Heterophil function in healthy chickens and in chickens with experimentally induced staphylococcal tenosynovitis.

Heterophil function was evaluated in 16 healthy chickens and in 46 chickens with experimentally induced staphylococcal tenosynovitis. In paired blood samples, heterophils from chickens with tenosynovitis had a significant increase in adherence, chemotaxis, phagocytosis, and bacterial killing of Staphylococcus aureus compared to heterophils from healthy chickens. The percent adherence of heterophils to nylon fiber columns increased significantly from a 78.4% mean +/- 6.6% standard deviation to 87.6% +/- 3.2% after induction of staphylococcal tenosynovitis. Heterophil movement following in vitro exposure to saline or endotoxin was increased in chickens with tenosynovitis; 3 +/- 1 heterophils/0.25 mm2 to 10 +/- 6 heterophils/0.25 mm2 and 136 +/- 29 heterophils/0.25 mm2 to 340 +/- 74 heterophils/0.25 mm2, respectively. Endotoxin-activated serum was chemoattractive for heterophils from all chickens. Flow cytometry was used to define the heterophil population on light scatter histograms, evaluate individual cell phagocytosis of latex beads, and quantitate the number of beads phagocytosed per heterophil. When incubated with increased numbers of beads, only heterophils from chickens with tenosynovitis phagocytosed higher numbers of beads. At heterophil to bead ratios of 1:10, the percentage of heterophils that phagocytosed beads increased from baseline values of 37.8% +/- 9.0% to post-infection values of 67.3% +/- 7.5%. Using 1:20 heterophil to bead ratios, heterophil phagocytosis increased from 38.7% +/- 9.9% to post-infection values of 79.8% +/- 7.3%. Heterophils from all chickens were able to phagocytose and kill log phase staphylococcal bacteria. After phagocytosis, the heterophils from chickens with staphylococcal tenosynovitis rapidly decreased the number of viable bacterial colony forming-units per milliliter by approximately one log.(ABSTRACT TRUNCATED AT 250 WORDS)     

Heterophil function and resistance to staphylococcal challenge in broiler chickens naturally infected with avian leukosis virus subgroup J

Avian leukosis virus subgroup J has a high tropism for myeloid lineage cells and frequently induces neoplastic transformation of myelocytes. The impact of congenital avian leukosis virus subgroup J infection on the function of circulating heterophils and susceptibility to staphylococcal infection was investigated. Six-week-old broiler chickens negative for exogenous avian leukosis viruses or congenitally infected with avian leukosis virus subgroup J were inoculated intravenously with 10(6) colony-forming units of Staphylococcus aureus, and pre- and postinoculation heterophil function was assessed. All chickens developed a leukocytosis with heterophilia after inoculation, but total leukocyte and heterophil counts were significantly higher in leukosis-negative chickens than in virus-infected chickens. Tenosynovitis was more severe in leukosis-negative chickens, and 2/10 (20%) of the virus-infected chickens had no histologic evidence of tenosynovitis. Osteomyelitis in the tibiotarsus or tarsometatarsus developed in 5/10 (50%) of the chickens in each group. S. aureus was recovered from the hock joint of 6/10 (60%) of the chickens in each group. Heterophils from all chickens exhibited similar phagocytic ability pre- and postinoculation. Heterophils from virus-infected chickens exhibited less bactericidal ability preinoculation than did heterophils from leukosis-negative chickens. However, postinoculation bactericidal ability was similar in both groups. Avian leukosis virus subgroup J provirus was present in heterophils isolated from congenitally infected chickens. Heterophils isolated from broiler chickens congenitally infected with avian leukosis virus subgroup J exhibit no significant functional deficits, and infected and uninfected chickens exhibit similar susceptibility to staphylococcal infection.     

Changes in lymphocyte blastogenic response of mares during the perinatal period

A fluorometric assay was applied to evaluate blastogenesis of equine lymphocytes. Optimal culture conditions were as follows; concentrations of phytohaemagglutinin-P (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) were 1 microgram/ml, 40 micrograms/ml and 10 micrograms/ml, respectively, when 5 X 10(5) lymphocytes were incubated with culture medium containing 20% pooled horse serum (PHS) for 120 hours. The relative mean stimulation index of healthy non-pregnant mares were 5.107 +/- 0.323 (M +/- SE) with PHA, 4.019 +/- 0.183 with Con A and 3.610 +/- 0.131 with PWM. Sequentially the blastogenic responses of lymphocytes from twenty mares were observed during various stages of the perinatal period. Response decreased gradually before parturition was lowest at the time of parturition (PHA: 1.923 +/- 0.174, Con A: 1.698 +/- 0.206 and PWM: 1.706 +/- 0.177), and then increased gradually after parturition towards non-pregnant levels.     

