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).

Global distribution, toxicity to humans and animals, biodegradation, and nutritional mitigation of deoxynivalenol: A review

Deoxynivalenol (DON) is one of the main types of B trichothecenes, and it causes health-related issues in humans and animals and imposes considerable challenges to food and feed safety globally each year. This review investigates the global hazards of DON, describes the occurrence of DON in food and feed in different countries, and systematically uncovers the mechanisms of the various toxic effects of DON. For DON pollution, many treatments have been reported on the degradation of DON, and each of the treatments has different degradation efficacies and degrades DON by a distinct mechanism. These treatments include physical, chemical, and biological methods and mitigation strategies. Biodegradation methods include microorganisms, enzymes, and biological antifungal agents, which are of great research significance in food processing because of their high efficiency, low environmental hazards, and drug resistance. And we also reviewed the mechanisms of biodegradation methods of DON, the adsorption and antagonism effects of microorganisms, and the different chemical transformation mechanisms of enzymes. Moreover, nutritional mitigation including common nutrients (amino acids, fatty acids, vitamins, and microelements) and plant extracts was discussed in this review, and the mitigation mechanism of DON toxicity was elaborated from the biochemical point of view. These findings help explore various approaches to achieve the best efficiency and applicability, overcome DON pollution worldwide, ensure the sustainability and safety of food processing, and explore potential therapeutic options with the ability to reduce the deleterious effects of DON in humans and animals.

Mycotoxins in Cereal-Based Products and Their Impacts on the Health of Humans, Livestock Animals and Pets

Cereal grains are the most important food staples for human beings and livestock animals. They can be processed into various types of food and feed products such as bread, pasta, breakfast cereals, cake, snacks, beer, complete feed, and pet foods. However, cereal grains are vulnerable to the contamination of soil microorganisms, particularly molds. The toxigenic fungi/molds not only cause quality deterioration and grain loss, but also produce toxic secondary metabolites, mycotoxins, which can cause acute toxicity, death, and chronic diseases such as cancer, immunity suppression, growth impairment, and neural tube defects in humans, livestock animals and pets. To protect human beings and animals from these health risks, many countries have established/adopted regulations to limit exposure to mycotoxins. The purpose of this review is to update the evidence regarding the occurrence and co-occurrence of mycotoxins in cereal grains and cereal-derived food and feed products and their health impacts on human beings, livestock animals and pets. The effort for safe food and feed supplies including prevention technologies, detoxification technologies/methods and up-to-date regulation limits of frequently detected mycotoxins in cereal grains for food and feed in major cereal-producing countries are also provided. Some important areas worthy of further investigation are proposed.

Mycotoxin Contamination Status of Cereals in China and Potential Microbial Decontamination Methods

The presence of mycotoxins in cereals can pose a significant health risk to animals and humans. China is one of the countries that is facing cereal contamination by mycotoxins. Treating mycotoxin-contaminated cereals with established physical and chemical methods can lead to negative effects, such as the loss of nutrients, chemical residues, and high energy consumption. Therefore, microbial detoxification techniques are being considered for reducing and treating mycotoxins in cereals. This paper reviews the contamination of aflatoxins, zearalenone, deoxynivalenol, fumonisins, and ochratoxin A in major cereals (rice, wheat, and maize). Our discussion is based on 8700 samples from 30 provincial areas in China between 2005 and 2021. Previous research suggests that the temperature and humidity in the highly contaminated Chinese cereal-growing regions match the growth conditions of potential antagonists. Therefore, this review takes biological detoxification as the starting point and summarizes the methods of microbial detoxification, microbial active substance detoxification, and other microbial inhibition methods for treating contaminated cereals. Furthermore, their respective mechanisms are systematically analyzed, and a series of strategies for combining the above methods with the treatment of contaminated cereals in China are proposed. It is hoped that this review will provide a reference for subsequent solutions to cereal contamination problems and for the development of safer and more efficient methods of biological detoxification.

Does Deoxynivalenol Affect Amoxicillin and Doxycycline Absorption in the Gastrointestinal Tract? Ex Vivo Study on Swine Jejunum Mucosa Explants

The presence of deoxynivalenol (DON) in feed may increase intestinal barrier permeability. Disturbance of the intestinal barrier integrity may affect the absorption of antibiotics used in animals. Since the bioavailability of orally administered antibiotics significantly affects their efficacy and safety, it was decided to evaluate how DON influences the absorption of the most commonly used antibiotics in pigs, i.e., amoxicillin (AMX) and doxycycline (DOX). The studies were conducted using jejunal explants from adult pigs. Explants were incubated in Ussing chambers, in which a buffer containing DON (30 µg/mL), AMX (50 µg/mL), DOX (30 µg/mL), a combination of AMX + DON, or a combination of DOX + DON was used. Changes in transepithelial electrical resistance (TEER), the flux of transcellular and intracellular transport markers, and the flux of antibiotics across explants were measured. DON increased the permeability of small intestine explants, expressed by a reduction in TEER and an intensification of transcellular marker transport. DON did not affect AMX transport, but it accelerated DOX transport by approximately five times. The results suggest that DON inhibits the efflux transport of DOX to the intestinal lumen, and thus significantly changes its absorption from the gastrointestinal tract.

Evaluation of dietary mycotoxin control strategies on nursery pig growth performance and blood measures

A total of 4,318 pigs (337 × 1,050, PIC; initially 6.5 ± 0.08 kg) were used in a 35-day study to evaluate dietary mycotoxin control strategies on nursery pig performance and blood measures. Pigs were weaned at approximately 21 d of age and randomly allotted to 1 of 5 dietary treatments in a randomized complete block design with blocking structure including sow farm origin, date of entry into facility, and average pen BW. A total of 160 pens were used with 80 double-sided 5-hole stainless steel fence line feeders, with feeder serving as the experimental unit. For each feeder, 1 pen contained 27 gilts and 1 pen contained 27 barrows. There were 16 replications per dietary treatment. A common phase 1 diet was fed to all pigs in pelleted form for 7 day prior to treatment diets. Experimental treatments were fed from days 7 to 42 after weaning (days 0 to 35 of the study) and included a low deoxynivalenol (DON) diet (1.12 ± 0.623 mg/kg), high DON diet (2.34 ± 1.809 mg/kg), high DON+ 0.50% sodium metabisulfite (SMB), high DON+ one of two mitigating products; 0.30% Technology1, or 0.30% Technology1+. Technology1 and 1+ are comprised of clays, yeast cell wall components, and a blend of plant extracts. Technology1+ also contains SMB. Overall (days 0 to 35), pigs fed high DON had decreased (P < 0.05) final BW, ADG, and ADFI compared with low DON. Additionally, pigs fed high DON+SMB had increased (P < 0.05) ADG compared with all other treatments. An improvement (P < 0.05) in G:F was observed in pigs fed high DON + SMB or high DON + Technology1+ compared with the low DON or high DON + Technology1 diets with high DON diets intermediate. Pigs fed high DON + SMB or high DON + Technology1 diets had reduced (P < 0.05) total removals and mortality compared with pigs fed low DON diets with high DON and high DON + Technology1+ intermediate. Liquid chromatography/mass spectrometry analysis of circulating blood collected on day 35 revealed that pigs fed high DON or high DON + Technology1 had increased (P < 0.05) DON concentrations compared to low DON with high DON + SMB and high DON + Technology1+ intermediate. In summary, pigs fed high DON diets had reduced performance compared with pigs fed low DON. Sodium metabisulfite in high DON diets provided a benefit in growth performance with ADG and G:F exceeding growth performance in the low DON diet while, the improved G:F ratio combined with other immunometabolic changes (gamma glutamyltransferase and creatine kinase) associated with Technology1+ warrant further investigation.

