher HI antibody titres than chickens vaccinated by the orotracheal, intranasal and intraocular routes. HI antibody titres in chickens vaccinated with the V4 strain reached peak levels 3 to 5 weeks after vaccination and waned considerably during the next 2 to 4 weeks. However, low levels of HI antibody persisted for at least 36 weeks after vaccination. Intramuscular vaccination with the V4 strain of one-day-old chicks lacking maternal antibody to Newcastle disease virus resulted in 42–70% mortality and the survivors developed very high titres of HI antibody. Similar chickens inoculated orotracheally showed signs of depression and developed high titres of HI antibody, but there were no mortalities. Chickens 1-, 2-, 3- and 4-weeks-old and lacking maternally derived HI antibody to Newcastle disease virus suffered no adverse reaction to intramuscular or orotracheal vaccination. The antibody response of the 1-week-old chickens was considerably poorer than that of the older chickens. Following orotracheal vaccination with the V4 strain, chickens with low levels of maternally derived antibody responded with low levels of HI antibody. On the other hand, in the progeny of hens hyperimmunised with the V4 strain the production of active antibody following orotracheal vaccination was delayed until the level of passive antibody had declined considerably. There was no response to intramuscular vaccination in congenitally hyperimmune chickens. The minimum HI antibody inducing dose of V4 vaccine, when measured 3 weeks after vaccination of 6-weeks-old chickens, was 10^5.6 50% egg infectious doses.     

Serological evidence of chicken anaemia virus infection in Nigerian indigenous chickens

Serum samples from 20 out of 180 (11.1%) apparently healthy Nigerian indigenous chickens were negative for antibodies against chicken anaemia virus using the enzyme-linked immunosorbent assay (ELISA). Of the 160 positive sera (88.9%), 12 (7.5%) had titres ranging from 1500-3000, 46 (28.8%) had titres from 3000-5000 while 102 (63.8%) had titres between 5000-11000. The overall mean titre value was 5845 +/- 2402. This appears to be evidence of a natural outbreak of the infection since the chickens had no history of vaccination against any poultry disease.     

Egg production,fertility, hatchability and immune responses of some chicken strains under high ambient temperatures

This experiment was designed to investigate and compare the egg production, fertility, hatchability and immune responses of some local developed Egyptian chicken strains under high ambient temperatures. A total of 108 (26 weeks old) laying hens of Matrouh, Silver Montazah, Mandarah and Inshas (9 hens × 3 replicates × 4 strains) were used to evaluate the impact of thermal stress (24-34ºC) during summer season (June, July and August) on egg production, fertility, hatchability and immune responses. The obtained results revealed that final body weight (FBW/g) and body weight change (BWC/g) among different chicken strains were not affected. The daily feed consumption (FC/g) and feed conversion ratio (FCR) for Silver Montazah and Inshas strains were significantly (p ≤ .05) higher than those of Matrouh and Mandarah strains. The mean egg production (EP/%) and egg mass (EM) for Silver Montazah and Inshas strains were significantly (p ≤ .05) higher than those of Matrouh and Mandarah strains. The highest percentages of hatchability of total eggs (HTE) and fertile eggs (HFE) were recorded in Inshas chickens, while the lowest value was recorded in Mandarah chickens. Also, the highest embryonic mortalities (p ≤ .05) and lowest chick weight at hatch (CWH/g) were recorded in Mandarah chickens compared with the other strains. The highest values for antibody titres against phytohemagglutinin-P (PHA-P) were recorded in Mandarah chickens, while the least values were recorded in Inshas chickens.     

Clinical effects, virological and serological responses in chickens following in-ovo inoculation of reticuloendotheliosis virus

Six-day-old embryonated specific pathogen free chicken eggs were inoculated with reticuloendotheliosis virus (REV) into the yolk sac and were incubated until they hatched. The hatchability of eggs inoculated with REV was significantly less (P less than 0.025) than that of media-inoculated controls. Although there were no significant differences in the body weights of these chickens at hatching, there were differences (P less than 0.001) at 6, 25 and 51 days of age between the infected and control chickens. Six of 10 chickens hatched from eggs inoculated with REV had feathering defects at 6 days of age. All chickens hatched from infected eggs had cell-free viraemia and antigenaemia, but not precipitating antibodies. Some of these chickens had very low neutralising antibody titres (less than 45) when examined at 25 and 37 days of age, as did all 10 chickens at 51 days of age. A low rate of horizontal transmission was indicated by the detection of antibodies at 37 and 51 days of age in chickens running in contact with the chickens hatched from eggs inoculated with REV.     

