Lymphocyte subpopulations in blood and duodenal epithelium of broilers fed diets contaminated with deoxynivalenol and zearalenone

Effects of deoxynivalenol contaminated corn distiller's dried grains with solubles on growth performance, body composition, immunological response, and gastrointestinal health in young pullets

Mycotoxins, particularly deoxynivalenol (DON), are common contaminants in feed ingredients such as corn distiller's dried grains with solubles (DDGS) and pose significant risks to poultry health. This study investigated the effects of feeding naturally DON contaminated DDGS on growth performance, body composition, immunological response, and gastrointestinal health in young pullets. A total of 360, 4-week-old Hy-Line W36 pullets were randomly assigned to diets with increasing levels of naturally DON contaminated DDGS (0, 5, 10, 15, and 20%) over 28 days, resulting in dietary DON concentrations ranging from below the limit of quantification to 15.4 ppm. Diets with DON concentration exceeding 8.9 ppm, corresponding to 15% and 20% DDGS inclusion, resulted in significantly lower body weight gain (BWG) and feed intake (FI) from experimental day 14 to day 28 compared to DON concentration below 5.9 ppm (0, 5 and 10% DDGS groups; P = 0.024 and P = 0.007, respectively). Body composition analysis showed a higher tissue fat percentage in the 20% DDGS group (15.4 ppm DON) by day 28 compared to lower inclusion levels (P = 0.021). Immunologically, a significant increase in the CD4+:CD8+ ratio in spleen was observed in the 20% DDGS group compared to the 0% DDGS group (P = 0.013), whereas both 15 and 20% DDGS inclusion levels significantly increased the ratio in cecal tonsil (P < 0.001). Additionally, interleukin 1β (IL-1β) expression significantly increased in the cecal tonsil by day 28 with 15 and 20% DDGS inclusions (P = 0.002). Gut health was compromised as gut permeability increased linearly with increasing DDGS inclusion (linear, P = 0.043), aligning with significant alterations in the expression of the tight junction protein occludin (OCLN; P = 0.007). Antioxidant responses in the liver showed increased superoxide dismutase (SOD) activity in early exposure (day 13, P = 0.038), followed by decreased SOD activity (P = 0.001) and reduced glutathione (GSH) levels (P < 0.001) by day 28. In conclusion, feeding DON-contaminated DDGS at higher inclusion levels (15% and 20%) with final diet DON concentrations exceeding 8.9 ppm over 28 days adversely affects growth performance, immune function, and gut integrity in young pullets.

No-observed adverse effect levels of deoxynivalenol and aflatoxin B1 in combination induced immune inhibition and apoptosis in vivo and in vitro

Mycotoxins are toxic metabolites produced by fungal species, commonly exist in animal feeds, and pose a serious risk to human as well as animal health. But limited studies have focused on combined effects of no-observed adverse effect levels. In vivo study, 6 weeks old twenty-four mice were individually exposed to Deoxynivalenol (DON) at 0.1 mg/kg BW, Aflatoxin B1 (AFB1) at 0.01 mg/kg BW, and mixture of DON and AFB1 (0.1 mg/kg BW and 0.01 mg/kg BW, respectively) for 28 days. Then, DON at 0.5 μg/mL, AFB1 at 0.04 μg/mL, and mixtures of DON and AFB1 (0.5 μg/mL, 0.04 μg/mL, respectively) were applied to porcine alveolar macrophages (PAMs) in vitro study. Our in vivo results revealed that the combined no-observed adverse effect levels of DON and AFB1 administration decreased IgA and IgG levels in the serum, the splenic TNF-α, IFN-γ, IL-2 and IL-6 mRNA expression and T-lymphocyte subset levels (CD4+ and CD8+) in the spleen. Additionally, the combined administration increased caspase-3, caspase-9, Bax, Cyt-c, and decreased Bcl-2 protein expression. Taken together, the combined no-observed adverse effect levels of DON and AFB1 could induce immunosuppression, which may be related to apoptosis. This study provides new insights into the combined immune toxicity (DON and AFB1).