Impacts of weaning weights and mycotoxin challenges on jejunal mucosa-associated microbiota, intestinal and systemic health, and growth performance of nursery pigs

Background

This study aimed at investigating the effects of mycotoxin challenge on the growth and physiology of nursery pigs with different weaning weights.

Results

At weaning, 10 pigs were euthanized to collect jejunal mucosa and 90 pigs were assigned following a randomized complete block design in a 2 × 2 factorial arrangement of treatments with 3 pigs per pen. Factors were: weaning weight (light: body weight, BW < 7.5 kg or heavy: BW > 9.0 kg); and dietary mycotoxins (supplementation of 0.2 mg/kg aflatoxins, 2.0 mg/kg deoxynivalenol). All diets had titanium dioxide as an external marker at 0.5%. Growth performance and fecal score were recorded until pigs achieved 20 kg BW (light pigs average BW = 21.1 kg and heavy pigs average BW = 20.5 kg). Pigs were sampled for blood, ileal digesta, jejunal tissue and mucosa at 20 kg BW. Data were analyzed using the mixed procedure of SAS. At weaning, light pigs had decreased (P < 0.05) jejunal interleukin-8, increased (P < 0.05) tumor necrosis factor-α, and increased (P < 0.05) α-diversity indexes of jejunal mucosa-associated microbiota. At 20 kg of BW, light pigs had decreased (P < 0.05) average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G/F). Mycotoxins decreased (P < 0.05) BW, ADG, ADFI, and G/F. Light pigs tended to have increased fecal score on d 0 (P = 0.080), d 10 (P = 0.069), and increased (P < 0.05) fecal score at 20 kg. Mycotoxins decreased the apparent ileal digestibility of nitrogen (P < 0.05). Light pigs had increased (P < 0.05) intestinal malondialdehydes and interleukin 8. Mycotoxins tended to increase (P = 0.060) intestinal tumor necrosis factor-α.

Conclusions

Nursery pigs with light weaning weight were more susceptible to jejunal inflammation and had impaired intestinal health due to weaning stress, whereas mycotoxins diminished the health and growth of nursery pigs regardless of weaning weight.

The effects of deoxynivalenol-contaminated corn in low-complexity diets supplemented with either an immune-modulating feed additive, or fish oil on nursery pig growth performance, immune response, small intestinal morphology, and component digestibility

Three hundred twenty newly weaned pigs (21 days of age; 6.7 ± 0.3 kg BW) were used to determine the effects of supplementing low-complexity (LC) deoxynivalenol- (DON) contaminated nursery diets with a feed additive or fish oil on growth performance and immune response to an Escherichia coli lipopolysaccharide (LPS) challenge. Pens were randomly assigned to 1 of 5 dietary treatments (n = 8 pens per treatment): positive control (PC; contained multiple animal protein sources), or 1 of 4 LC diets (contained only plant-based protein sources) without (NC; negative control) or with ~ 3.5 ppm DON contamination, without (DON-) or with a feed additive containing a blend of immune-modulating components (DON+; 2 mg/kg, as-fed) or fish oil (DONω3; 2.5%, as-fed). Dietary treatments were fed during phases I and II (7 and 15 days, respectively) and a common phase III diet was fed for 20 days. On day 22, two pigs per pen were injected IM with 30 μg/kg BW LPS and 1 pig per pen with 1 mL saline. Rectal temperatures were recorded at 0, 1, 2, 3 h after injection. At 3 h, blood was collected for plasma cytokine analysis and small intestinal histomorphology was assessed. In phase I, pigs fed PC and NC did not differ for ADG, ADFI and G:F, but these outcomes were greater than for pigs fed DON+ and DONω (P < 0.05). In phase II, pigs fed NC had greater ADG and PC had greater ADFI but lower G:F than pigs fed DON- and DONω3 (P < 0.05). At the end of phase II, pigs fed DONω3 tended to have lower BW than PC and NC (P = 0.084 and 0.079, respectively). In phase III and overall, there were no differences among dietary treatments for ADG, ADFI, G:F, or final BW. The LPS injection increased rectal temperature and reduced jejunal and ileal villus height (versus saline; P < 0.05). Plasma interferon-γ concentration was only increased by LPS for pigs fed PC, NC, and DON+ compared to the saline-injected counterparts (P < 0.05). Regardless of LPS injection, jejunal villus height was greater for pigs fed DON+ than DONω3 (P < 0.05) and ileal villus height was greater for pigs fed DON+ and PC than DONω3 (P < 0.05). Therefore, nursery diet complexity did not affect growth performance or immune response to LPS. Regardless of DON contamination and feed additive inclusion in phases I and II, pigs were able to achieve nursery exit BW not different from those fed PC. The feed additive offered marginal benefits for small intestinal villus height and immune response for pigs fed DON-contaminated LC nursery diets.

