Interference with the humoral immune response in diverse genetic lines of chickens. I. The effect of carrageenan

Two experiments were conducted in which the effect of carrageenan (CGN) on humoral immune response of chicks selected on either high (H) or low (L) antibody production to sheep red blood cells (SRBC) was determined. H and L line chicks were injected i.p. with different doses of CGN prior to immunization with SRBC or Brucella abortus (BA). Four weeks later chicks were reimmunized with the same antigens. In general, control H and L chicks had significantly higher total anti-SRBC titers than CGN-treated chicks in primary response. Also, total anti-BA titers were significantly higher in control chicks than CGN-treated chicks on days 3 and 5 following primary immunization and on days 0 and 7 of the secondary response. Overall, the 2-mercaptoethanol (2ME)-resistant anti-SRBC titers did not differ significantly among the CGN-treated groups. However, control chicks tended to have higher anti-BA 2ME-resistant titers from day 14 p.i. of primary response on. Regardless of antigen or CGN treatment, the H line chicks had significantly higher titers than L line chicks. However, the CGN treatments did not affect the antibody response to BA nor to SRBC differently between L and H line chicks. It would appear that since CGN is cytotoxic for macrophages, selection for antibody production did not result in different abilities of the macrophages of these chicken lines to respond to an antigenic challenge.     

Antibody responses of hens fed vitamin E and passively acquired antibodies of their chicks

Antibody responses of hens and their progeny were studied in commercial broiler nuclear lines. Starting at 168 days of age, individually housed pullets from lines A and B were fed a 16% crude protein and 2752 kcal metabolizable energy/kg mash diet supplemented with either 10 or 300 IU/kg of vitamin E fed as dl-alpha-tocopherol acetate. Fifty-eight days later (226 days of age), 12 hens per line-vitamin E subclass were inoculated i.v. with 0.1 ml of a 2.5% suspension of sheep red blood cells (SRBC). Plasma antibody titers were measured 6, 20, 40, 54, 70, and 88 days after inoculation. Hens from both lines were artificially mated to males from line C, and progeny from eggs collected 9-15, 25-30, and 65-70 days after inoculation were tested for antibodies to SRBC. Hens were reinoculated i.v. with 0.1 ml of 0.25% SRBC 88 days after the first inoculation, and their antibody levels were measured 3, 6, and 20 days later. Eggs laid 10-13 days after reinoculation were incubated, and antibody titers of chicks were measured at hatch. Antibody response of hens to an initial inoculation of SRBC was line-diet-time after inoculation specific. In line A, titers were greater for hens fed the lower than the higher vitamin E diet, whereas diet had no effect on the antibody levels in line B. Line effects (A > B) were observed on days 6 and 20 after inoculation but not thereafter. After the second inoculation, dietary vitamin E level had no effect on antibody levels of hens within lines, whereas a between-line difference (A > B) was observed for the lower but not the higher level of dietary vitamin E. Although there was no difference between diets for antibody transferred to progeny by line B, there was a difference (lower > higher) for line A. After reinoculation of their dams, antibody titers of chicks from line A, but not line B, reached levels similar to those after the first inoculation. Antibody levels were higher for chicks at hatch than in 16-day embryos or 10 days posthatch. The results of this research suggest genetic variation in response to immune stimulation by dietary vitamin E.     

Immune Competence,Resistance to Escherichia coli and Growth in Male Broiler Parent Chicks Fed Different Levels of Crude Protein

Immune competence, resistance to Escherichia coli and growth were measured in female chicks of broiler male parent lines from four different commercial sources. These chicks were fed with three levels of dietary crude protein (CP) from day-old. The protein contents in the diets were 18%, 20.5% and 23%; these diets are referred to as the low-, medium- and high-protein diets, respectively. There was a significant genotype by dietary protein interaction for body weight at 35 days of age but not at 14 or 28 days of age. At 14 days of age, the chicks fed on the high-protein diet weighed significantly more than those fed on the low-protein diet, but there were no differences between the chicks fed on the medium- and low-protein diets. The influence of CP content on body weight had disappeared by 28 days of age. There were significant differences between the genotypes in antibody production in response to sheep red blood cell (SRBC) inoculation, but no such differences were observed between the chicks fed the different levels of dietary protein. Chicks fed on the high-protein diet had lower lesion scores following E. coli inoculation than those fed on the low-protein diet. There were also significant differences in lesion scores among the genotypes. Genotypes with heavier body weights had significantly higher lesion scores and lower antibody titres than those with less body weight. Also, genotypes of lower body weight had a greater cutaneous basophilic hypersensitivity response to phytohaemaglutinin-P inoculation, and a better humoral response against SRBC and a lower heterophil to lymphocyte ratio.     

