Effect of vitamin E levels on the cell-mediated immunity of broilers vaccinated against coccidiosis

Studies on the relationships between animal nutrition and immunity have sought reliable methodologies to measure responses. Cell-mediated immune response is similarly studied in humans. The cutaneous basophil hypersensitivity test (CBH) is one of the methods to measure that response and consists in the infiltration of inflammatory cells, particularly of lymphocytes and basophils, as result of the application of substances capable of inducing cell proliferation in determined sites, such as wings, wattle, and interdigital space in birds. CBH is considered a simple and fast method and can be applied in birds of different ages. In immunocompetence studies with poultry, phytohemagglutinin-P (PHA-P) is a commonly used substance, despite the variability of the response related to the method of application (intradermal injection) and the antigens used. In the present experiment, PHA-P was used to observe the cell-mediated immune response of 216 chicks fed three dietary levels of vitamin E from 1 to 36 days of age. All birds were immunologically challenged by vaccination against coccidiosis at three days of age and against Newcastle Disease (NCD) at 14 and 30 days of age. At 36 days of age, birds were submitted to the CBH test according to the methodology of Corrier & DeLoach (1990). Birds fed 65mg/kg of vitamin E presented lasting cell reaction (p<0.08), which indicates that this vitamin E level improved cell immune response of birds due to its antioxidant and immunomodulating properties. The use of this vitamin E level can be considered by nutritionists under practical conditions, aiming to improve broiler immunity

Influence of glutamine and vitamin E on the performance and the immune responses of broiler chickens

This study aimed at evaluating the influence of Glutamine (Gln) and Vitamin E (VE) supplementation on the performance and immune response of broilers. A completely randomizes experimental design with a 2 x 3 (VE x Gln) factorial arrangement was used. VE was supplemented at 10 and 500 mg/kg feed, with or without Gln (1%) addition, and two periods of supplementation in the starter diets (1-7 and 1-14 days of age), with five replicates of 50 birds each. The analyzed parameters were: live performance (weight gain, feed intake, and feed conversion ratio); relative weights of the spleen, bursa, and thymus; antibody titers (with sheep red blood cells suspension - SRBC) and cutaneous basophilic hypersensivity (CBH). Data were submitted to the analysis of variance, and means were compared using the test of Tukey. Treatments did not influence (P>0.05) live performance parameters or antibody titers. VE reduced (P=0.01) CBH, with the level of 10 mg VE/kg allowing higher cell proliferation as compared to 500 mg VE/kg. As to lymphoid organs, only the spleen was affected (P=0.035) by Gln, which resulted in higher spleen relative weight when fed during the first week of age. Results showed that 10 mg VE/kg with Gln (1-7 days) promoted better immune responses

Unique genetic responses revealed in RNA-seq of the spleen of chickens stimulated with lipopolysaccharide and short-term heat

<div><p>Climate change and disease have large negative impacts on poultry production, but little is known about the interactions of responses to these stressors in chickens. Fayoumi (heat and disease resistant) and broiler (heat and disease susceptible) chicken lines were stimulated at 22 days of age, using a 2x2x2 factorial design including: breed (Fayoumi or broiler), inflammatory stimulus (lipopolysaccharide (LPS) or saline), and temperature (35°C or 25°C). Transcriptional changes in spleens were analyzed using RNA-sequencing on the Illumina HiSeq 2500. Thirty-two individual cDNA libraries were sequenced (four per treatment) and an average of 22 million reads were generated per library. Stimulation with LPS induced more differentially expressed genes (DEG, log₂ fold change ≥ 2 and FDR ≤ 0.05) in the broiler (N = 283) than the Fayoumi (N = 85), whereas heat treatment resulted in fewer DEG in broiler (N = 22) compared to Fayoumi (N = 107). The double stimulus of LPS+heat induced the largest numbers of changes in gene expression, for which broiler had 567 DEG and Fayoumi had 1471 DEG of which 399 were shared between breeds. Further analysis of DEG revealed pathways impacted by these stressors such as Remodelling of Epithelial Adherens Junctions due to heat stress, Granulocyte Adhesion and Diapedesis due to LPS, and Hepatic Fibrosis/Hepatic Stellate Cell Activation due to LPS+heat. The genes and pathways identified provide deeper understanding of the response to the applied stressors and may serve as biomarkers for genetic selection for heat and disease tolerant chickens.</p></div