Zearalenone promotes follicle development through activating the SIRT1/PGC-1α signaling pathway in the ovaries of weaned gilts

This study aimed to investigate the effect of zearalenone (ZEA) exposure on follicular development in weaned gilts, and its mechanism based on the silent information regulator 1 (SIRT1)/peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α) signaling pathway. A total of 32 healthy female weaned piglets (Landrace × Yorkshire × Duroc) with an average body weight of 12.39 ± 0.24 kg were randomly allotted to a basal diet supplemented with 0, 0.15, 1.5, or 3.0 mg/kg ZEA for a 32-d feeding test. Blood and ovarian samples were obtained at the end of the experiment to determine serum toxin concentrations, ovarian histology, and the expressions of proliferating cell nuclear antigen (PCNA) and SIRT1/PGC-1α signaling pathway-related genes. Results showed that the vulva area, serum concentrations of ZEA, α-zearalenol and β-zearalenol, the thickness of the growing follicular layer, and the diameter of the largest growing follicles, as well as the expressions of SIRT1, PGC-1α, estrogen-related receptor α (ERRα), ATP synthase subunit beta (ATP5B), and PCNA, increased linearly (P < 0.05) with increasing dietary ZEA, whereas the thickness of the primordial follicle layer decreased linearly (P < 0.05). Immunohistochemical analysis showed that the immunoreactive substances of SIRT1 and PGC-1α in the ovaries enhanced with the increasing dietary ZEA (P < 0.05). In addition, the thickness of the growing follicular layer and the diameter of the largest growing follicle were positively correlated with relative mRNA and protein expressions of SIRT1, PGC-1α, ERRα, ATP5B, and PCNA (P < 0.05). However, the thickness of the primordial follicle layer was negatively correlated with the mRNA and protein expression of SIRT1, PGC-1α, ERRα, ATP5B, and PCNA (P < 0.05). Interestingly, the 1.5 mg/kg ZEA treatment had highly hyperplastic follicles, whereas 3.0 mg/kg ZEA resulted in a large number of follicular atresia, which indicated that low-dose ZEA exposure accelerated follicular proliferation, while high-dose ZEA promoted follicular atresia, although the critical value interval needs further confirmation. Results provide a theoretical basis for finding the therapeutic target of ZEA-induced reproductive disorders in weaned gilts.

Comparison of Ameliorative Effects between Probiotic and Biodegradable Bacillus subtilis on Zearalenone Toxicosis in Gilts

This study was conducted to compare the potential ameliorative effects between probiotic Bacillus subtilis and biodegradable Bacillus subtilis on zearalenone (ZEN) toxicosis in gilts. Thirty-six Landrace×Yorkshire gilts (average BW = 64 kg) were randomly divided into four groups: (1) Normal control diet group (NC) fed the basal diet containing few ZEN (17.5 μg/kg); (2) ZEN contaminated group (ZC) fed the contaminated diet containing an exceeded limit dose of ZEN (about 300 μg/kg); (3) Probiotic agent group (PB) fed the ZC diet with added 5 × 10⁹ CFU/kg of probiotic Bacillus subtilis ANSB010; (4) Biodegradable agent group (DA) fed the ZC diet with added 5 × 10⁹ CFU/kg of biodegradable Bacillus subtilis ANSB01G. Results showed that Bacillus subtilis ANSB010 and ANSB01G isolated from broiler intestinal chyme had similar inhibitory activities against common pathogenic bacteria. In addition, the feed conversion ratio and the vulva size in DA group were significantly lower than ZC group (p < 0.05). The levels of IgG, IgM, IL-2 and TNFα in the ZC group were significantly higher than PB and DA groups (p < 0.05). The levels of estradiol and prolactin in the ZC group was significantly higher than those of the NC and DA groups (p < 0.05). Additionally, the residual ZEN in the feces of the ZC and PB groups were higher than those of the NC and DA groups (p < 0.05). In summary, the ZEN-contaminated diet had a damaging impact on growth performance, plasma immune function and hormone secretion of gilts. Although probiotic and biodegradable Bacillus subtilis have similar antimicrobial capacities, only biodegradable Bacillus subtilis could eliminate these negative effects through its biodegradable property to ZEN.

Deoxynivalenol: Mechanisms of action and its effects on various terrestrial and aquatic species

Deoxynivalenol, a type B trichothecene mycotoxin produced by Fusarium species of fungi, is a ubiquitious contaminant of cereal grains worldwide. Chronic, low dose consumption of feeds contaminated with DON is associated with a wide range of symptoms in terrestrial and aquatic species including decreased feed intake and feed refusal, reduced weight gain, and altered nutritional efficiency. Acute, high dose exposure to DON may be associated with more severe symptoms such as vomiting, diarrhea, intestinal inflammation and gastrointestinal hemorrhage. The toxicity of DON is partly related to its ability to disrupt eukaryotic protein synthesis via binding to the peptidyl transferase site of the ribosome. Moreover, DON exerts its effects at the cellular level by activating mitogen activated protein kinases (MAPK) through a process known as the ribotoxic stress response (RSR). The outcome of DON-associated MAPK activation is dose and duration dependent; acute low dose exposure results in immunostimulation characterized by the upregulation of cytokines, chemokines and other proinflammatory-related proteins, whereas longer term exposure to higher doses generally results in apoptosis, cell cycle arrest, and immunosuppression. The order of decreasing sensitivity to DON is considered to be: swine > rats > mice > poultry ≈ ruminants. However, studies conducted within the past 10 years have demonstrated that some species of fish, such as rainbow trout, are highly sensitive to DON. The aims of this review are to explore the effects of DON on terrestrial and aquatic species as well as its mechanisms of action, metabolism, and interaction with other Fusarium mycotoxins. Notably, a considerable emphasis is placed on reviewing the effects of DON on different species of fish.

The effect of deoxynivalenol-contaminated corn and an immune-modulating feed additive on growth performance and immune response of nursery pigs fed corn- and soybean meal-based diets

