Cutaneous Basophil Hypersensitivity Response Research Articles

Assessment of the Impact of Humic Acids on Intestinal Microbiota, Gut Integrity, Ileum Morphometry, and Cellular Immunity of Turkey Poults Fed an Aflatoxin B1-Contaminated Diet.

A recent study published data on the growth performance, relative weights of the organs of the gastrointestinal tract, liver histology, serum biochemistry, and hematological parameters for turkey poults fed an experimental diet contaminated with aflatoxin B1 (AFB1) and humic acids (HA) extracted from vermicompost. The negative effects of AFB1 (250 ng AFB1/g of feed) were significantly reduced by HA supplementation (0.25% w/w), suggesting that HA might be utilized to ameliorate the negative impact of AFB1 from contaminated diets. The present study shows the results of the remaining variables, as an extension of a previously published work which aimed to evaluate the impact of HA on the intestinal microbiota, gut integrity, ileum morphometry, and cellular immunity of turkey poults fed an AFB1-contaminated diet. For this objective, five equal groups of 1-day-old female Nicholas-700 turkey poults were randomly assigned to the following treatments: negative control (basal diet), positive control (basal diet + 250 ng AFB1/g), HA (basal diet + 0.25% HA), HA + AFB1 (basal diet + 0.25% HA + 250 ng AFB1/g), and Zeolite (basal diet + 0.25% zeolite + 250 ng AFB1/g). In the experiment, seven replicates of ten poults each were used per treatment (n = 70). In general, HA supplementation with or without the presence of AFB1 showed a significant increase (p < 0.05) in the number of beneficial butyric acid producers, ileum villi height, and ileum total area, and a significant reduction in serum levels of fluorescein isothiocyanate-dextran (FITC-d), a marker of intestinal integrity. In contrast, poults fed with AFB1 showed a significant increase in Proteobacteria and lower numbers of beneficial bacteria, clearly suggesting gut dysbacteriosis. Moreover, poults supplemented with AFB1 displayed the lowest morphometric parameters and the highest intestinal permeability. Furthermore, poults in the negative and positive control treatments had the lowest cutaneous basophil hypersensitivity response. These findings suggest that HA supplementation enhanced intestinal integrity (shape and permeability), cellular immune response, and healthier gut microbiota composition, even in the presence of dietary exposure to AFB1. These results complement those of the previously published study, suggesting that HA may be a viable dietary intervention to improve gut health and immunity in turkey poults during aflatoxicosis.

Immunocompetence Profile of Indian Native vs Exotic Chicken Breeds

Background: The native chicken breeds were evolved over natural selection since time immemorial. The immunocompetence status of chicken breed tells us about its general response to diseases. It was assumed that the native birds survive in harsh climatic conditions and has a higher degree of resistance to diseases as compared with other exotic breeds. Methods: Indian native chicken breeds viz. Black Nicobari, Ghagus and exotic breed, Dahlem Red were studied for their growth and immunocompetence traits under deep litter management system. The native and exotic breeds were evaluated for Cutaneous Basophil Hypersensitivity (CBH) response against Phytohaemagglutinin-P (PHA-P), humoral immune response against Newcastle disease virus (NDV) antigen and Flow Cytometry analysis of CD8+ Cytotoxic T lymphocytes (CTLs). Result: The Cytotoxic T lymphocyte (CTL/µl) population significantly differed (P less than 0.05) between native Ghagus (2132.34±69.526) and Black Nicobari (2023.53±75.14) vs exotic breeds Dahlem Red 1649.49±64.54) of chicken.CBH response to PHA-P significantly differed (P less than 0.05) between Ghagus (375.836±15.04) and Dahlem Red (267.603±13.99). Sex wise CBH response (based on pooled samples across breeds) showed that females had significantly higher response as compared to males. Serum haemagglutination inhibition titre (log2) in response to ND vaccine was significantly (P less than 0.05) higher in Dahlem Red chicken (2.44±0.12) as compared to the two native breeds. Females were having significantly higher HI titre compared to males. In conclusion, the NDV response was considerably higher in exotic breeds as compared to native breeds; however, the trend was just the reverse in case of CBH response.

Chromium Supplementation on the Growth Performance, Carcass Traits, Blood Constituents, and Immune Competence of Broiler Chickens Under Heat Stress: a Systematic Review and Dose-Response Meta-analysis.