Interaction between genotype and dietary concentrations of methionine for immune function in commercial broilers

1. Growth, antibody response to sheep red blood cells (SRBC) and resistance to Escherichia coli were measured in broiler female chicks received from 4 (n = 100 in each) commercial genotypes (A, B, C and D) and fed with maize-soybean-deoiled rice bran based diets containing 4 concentrations of methionine (3.91, 4.46, 5.00 and 5.54 g/kg). The diets were fed ad libitum from 1 to 49 d of age. 2. Body weight gain and weight gain/food intake at 2 week intervals, response of broilers to inoculation of 0.5 ml of SRBC (0.5 or 2.5%), 0.1 ml of E. coli (10(-4) dilutions) culture, and 100 microg phytohaemogglutinin-P (PHA-P) at 43 d of age were measured. The responses to SRBC and E. coli inoculation were recorded at 5 d post inoculation (PI), while the responses to PHA-P were recorded at 12 and 24 h PI. 3. Genotype by methionine interaction was not significant for body weight gain, but significant differences in weight gain were observed among different genotypes. Variation in methionine concentration did not influence body weight gain or weight gain/food intake at 1 to 14, or 42 d of age. At 28 d of age, chicks fed on the 3.91 g methionine/kg diet weighted significantly less than those on the other methionine concentrations. Genotype by methionine interaction was observed for food efficiency at 0 to 28 d of age but not at other ages. 4. Antibody titres against SRBC and heart and air sac lesion score to E. coli challenge were not influenced by genotype-methionine interaction. Chicks given higher concentrations of methionine had higher antibody titres and greater cutaneous basophilic hypersensitivity (CBH) response than those given low levels of methionine. Also, variation was observed in expression of CBH response to PHA-P among different genotypes. 5. It may be concluded that, although the commercial broiler chicks do not require more than 3.91 g methionine/kg for optimum growth and food efficiency, the immunity in terms of CBH response and antibody production to SRBC increased with the concentration of methionine in the diet in the majority of genotypes, indicating a higher methionine requirement for immunity than for weight gain.     

Salmonella enterica serovar enteritidis burden in broiler breeder chicks genetically associated with vaccine antibody response

The relationship between antibody response to Salmonella enteritidis vaccine and internal organ burden of S. enteritidis is not fully understood. The genetic relationship, therefore, between postchallenge S. enteritidis burden and antibody response to S. enteritidis vaccine was determined in broiler breeder chicks. Sibling chicks from a broiler breeder male line were either inoculated with a pathogenic S. enteritidis or vaccinated with a commercial S. enteritidis vaccine. Spleen, liver, cecal wall, and cecal content samples from S. enteritidis-challenged chicks (n = 120) were cultured for enumeration of bacteria. Unchallenged chicks (n = 314) were vaccinated at 11 days of age, and serum samples were taken at 10 days postvaccination. Antibody response to vaccination and number of S. enteritidis in cecal content cultures were negatively correlated (-0.772), demonstrating that genetic potential for greater antibody response to S. enteritidis vaccine is associated with lesser S. enteritidis bacterial burden in cecal content of broiler breeder chicks. The findings suggest that genetic selection for vaccine antibody responsiveness can lower bacterial burden in the gut lumenal content and, thus, potentially reduce contamination of poultry products at processing.     