不同鸡新城疫疫苗免疫鸡血清HI抗体的测定

将试验鸡分成3个试验组和1个对照组。A组鸡接种鸡新城疫系疫苗,B组鸡接种油乳剂灭活苗,C组鸡接种鸡新城疫系疫苗,并在接种疫苗后第3、4、5、6、7、9、11、13、15、20、25d采取各组鸡血并分离血清,检测HI抗体。结果表明,接种系疫苗的组,HI抗体效价均值从4.67log2上升到10log2,接种后第5d开始上升,接种后第11d达到峰值,持续6d保持高滴度抗体水平。接种系疫苗的组,HI抗体效价均值从4.67log2上升到7log2,接种后第4d开始上升,接种后第9d达到峰值。接种油乳剂灭活苗的组,HI抗体效价均值从4.67log2上升到9.33log2,接种后第5d开始上升,接种后第11d达到峰值,持续16d保持高滴度抗体水平。系疫苗HI抗体效价上升快,效价高,较适合于紧急接种,油乳剂灭活苗HI抗体效价可在高水平维持较长时间,较适合于预防接种。     

Genetic diversity of Forest and Savannah chicken populations of Ghana as estimated by microsatellite markers

The characterization of indigenous animal genetic resources is a requisite step in providing needed information for the conservation of useful genotypes against future needs. Thus, in this study, 22 microsatellite markers were used to genotype 114 local chickens from the Forest (n = 59) and Savannah (n = 55) eco‐zones of Ghana and the results compared to those of the ancestral red junglefowl (n = 15) and two European commercial chicken populations – a broiler (n = 25) and white leghorn (n = 25). A total of 171 alleles were observed, with an average of 7.8 alleles per locus. The local Ghanaian chickens showed higher diversity in terms of the observed number of alleles per locus (6.6) and observed heterozygosity (0.568) compared with the combined control populations (6.0 and 0.458, respectively). However, Wright's F‐statistics revealed negligible genetic differentiation (F_ST) in local Ghanaian chicken populations. In addition, 65% of the Savannah chickens were inferred to be more likely from the Forest, suggesting a south‐north dispersal of chickens from their probable original location in the Forest zone to the Savannah areas. It is concluded that the Forest and Savannah chickens of Ghana are a single, randomly mating unselected population, characterized by high genetic diversity and constitute a valuable resource for conservation and improvement.     

四川盆地6个地方鸡群体遗传关系研究

随着交通便利与市场化杂交利用,我国地方鸡遗传资源面临血液混杂、品种来源和品种间的遗传关系不清晰的问题。为了给第三次全国畜禽遗传资源普查工作提供依据。本研究对位于中国大巴山脉和乌蒙山区的6个地方鸡群体（每个群体公、母各10只）共118个个体进行了简化基因组GBS测序,分析了核酸多态性（Pi）、观测杂合度（Ho）、期望杂合度（He）、多态信息含量（PIC）、观测等位基因数（Na）、有效等位基因数（Ne）、遗传分化（Fst）、遗传距离（DR）和基因流（Nm）等指标。研究发现,岩水鸡黑羽群体的遗传多样性较低（He=0.154;PIC=0.125）,大宁河鸡遗传多样性最为丰富（He=0.197,PIC=0.162）。城口山地鸡和大宁河鸡之间的遗传分化最低（Fst=0.053）,基因流最高（Nm=4.50）,丰岩乌骨鸡和岩水鸡黑羽群体之间的遗传分化最高（Fst=0.183）,对应的基因流最低（Nm=1.12）。系统发生树和主成分分析显示,岩水鸡白羽群体和黑羽群体聚为一类,城口山地鸡、大宁河鸡和旧院黑鸡聚为一类,丰岩乌骨鸡单独为一类。Structure分析表明,城口山地鸡与岩水鸡白羽群体血缘混杂。本研究探明了邻近区域地方品种的遗传关系,位于乌蒙山区的丰岩乌骨鸡与大巴山脉的旧院黑鸡、城口山地鸡、大宁河鸡、岩水鸡黑羽和白羽具有较远的遗传距离。本研究为地方品种的保护和开发利用提供了依据。     

The effect of including anti-Ig sera in the haemagglutination inhibition test forMycoplasma gallisepticum

Addition of anti-immunoglobulin M (anti-IgM), G (anti-IgG) and A (anti-IgA) sera to the haemagglutination-inhibition (HI) test (anti-Ig HI test) forMycoplasma gallisepticum resulted in 2- to 8-fold increases in the HI titres. On investigating the anti-Ig HI reaction using IgM and IgG antibodies separated by affinity chromatography, it was confirmed that, in the enhanced HI titres, specificity existed between the chicken Ig classes having antibody activity and the antisera used in the test. Four days after inoculation ofM. gallisepticum, the anti-Ig HI reaction was markedly enhanced by anti-IgM antiserum in the intravenously inoculated chickens and by anti-IgA serum in the nasally inoculated chickens. Ten days after inoculation ofM. gallisepticum marked enhancement of the reaction was produced by anti-IgG serum in both intravenously and nasally inoculated chickens, but the enhancement of the anti-Ig HI reaction diminished from the second week after inoculation.