One hundred eighty newly weaned pigs (21 days of age; 6.9 ± 0.2 kg BW) were used to determine the effects of deoxynivalenol- (DON) contaminated corn and an immune-modulating feed additive on growth performance and immune response of nursery pigs fed corn- and soybean meal-based diets. Pens were randomly assigned to one of five diets: a high-complexity (HC; containing animal protein sources) or one of four low-complexity diets (LC; containing soybean meal as the main protein source) arranged in a 2 × 2 factorial with low (lDON; average 1.4 ppm) or high (hDON; average 3.5 ppm) DON and with or without a feed additive (2 g/kg in complete feed; n = 6 pens per treatment) provided in a three-phase feeding program. On day 7, small intestinal histomorphology was assessed in two pigs per pen. On days 8 and 25, two pigs per pen were immunized with ovalbumin (OVA). Blood was collected on days 8, 25, and 38 for determination of OVA-specific IgG. There were no corn type by feed additive interactions or feed additive effects for growth performance. The ADG, ADFI, and G:F in phase I were not different for pigs fed hDON vs. lDON, but were less than those fed the HC diet (contrasts; P < 0.05). Over the entire nursery period, ADG and ADFI were less for pigs fed hDON vs. those fed lDON (407 vs. 484 g and 651 vs. 769 g, respectively; P < 0.05), ADG was less for pigs fed hDON vs. HC (496 g; P < 0.05), and pigs fed lDON had ADG and ADFI not different from those fed the HC diet. Pigs fed hDON had lower final BW than those fed lDON (24.6 vs. 27.6 kg; P < 0.01) and tended to have lower final BW than pigs fed the HC diet (27.3 kg; contrast; P = 0.052); final BW was not different between pigs fed lDON and HC diets. Jejunal villus heights were shorter for pigs fed hDON and lDON compared to pigs fed HC (438 and 466 vs. 538 µm; contrasts; P < 0.05 and P = 0.090, respectively) and the villus:crypt ratio tended to be less for pigs fed hDON vs. those fed HC (1.87 vs. 2.22; contrast; P = 0.091). On day 38, plasma OVA-specific IgG 1 tended to be less for pigs fed hDON compared to HC (contrast; P = 0.075) and OVA-specific total IgG were less for pigs fed LC diets without the feed additive vs. HC (P < 0.05). Therefore, high DON (~3.5 ppm) in LC nursery diets interfered with compensatory growth and the humoral immune response. The feed additive did not rescue growth performance, regardless of DON contamination level in LC nursery diets.

Deoxynivalenol interferes with intestinal motility via injuring the contractility of enteric smooth muscle cells: A novel hazard to the gastrointestinal tract by environmental toxins

Deoxynivalenol (DON) is a prevalent Fusarium mycotoxin, occurs predominantly in the global environment, especially in cereals, animal feed and food commodities. The widespread contamination causes a serious risk to human and animal health. DON usually impairs weight gain, which is presumably from its capacity to reduce feed intake by interfering with intestinal motility. To clarify the role of smooth muscle cells (SMCs) contractility in intestinal motility and growth inhibition caused by DON, twelve weaned piglets were firstly divided into two groups to feed control or Fusarium mycotoxin-contaminated (MC) diet. Results showed that the final body weight, average daily gain and average daily feed intake were significantly reduced in piglets fed the MC diet. Exposure to the MC diet also significantly decreased the thickness of smooth muscle layer and SMCs contractile markers expression (myosin heavy chain 11, smooth muscle actin gamma 2, transgelin, calponin 1) in jejunum and ileum of piglets. Furthermore, oral DON supplementation (3 mg/kg body weight) to mice in six consecutive days could significantly inhibit the upper intestinal transit, impede normal defecation and downregulate SMCs contractile markers expression in small intestine. Finally, we generated a porcine enteric smooth muscle cell line (PISMC), and found that DON could depress its contractility by decreasing PISMC proliferation, migration and contractile markers expression. In conclusion, these findings in vivo and in vitro suggest that DON, as a common environmental toxin, can not only reduce proliferative and motile phenotype, but also decrease contractile apparatus components (contractile markers expression) in SMCs, which in turn influences SMCs contractility and then interferes with intestinal motility and growth performance.

Effect of fosfomycin, Cynara scolymus extract, deoxynivalenol and their combinations on intestinal health of weaned piglets

Weaning is a challenging stage of pig farming. Animals undergo environmental, social and dietary changes leading to weaning stress syndrome. In order to compensate for the detrimental effects of weaning stress, antibiotics and natural extracts are used as feed additives, sometimes without fully understanding the interactions between them or even with low concentrations of mycotoxins that are frequently present in feed. The aim of this study was to evaluate the effect of fosfomycin (FOS), Cynara scolymus extract (CSE), deoxynivalenol (DON) and their combined administration on intestinal health of weaned piglets. The experiment was designed as a 2 × 2 × 2 factorial arrangement with 3 factors (FOS, CSE and DON treatments), 2 levels each (presence and absence) and 3 repeats. Weaned piglets (n = 24) were randomly divided in groups to receive the different treatments, namely DON administered in diet (50 μg/kg BW), FOS administered into the drinking water (30 mg/kg BW), CSE administered in diet (15 mg/kg BW) and all their combinations. After 15 d, the animals were euthanized and gastrointestinal tract samples were immediately taken to evaluate gastrointestinal pH, Enterobacteriaceae to lactic acid bacteria (E:L) ratio, volatile fatty acid (VFA) concentrations, disaccharidase (lactase, sucrase and maltase) activity, histology (intestinal absorptive area [IAA] and goblet cells count) and mucus ability to adhere pathogenic Escherichia coli. From our results, FOS and CSE treatments, individually or combined, produced a lower E:L ratio, an enhanced production of butyrate, increased disaccharidase activity (particularly maltase), and a greater IAA and goblet cells count along with an increase in pathogenic bacteria adherence to intestinal mucus. Deoxynivalenol did not show interactions with the other factors and its administration produced decreases on VFA, disaccharidase activity and goblet cells count. In conclusion, weaning piglets receiving diets containing FOS, CSE or both exhibited evident beneficial intestinal effects compared to animals receiving diets free from these compounds. On the contrary, the presence of DON at sub-toxic concentrations produced detrimental effects on intestinal health. The knowledge of the physiological and pathological gut changes produced by these compounds contributes to understand their potential productive consequences.

The impact of chlorophyllin on deoxynivalenol transport across jejunum mucosa explants obtained from adult pigs

Regardless of the efforts put into preventing or reducing fungal growth, extensive mycotoxin contamination has been reported in animal feeds. In the case of pigs, one of the mycotoxins of major concern is deoxynivalenol (DON). The use of adsorbents as feed additives represents one of the strategies to control mycotoxins' contamination in feedstuff. Therefore, the aim of the study was to verify the ability of chlorophyllin (CHL) to reduce the absorption rate of DON in swine mucosa explants. Intestine was obtained from routinely slaughtered adult pigs. The mucosa explants were studied by means of Ussing chamber technique. The effect of DON (10 and 30 μg/ml) on mucosa viability and permeability and CHL (100 μg/ml) impact on DON (30 μg/ml) absorption was verified. The results revealed that mucosa explants isolated from adult animals remained unaffected for 90 min in the presence of DON in the lower concentration (10 μg/ml). Mycotoxin in the higher dose (30 μg/ml) increased mucosa permeability (decreased transepithelial electrical resistance value) and enhanced paracellular transport of lucifer yellow and mannitol but did not affect lactate dehydrogenase leakage. The introduction of CHL neither diminished the absorption rate of DON across swine mucosa explants nor prevented the toxic effects of DON on intestine. In conclusion, the results confirm the negative effect of DON on pig jejunum mucosa. However, the toxic effect of DON was observed only when it was used in relatively high doses. A promising adsorbent agent, CHL, failed to reduce the intensity of DON transport across intestine under in vitro conditions.