Several studies have been conducted to assess the effects of supplemental dietary chromium (Cr) on broiler chickens under heat stress (HS) conditions, but the shape and strength of the associations between Cr supplementation and broiler chickens' responses to HS remain unclear. Therefore, the current systematic review and meta-analysis investigated the effectiveness and dose-response relationship of Cr. The results indicated non-linear dose-response associations between Cr supplementation and body mass gain (BMG), feed intake (FI), feed conversion ratio (FCR), carcass, breast, leg, and abdominal fat relative weight (Pnon-linearity < 0.05). The maximum BMG, FI, and the relative weight of carcass, breast, and leg would be achieved with 1200, 1100, 900, 800, and 800ppb of Cr, respectively, while the lowest FCR and abdominal fat relative weight might be obtained with the supplementation of 1100 and 1000ppb of Cr, compared with no Cr supplementation. Referring to BMG, supplementation with 1200-1700ppb inorganic Cr or 2700ppb or less organic Cr had a significant beneficial effect on the BMG, while NanoCr supplementation did not influence this outcome variable. A non-linear association was observed for blood total cholesterol concentration (TC, Pnon-linearity < 0.05), with the maximum reduction of TC concentration observed at approximately 900ppb of Cr. The cholesterol-lowering effect of Cr (≤ 2400ppb) was only found in severe HS conditions. Moreover, supplemental Cr caused a significant linear reduction in the blood triglycerides and glucose concentrations (P < 0.05). The blood concentrations of triiodothyronine, thyroxine, and insulin increased linearly, and the corticosterone concentration reduced, with increasing supplemental Cr (P < 0.05). There was a non-linear inverse association between Cr supplementation and cortisol level (Pnon-linearity < 0.05), and the lowest concentration of cortisol was observed with the supplementation of 1000ppb of Cr. Meanwhile, significant positive linear associations between Cr supplementation and bursa percentage, thymus percentage, infectious bronchitis vaccine titer, avian influenza vaccine titer, Newcastle disease vaccine titer, cutaneous basophil hypersensitivity response, and serum immunoglobulin G level were found (P < 0.05). However, Cr supplementation caused a linear reduction in the heterophil/lymphocyte ratio (P < 0.05). Based on the obtained results, the recommended optimum amount of supplemental Cr is 1100ppb.

Effect of L-threonine and NSP-degrading Enzyme on the Performance, Intestinal Morphometry and Immunocompetence of the Broiler Chickens Fed Wheat-based Diet during the Starter Period

This study was conducted to evaluate the effects of supplemental L-threonine and enzyme in a wheat-based starter diet (WBD) on the growth performance, intestinal morphology, and immune responses of male ROSS 308 broiler chickens. A total of 240 one-day-old chicks were allocated to six different dietary treatments in a completely randomized design with a 2×3 factorial arrangement. The treatments were two WBD (with or without enzyme) each supplemented with three levels of L-threonine (100%, 120%, and 140% of the NRC recommendation). To evaluate the humoral immune system, sheep red blood cells (SRBC) antigen was injected, and for evaluation of cutaneous basophil hypersensitivity (CBH) response, the phytohemagglutinin-P was injected subcutaneously. On day 21, two chicks were selected out of each replicate and were bled, slaughtered, and then their internal organs were dissected and weighed. Blood samples were used for malondialdehyde (MDA) measurement. Jejunal and ileal contents and tissues were sampled for the viscosity and morphometric measurements. The supplemental L-threonine at the level of 120% of the NRC recommendation improved body weight gain, feed conversion ratio, and anti-SRBC titer (P 0.05). The enzyme supplementation decreased the viscosity of jejunal contents and increased the villus height to crypt depth ratio in the jejunum (P < 0.05). In conclusion, it seems that more dietary L-threonine is needed to support the performance and health of the broilers when fed the WBD. However, no synergism was observed when L-threonine and enzyme supplementation were simultaneously applied in this study.

Effect of dietary supplementation of phytogenic feed additive on performance traits, serum neopterin, and cutaneous basophil hypersensitivity response in heat-induced stress model of broiler chickens.

