Effect of a post-hatch lipopolysaccharide challenge in Turkey poults and ducklings after a primary embryonic heat stress

Short-term exposure to fumonisins and deoxynivalenol, on broiler growth performance and cecal Salmonella load during experimental Salmonella Enteritidis infection

Fumonisins (FUM) and deoxynivalenol (DON) are two common mycotoxins in poultry feed. Salmonella enterica ser. Enteritidis (S. Enteritidis) is a primary foodborne bacterium in broilers. This trial was conducted to evaluate the effects of naturally occurring FUM and DON and their combination at subclinical doses on broiler performance during a S. Enteritidis challenge. The experiment consisted of five treatments: NCC, no-challenge no-mycotoxin treatment; CC, Salmonella challenge + no-mycotoxin treatment; DON, DON 0.6 mg/kg + Salmonella challenge; FUM, FUM 14 mg/kg + Salmonella challenge; DON + FUM + T-2 + neosolaniol, DON 0.6 mg/kg + FUM 14 mg/kg + T-2 toxin 0.6 mg/kg + 0.8 mg/kg neosolaniol + Salmonella challenge. On d 4, birds were challenged with either 0 or 1 × 10⁹ CFU/mL S. Enteritidis orally. There were no significant effects on growth performance among treatments at 0, 3, 7, and 14 d of post-inoculation (dpi). On 14 dpi, the combined DON + FUM + T-2 + neosolaniol significantly increased the Salmonella load by 1.5 logs compared to the control groups (P < 0.05). FUM significantly increased the cecal tonsil IL-10 gene expression by 1.2-fold at 7 dpi (P < 0.05) and downregulated TNF-α by 1.8-fold on 14 dpi compared to the control, nonchallenge groups (P < 0.05). On 7 dpi, the combined DON + FUM + T-2 + neosolaniol reduced occludin by 4.4-fold (P < 0.05) when compared to the control groups. Similarly, combined DON + FUM+ T-2 + neosolaniol decreased zona-occluden transcription by 2.3 and 7.6-fold on 3 and 14 dpi, respectively (P < 0.05). Furthermore, combined DON + FUM + T-2 + neosolaniol decreased Claudin-1 by 2.2-fold and Claudin-4 by 5.1-fold on 14 dpi when compared to the control groups (P < 0.05). In conclusion, short-term exposure to a subclinical dose of combined DON + FUM + T-2 + neosolaniol had an impact on broiler intestinal tight junction proteins and cecal Salmonella abundance under experimental Salmonella challenge.

Subclinical Doses of Combined Fumonisins and Deoxynivalenol Predispose Clostridium perfringens–Inoculated Broilers to Necrotic Enteritis

Fumonisins (FB) and deoxynivalenol (DON) are mycotoxins which may predispose broiler chickens to necrotic enteritis (NE). The objective of this study was to identify the effects of subclinical doses of combined FB and DON on NE. A total of 480 day-old male broiler chicks were divided into four treatment groups; 1) control group (basal diet + Clostridium perfringens); 2) necrotic enteritis group (basal diet + Eimeria maxima + C. perfringens); 3) FB + DON group (basal diet + 3 mg/kg FB + 4 mg/kg DON + C. perfringens); and 4) FB + DON + NE group (basal diet + 3 mg/kg FB + 4 mg/kg DON + E. maxima + C. perfringens). Birds in NE and FB + DON + NE groups received 2.5 × 10³E. maxima on day 14. All birds were inoculated with C. perfringens on days 19, 20, and 21. On day 35, birds in the NE, FB + DON, and FB + DON + NE groups had 242, 84, and 339 g lower BWG and a 19-, 2-, and 22-point increase in FCR respectively, than in the control group. Subclinical doses of FB + DON increased (p < 0.05) the NE lesion scores compared to the control group on day 21. On day 21, birds in the NE, FB + DON, and FB + DON + NE groups had increased (p < 0.05) serum FITC-D, lower (p < 0.05) jejunal tight junction protein mRNA, and increased (p < 0.05) cecal tonsil IL-1 mRNA compared to control group. On day 21, birds in the NE group had decreased (p < 0.05) villi height to crypt depth ratio compared to the control group and the presence of FB + DON in NE-induced birds further decreased the villi height to crypt depth ratio. Birds in the NE, FB + DON, and FB + DON + NE groups had increased (p < 0.05) C. perfringens, lower (p < 0.05) Lactobacillus loads in the cecal content, and a lower (p < 0.05) CD8⁺: CD4⁺ cell ratio in the cecal tonsils compared to the control group. It can be concluded that subclinical doses of combined FB and DON predispose C. perfringens-inoculated birds to NE, and the presence of FB + DON in NE-induced birds exacerbated the severity of NE.

Effect of Immune Stress on Growth Performance and Immune Functions of Livestock: Mechanisms and Prevention

Simple Summary

Immune stress is an important stressor in domestic animals that leads to decreased feed intake, slow growth, and reduced disease resistance of pigs and poultry. Especially in high-density animal feeding conditions, the risk factor of immune stress is extremely high, as they are easily harmed by pathogens, and frequent vaccinations are required to enhance the immunity function of the animals. This review mainly describes the causes, mechanisms of immune stress and its prevention and treatment measures. This provides a theoretical basis for further research and development of safe and efficient prevention and control measures for immune stress in animals.

Abstract

Immune stress markedly affects the immune function and growth performance of livestock, including poultry, resulting in financial loss to farmers. It can lead to decreased feed intake, reduced growth, and intestinal disorders. Studies have shown that pathogen-induced immune stress is mostly related to TLR4-related inflammatory signal pathway activation, excessive inflammatory cytokine release, oxidative stress, hormonal disorders, cell apoptosis, and intestinal microbial disorders. This paper reviews the occurrence of immune stress in livestock, its impact on immune function and growth performance, and strategies for immune stress prevention.