Hydrogen-Rich Water and Lactulose Protect Against Growth Suppression and Oxidative Stress in Female Piglets Fed Fusarium Toxins Contaminated Diets

The objective of the current experiment was to evaluate whether hydrogen-rich water (HRW) or lactulose (LAC) could protect against the adverse effects of Fusarium mycotoxins-contaminated diet on the growth performance and antioxidant status in weaning piglets. A total of 24 individually housed female piglets were randomly assigned to receive four treatments for 25 days (six pigs/treatment): uncontaminated basal diet (negative control), mycotoxin-contaminated (MC) diet, MC diet + HRW (MC + HRW) and MC diet + LAC (MC + LAC). The plasma hydrogen levels before and after 2 h hydrogen-free water/HRW administration were detected at day 21, and the liver hydrogen levels were detected at the end of the experiment. Serum hormones related to appetite regulation, and serum and liver oxidant and antioxidant status were also measured at the end of the experiment. Results showed that both HRW and LAC treatments significantly attenuated the reduction of average daily gain (ADG) and average daily feed intake (ADFI) caused by Fusarium mycotoxins. LAC administration increased the hydrogen concentrations in plasma and liver. HRW treated group had higher plasma hydrogen levels than the MC group. Compared with the NC group, the MC group had significantly increased serum peptide YY (PYY) and cholecystokinin (CCK) levels. Interestingly, both HRW and LAC administrations had a lower reduced serum PYY and CKK levels. Most importantly, oral administration of HRW and LAC attenuated the Fusarium mycotoxins-induced oxidative stress. In conclusion, oral administration of hydrogen-rich water or lactulose could both protect against the growth reduction and oxidative damage caused by Fusarium mycotoxins.

Effects and biotransformation of the mycotoxin deoxynivalenol in growing pigs fed with naturally contaminated pelleted grains with and without the addition of Coriobacteriaceum DSM 11798

Deoxynivalenol (DON) is one of the most prevalent Fusarium mycotoxins in grain and can cause economic losses in pig farming due to reduced feed consumption and lower weight gains. Biodetoxification of mycotoxins using bacterial strains has been a focus of research for many years. However, only a few in vivo studies have been conducted on the effectiveness of microbial detoxification of fusariotoxins. This study was therefore aimed at investigating the effect of a feed additive containing the bacterial strain Coriobacteriaceum DSM 11798 (the active ingredient in Biomin® BBSH 797) on growth performance and blood parameters, as well as uptake and metabolism of DON, in growing pigs. Forty-eight crossbred (Landrace-Yorkshire/Duroc-Duroc) weaning pigs were fed with pelleted feed made from naturally contaminated oats, with DON at four concentration levels: (1) control diet (DON < 0.2 mg kg^-1), (2) low-contaminated diet (DON = 0.92 mg kg^-1), (3) medium-contaminated diet (DON = 2.2 mg kg^-1) and (4) high-contaminated diet (DON = 5.0 mg kg^-1) and equivalent diets containing DSM 11798 as feed additive. During the first 7 days of exposure, pigs in the highest-dose group showed a 20-28% reduction in feed intake and a 24-34% reduction in weight gain compared with pigs in the control and low-dose groups. These differences were levelled out by study completion. Towards the end of the experiment, dose-dependent reductions in serum albumin, globulin and total serum protein were noted in the groups fed with DON-contaminated feed compared with the controls. The addition of DSM 11798 had no effect on the DON-related clinical effects or on the plasma concentrations of DON. The ineffectiveness of the feed additive in the present study could be a consequence of its use in pelleted feed, which might have hindered its rapid release, accessibility or detoxification efficiency in the pig's gastrointestinal tract.

Effects of purified zearalenone on selected immunological and histopathologic measurements of spleen in post-weanling gilts

The present study was aimed at investigating the adverse effects of dietary zearalenone (ZEA) on the lymphocyte proliferation rate (LPR), interleukin-2 (IL-2), mRNA expressions of pro-inflammatory cytokines, and histopathologic changes of spleen in post-weanling gilts. A total of 20 crossbred piglets (Yorkshire × Landrace × Duroc) with an initial BW of 10.36 ± 1.21 kg (21 d of age) were used in the study. Piglets were fed a basal diet with an addition of 0, 1.1, 2.0, or 3.2 mg/kg purified ZEA for 18 d ad libitum. The results showed that LPR and IL-2 production of spleen decreased linearly (P < 0.05) as dietary ZEA increased. Splenic mRNA expressions of interleukin-1β (IL-1β) and interleukin-6 (IL-6) were linearly up-regulated (P < 0.05) as dietary ZEA increased. On the contrary, linear down-regulation (P < 0.05) of mRNA expression of interferon-γ (IFN-γ) was observed as dietary ZEA increased. Swelling splenocyte in 1.1 mg/kg ZEA treatments, atrophy of white pulp and swelling of red pulp in 2.0 and 3.2 mg/kg ZEA treatments were observed. The cytoplasmic edema in 1.1 mg/kg ZEA treatments, significant chromatin deformation in 2.0 mg/kg ZEA treatment and phagocytosis in 3.2 mg/kg ZEA treatment were observed. Results suggested that dietary ZEA at 1.1 to 3.2 mg/kg can induce splenic damages and negatively affect immune function of spleen in post-weanling gilts.

Effects of purified zearalenone on selected immunological measurements of blood in post-weaning gilts