Objective:The trial was aimed at assessing the effect of phytogenic feed additive (PFA), a natural adaptogen, on growth performance, serum neopterin level, and cutaneous basophil hypersensitivity (CBH) response in heat-induced stress model of broilers.Materials and Methods:One-day-old Ross 308 chicks (N = 360) were randomly distributed among normal control (NOR), heat-stress control (HSC), and PFA treatment (HSC plus PFA at 200 gm/ton of feed) group. HSC and PFA groups were subjected to heat stress (HS) (32°C–36°C) from 9:00 a.m. to 5:00 p.m. for 35 days. The impact of HS on growth performance, serum neopterin level, and CBH response was assessed.Results:High ambient temperature worsened the performance traits [bodyweight (p < 0.05) and feed conversion ratio] and significantly lowered the serum neopterin level and CBH response in the HSC group when compared to the NOR group. However, supplementation of PFA at 200 gm/ton of feed to birds mitigated the detrimental effects of HS.Conclusion:PFA at 200 gm/ton demonstrated the immunomodulatory effect through the restoration of serum neopterin level, CBH response, and growth performance traits in heat-stressed broiler chickens. Thus, PFA can be used as a natural adaptogen to increase the stress resistance and mitigate the negative consequences of various stressors in broiler chickens.

Studies on immune response to Newcastle disease virus in broiler chickens fed with Lactobacillus reuteri PIA16 isolated from the gut of indigenous chicken of Assam, India.

Background and Aim:The chicken gut harbors microflora which impacts the health, production performance and immune response against pathogens. Assam local chickens reared under natural conditions are known to possess high immunocompetence which may be attributable to its gut microbiota make-up. This study aimed to investigate the individual effect of two strains of Lactobacillus reuteri PIA16 isolated separately from cecum and jejunum of Assam indigenous chicken on the immunity of broiler chickens against Newcastle disease virus (NDV) when fed singly and in combination with a prebiotic.Materials and Methods:A total of 240 birds (48 per group) were vaccinated with Lasota strain of NDV on the 5th and 21st day of age. Blood samples were collected before and after immunization against ND for the detection of humoral antibody response by hemagglutination inhibition test. The cell-mediated immune (CMI) response was estimated through response to phytohemagglutinin-P (PHA-P) and expressed as web index.Results:A significant influence on the immune response to NDV was observed in all the L. reuteri PIA16 as well as mannan oligosaccharide (MOS) supplemented groups revealing higher antibody titer than the control counterpart. The CMI response revealed a better cutaneous basophilic hypersensitivity response to PHA-P in the treated groups than the control.Conclusion:Enhancement in immunity was perceived in the broilers fed with L. reuteri PIA16 and in combination with MOS due to the stimulation of the host’s humoral and CMI response by the probiotics and prebiotics used.

In vivo cell-mediated immune, hemagglutination inhibition response, hematological and biochemical values in native vs. exotic chicken breeds.

Birds (364) of both sexes, 11-wk-old, belonging to 2 native (Brown Nicobari and Ghagus) breeds and 1 exotic breed (Dahlem Red) were evaluated for cell-mediated immune response (CMI) by phytohemagglutinin-P (PHA-P), hemagglutination inhibition (HI) assay against Newcastle disease virus (NDV) antigen (LaSota stock virus), flow cytometric analysis of CD8+ cytotoxic T lymphocytes (CTLs), and hematology and biochemical assays. The cutaneous basophil hypersensitivity response PHA-P% increase in wattle thickness (mm) was highest in Ghagus (431.14 ± 22.56) which differed significantly with that of Brown Nicobari (269.1 ± 22.66) and Dahlem Red (218.42 ± 22.30). Sex-wise observation showed that females are having significantly higher response than males. Hemagglutination inhibition test was performed to determine the serum antibodies against Newcastle disease (ND) virus. Brown Nicobari showed highest HI antibody titer than Ghagus and Dahlem Red to similar vaccination program after booster NDV dose. Flow cytometry assay revealed significantly higher CTLs proliferation in Brown Nicobari than Ghagus and Dahlem Red. Moreover, CTLs were found to be higher in control group than the treatment group. Other hematological parameters (103/μL) significant difference was found in white blood cell count between Dahlem Red (38.41 ± 1.03) with that of Brown Nicobari (35.28 ± 1.04) and Ghagus (34.57 ± 1.04) in treatment groups. Same trend was observed in the Lymphocyte treatment group. However, in Granulocyte treatment group, Brown Nicobari (11.04 ± 0.35) was found to be significantly different from Dahlem Red (8.68 ± 0.34) and Ghagus (9.27 ± 0.35). Correlations between body weight at 11 wk of age and CMI, HI, cytotoxic T cell were -0.093, 0.047, and -0.036, respectively. Egg weight was found to be positively correlated with that of chick weight. Serum biochemical values showed that Dahlem Red was having significantly higher creatinine levels compared to Ghagus. Triglycerides level was also significantly higher in Ghagus compared to Dahlem Red. No significant breed effect was observed for alkaline phosphate, aspartate transaminase, and alanine transaminase. Cholesterol and total serum protein levels were significantly higher in Dahlem Red compared to Brown Nicobari.