Deoxynivalenol damages the intestinal barrier and biota of the broiler chickens

Background

In the livestock feed industry, feed and feed raw materials are extremely susceptible to mycotoxin contamination. Deoxynivalenol (DON) is one of the main risk factors for mycotoxin contamination in broiler feed and feedstuff, however, there is still little knowledge about this. Hence, the purpose of this study was to explore the toxicity effect of DON on the intestinal barrier and the microecological balance of the biota in broiler chickens.

Results

In our present study, we compared the pathological scores of the small intestines of broilers on the 5^th, 7^th, and 10^th day, and chose the 7^th day to analyze the small intestine histomorphology, tight junctions, and cecal biota of the broilers. The results showed the damage to the small intestine worsened over time, the small intestinal villi of broilers were breakage, the tight junctions of the small intestine were destroyed, the cecal biota was unbalanced, and the growth performance of broilers was reduced on the 7^th day.

Conclusions

DON could damage the functional and structural completeness of the intestinal tract, disorder the Intestinal biota, and finally lead to declined broiler performance. Our study provided a basis for the prevention and treatment of DON in broiler production.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03392-4.

Preparation monoclonal β-type anti-idiotype antibody of zearalenone and development of green ELISA quantitative detecting technique

Immunoassay has been widely used in the screening of mycotoxins, which may be hazardous to the operator or the environment. This study was to develop a green way to measure zearalenone (ZEN) with a monoclonal β-type anti-idiotype antibody (Ab2β) against ZEN in place of ZEN standard. Six monoclonal β-type anti-idiotype antibodies were prepared. The 50% inhibitory concentration (IC₅₀) value to ZEN of the six antibodies was between 34.45 ± 1.12-182.12 ± 15.40 nM. A green ELISA was then developed and validated. The quantitative conversion formula between ZEN and the monoclonal Ab2β against ZEN was y = 0.092x^0.722, R² = 0.990. The working range was 2.63-100.64 ng ml^-1. The recovery rate in spiked feed samples was from 82.15% to 102.79%, and the within-assay and between-assay coefficient variation (CV) level were less than 10.00%. A good correlation was obtained by high-performance liquid chromatography method (HPLC) to validate the developed method.

The protective effects of modified palygorskite on the broilers fed a purified zearalenone-contaminated diet

This study was conducted to evaluate the protective effects of dietary modified palygorskite (Pal) supplementation on broiler chickens fed a purified zearalenone (ZEN)-contaminated diet. A total of 144 1-day-old male chicks were allocated to one of the 3 treatments, with each treatment being composed of 6 replicates of 8 birds each. The birds were fed with a control diet (Control group), the ZEN-contaminated diet (2.0 mg ZEN/kg diet), and the ZEN-contaminated diet supplemented with 1.0 g/kg diet of modified Pal for 42 d, respectively. Compared with control group, feeding ZEN-contaminated diet reduced weight gain and feed conversion efficiency of broilers during the finisher and overall experimental period (P < 0.05), while the values of these parameters in broilers fed the diet contaminated with ZEN increased after modified Pal administration (P < 0.05). ZEN challenge increased the 21-d serum aspartate aminotransferase and 42-d serum alanine aminotransferase activities, 42-d relative liver weight, and ZEN residues in the liver at both 21 and 42 d and kidney at 42 d (P < 0.05). In contrast, birds fed the ZEN-contaminated diet that was supplemented with modified Pal exhibited lower serum alanine aminotransferase activity at 42 d, relative liver weight at 42 d, and hepatic and renal ZEN accumulation at both 21 and 42 d (P < 0.05), when compared with their counterparts fed the contaminated diet. ZEN contamination decreased superoxide dismutase activity in the serum at 21 d, kidney at 42 d, and liver at both 21 and 42 d, respectively (P < 0.05). The hepatic and renal malondialdehyde accumulation at 42 d increased, while renal glutathione level at 42 d decreased, when feeding broilers with the ZEN-contaminated diet (P < 0.05). Dietary modified Pal supplementation reduced hepatic malondialdehyde accumulation, whereas increased renal superoxide dismutase activity in broilers fed a ZEN-contaminated diet at 42 d (P < 0.05). This finding suggested that dietary modified Pal administration could promote growth performance, reduce hepatonephric ZEN residues, and improve liver function and antioxidant status of broiler chickens receiving a ZEN-contaminated diet.