Zearalenone (ZEA), an estrogenic mycotoxin, is produced mainly by Fusarium fungi. Previous studies have indicated that acute ZEA exposure induced various damages in different species; however, its transparent hematotoxicity in female piglets at dietary levels of 1.1 to 3.2 mg/kg has not been shown. The present study was conducted to investigate the effects of dietary ZEA (1.1–3.2 mg/kg) on hematology, T lymphocyte subset, immunoglobulin, antibody titer, lymphocyte proliferation rate (LPR), and interleukin-2 (IL-2) in peripheral blood of post-weaning gilts. A total of 20 female piglets (Landrace × Yorkshire × Duroc), weaned at 42 d with an average body weight of 10.36 ± 1.21 kg were used in the study. Female piglets were kept in a temperature controlled room, divided into four treatments, and fed a diet based on corn-soybean meal-fishmeal-whey, with an addition of 0, 1.1, 2.0, or 3.2 mg/kg purified ZEA for 18 d ad libitum. Feed intake and refusal were measured daily and individual pigs were weighed weekly. Blood and serum samples were collected for selected immunological measurements. Female piglets fed different levels of dietary ZEA grew similarly with no difference in feed intake. Hematological values including leukocytes, platelets, lymphocytes, hematocrit, and mean corpuscular hemoglobin (MCH) decreased linearly (P < 0.05) as dietary ZEA increased. Female piglets fed diets containing 2.0 mg/kg ZEA or greater showed significantly decreased CD4⁺CD8⁺, CD4⁺, and CD4⁺/CD8⁺ in comparison to the control (P < 0.05), whereas CD8⁺ was significantly increased (P = 0.026) in the gilts which were fed the diet containing 3.2 mg/kg ZEA. Serum immunoglobulin G (IgG) and the antibody titer on d 18 were reduced linearly as dietary ZEA levels increased (P < 0.001). Linear decrease in LPR was observed (P < 0.05). Female piglets fed diets containing 2.0 mg/kg ZEA or more showed significantly decreased IL-2 in comparison to the control (P < 0.05). The results suggested that dietary ZEA at the levels of 1.1 to 3.2 mg/kg can induce different degrees of hematotoxicity and negatively affect immune function in female piglets.

Protective effect of two yeast based feed additives on pigs chronically exposed to deoxynivalenol and zearalenone

To evaluate the effects of the mycotoxins deoxynivalenol (DON) and zearalenone (ZEA) on pigs and the benefits of two mycotoxin mitigation strategies, gilts (n = 84, 9.1 ± 0.1 kg) were allotted to four treatments: CON (control); MT (4.8 mg/kg feed DON and 0.3 mg/kg feed ZEA); MT-YC (MT + 2 g/kg of yeast cell wall product); and MT-YF (MT + 2 g/kg of yeast fermentation product). After 42 days of feeding, pigs fed MT had reduced (p < 0.05) growth performance compared with pigs fed CON. Pigs fed MT-YF had greater (p < 0.05) average daily gain and tended to have greater (p = 0.080) average daily feed intake than MT, whereas pigs fed MT-YC did not differ from MT. Oxidative DNA damage increased (p < 0.05) in MT, whereas pigs fed MT-YF tended to have lower (p = 0.067) oxidative stress. Liver hydropic degeneration was increased (p < 0.05) in MT in contrast to CON and MT-YF, and tended to be greater (p = 0.079) than MT-YC. Collectively, feeding diets contaminated with mycotoxins significantly reduced growth performance and impacted pig health. The yeast additives had varied ability to reduce mycotoxin effects on pig growth and health, but may still play a beneficial role in reducing the overall impacts of a mycotoxin challenge on pigs.

Ameliorative effects of Bacillus subtilis ANSB01G on zearalenone toxicosis in pre-pubertal female gilts

The purpose of this research was to investigate the toxicity of zearalenone (ZEA) on the growing performance, genital organs, serum hormones and histopathological changes of pre-pubertal female gilts, and to evaluate the efficacy of Bacillus subtilis ANSB01G in alleviating ZEA toxicosis in gilts. Eighteen pre-pubertal female gilts were randomly allocated to three treatments with one replicate per treatment. The gilts were fed following three diets for 24 days: the Control group was given a basic diet with normal corn; Treatment 1 (T1) was prepared by substituting corn naturally contaminated with ZEA for all normal corn in the basic diet (with a final concentrations of 238.57 μg kg(-1) of ZEA); and Treatment 2 (T2) was prepared by mixing the T1 diet with 2 kg T(-1) of fermented-dried culture of ANSB01G. The results showed that the presence of ZEA in diets significantly increased the vulva size and reproductive organ weight of the T1 gilts as compared with the Control group, and the addition of ANSB01G to diet naturally contaminated with ZEA obviously ameliorated these symptoms, as was observed in the T2 group. The presence of low doses of ZEA in the T1 diet had no significant effect on the level of follicle-stimulating hormone (FSH), luteotrophic hormone (LH) or serum oestradiol (E2) in the serum of gilts, but the prolactin (PRL) level in group T1 increased significantly. The gilts of the T1 group exhibited conspicuous cell enlargement and fatty degeneration of the corpus uteri, swelling, inflammation and lymphocyte infiltration of liver cells as compared with the Control group. The presence of ANSB01G can alleviate these hyperoestrogenic effects caused by ZEA, maintaining the body of gilt in a normal and healthy status. It is suggested that reproductive organs of gilts are seriously affected even if they are fed a low dose of ZEA in less time, and the addition of B. subtilis ANSB01G can effectively alleviate ZEA toxicosis in gilts.

Effects of feed contaminant deoxynivalenol on plasma cytokines and mRNA expression of immune genes in the intestine of broiler chickens

An experiment was conducted to investigate the individual and combined effects of dietary deoxynivalenol (DON) and a microbial feed additive on plasma cytokine level and on the expression of immune relevant genes in jejunal tissues of broilers. A total of 40 broiler chicks were obtained from a commercial hatchery and divided randomly into four groups (10 birds per group). Birds were reared in battery cages from one day old for 5 weeks. The dietary groups were 1) control birds fed basal diet; 2) DON group fed basal diet contaminated with 10 mg DON/ kg feed; 3) DON + Mycofix group fed basal diet contaminated with 10 mg DON/ kg feed and supplemented with a commercial feed additive, Mycofix® Select (MS) (2.5 kg/ton of feed); 4) Mycofix group fed basal diet supplemented with MS (2.5 kg/ton of feed). At 35 days, the plasma levels of tumor necrosis factor alpha (TNF-α) and interleukin 8 (IL-8) were quantified by ELISA test kits. Furthermore, the mRNA expression of TNF-α, IL-8, IL-1β, interferon gamma (IFNγ), transforming growth factor beta receptor I (TGFBR1) and nuclear factor kappa-light-chain-enhancer of activated B cells 1 (NF-κβ1) in jejunum were quantified by qRT-PCR. The results showed that the plasma TNF-α decreased in response to DON, while in combination with MS, the effect of DON was reduced. DON down-regulated the relative gene expression of IL-1β, TGFBR1 and IFN-γ, and addition of MS to the DON contaminated diet compensates these effects on IL-1β, TGFBR1 but not for IFN-γ. Furthermore, supplementation of MS to either DON contaminated or control diet up-regulated the mRNA expression of NF-κβ1. In conclusion, DON has the potential to provoke and modulate immunological reactions of broilers and subsequently could increase their susceptibility to disease. The additive seemed to have almost as much of an effect as DON, albeit on different genes.