Effect of light emitting diodes with different color temperatures on immune responses and growth performance of male broiler

Abstract The aim of the present study was to evaluate the effects of the different color temperatures (Kelvin; K) of the light emitting diodes (LEDs) on broiler chicken health and growth performance compared to incandescent (ICD) light bulbs. Three hundred and sixty one-day-old Ross 308 male chicks were tested for 42 days. The chicks were randomly distributed into three treatment groups [neutral-white (4,286 K), warm-white (2,990 K), and ICD (2,790 K) light bulbs] of 120 chicks/treatment with six replicates each by adopting complete randomized design. The diets were similar for all treatment groups. The live body weight and feed intake were recorded weekly and feed conversion ratio (FCR) was calculated (weekly and whole period). Indices of humoral immunity [antisheep red blood cell (SRBC) titer, IgG, and IgM at 26 and 34 days of age], Newcastle disease (ND) virus and avian influenza (AI) virus antibody at 40 days of age, cell-mediated immunity [cutaneous basophilic hyper-sensitivity (CBH) response at 41 days of age)] as well as total and differential leukocyte numbers at 42 days of age) were measured. Effects of different color temperatures of the LEDs and ICD light bulbs on body weight, feed consumption, and FCR were not statistically significant (P&gt;0.05). Also, the effect of color temperatures of light on secondary titers of SRBC, AI antibody response, CBH response, the total number of leukocytes and percentage of lymphocytes were not significant. However, the different color temperatures of LEDs have a significant effect on primary SRBC and ND antibody titers (P≤0.05). The highest primary SRBC (P≤0.05) and ND (P≤0.05) antibody titers were observed in warm-white light. It was concluded that based on the 3 color temperatures examined, it seems that the most suitable to provide the optimum level of immunity and energy-saving in commercial broiler houses is warm-white light.

تأثیر تراکم مواد مغذی و اسید آمینۀ ال- گلوتامین افزودنی بر عملکرد رشد، مورفولوژی روده کوچک و پاسخ ایمنی جوجههای گوشتی

این مطالعه به منظور بررسی اثر سطوح مختلف تراکم مواد مغذی و گلوتامین افزودنی بر عملکرد رشد، مورفولوژی ژژنوم و پاسخ‌های ایمنی جوجه‌های گوشتی در دورۀ آغازین (10-0 روزگی)، رشد (24-11 روزگی) و پایانی (42-25 روزگی) انجام گرفت. آزمایشی با 320 قطعه جوجه گوشتی نر سویه راس 308 در قالب یک طرح کاملا تصادفی با 8 تیمار، 4 تکرار و 10 قطعه جوجه در هر تکرار انجام شد. در این آزمایش از دو سطح تراکم مواد مغذی (توصیه راس و 5 درصد رقیق شده) و 4 سطح گلوتامین (0، 5/0، 1 و 5/1 درصد) در قالب طرح کاملا تصادفی به صورت فاکتوریل 2×4 استفاده شد. نتایج آزمایش نشان داد که در دورۀ رشد و پایانی، تراکم مواد مغذی توصیه شده و گلوتامین افزودنی در جیرۀ غذایی موجب بهبود ضریب تبدیل خوراک می‌شود. افزودن گلوتامین موجب افزایش وزن نسبی ژژنوم، کل روده کوچک، تیموس و بورس گردید. سطح تراکم مواد مغذی و گلوتامین بر ارتفاع ویلی و عمق کریپت ژژنوم تأثیر معنی‌داری داشت. در بررسی ایمنی هومورال، بیشترین تیتر آنتی‌بادی بر علیه SRBC اولیه و ثانویه در تیمار حاوی 5/1 درصد گلوتامین و کمترین آن در گروه شاهد (بدون گلوتامین افزودنی) مشاهده شد. با تزریق زیر جلدی فیتوهماگلوتینین- P مشخص شد که گلوتامین افزودنی موجب افزایش ضخامت پردۀ بین انگشتان پای پرندگان گردید. بطور کلی نتایج حاصل از این تحقیق نشان داد که با تنظیم جیره‌های ‌غذایی با تراکم مواد مغذی توصیه شده برای سویه راس و افزودن 5/0 درصد گلوتامین، عملکرد رشد بهبود می‌یابد و تغذیه جوجه‌ها با جیرۀ حاوی 1 درصد گلوتامین افزودنی و تراکم مواد مغذی توصیه شده پاسخ‌های ایمنی ارتقاء می‌یابد.