左旋咪唑对鸡细胞免疫和体液免疫功能的作用

系统研究了左旋咪唑对鸡细胞免疫和体液免疫功能的作用。结果表明左旋咪唑可影响正常鸡的免疫功能 :左旋咪唑可显著促进鸡外周血T淋巴细胞增殖 ,但对B淋巴细胞无明显影响 :2 5～ 1 0mg/kg左旋咪唑可使CD+4/CD+8淋巴细胞比值明显升高 ;左旋咪唑可使鸡体内抗颗粒性、胸腺依赖性抗原SRBC抗体滴度 ,抗可溶性、胸腺依赖性抗原BSA抗体滴度和抗非胸腺依赖性抗原BA抗体滴度均明显升高 ;2 5～ 1 0mg/kg左旋咪唑可使鸡血清总补体活性明显升高。左旋咪唑影响正常鸡回忆性免疫应答反应 :左旋咪唑 ( 1 0mg/kg)可使二次免疫鸡抗SRBC抗体滴度和抗BA抗体滴度回忆性免疫应答反应明显升高 ;但使鸡对抗BSA抗体滴度回忆性免疫应答反应明显降低。     

Effect of breeder vaccination on immunization of progeny against Newcastle disease

Two experiments were conducted to determine the effect of breeder vaccination program and maternal antibody on the efficacy of Newcastle disease immunization of 1-day-old chicks. Experimental protocol was the same for both. In the first experiment, broilers were from breeders that were 32 weeks old, and in the second experiment, broilers were from breeders 50 weeks old. Breeders received three live Newcastle disease virus (NDV) vaccines and either a killed vaccine at 18 weeks or continual live boosting at 60-to-70-day intervals through lay. Broilers were vaccinated at 1 day of age with a commercial coarse-spray machine; they were bled, sera were examined for antibody against NDV, and broilers were challenged with virulent NDV at 2, 4, and 6 weeks of age. In the first experiment, maternal antibody was higher in chicks from the younger breeders given the inactivated vaccine, and in the second experiment maternal antibody was higher in chicks from older breeders given continual live vaccines. Higher antibody in 1-day-old broilers resulted in fewer vaccine-induced reactions, less vaccine virus shed, and decreased duration of vaccine-induced immunity from coarse-spray vaccination.     

Immune response of chicks to oral vaccination against Newcastle disease and fowl pox

The humoral immune response and immunity conferred in chicks were compared following separate and combined oral vaccination with F strain of Newcastle disease virus (NDV) and HP1 strain of fowl pox virus. The haemagglutination inhibition (HI) antibody titre against NDV and passive haemagglutination (PHA) antibody titre against fowl pox virus were comparable in two respective groups. The serum IgG concentration increased significantly after the second vaccination in all the groups. The NDV vaccine induced significantly higher IgG production as compared to fowl pox virus vaccine. There was no significant difference in serum IgG concentration produced by combined vaccine and separate F strain vaccine. The protection afforded by combined and separate vaccinations did not vary significantly against challenge with virulent strains of NDV and fowl pox virus at different stages.     

Interference with the humoral immune response in diverse genetic lines of chickens. II. The effect of colloidal carbon

Two experiments were conducted to study the difference in humoral immune responses between lines of chickens selected for high (H) or low (L) antibody production to sheep red blood cells (SRBC). Prior to i.v. immunization with SRBC or Brucella abortus (BA), chicks of both lines were injected with either 2, 3 or 4 ml carbon suspension (59 mg carbon/ml) per kg body weight; controls were not injected. In both the H and L line, a higher dose of carbon showed a more progressive depression of the total antibody titer to SRBC during the initial stage of the primary response. The 2ME-resistant antibody titers to SRBC showed the same tendency during the latter phase of the primary response. However, chicks treated with 3 ml carbon had lower 2ME-resistant antibody titers than any other group. Following i.m. reimmunization with SRBC, the previous treatment with carbon doses enhanced total antibody titers throughout the secondary response, when compared to the controls. The 3 ml carbon-treated chicks had the highest total anti-SRBC titers in the secondary response. The secondary 2ME-resistant anti-SRBC titers were not affected by the carbon doses. Carbon treatment did not affect the antibody titers to BA. No differences between the H and L line were found in the effects of carbon on the humoral immune responses to SRBC or BA.     