Effects of dietary arginine and glutamine on alleviating the impairment induced by deoxynivalenol stress and immune relevant cytokines in growing pigs

Deoxynivalenol (DON) is a mycotoxin that reduces feed intake and animal performance, especially in swine. Arginine and glutamine play important roles in swine nutrition. The objective of this study was to determine the effects of dietary supplementation with arginine and glutamine on both the impairment induced by DON stress and immune relevant cytokines in growing pigs. A total of forty 60-d-old healthy growing pigs with a mean body weight of 16.28±1.54 kg were randomly divided into 5 groups, and assigned to 3 amino acid treatments fed 1.0% arginine (Arg), 1.0% glutamine (Gln) and 0.5% Arg+0.5% Gln, respectively, plus a toxin control and a non-toxin control. Pigs in the 3 amino acid treatments were fed the corresponding amino acids, and those in non-toxin control and toxin control were fed commercial diet with 1.64% Alanine as isonitrogenous control for 7 days. The toxin control and amino acid treatments were then challenged by feeding DON-contaminated diet with a final DON concentration of 6 mg/kg of diet for 21 days. No significant differences were observed between toxin control and the amino acid groups with regard to the average daily gain (ADG), although the values for average daily feed intake (ADFI) in the amino acid groups were significantly higher than that in toxin control (P<0.01). The relative liver weight in toxin control was significantly greater than those in non-toxin control, arginine and Arg+Glu groups (P<0.01), but there were no significant differences in other organs. With regard to serum biochemistry, the values of BUN, ALP, ALT and AST in the amino acid groups were lower than those in toxin control. IGF1, GH and SOD in the amino acid groups were significantly higher than those in toxin control (P<0.01). The IL-2 and TNFα values in the amino acid groups were similar to those in non-toxin control, and significantly lower than those in toxin control (P<0.01). These results showed the effects of dietary supplementation with arginine and glutamine on alleviating the impairment induced by DON stress and immune relevant cytokines in growing pigs.

The use of feed additives to reduce the effects of aflatoxin and deoxynivalenol on pig growth, organ health and immune status during chronic exposure

Three feed additives were tested to improve the growth and health of pigs chronically challenged with aflatoxin (AF) and deoxynivalenol (DON). Gilts (n = 225, 8.8 ± 0.4 kg) were allotted to five treatments: CON (uncontaminated control); MT (contaminated with 150 µg/kg AF and 1100 µg/kg DON); A (MT + a clay additive); B (MT + a clay and dried yeast additive); and C (MT + a clay and yeast culture additive). Average daily gain (ADG) and feed intake (ADFI) were recorded for 42 days, blood collected for immune analysis and tissue samples to measure damage. Feeding mycotoxins tended to decrease ADG and altered the immune system through a tendency to increase monocytes and immunoglobulins. Mycotoxins caused tissue damage in the form of liver bile ductule hyperplasia and karyomegaly. The additives in diets A and B reduced mycotoxin effects on the immune system and the liver and showed some ability to improve growth. The diet C additive played a role in reducing liver damage. Collectively, we conclude that AF and DON can be harmful to the growth and health of pigs consuming mycotoxins chronically. The selected feed additives improved pig health and may play a role in pig growth.

Biotransformation approaches to alleviate the effects induced by fusarium mycotoxins in swine

Mycotoxin mitigation is of major interest as ingestion of mycotoxins results in poor animal health, decreased productivity, as well as substantial economic losses. A feed additive (FA) consisting of a combination of bacteria (Eubacterium BBSH797) and enzyme (fumonisin esterase FumD) was tested in pigs for its ability to neutralize the effects of mono- and co-contaminated diets with deoxynivalenol (DON) and fumonisins (FB) on hematology, biochemistry, tissue morphology, and immune response. Forty-eight animals, allocated into eight groups, received one of eight diets for 35 days: a control diet, a diet contaminated with either DON (3 mg/kg) or FB (6 mg/kg), or both toxins, and the same four diets with FA. Inclusion of FA restored the circulating number of neutrophils of piglets fed the FB and DON + FB diets. Similarly, FA counteracted the minor changes observed on plasma concentrations of albumin and creatinine. In lung, the lesions induced by the ingestion of FB in mono- and co-contaminated diets were no longer observed after addition of FA in these diets. Lesions recorded in the liver of pigs fed either of the contaminated diets with FA were partly reduced, and the increased hepatocyte proliferation was totally neutralized when FA was present in the co-contaminated diet. After 35 days of exposure, the development of the vaccinal response was significantly improved in animals fed diets supplemented with FA, as shown by results of lymphocyte proliferation, cytokine expression in spleen, and the production of specific Ig. Similarly, in jejunum of animals fed diets with FA, occurrence of lesions and upregulation of pro-inflammatory cytokines were much less obvious. The ameliorative effects provided by FA suggest that this approach would be suitable in the control of DON and FB that commonly co-occur in feed.

Intestinal transport of deoxynivalenol across porcine small intestines

Deoxynivalenol (DON) is one of the most important trichothecenes, due to its worldwide distribution and common contamination of animal feed. It mainly affects the gastrointestinal tract and the immune system with a high susceptibility for swine. Lipopolysaccharides (LPS) are endotoxins and are part of the outer membrane of most gram-negative bacteria. They induce inflammatory responses under systemic application. We hypothesised that dietary DON as well as LPS challenge could affect the transport of DON in vitro. For assessment of this hypothesis, a total of 16 pigs were divided into two groups, Control and DON-feeding. In each group, four animals were injected intraperitoneally with LPS (5 µg/kg BW). Jejunal preparations were mounted on the Ussing chambers, and after luminal addition of DON at two different concentrations (4000 and 8000 ng/ml), buffer samples were collected at different time points to measure the concentration of DON using LC-MS/MS analysis. Our findings revealed a significant interaction effect between dietary DON and DON in vitro represented by higher mucosal uptake of DON in DON-fed animals. Animals challenged with LPS showed higher mucosal uptake but without significant effect of LPS. We concluded that the transport of DON was proportional to its concentration and DON in feed could have an effect on the transport of DON across porcine jejunal mucosa. LPS challenge induced no apparent significant effect on DON transport, although induction of acute phase reaction was present.