Effect of Azolla Supplementation on Growth, Immunocompetence and Carcass Characteristics of Commercial Broilers

One hundred and twenty, one week old, Cobb 400 broiler chickens were randomly distributed into three dietary treatments having four replicates each with ten birds. The birds of the control group (T1) were fed a basal diet (23.16% CP 1–3 weeks & 19.68% CP 3–6 weeks) while the other two groups were offered the treatment diets (T2& T3) replacing 4.50% or 5.50%, of the dry matter of the basal diet with dry Azolla pinnata powder on dry matter basis, respectively. Feeding azolla meal did not significantly (p>0.05) affect the weekly body weight gain of the birds during the experimental period. Total immunoglobulins and mercaptoethanol sensitive (IgM) antibody titer (log 2) values in response to sheep red blood cells (SRBC) was significantly higher (P<0.05) in the birds fed T3 diet compared to the other two dietary treatments at 6 weeks of age. Cell mediated immune response i.e. in vivo cutaneous basophilic hypersensitivity response to lectin phytohaemagglutinin from Phaseolus vulgaris (PHA-P) determined as foot web index was significantly (p<0.05) higher in the T3 birds compared to the other two dietary treatments. Dressing percentage was significantly higher (P<0.05) in T2 compared to the other two treatment groups. However, there was no significant difference among the treatment groups in the other carcass traits. Thus, it may be inferred that replacement of basal diet with dry Azolla pinnata meal on dry matter basis did not adversely affect the growth and carcass characteristics. Moreover, Azolla pinnata possesses promising immunomodulatory potential in commercial broilers.

Immune Responses in Broiler Chicks Fed Propolis Extraction Residue-supplemented Diets.

This study was conducted to evaluate the effect of inclusion of propolis extraction residue in the feed of broilers from 1 to 21 d of age on phagocytic activity of macrophages, cutaneous basophil hypersensitivity response to phytohemagglutinin, antibody production against Newcastle disease, lymphoid organ weight and hematological profile and to determine the optimal level of inclusion. 120 chicks, reared in metabolism cages until 21 days of age, were distributed in a completely randomized design, with five treatments (0%, 1%, 2%, 3%, and 4% of propolis residue) and six replications. The relative weight of thymus and monocyte percentage were affected by propolis residue, with a quadratic response (p<0.05) and lowest values estimated at 2.38% and 2.49%, respectively. Changes in relative weight of cloacal bursa and spleen, percentage of lymphocyte, heterophil, basophil, eosinophil, and heterophil:lymphocyte ratio, antibody production against Newcastle disease, phagocytic activity of macrophages and the average number of phagocytosed erythrocytes were not observed. The nitric oxide production with regard to positive control (macrophages+erythrocytes) decreased linearly (p<0.05) with increased doses of propolis residue. The remaining variables of nitric oxide production (negative control – macrophages, and difference between the controls) were not affected by propolis residue. The cutaneous basophil hypersensitivity response to phytohemagglutinin as determined by the increase in interdigital skin thickness exhibited a quadratic response (p<0.05), which predicted a lower reaction response at a dose of 2.60% of propolis residue and highest reaction response after 43.05 hours of phytohemagglutinin injection. The inclusion of 1% to 4% of propolis extraction residue in broiler diets from 1 to 21 days of age was not able to improve the immune parameters, despite the modest changes in the relative weight in thymus, blood monocyte percentage, nitric oxide concentration, and interdigital reaction to phytohemagglutinin.

Effects of in ovo injection of conjugated linoleic acid on immune status and blood biochemical factors of broiler chickens

This experiment evaluated the effects of an in ovo injection of conjugated linoleic acid (CLA) on immune status and blood metabolites of broiler chicks at 21 and 42 days of age. One hundred and sixty fertilized eggs were selected from a young broiler breeder flock and allocated to4 treatments with 4 replicates each. CLA was injected into the air sack of the selected eggs (150 and 300 mg, dissolved in 100 mL of commercial diluents, CLA150 and CLA300) on Day18 of incubation. Two control groups (injected with or without diluent) were also included. In ovo injection of 150 or 300 ppm CLA increased (p&lt;0.05) feed intake of chickens as compared to control groups up to 42 days of age. Weight gain and feed conversion ratio of chickens from CLA300, were improved (p&lt;0.05) as compared to chicks hatched from eggs injected diluent or control group during total period. Cutaneous basophil hypersensitivity response to injection of phytohaemagglutinin-P significantly (p&lt;0.05) increased in chickens from CLA300 comparing to chicks from CLA150 or control ones. In ovo injection of 300 ppm CLA, decreased blood serum cholesterol and low density lipoprotein (LDL) of chickens as compared to control chicks or those from CLA150 (p&lt;0.05). Central lymphoid tissues such as bursa of Fabricius and thymus relative weights were increased (p&lt;0.05) in chickens from CLA300 as compared to chicks injected diluent or control groups. It is concluded that feeding 300 ppm CLA through in ovo injection may be effective to subsequent growth rate, immune response and decrease blood serum cholesterol and LDL of broiler chickens during whole experimental period.