A vaccine against avian colibacillosis based on ultrasonic inactivation of Escherichia coli

Ultrasonic inactivation of Escherichia coli followed by irradiation was found to be the most efficient method for preparation of an effective vaccine against colibacillosis. Challenge experiments revealed that this vaccine provided the best protection compared with other methods of inactivation: heat, formaldehyde, and irradiation. Preparing the ultrasonicated vaccine from O2:K1 strain increased its range and also supported adequate protection against homologous strain O78:K80. The degree of protection conferred by the vaccine was positively correlated with the antibody titer against E. coli as measured on day of challenge. Low antibody titers detected 5 days post-vaccination resulted in only 20% protection. High antibody titers detected at 8 and 15 days post-vaccination correlated with a low number of chicks with lesions. In each challenged group, the live chicks that did not develop lesions had higher antibody titers than chicks with lesions, revealing a correlation between numbers of chicks with lesions and antibody titers as measured by enzyme-linked immunosorbent assay.     

鸡新城疫（ND）各种免疫程序的测定

本试验进行了三批鸡的免疫研究。第一批试验检测不同类型新城疫疫苗在不同母源抗体水平（高和低）的鸡体上的免疫效果。结果显示,在高母源抗体时免疫,Ｖ４组和油乳剂灭活苗级抗体水平表现较低,而在低母源抗体时免疫,几种疫苗的抗体水平上升得很快,特别Ｌａｓｏｔａ－克隆３０组最明显,而油乳剂灭活苗组的抗体水平保持最长。根据此结果而制定了不同的免疫程序,进行了第二、第三批免疫试验,并分别在４５天龄及７０天龄时进行强     

Effect of adjuvants on in ovo vaccination against Newcastle disease on hatchability,performance and antibody titres in commercial pullets

This study was conducted to investigate the efficacy of in ovo administration of aluminium hydroxide (AH) and/or mannan oligosaccharide (MOS) adjuvants along with lentogenic VG/GA strain‐Avinew to alleviate the embryonic pathogenicity of Newcastle disease virus. Six hundred and thirty fertilized Bovans eggs were divided into nine groups of 70 each incubated in a commercial hatchery and administered with eight types of in ovo injections in a factorial design of 2 × 2 × 2 including with/without AH, MOS and Newcastle disease vaccine (NDV), and one uninjected group on day 18 of incubation. Hatchability was higher in the eggs received MOS and/or AH adjuvants plus NDV compared those injected with NDV alone which confirmed the attenuation of NDV. However, the average daily feed intake and feed conversion ratio of pullets hatched from NDV‐injected eggs were significantly reduced, but did not affect growth performance during 0‐42 days of age. The performance of pullets hatched from eggs injected with AH, MOS or their mixture with NDV was not significantly different during all growth periods. Pullets from MOS + vaccine injected eggs had significantly higher antibody titres against NDV compared to those hatched from either injected with saline or uninjected on d 28 (p < .05). In addition, AH plus vaccine and MOS significantly improved total anti‐SRBC and IgG respectively. Histological observation revealed that injection of MOS adjuvant into eggs led to increase crypt depth, whereas AH injection caused a reduction in villus surface area of jejunum in chicks on d 14 post‐hatch. It is concluded that in ovo MOS injection as compared to AH may be more effective to attenuate the embryonic pathogenicity of in ovo NDV injection.     

不同类型鸡新城疫La Sota疫苗的免疫应答比较

A、B、C、D组SPF鸡分别接种La Sota加佐剂活疫苗,未加佐剂活疫苗,氢氧化铝胶佐剂苗和油佐剂灭活疫苗,通过采集血清进行红细胞凝集抑制试验,测定其抗体水平,并进行比较。结果表明,La Sota加佐剂活疫苗组可产生较高的抗体滴度,并持续较长时间;而未加佐剂疫苗组血清阳转较弱,且持续时间较短;油佐剂灭活疫苗组抗体滴度最高,维持时间最长。     

Antibody transmitting ability of hens from lines of chickens differing in response to SRBC antigen

1. Hens from White Leghorn lines selected for high (HA) or low (LA) antibody response to sheep red blood cells (SRBC) were inoculated with 0.1 ml of either 0.25% or 2.50% SRBC suspension. Eggs laid over the next 15 d were grouped into 5, 3‐d collection periods and incubated. Maternal antibody titres were determined in chicks at hatch and 7 d after hatch.