Heterophil/lymphocyte ratio as a selection criterion for heat resistance in domestic fowls

1. Two experiments were conducted to examine the Heterophil/Lymphocyte ratio (H/L) as criterion for selection for resistance to heat stress and some aspects of general resistance in domestic fowls.

2. The first experiment on a small sample (n = 64) of light breed Iraqi local fowls showed that this ratio could be used as an indicator of heat stress resistance.

3. The second experiment on a large sample (n= 1160) of heavy parent stock confirmed the results. It showed that there was a different H/L ratio for the two strains and that there was much individual variability in the H/L ratio within‐strain that could be utilised for individual selection for heat resistance.

4. The H/L ratio was highly heritable; Resistant and Sensitive groups, defining all individuals with an H/L ratio over the upper 95% confidence limit as ‘Sensitive’ and those below as ‘Resistant’, produced progeny with significantly different H/L ratios.

5. There were indications of differences in mortality between the progeny of the Resistant and the Sensitive groups.

6. The H/L indicator could be used as a criterion to select for heat stress resistance.     

T lymphocyte subpopulations diverge in commercially raised chickens

To evaluate immunocompetence in commercially raised chickens, we immunophenotyped Dekalb Delta and H&N White Leghorn (WLH) hybrids, 20 chickens in each of 3 age groups (9 wk [juvenile], 25 wk [young adult], and 79 or 80 wk [adult]), for circulating CD3+, CD4+, CD8+, TCR1+, TCR2+, and TCR3+ lymphocytes. The proportion of CD3+ T cells, including CD4+ and CD8+ subsets, was increased in the hybrids as compared with published values for laboratory-raised outbred WLH chickens. The proportion of the TCR2+ (Vbeta1) T cell subpopulation was also increased. An age-related decrease in the proportion of TCR1+ (gammasigma) T cells was noted in both hybrids. Further, a remarkably low CD4:CD8 ratio was evident in all age groups of both hybrids, indicating decreased immunocompetence. Overall, these experiments provide age-related proportions of various peripheral-blood T lymphocyte subpopulations in commercially raised Dekalb Delta and H&N chickens that diverge from the proportions in laboratory-raised outbred WLH chickens and suggest reduced immunocompetence. Such a decline in immunocompetence, including humoral immune capacity, could be attributed to genetic selection for production traits, environmental factors associated with commercial operations, and intense immunization.     

Tonic immobility,heterophil to lymphocyte ratio,and organ weights in slow-growing chickens

Effects of sex and strain of bird on factors influencing welfare in chickens were investigated in 288 21-week-old Potchefstroom Koekoek (PK), Ovambo (OV), and Naked Neck (NN) chickens. The birds were allocated to 4 paddocks of Chloris gayana and a house subdivided into 4 pens. There were 12 males per strain and 12 females per strain in each paddock. Similarly, 12 males per strain and the same number of females were placed in each pen in the house. Twelve birds, 4 each of NN, OV, and PK, were randomly selected per paddock and per pen, and tonic immobility (TI) was determined. Ambient temperature and humidity were recorded and fitted into a PROC MIXED model as random effects, with strain and sex as main effects. On the last d of the trial, blood samples were collected from 9 (3 of each strain) randomly selected birds per paddock, via brachial venepuncture, using 5 mL syringes and 22 gauge needles. At slaughter, the liver and spleen were recovered and weighed immediately. Organ weights were expressed relative to body weight (BW) of each bird. Sex of bird influenced (P < 0.05) BW, spleen, and relative liver weights and heterophil to lymphocyte (H/L) ratio. Strain did not influence (P > 0.05) TI but affected (P < 0.05) all other parameters. Rearing system (P < 0.05) influenced all parameters. Strain × sex interactions were significant (P < 0.05) on all organ weights. Males appeared more stressed than females. The free-range system could minimize stress in birds though mechanisms should be devised to prevent attacks by predators. Perhaps future research could be designed to study similar parameters over a longer observation period using younger slow-growing chickens.     