Effect of vitamins E and C supplementation on the immunity status of coloured hens during summer

The present investigation was carried out to evaluate effects of vitamins E and C supplementation on immunity status of breeder birds and transfer of passive immunity to day-old chicks during heat stress. Broiler breeder birds (270) were divided into 9 groups with 3 replicates having 10 birds in each and were supplemented with 2 levels of antioxidant vitamins E (250 mg or 500 mg/kg) and C (200 mg or 400 mg/kg) alone and in combinations for 8 weeks during the peak summer. Antibody titre against Newcastle disease vaccine(NDV), cutaneous basophilic hypersensitivity (CBH) test against phytohaemaglutinin- P at fourth and eighth week and passive immunity in chicks were undertaken. At fourth week control group which was not supplemented any vitamins showed the lowest CBH response and at eighth week all the combined vitamins supplemented groups showed significantly higher response than control and individual vitamin supplemented groups. At fourth week antibody titre against NDV did not differ significantly from first day in all the groups and on eighth week there was significant decline in antibody titre in control and individual vitamin supplemental groups compared to first and fourth week but decrease in titre in combined vitamin supplemented groups was not significant. The passive immunity as determined by titre (log2) against NDV in day-old chicks hatched from the eggs of breeder hens did not differ among the treatments. It can be concluded that the combination of the antioxidant vitamins at lower level i.e. C 200 + E 250mg/kg have higher immunity in the coloured broiler breeder hens compared to individual vitamin supplementation during hot and humid stress.

Oral exposure of broiler breeder hens to extra thyroxine modulates early adaptive immune responses in progeny chicks

Based on the findings of a recent study suggesting a decreased cold-induced ascites incidence in broiler progeny from hyperthyroid (HYPER) breeder hens, and a controversy on the effects of hyperthyroidism on immunocompetence, the present study was conducted to determine the probable adverse effect of induced maternal hyperthyroidism on immune function in progeny chicks. Breeder hens (n = 88) were randomly allotted to the control or HYPER groups and received common or thyroxine (T4)-added (1 mg/L) water, respectively. The hens were artificially inseminated, and hatching eggs (n = 924) were incubated. Thereafter, the male hatchlings (n = 288) were reared for 42 d, and several cellular and humoral immune responses were evaluated at standard or low ambient temperature. Prevaccination antibody titers to Newcastle disease, infectious bronchitis, and infectious bursal disease virus were higher in HYPER chicks during 1 wk of age, although not different in their dams. For primary response to SRBC administered at 7 d of age, HYPER chicks recorded higher total, IgM (d 14), and IgG (d 21) anti-SRBC antibody titers. Higher cutaneous basophilic hypersensitivity response in HYPER chicks (d 10) was not observed at 35 d of age. Carbon clearance assay showed no difference, but in vitro lymphoproliferative response to concanavalin A was higher in 19-d-old HYPER chicks, independent of temperature treatment. An increase in lymphocyte percentage coincided with a decreased heterophil percentage and heterophil to lymphocyte ratio (d 14) in the HYPER group. The weight of lymphoid organs in progeny was not influenced by the oral exposure of dams to extra T4. Independent of T4 treatment, cold exposure was generally associated with decreased immune functions at early stages. The data suggested that oral exposure of broiler breeder hens to 1 mg/L of T4 not only had no adverse effect on immune function, but also modulated early adaptive immune responses in progeny chicks for which the causal mechanisms remain to be unraveled.

