Effects of Corticosterone and Dietary Energy on Immune Function of Broiler Chickens

Abstract

An experiment was conducted to investigate the effects of dietary energy level on the performance and immune function of stressed broiler chickens (Gallus gallus domesticus). A total of 96 three-day-old male broiler chickens (Ross × Ross) were divided into two groups. One group received a high energy (HE) diet and the other group received a low energy (LE) diet for 7 days. At 5 days of age, the chickens from each group were further divided into two sub-groups and received one of the following two treatments for 3 days: (1) subcutaneous injection of corticosterone, twice per day (CORT group; 2 mg of CORT/kg BW in corn oil) and (2) subcutaneous injection of corn oil, twice per day (Control/Sham treatment group). At 10 days of age, samples of blood, duodenum, jejunum, and ileum were obtained. Compared with the other three groups, the LE group treated with CORT had the lowest average daily gain (ADG) and the poorest feed conversion ratio (FCR, P < 0.05). Furthermore, CORT treatment decreased the relative weight (RW) of the bursa independent of the dietary energy level, but it decreased the RW of the thymus only in the chickens fed the LE diet. By contrast, CORT administration decreased the RW of the spleen only in the chickens fed the HE diet (P < 0.05). The plasma total protein, albumin, tumor necrosis factor alpha, interleukin 2 and immunoglobulin G (IgG) levels were affected by the CORT treatment (P < 0.05); however, these factors were not significantly affected by the dietary energy level. Toll-like receptor-5 mRNA level was down-regulated by CORT injection in the duodenum and ileum (P < 0.05) and showed a trend of down-regulation in the jejunum (P=0.0846). The present study showed that CORT treatment induced immunosuppressive effects on the innate immune system of broiler chickens, which were ameliorated by consumption of higher dietary energy.

Effects of vitamin E, inorganic selenium, bacterial organic selenium, and their combinations on immunity response in broiler chickens

“…The down-regulation of pro-inflammatory cytokines observed in this study was due to IL-10 elevation, which is a known potent anti-inflammatory cytokine and deactivator of pro-inflammatory cytokine synthesis, macrophage, and monocyte [ 31 ]. However, the IL-2 up-regulation in this study was unexpected but according to Yang et al [ 34 ], IL-2, is also required for the growth, proliferation, and differentiation of T cells, and the spleen sight is highly enriched with T cells, B cells, and monocytes.…”

Effect of dietary supplementation with &lt;i&gt;Rhizopus oryzae&lt;/i&gt; or &lt;i&gt;Chrysonilia crassa&lt;/i&gt; on growth performance, blood profile, intestinal microbial population, and carcass traits in broilers exposed to heat stress

“…Apart from the physiological adjustment derived from depressed feed intake (Zeferino et al, 2016), the increased corticosterone level in HS broilers may be responsible for the lower percentage of the organs (Hu et al, 2010). Corticosterone may decrease glucose transport to a variety of tissues/organs, resulting in tissue regression and weight loss (Yang et al, 2015). Interestingly, the percentage of heart was not different between CONT and HS birds receiving fungi or rice bran in the present study.…”

Effects of xylo-oligosaccharide and flavomycin on the immune function of broiler chickens

“…The level of plasma IgG in the XOS group of broilers significantly increased compared with the other two groups at 21 days, suggesting that XOS could improve broiler immune function. Furthermore, the plasma IL-2 concentration of the FLA test group was lower than that of the control group; IL-2 is a proinflammatory cytokine, which can promote the growth, proliferation and differentiation of T cells ( Yang et al, 2015 ). Interleukins belong to a class of cytokines that function in the immune system by playing an important physiological and pathological role in the inflammatory response process.…”