铜中毒对雏鸡淋巴细胞凋亡的影响

选用1日龄艾维菌肉鸡健雏180只，随机分为3组，分别喂以对照日（Cu 11．97mg／kg）、中毒Ⅰ日（Cu 650mg／kg）和中毒Ⅱ日粮（Cu 850mg／kg），为期6周，以流式细胞术的5r法观察研究了铜中毒对雏鸡免疫器官淋巴细胞凋亡的影响。研究结果表明，铜中毒可诱导淋巴细胞凋亡，2个中毒组免疫器官淋巴细胞凋亡百分率显著高于对照组（P〈0．05或P〈0．01）。     

Heterophil functional responses to dietary immunomodulators vary in genetically distinct chicken lines

The effect of dietary supplementation of immunomodulators on in vitro chicken heterophil function was investigated using three diverse genetic lines of chickens (broiler, Fayoumi, and Leghorn). Dietary supplementation with β-glucan, ascorbic acid, and corticosterone was fed from 8 to 11 weeks of age. Heterophil function was evaluated weekly during supplementation using phagocytosis, bacterial killing, and heterophil extracellular traps (HETs)-DNA release. Fayoumis fed the basal diet had significantly higher HETs-DNA release (P=0.002) than Leghorns and broilers. Both genetic line and immunomodulator diet supplementation had significant effects on bacterial killing (line and diet effect: P<0.001) and HETs-DNA release (line: P<0.001; diet: P=0.043). Dietary supplementation with immunomodulators, therefore, shows potential to affect and augment heterophil function in chickens. The current results also suggest the important role of genetics in innate immune responses.     

雏鸡T淋巴细胞及其亚群的变化规律

白细胞分化抗原是白细胞在分化成熟为不同谱系和分化不同阶段以及活化过程中 ,出现或消失的细胞表面标记 [1]。鸡的 T淋巴细胞表面分化抗原的研究近年来进展较快 ,证明与哺乳动物的 T淋巴细胞表面分化抗原有许多相似之处 ,尤其以 CD3,CD4,CD8为突出。 CD3分子表达于所有成熟 T细胞表面 ,可与 TCR( T细胞抗原识别受体 )分子以非共价结合形成一个 TCR- CD3复合物 ,其中 TCR是识别异种抗原和自身 MHC分子多态性决定簇的受体 ,而 CD3分子具有稳定 TCR结构和传递活化信号的作用 [2 ] ,CD3是鉴定 T细胞的重要标记。T细胞可分为辅助…     

Effects of corticosteroids on lymphocyte subpopulations and lymphokine secretion in chickens.

Various effects of glucocorticosteroids on the avian immune system were examined in chickens treated intramuscularly with 0.1 to 2.5 mg dexamethasone or prednisolone. Kinetic changes in body weight gain, percentages of lymphocyte subpopulations, and T-cell functions were examined following treatment with dexamethasone or prednisolone every other day. Chickens treated with dexamethasone or prednisolone showed a decrease in body-weight gain compared with age-matched, untreated chickens. In general, the total number of splenic lymphocytes of chickens treated with the two drugs was significantly lower than in controls in a dose-dependent manner. Flow cytometric analysis of splenic lymphocyte subpopulations revealed that the percentages of lymphocytes expressing CD8, gamma delta T-cell receptor, Ia, or IgM antigens and natural killer cells were lower in dexamethasone-treated chickens than in the controls, whereas the percentages of T lymphocytes bearing CD3, CD4, or alpha beta TCR antigens were higher. Furthermore, splenic T cells obtained from dexamethasone-treated chickens showed a significant depression in concanavalin A-induced lymphoproliferation and interleukin 2 and gamma-interferon production. The results characterize a variety of immunosuppressive effects of glucocorticoids on the avian immune system.     