2. In a subsequent experiment, hens of the 2 lines were inoculated with 0.1 ml of 2.50% suspension of SRBC, and eggs laid on days 10 to 13 after inoculation were incubated. Maternal antibody titres were determined in 15 and 18‐d embryos as well as in chicks at 0, 5, 10, 15, 20, and 25 d after hatch.

3. Dosage of SRBC had no effect on the antibody titres in line HA; however, the higher dosage elicited greater antibody titres than the lower dosage in line LA.

4. Maternal antibodies were detected earlier in chicks of line HA (eggs laid on days 7 to 9) than those of line LA (eggs laid on days 10 to 12) regardless of dosage administered to the hens.

5. In both lines, antibodies specific to SRBC were observed on day 15 of incubation, with the frequency of responders greatest at hatch. The high frequency of HA responders was maintained for 15 d after hatch, whereas there was an immediate decline with age in LA responders.

6. It was concluded that lines HA and LA have diverged in the pattern of maternal antibody levels as a result of the divergent selection for antibody response to SRBC.     

Effect of supplementation of vitamin E, selenium and their different combinations on the performance and immune response of broilers

1. The effect of dietary vitamin E, selenium (Se) and their different combinations on body weight gain, food consumption, food conversion efficiency, leukocyte migration inhibition and antibody production was determined in broilers. 2. Chicks were fed on maize-soya bean based diets with concentrations of supplemental vitamin E varying from 0 to 300 IU/kg and selenium concentrations varying from 0 to 1 mg/kg either alone or in combination from 1 to 42 d of age. 3. The chicks were immunised for Newcastle Disease Virus (NDV) vaccine at 21 d. Per cent leukocyte migration inhibition (LMI) was studied on 42 d. Antibodies to NDV in serum were determined at 10 and 21 d post immunisation (PI). 4. Chicks receiving Se, 1 mg/kg and vitamin E 300 IU/kg had significantly higher cellular immune responses in terms of per cent LMI. 5. Maximum body weight gain and best efficiency of food utilisation were obtained in chicks fed diets containing 0.50 mg/kg Se and 300 IU/kg vitamin E. 6. Significantly higher antibody titres (HI and ELISA) at 10 d PI were attributed to 0.06 mg/kg and 150 IU/kg Se and vitamin E, respectively. 7. These data suggest that optimum growth and immune response may be achieved at supplemental level of Se of 0.06 mg/kg and vitamin E at 150 IU/kg. The vitamin E level is higher than that recommended by NRC (1984, 1994).     

Nonspecific innate immunity against Escherichia coli infection in chickens induced by vaccine strains of Newcastle disease virus

The objective was to test the hypothesis that vaccine strains of Newcastle disease virus (NDV) induce nonspecific immunity against subsequent infection with Escherichia coli. White leghorn chickens at 5 wk of age were vaccinated with a NDV vaccine at various days before challenge exposure with O1:K1 strain of E. coli via an intra-air sac route. Immunity was determined on the basis of the viable number of E. coli in the spleen 24 hr after the infection. Roakin strain induced significant (P < 0.05) immunity against E. coli at 4, 6, and 8 days, and La Sota strain at 2, 4, and 8 days, postvaccination. Secondary NDV vaccination administered 14 days later failed to induce immunity against E. coli when chickens were infected 1 or 5 days after the vaccination. Significant (P < 0.05) suppression of this nonspecific immunity was observed in birds treated with corticosterone, 40 mg/kg in feed, given for three consecutive days immediately prior to the bacterial exposure but not in those treated prior to the period. The results indicate that innate immunity induced by the primary NDV vaccination may significantly suppress the multiplication of E. coli in chickens for a period of 2-8 days postvaccination. The NDV-induced immunity was inhibited by corticosterone, which is known to mediate physiological responses to stress.     

