Effects of heat stress on peripheral T and B lymphocyte profiles and IgG and IgM serum levels in broiler chickens vaccinated for Newcastle disease virus

Abstract

Multiple factors, such as environment, nutritional status, and disease, induce stress in animals during livestock production. It has been shown that poultry exposed to stressors for prolonged periods had decreases in their performance parameters, mortality and decreased host resistance to pathogenic agents. It seems that early age stress may have long-lasting impact and could possibly modify the expression of their genetic potential on growth performance and immunity. This study aimed to discuss the effects of early-age heat stress on the blood lymphocyte phenotypes (B and T lymphocytes) and plasma immunoglobulin levels (IgM and IgG) in chickens vaccinated against paramixovirus of the Newcastle (NC) disease (LaSota strain). For this purpose, 96 male chickens (Cobb) were divided into 4 groups: 1) control (C), 2) heat-stressed (HS), 3) control vaccinated (C/V), and 4) heat-stressed and Vaccinated (HS/V). The NC vaccine was administered twice on experimental day (ED) 7 and ED14, and the heat stress (38 ± 1°C) was applied from ED2 to ED6. The data showed that HS increased the corticosterone serum levels in the HS group compared with the control groups (C and C/V groups). At ED7, increased concentrations of IgM were observed in birds in the HS and HS/V groups compared with C and C/V animals; chickens from the HS/V group presented increased IgG levels compared with those in the birds of the C group. The heat stress shifted the immune cell profile from B-lymphocyte to a T-cytotoxic and T-helper lymphocyte profile, and this immune cell pattern persisted until the end of the study period. It was concluded that heat stress immunomodulated the immune function response of the chickens to the NC disease vaccine challenge.

Bone parameters and organ morphometry of two broiler chicken lines exposed to heat for different periods

“…This is in contrast to results reported by some authors such as Engan and Schagatay (2015), who declared that any stressful factor leads to hemodynamic alterations, causing a reduction in the size and relative weight of the spleen. Many studies in birds report chronic heat stress as an immunosuppressant factor, which shows that the bird's cloacal bursa is subject to environmental alterations (DHABHAR, 2014) that can induce an immune response in the animal (HONDA et al, 2015).…”

Adenoviral Gizzard Erosions in Commercial Layer Chickens

“…Recently, it was shown that heat stress induced negative effects on immune function as well as changes in the intestinal mucosa of young chickens (Quinteiro et al, 2012). Furthermore, an increase in temperature of 8 degrees for several hours over a few days immunomodulated the immune response of chickens to the vaccine against Newcastle disease (Honda et al, 2015). It couldn't be excluded that sudden temperature fluctuations accompanying observed disease cases altered the immune system ability to function normally, making some birds more sensitive to infection with FAdV but the influence of other contributory factors not assessed in this study was also possible.…”

Effect of Mangosteen (Garcinia Mangostana) Pericarp Extract in Reducing the Heat Stress of Laying Quails

“…It has been established that an increase in temperature to 34 °C daily causes detrimental intestinal injury in broiler chickens by activation of the hypothalamic-pituitary-adrenal (HPA) axis and corticosterone concentrations (Garriga et al, 2006;Quinteiro-Filho et al, 2010;Sahin et al, 2017). High circulating levels of cor-ticosterone are known to induce immunosuppression and susceptibility to infectious disease (Honda et al, 2015). In laying birds, daily exposure to high temperature (42 °C ± 3 °C) for 12 h is associated with decreases in ovarian function, egg production, egg size, ovarian weight, and the number of large follicles due to inhibition of the secretion of steroidogenic enzymes (Rozenboim et al, 2007).…”