Effects of Different Levels of Organic and Inorganic Chromium on Growth Performance and Immunocompetence of Broilers under Heat Stress

This experiment was carried out to investigate the effects of different levels of organic and inorganic chromium on the performance, immune function and some serum mineral concentrations of broilers under heat stress condition (23.9-37°C cycling). A total of 150 one-day-old broiler chicks according to a completely randomized design were assigned into five treatment groups. Each treatment consisted of three replicates and each replicate contained ten chicks. Chicks were fed on corn-soybean meal basal diets with added different concentrations of chromium (0, 600 and 1,200 μg kg(-1) chromium chloride or 600 and 1,200 μg/kg chromium L-methionine) from 1 to 49 days of age. Humoral immunity was assessed by intravenous injection of 7% sheep red blood cell (SRBC) followed by evaluation of serum for antibody titers in primary and secondary responses. Cell-mediated immunity was assessed by the cutaneous basophil hypersensitivity (CBH) test to phytohemagglutinin (PHA)-P at day 32 and PHA-M at day 48. Heterophil/lymphocyte (H/L) ratio was also measured as a reliable indicator of stress. The body mass, feed intake and conversion ratio were not influenced by dietary chromium (P > 0.05). Dietary supplementation of both organic and inorganic chromium significantly increased primary and secondary antibody responses (P < 0.01), and also improved H/L ratio (P < 0.05), CBH response (P < 0.01) as well as relative weights of thymus (P < 0.05) and spleen (P < 0.01). Both dietary organic and inorganic chromium caused an increase in serum concentrations of Cr and Zn (P < 0.01), but decreased the serum concentration of Cu (P < 0.01). These results suggest that supplemental chromium especially in organic form offers a good management practice to reduce heat stress-related depression in immunocompetence of broiler chicks.

Carcass Characteristics and immunocompetence Parameters of Four Commercial Broiler Strain Chickens under Summer Season of Egypt

Selection for faster growth rate is accompanied by changes in the humoral and cell-mediated immunity that may potentially affect the overall immune response. The goal of the present study was to compare the carcass characteristics and immune response of four modern broiler strains. Four different genetic lines of meat-type chicks (125 Avian, 125 Arbor Acres, 125 Cobb and 125 Hubbard) were reared under similar managerial, environmental and hygienic conditions during summer season of Egypt. The high and low ambient temperatures recorded during experimental period were 32.7 and 27.8 C, respectively. The o present results revealed that the Cobb and Avian broiler chicks had significantly heaviest marketing body weight compared to remaining strains. The Arbor Acres strain recorded significantly lowest breast muscle percentage compared to other strains. With respect to Cutaneous Basophilic Hypersensitivity (CBH) response, it could be observed that the Cobb strain had a greater dermal swelling response to Phytohemagglutinin-P (PHA-P) followed by Hubbard one when compared to other strains at 24 and 48 h post injection. The Hubbard strain exhibited greater bursa and spleen (as a percentage of live body weight) compared to the Avian ones. The mortality rate of Arbor Acres strain was the highest than those of other broiler strains. We concluded that some parameters of immunocompete nce could be considered as a selection criterion when selecting for productive performance under high ambient temperatures.

Turkey Origin Reovirus-Induced Immune Dysfunction in Specific Pathogen Free and Commercial Turkey Poults

Recently, pathogenesis studies, using genetically distinct turkey-origin reoviruses (TRVs), revealed that poults infected with certain TRV isolates had moderate to severe bursal atrophy, suggesting virus-induced immune dysfunction. In order to characterize the effect of TRV infection on the turkey immune system, classical assays were undertaken to quantify the humoral and cell-mediated immune responses in small Beltsville and broad-breasted white poults infected with the TRV isolate NC/SEP-R44/03. A marked effect on the cutaneous basophil hypersensitivity response, and on the antibody response to Newcastle disease virus (NDV) exposure, was noted in commercial and specific pathogen free (SPF) poults inoculated with NC/SEP-R44/03 at three days of age. Moderate to severe bursal atrophy, similar to that noted previously in SPF poults, occurred in commercial poults inoculated at three days of age. This immune dysfunction and bursal atrophy was not present in commercial poults inoculated at three weeks of age.