Effects of dietary supplements of selenium, vitamin E or combinations of the two on antibody responses of broilers

1. The effects of selenium and vitamin E supplementation on some immune parameters were investigated in broilers. 2. Broiler chicks were fed on maize-soybean diets with different concentrations of vitamin E (0-200 mg/kg) and selenium (0-0.2 mg/kg diet) either alone or in combinations from 1 to 42 d of age. 3. Chicks were immunised against Newcastle disease virus (NDV) vaccine at 21 d of age and haemagglutination inhibition (HI) titres were determined after 10 d. 4. Chicks receiving supplements of 200 mg vitamin E/kg and 0.2 mg selenium/kg produced significantly higher HI antibody titres. This was associated with an increased serum concentration of total immunoglobulins and circulatory immune complexes. 5. The chicks given 200 mg vitamin E/kg and 0.2 mg selenium/kg had significantly heavier spleen and bursa. 6. These results suggested that vitamin E and selenium have synergistic effects on immune responses.     

芦荟乙酰化甘露聚糖对肉仔鸡cAMP/cGMP与免疫功能的影响

本试验研究了肉仔鸡日粮中添加芦荟乙酰化甘露聚糖对环核苷酸含量与免疫功能的影响。结果表明:芦荟凝胶、多糖和乙酰化甘露聚糖均能显著(P<0.05)增加肉鸡体重和肝脏重量,提高血浆和肝脏的cAMP和血浆、肝脏的cGMP水平,以及血浆和肝脏的cAMP/cGMP比值。注射绵羊红细胞,一免后,7 d抗体总量和IgG含量达到峰值。与对照组相比,一免后,7,11,14 d肉仔鸡的抗体总量和IgG值较高,差异显著(P<0.05);二免后,4 d抗体总量和IgG含量达到峰值,并长时间内维持高水平。二免后乙酰化甘露聚糖显著(P<0.05)提高了肉仔鸡对新城疫疫苗(NDV)的抗体水平,同时还增强了肉仔鸡对NDV的免疫应答。本研究表明乙酰化甘露聚糖能提高肉仔鸡的体液免疫功能。     

Unexpected newcastle disease virus in day old commercial chicks and breeder hen

Newcastle disease virus (NDV) specific antigen in the gut contents and NDV specific antibody in blood circulation were seen in day old chicks belonging to nine different commercial hatcheries of Tamil Nadu, India. Antigen disappeared by 4th week and antibody by 6th week of age. Fourteen NDV isolates obtained from the gut contents of day old chicks of different commercial hatcheries, one NDV isolate from dead in shell eggs and one NDV isolate from breeder hen were characterized and grouped under velogenic, mesogenic and lentogenic pathotypes. Four isolates were grouped under F and another four isolates were grouped under E based on reaction with monoclonal antibodies (Mabs) but found to be velogenic based on pathogenicity tests. In one particular flock velogenie NDV was isolated from breeder hen, dead in shell embryos and day old chicks and they all belong to Mabs group E. Vertical transmission of velogenic, mesogenic and lentogenic NDVs and role of NDVs in the gut contents have been discussed.     

Protection of the Reproductive Tract of Young Chicks by Newcastle Disease Virus-induced Haemagglutinationinhibition Antibodies

The present study was conducted to assess the haemagglutination-inhibition (HI) titres required to protect the chicken reproductive tract against direct damage caused by Newcastle disease virus (NDV). Precociously induced oviduct and uterus by oestrogen treatment of young chicks were used to assess the damage or protection against the damage by analysis of ciliostasis or histopathological lesions. Unvaccinated day-old female white leghorn chickens were used as the maternally derived antibody (MDA) group. Chickens were vaccinated with either a live lentogenic vaccine on day 14 of age or, along with it, an inactivated vaccine at day 36 of age, to generate birds with a range of primary or secondary response induced HI antibodies. Birds with different HI antibody levels were challenged with virulent NDV. It was found that a HI antibody titre of 128 and above was protective against direct damage of the reproductive tract, while the 32–64 titre range was protective when derived through secondary vaccination only.