Pre‐cold acclimation improves the immune function of trachea and resistance to cold stress in broilers

Abstract

Acclimation can alleviate the damage caused by adverse environmental factors. To investigate the effects of cold stimulation on immunity in tracheal of broilers, 360 one-day-old chicks were raised at normal temperatures during 1-7 days. From 8 day, G1 (control) continued to be raised at normal temperatures, whereas G2 and G3 (treatment groups) were cold-stimulated at 3°C and 12°C below the temperature of G1, respectively. At 42 day, all the groups were subjected to a 24-hr acute cold stress, designated as S1, S2, and S3. Tracheal tissues were collected to detect gene levels of immunoglobulins, antimicrobial peptides, Hsps, and cytokines, and oxidative stressrelated indicators at 14 day, 42 day, and 43 day, and protein levels of Hsps and proinflammatory cytokines as well as morphology changes at 42 day and 43 day. The results showed that, compared with 42G1, tracheal structure of 42G2 was basically intact, and gene levels of immunoglobulins and antimicrobial peptides increased (p < 0.05), whereas tracheal structure of 42G3 was destroyed, with decreased levels of immunoglobulins (p < 0.05), and increased levels of Hsps and proinflammatory cytokines (p < 0.05). At 43 day, tracheal damage was visible and gene levels of immunoglobulins and antimicrobial peptides decreased in S1 (p < 0.05). Tracheal structure was relatively intact and gene levels of antimicrobial peptides increased in S2 (p < 0.05). Compared with S1 and S3, immune-related gene levels in S2 were higher, and Hsps and proinflammatory cytokines levels were lower. The results demonstrate that cold stimulation of lower 3°C from 8 to 42 day led to cold acclimation, which improved immunity of tracheal mucosa and resistance to cold stress in broilers.

Cold Exposure-Induced Up-Regulation of Hsp70 Positively Regulates PEDV mRNA Synthesis and Protein Expression In Vitro

“…Seasonality of the PED epidemic may link to environmental factors such as the drop of ambient temperature. Physiological stress experienced under cold exposure leads to a weakening of immune response [36] and increased Hsp70 levels [13,14]. It has been reported that Hsp70 could promote influenza A virus replication through modulates polymerase activity [18].…”

“…Heat shock proteins (Hsps), molecular chaperones originally discovered based on their up-regulation in response to heat stress. Evidence is growing that exposure of cells and tissues to low ambient temperature leads to transcription and translation of heat shock proteins 70 KDa (Hsp70) [9][10][11][12][13][14]. Moreover, Hsp70 has been shown to be one key factor for multiple virus infection including rabies virus [15], porcine circovirus type 2 [16], porcine reproductive and respiratory syndrome virus [17], influenza A virus [18], dengue virus [19], infectious bronchitis virus [20], Epstein-Barr virus [21], ectromelia virus [22], hepatitis B virus [23], enterovirus A71 [24] and zika virus [25,26].…”

Avian Pathogenic Escherichia coli and Clostridium perfringens: Challenges in No Antibiotics Ever Broiler Production and Potential Solutions

“…Broilers are also susceptible to spikes in cooler weather. Su et al noted that immunity in tracheal mucosa decreased in broilers exposed to acute 24-h cold stress from 20 °C to 7 °C [ 56 ]. Temperature stress from cold or heat, can cause oxidative stress and increase the expression levels of heat shock proteins, which can initiate an inflammatory response and decrease immune function [ 57 ].…”

Effects of different stocking densities on the trachea barrier function and its plasma metabolic profile of finishing broilers

“…Tracheal defense function mainly depends on the integrity of its mucosa and the secretion of protective proteins [31]. To the best of our knowledge, most of the previous experiment reported that increasing stocking density linearly decreased intestinal barrier function [32], but there is rarely any report on the effects of high-stocking density on trachea barrier function.…”