The Effect of Lighting Program and Melatonin on the Alleviation of the Negative Impact of Heat Stress on the Immune Response in Broiler Chickens

Two experiments were conducted to study the effect of lighting program and melatonin addition to the diet on the immune responses of broiler chickens under chronic heat stress. In the first experiment, two groups of male broiler chickens received Continuous Light (CL) (23L: 1D) while another two groups received Intermittent Light (IL) (1L: 3D). From 4 to 6 wk of age, a group from each light program was exposed to 35°C versus 24°C for the other two groups. Heat stressed chickens under IL had significantly lower (p<0.05) body temperatures, pro-inflammatory cytokines levels and corticosterone concentrations in their plasma, compared to the heat stressed chickens under CL. Furthermore, in the heat stressed groups, the IL group had a significantly higher (p<0.05) cutaneous basophil hypersensitivity response and T-cell proliferation, compared to the CL group. In the second experiment, two groups of male broiler chickens were fed a diet containing melatonin (40 ppm), while the other two groups received a melatonin free diet (0 ppm), from 4 to 6 wk of age. Concurrently, a group from each melatonin treatment was exposed to 35°C versus 24°C in the other group. The heat stressed chickens receiving melatonin had significantly lower (p<0.05) body temperatures, pro-inflammatory cytokines IL-1 and IL-6 and corticosterone concentrations. Furthermore, in the heat stressed birds, the melatonin group had a higher but not significant cutaneous basophil hypersensitivity response and T-cell proliferation. The current study indicates that intermittent light and melatonin administration can be used to ameliorate immunosuppression associated with heat stress in broiler chickens.

Relative Performance and Immune Response in White Leghorn Layers Fed Liquid DL-methionine Hydroxy Analogue and DL-methionine

The relative performance and immune response was evaluated in White Leghorn layers fed liquid DL-methionine hydroxyl analogue-free acid (MHA-FA) relative to dry DL-methionine (DLM) in maize-soybean-sunflower based diets. Three graded levels of methionine (Met) from DLM or MHA-FA were added to the basal diet containing 0.27% Met on an equimolar basis to achieve 0.30, 0.36 and 0.42% Met in the diet. Each diet was fed ad libitum to 25 replicates of one bird (individual feeding) each, from 24 to 40 weeks of age. A regime of 16 h light was provided and all the layers were kept under uniform management throughout the experimental period. None of the parameters studied were influenced by the interaction between source and level of Met in diets. Similarly, the majority of parameters, except for daily feed consumption and immune response (influenced by level) and egg specific gravity and shell thickness (influenced by source), were not affected by either source or level of Met in the diets. Feed consumption was significantly lower in the birds fed a diet containing 0.42% Met compared to those fed lower levels of Met. The cutaneous basophilic hypersensitivity response to PHA-P and antibody titre (32 and 40 wk) to inoculation of sheep red blood cells increased significantly by increasing the concentration of Met in the diet from 0.30 to 0.36%. Thus, the Met requirement for immune competence was higher than for optimum production. The source of Met significantly influenced the egg specific gravity and shell thickness. The specific gravity and shell thickness of eggs increased significantly when MHA-FA was used as the source of Met in the diet compared to DLM. From the study it is concluded that Met requirement for immune competence (360 mg/b/d) is higher than for optimum production (300 mg/b/d). MHA-FA was comparable with DLM as a source of Met for production performance and immunity, when the bioavailability of MHA-FA was considered as 88% of DLM. Further, MHA-FA improved egg shell quality compared to DLM.

Effects of Vitamin C and Vitamin D Interaction on the Performance, Immunity, and Bone Characteristics of Commercial Broilers

This research was conducted to evaluate the efficacy of supplemental vitamin C (VC) at 0 or 200 mg/kg on the performance of commercial broilers fed vitamin D (VD) levels as per NRC recommendations (200 IU) or as per the levels followed in the commercial vitamin premixes (1,800 IU). The on-farm trial was conducted for 4 wk with Ross broilers using a 2 × 2 factorial design; 726 chicks per treatment made up 3 replicates. The weekly performance data showed greater weight gain in the chicks fed supplemental VC at 200 mg/kg when compared with the unsupplemented group, except during the second week. Significantly higher weight gain was noticed in 200 IU VD-fed chicks over those fed 1,800 IU during first and second weeks and for the overall (0 to 3 wk) study. Significant interactions were observed in weight gains between VC and VD, except during the third week. Bone strength was higher for birds fed the VC-supplemented diet at 200 IU of VD. Weekly serum biochemicals were higher (P = 0.009) for total protein for birds on the VC-supplemented diet only during first week, but serum calcium, phosphorus, and alkaline phosphatase showed no particular trend. Antibody titers to SRBC, cutaneous basophilic hypersensitivity response to phytohemagglutinin-P, and heterophil:lymphocyte ratio did not show any difference within groups given supplemental VC or VD. It could be concluded that the VD levels as suggested by NRC (200 IU) promoted better performance of commercial broilers than 1,800 IU in the present study and that supplementing VC at 200 mg/kg improved the performance under commercial growing conditions.