The Effect of Deoxynivalenol on Selected Populations of Immunocompetent Cells in Porcine Blood-A Preliminary Study

Deoxynivalenol (DON) is one of the most prevalent mycotoxins in Europe. Pigs are an animal species that is most susceptible to this mycotoxin. Deoxynivalenol causes significant losses in pig production by lowering feed intake, decreasing daily weight gains, disrupting immune responses, and increasing susceptibility to diseases. The aim of this experiment was to determine the influence of feed contaminated with DON at concentrations insignificantly higher than recommended by the European Commission (900 µg/kg). The experimental feed contained 1008 μg DON/kg. The experiment was performed on eight weaners from the same litter. The animals were randomly divided into two groups: an experimental group (M, n = 4) fed contaminated feed and a control group (C, n = 4) administered feed free of mycotoxins. The experiment lasted for six weeks, and peripheral blood samples were collected from the animals for analyses of selected morphological parameters and changes in the percentages of CD4⁺8-, CD4-8⁺, and CD4⁺8⁺ lymphocytes and antigen-presenting cells (APC) with CD14⁺172⁺ (monocytes), CD172ahigh4-14- (conventional dendritic cells, cDC), and CD172adim4⁺14- (plasmacytoid dendritic cells, pDC) phenotypes. The morphological parameters of porcine blood samples were determined by flow cytometry with non-fluorescent particle-size calibration standards, and no differences were observed between groups M and C. An immunophenotyping analysis of lymphocytes and dendritic cells (DC) revealed an increase in the percentage of CD4⁺8-, CD172ahigh4-14-, and CD172adim4⁺14- cells, and a decrease in the number of CD4-8⁺ cells in group M. The results of this experiment suggest that prolonged exposure to low doses of DON can change the proportions of immunocompetent cells (a shift towards humoral immunity), without affecting their overall counts.

Activity of Zearalenone in the Porcine Intestinal Tract

This study demonstrates that low doses (somewhat above the No Observed Adverse Effect Level, NOAEL) of the mycoestrogen zearalenone (ZEN) and its metabolites display multispecificity towards various biological targets in gilts. The observed responses in gilts were surprising. The presence of ZEN and zearalenols (ZELs) did not evoke a response in the porcine gastrointestinal tract, which was attributed to dietary tolerance. Lymphocyte proliferation was intensified in jejunal mesenteric lymph nodes, and lymphocyte counts increased in the jejunal epithelium with time of exposure. In the distal digestive tract, fecal bacterial counts decreased, the activity of fecal bacterial enzymes and lactic acid bacteria increased, and cecal water was characterized by higher genotoxicity. The accompanying hyperestrogenism led to changes in mRNA activity of selected enzymes (cytochrome P450, hydroxysteroid dehydrogenases, nitric oxide synthases) and receptors (estrogen and progesterone receptors), and it stimulated post-translational modifications which play an important role in non-genomic mechanisms of signal transmission. Hyperestrogenism influences the regulation of the host's steroid hormones (estron, estradiol and progesteron), it affects the virulence of bacterial genes encoding bacterial hydroxysteroid dehydrogenases (HSDs), and it participates in detoxification processes by slowing down intestinal activity, provoking energy deficits and promoting antiporter activity at the level of enterocytes. In most cases, hyperestrogenism fulfils all of the above roles. The results of this study indicate that low doses of ZEN alleviate inflammatory processes in the digestive system, in particular in the proximal and distal intestinal tract, and increase body weight gains in gilts.