Behaviour and reproductive performance of Nigerian native chickens subjected to different mating ratios for a short term

To date, there is no reported standard mating ratio for Nigerian native chickens despite their large population in the country. This study investigated the effect of mating ratio on behaviour, semen quality and level of stress. Sixty-three (9 cocks and 54 hens) sexually matured birds were randomly assigned to three mating ratios (MR) of 1 cock to 3 hens (1C:3H), 1 cock to 6 hens (1C:6H) and 1 cock to 9 hens (1C:9H), and each MR was replicated three times. Each cock spent 2 weeks in a particular MR before it was moved to another. By the 6th week, all cocks had experienced the three mating ratios. Behaviour of the hens and sexual behaviour of the cocks were observed in the morning and evening, respectively, for 6 weeks. At the end of 2nd week in each MR, semen samples were collected and evaluated for motility, morphology, liveability and concentration, and blood samples were also taken from the cocks to determine the heterophil/lymphocyte (H:L) ratio, an indicator of stress. There was also no significant effect of mating ratio on the fertility of eggs and hatchability of the chicks. The number of hen–hen aggression instances, frequency of visits to the nest box and duration of nesting was not influenced by the mating ratio. However, the duration of nest seeking was higher at 1C:3H and lower at 1C:9H. A mating ratio of 1C:9H is therefore recommended for farmers interested in raising Nigerian native chickens.     

Changes in blood and spleen lymphocyte populations following antigen challenge in immature male chickens

1. The effects of antigen (Ag) injection on the distribution of lymphocyte populations of Cornell K‐strain male chickens were studied.

2. Two experiments were conducted. In the first, chickens were injected with Brucella abortus (BA), a purported T‐independent antigen. In the second, chickens were injected with sheep red blood cells (SRBC), a T‐dependent antigen. Peripheral blood lymphocytes (PBL) and spleen lymphocytes isolated at 0, 3, 6, 9, 12 and 24 h following Ag injection were stained with monoclonal antibodies (mAb) detecting B‐lymphocytes, CD4⁺ and CD8⁺ cells.

3. B‐lymphocytes in the blood or spleen showed no significant changes following either BA or SRBC injection. In contrast, CD4⁺ cells were decreased in the blood and increased in the spleen following BA and SRBC injections. CD8⁺ cells were decreased in both blood and spleen following BA injection but were unchanged in either blood or the spleen following SR8C injection.

4. These results indicate that there is a change in both spleen and circulating lymphocyte populations, especially T‐helper cells, following Ag injection. T‐helper cells are apparently the primary population involved in the initiation of humoral immunity.     

围产科尔沁牛外周淋巴细胞HSP70的表达

选择经同期发情处理的妊娠科尔沁牛5头（2～3胎）,于分娩-14、-6、-2、0、2、6、14d颈静脉采血,分离淋巴细胞,采用RT～PCR、Westernblotting法分别检测淋巴细胞的HSP70mRNA与蛋白表达。结果显示,各受试牛的HSP70mRNA与蛋白表达变化趋势基本-致,即从-14d开始逐渐下调,0d最低,继而再逐渐上调。结果表明,HSP70作为淋巴细胞内重要伴侣分子,随着分娩的启动和发生其表达抑制显著增强,但在分娩后被迅速解除,其表达逐渐上调。     

围产科尔沁牛外周淋巴细胞HSP70的表达

选择经同期发情处理的妊娠科尔沁牛5头(2³胎),于分娩-14、-6、-2、0、2、6、14d颈静脉采血,分离淋巴细胞,采用RT-PCR、Western blotting法分别检测淋巴细胞的HSP70mRNA与蛋白表达。结果显示,各受试牛的HSP70mRNA与蛋白表达变化趋势基本一致,即从-14d开始逐渐下调,0d最低,继而再逐渐上调。结果表明,HSP70作为淋巴细胞内重要伴侣分子,随着分娩的启动和发生其表达抑制显著增强,但在分娩后被迅速解除,其表达逐渐上调。     

Growth and haematological response of indigenous Venda chickens aged 8 to 13 weeks to varying dietary lysine to energy ratios

The effect of feeding varying dietary lysine to energy levels on growth and haematological values of indigenous Venda chickens aged 8 – 13 weeks was evaluated. Four hundred and twenty Venda chickens (BW 362 ± 10 g) were allocated to four dietary treatments in a completely randomized design. Each treatment was replicated seven times, and each replicate had fifteen chickens. Four maize–soya beans‐based diets were formulated. Each diet had similar CP (150 g/kg DM) and lysine (8 g lysine/kg DM) but varying energy levels (11, 12, 13 and 14 MJ ME/kg DM). The birds were reared in a deep litter house; feed and water were provided ad libitum. Data on growth and haematological values were collected and analysed using one‐way analysis of variance. Duncan's test for multiple comparisons was used to test the significant difference between treatment means (p < 0.05). A quadratic equation was used to determine dietary lysine to energy ratios for optimum parameters which were significant difference. Results showed that dietary energy level influenced (p < 0.05) feed intake, feed conversion ratio, live weight, haemoglobin and pack cell volume values of chickens. Dry matter digestibility, metabolizable energy and nitrogen retention not influenced by dietary lysine to energy ratio. Also, white blood cell, red blood cell, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration in female Venda chickens aged 91 days were not influenced by dietary lysine to energy ratio. It is concluded that dietary lysine to energy ratios of 0.672, 0.646, 0.639 and 0.649 optimized feed intake, growth rate, FCR and live weight in indigenous female Venda chickens fed diets containing 8 g of lysine/kg DM, 150 g of CP/kg DM and 11 MJ of ME/kg DM. This has implications in diet formulation for indigenous female Venda chickens.     