Changes in the Subpopulations of Porcine Peripheral Blood Lymphocytes Induced by Exposure to Low Doses of Zearalenone (ZEN) and Deoxynivalenol (DON)

Zearalenone and deoxynivalenol are secondary metabolites of fungi of the genus Fusarium. The presence of mycotoxins in cereals and the resulting contamination of feeds and foods pose health risks for animals and humans. The dangers associated with high doses of mycotoxins have been extensively researched but very little is known about NOAEL (No Observed Adverse Effect Level) doses or exposure to a combination of mycotoxins (mixed mycotoxicoses). The aim of this study was to determine the effects of six-week exposure to NOAEL doses of individual and combined mycotoxins on the subpopulations of CD4⁺8(-), CD4(-)8⁺ and CD4⁺8⁺ lymphocytes in the peripheral blood of pigs. The experiment was performed on 72 gilts with average body weight of 25 kg, divided into three experimental groups (E1, E2 and E3, administered zearalenone (ZEN), deoxynivalenol (DON) and ZEN + DON, respectively, on a daily basis) and a control group (C) receiving placebo. Changes in lymphocyte subpopulations were evaluated by flow cytometry at weekly intervals (experimental days 7, 14, 21, 28, 35 and 42). A linear increase in the percentage of CD4⁺8⁺ lymphocytes was highly correlated with time (r = 0.682) in group C. The correlations and linear increase in the above subpopulation were disrupted in the remaining groups. In group E3, a statistically significant (p < 0.05) decrease in CD4⁺8⁺ counts was observed in week 5, which could point to a transient depletion of regulatory mechanisms of immune responses. The noted results also suggest that in mixed mycotoxicosis, ZEN and DON exerted stronger immunomodulatory effects.

The Fusarium toxin zearalenone and deoxynivalenol affect murine splenic antioxidant functions, interferon levels, and T-cell subsets

This study aimed to evaluate the effects of the Fusarium toxin zearalenone (ZEA) and deoxynivalenol (DON) on splenic antioxidant functions, IFN levels, and T-cell subsets in mice. Herein, 360 mice were assigned to nine groups for a 12-day study. Mice were administered an intraperitoneal injection for 4 consecutive days with different concentrations of ZEA alone, DON alone, or ZEA+DON. Spleen and blood samples were collected on days 0, 3, 5, 8, and 12. Mice in each of the experimental groups showed dysreglated splenic antioxidant functions, IFN levels, and T-cell subset frequencies, suggesting that the immune system had been affected. The ZEA+DON-treated groups, especially the group that received a higher concentration of ZEA+DON (Group D2Z2), showed more obvious effects on the dysregulation of splenic antioxidant functions, IFN levels, and T-cell subsets. This finding suggested that DON and ZEA exerted synergistic effects.

Duodenal morphology and immune responses of broiler chickens fed low doses of deoxynivalenol

Morphometry and flow cytometry for intraepithelial lymphocyte phenotyping were used to determine the changes in duodenal mucosae after administration of low doses of deoxynivalenol in chickens. Moreover, functions of phagocytes and immunocompetent cells in peripheral blood were evaluated by flow cytometry. In total, sixty chickens of Ross hybrid broilers 308 were used in this experiment. Two experimental groups of 20 birds were continually fed for 14 days a diet containing deoxynivalenol at a dose of 1 and 3 mg·kg-1; 20 birds of the control group were fed uncontaminated diet. Morphometry showed only tendency to decrease the height of villi and surface area of duodenal mucosae in chickens fed the diet supplemented with 3 mg·kg-1 deoxynivalenol. Phenotyping of intraepithelial lymphocytes showed a decrease of CD45+ (P < 0.034) in duodenum of birds fed diets supplemented with deoxynivalenol. Examination of white blood cells showed a decrease of monocytes (P < 0.020) in chickens fed 3 mg·kg-1 of deoxynivalenol. Both experimental groups revealed higher metabolic burst of peripheral blood heterophils (P < 0.001). Phenotyping of immunocompetent cells showed an increase (P < 0.003) of CD3+ and a decrease (P < 0.001) of MHC II+ cells in peripheral blood of chickens fed with 3 mg·kg-1 dose of deoxynivalenol. The experimental feeding of chickens with deoxynivalenol resulted in immunomodulation of immunocompetent cells in duodenum and blood with mild atrophy of intestinal villi, mainly after the feeding of the dose of 3 mg·kg-1. We proved that even low doses of deoxynivalenol can cause changes in haemathological, immunological and morphological profiles already during two weeks, and lead to the activation of compensatory-adaptive mechanisms with unfavourable impact on health and performance of birds.