Recovery of antibody-producing ability and lymphocyte repopulation of bursal follicles in chickens exposed to infectious bursal disease virus.

We studied the long-term effect of infectious bursal disease virus (IBDV) in chickens. Specifically, the restoration of virus-induced bursal lesions and the duration of humoral immunodeficiency were examined. One-week-old specific-pathogen-free chickens were intraocularly inoculated with an intermediate vaccine strain (IBDV-Vac) or a virulent strain (IM-IBDV). At intervals postinoculation (PI), chickens were examined for histopathologic lesions. At 1, 3, 5, 10, or 15 wk PI, the chickens were injected with a mixture of antigens, and primary antibody responses were examined at 10 days postimmunization. Initially, the virus caused extensive necrosis of bursal B lymphocytes. This lesion was accompanied by an infiltration of T lymphocytes. With time, the necrotic lesion in the bursa was resolved. The follicles became partly repopulated with B lymphocytes. The repopulation occurred faster in the chickens exposed to IBDV-Vac than in the chickens exposed to IM-IBDV. By 7 wk PI, 40% and 80% of bursal follicles in IM-IBDV- and IBDV-Vac-inoculated chickens, respectively, were repopulated with immunoglobulin M+ B lymphocytes. Both IBDV-Vac and IM-caused suppression of the primary antibody response to antigens. However, the antibody responses of the chickens exposed to either of the two IBDV strains used were compromised only during the first 6 wk of virus exposure. Subsequently, the antibody response returned to near normal levels.     

藏鸡与彭县黄鸡早期生长发育性能及蛋品质比较分析

为了解藏鸡和彭县黄鸡的早期长发育规律和蛋品质状况,各选取160枚种蛋进行孵化,出雏后分别选择50只鸡(公母各半)进行生长发育观察和蛋品质分析。结果显示:彭县黄鸡各周龄体重均显著高于藏鸡(P0.05),雏鸡增重高峰期出现在3周龄以前;第2、3、10周龄时,彭县黄鸡日增重显著高于藏鸡(P0.05),第2、3周龄彭县黄鸡的相对生长率显著高于藏鸡(P0.05),4周龄时藏鸡相对生长率显著高于彭县黄鸡(P0.05),其他周龄生长差异不显著(P0.05)。彭县黄鸡的蛋重、蛋黄颜色、哈氏单位显著高于藏鸡(P0.05),藏鸡壳色、蛋壳强度、蛋黄质量和蛋黄比率显著高于彭县黄鸡(P0.05)。     

Specific in vitro lymphocyte response of chickens injected with killed Mycobacterium tuberculosis.

An in vitro microassay for lymphocyte transformation, using 3H-thymidine incorporated into avian peripheral blood leukocytes, is described. The transformation responses of 1 X 10(6) leukocytes stimulated by the nonspecific mitogen, phytohemagglutinin-M (PHA-M), were equivalent with 68- and 92-hour incubation durations. The PHA-M in concentration of 50 micronl/ml produced greater stimulation than did that of 25 or 100 micronl/ml. The transformation response to PHA-M was significantly affected by the lot of bovine fetal serum used to supplement the RPMI 1640 culture medium. The specific antigen, purified protein derivative (PPD) of tuberculin, stimulated significant transformation in cultures of 1 X 10(6) leukocytes from Mycobacterium tuberculosis-sensitized fowl. The PPD at concentration of 50 microng/ml was superior to 100 or 150 microng/ml, and 68-hour incubation was significantly better than 92-hour incubation. The magnitude of the in vitro transformation response to PPD was greater at 6 weeks after sensitization than at 2 or 4 weeks, and it was not directly related to the magnitude of the in vivo wattle test response in sensitized chickens.