Effect of mycotoxin deactivator product supplementation on dairy cows

A total mixed ration (TMR) containing a blend of feedstuffs naturally contaminated with harmful mycotoxins was fed for 84 days to 24 primiparous and multiparous Holstein–Friesian × local dairy cows in a randomised complete block design. The dietary treatments consisted of a contaminated TMR diet plus various levels of the mycotoxin deactivator product (MDP) (0, 15, 30 or 45 g/head.day). Deoxynivalenol (DON), fumonisin B1 (FB1), zearalenone (ZON) and ochratoxin A (OTA) were found in the TMR at levels up to 720, 701, 541 and 501 μg/kg, whereas aflatoxin B1 (AfB1) and T-2 toxin (T-2) were found in the TMR at levels of 38 and 270 μg/kg, respectively. Rumen microbial ecology, ruminal volatile fatty acid (VFA) concentrations, ruminal microorganism populations, feed intake, total tract digestibility, milk yield, milk composition and serum immunoglobulin (Ig) concentrations were measured. The results revealed that the ruminal pH, ruminal ammonia nitrogen (NH3-N) concentration, total ruminal VFA concentrations and ruminal bacterial counts were significantly (P < 0.05) higher in supplemented than in non-supplemented cows. Ruminal protozoal counts were significantly (P < 0.05) lower in supplemented than in non-supplemented cows. DM intake, and digestibility of crude protein (CP) and neutral detergent fibre (NDF) were significantly (P < 0.05) higher in supplemented than in non-supplemented cows. Serum IgA concentrations were significantly (P < 0.05) higher in supplemented than in non-supplemented cows. Milk yield and milk protein were significantly (P < 0.05) higher in supplemented than in non-supplemented cows. On the basis of this experiment, it can be concluded that milk production and feed intake can be increased with the addition of MDP to cow diet in the presence of mycotoxins. These increases were accompanied by decreases in the negative effects of mycotoxins on rumen and immune function.

Effects of zearalenone in prepubertal gilts

Prepubertal gilts were fed with a diet containing zearalenone (ZEA) in a concentration of 0.75 mg/kg for 21 days. The effects of this mycotoxin on morphologic aspects of the reproductive tract as well as on complete blood count (CBC), serum biochemistry analysis (SBA) and humoral immune response against sheep red blood cells (SRBC) were evaluated. There was a significant increase (P<0.05) on the reproductive tract weight, vulvar area, height of the epithelial cells of endometrial glands and uterine mucosa. These results showed the ability of this nonsteroidal mycotoxin in mimicking actions of 17β estradiol at the concentration of 0.75mg/kg. No changes in weight gain, CBC, SBA parameters and humoral response against SRBC were observed.

Effects of zearalenone and its derivatives on porcine immune response

Zearalenone (ZEN), a mycotoxin produced by several Fusarium spp., is most commonly found as a contaminant in stored grain and has chronic estrogenic effects on mammals. In this in vitro study, we compared the effects of zearalenone (ZEN) and some of its derivatives: α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), and zearalanone (ZAN) on several peripheral blood mononuclear cell (PBMC) parameters: cytotoxicity, proliferation, as well as antibody and cytokine synthesis. The amounts of toxins necessary to inhibit viability, in a dehydrogenase enzyme activity assay (MTT test), by 50% were: 22.7 μM for ZEN, 29.1 μM for α-ZOL, 17.3 μM for β-ZOL and 26.3 μM for ZAN. The administration of 10 μM toxin induced a decrease in the ConA stimulated proliferation of PBMC by 19.6% for ZAN, 45.4% for ZEN, 43.6% for α-ZOL and 85.2% for β-ZOL, when compared to the control stimulated cells. Also, ZEN and its metabolites at concentrations higher than 5 μM induced a significant decrease of the IgG, IgA or IgM levels. Concentrations of 5 and 10 μM of ZEN and ZAN significantly decreased the TNF-α synthesis in the supernatant of the stimulated cells; 10 μM of ZAN also decreased IL-8 synthesis. In conclusion, our results show that ZEN and ZEN derivatives altered several parameters of the humoral and cellular immune response. Therefore, our results are clinically relevant as ZEN and its metabolites are frequent contaminants of animal feed and we have shown that intoxicated animals are incapable of inducing an adequate immune response.

Effects of purified zearalenone on growth performance, organ size, serum metabolites, and oxidative stress in postweaning gilts

Zearalenone (ZEA), an estrogenic mycotoxin, is produced mainly by Fusarium fungi. Previous studies indicated that acute ZEA exposure induced oxidative stress and damage in multiple organs. Therefore, the present study was designed to investigate the adverse effects of dietary ZEA (1.1 to 3.2 mg/kg of diet) on oxidative stress and organ damage in postweaning gilts. A total of 20 gilts (Landrace × Yorkshire × Duroc) weaned at d 21 with an average BW of 10.36 ± 1.21 kg was used in the study. Gilts were housed in a temperature-controlled room, divided into 4 treatments, and fed a basal diet only (control) or basal diet supplemented with purified ZEA at a dietary concentration of 1 (ZEA1), 2 (ZEA2), or 3 (ZEA3) mg/kg of diet for 18 d ad libitum. The actual ZEA contents (analyzed) were 0, 1.1 ± 0.02, 2.0 ± 0.01, and 3.2 ± 0.02 mg/kg for control, ZEA1, ZEA2, and ZEA3, respectively. Gilts fed different amounts of dietary ZEA grew similarly with no difference (P > 0.05) in feed intake. Vulva size increased linearly over the 18 d of feeding in gilts fed diets containing 1.1 mg of ZEA/kg or greater (P < 0.001). Relative weight of genital organs, liver, and kidney increased linearly (P < 0.05) in a ZEA-dose-dependent manner. Serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, γ-glutamate transferase, urea, and creatinine (P < 0.05), and malondialdehyde concentrations in both serum and liver (P < 0.001) were also increased linearly in a ZEA-dose-dependent manner. However, spleen relative weight (P = 0.002) and activities of total superoxide dismutase and glutathione peroxidase (in both serum and liver (P < 0.05) were decreased linearly as dietary ZEA increased. Results showed that besides genital organs, the liver, kidney, and spleen may also be target tissues in young gilts fed diets containing 1.1 to 3.2 mg of ZEA/kg for 18 d. Increased key liver enzymes in the serum suggest progressive liver damage caused by feeding ZEA, and an increase in oxidative stress in gilts is another potential impact of ZEA toxicity in pigs.

Performance of Coopworth ewe lambs exposed to low levels of ryegrass endophyte (Neotyphodium lolii) alkaloids and allowed access to a mycotoxin deactivator

During February–April, Coopworth ewe lambs grazing a pasture dominated by naturalised perennial ryegrass (PRG) exhibited slight signs of ill-thrift and heat stress. PRG represented 85% of the herbage; 90% of the PRG population was infected with Neotyphodium endophyte. Concentrations of ergovaline and lolitrem B in perennial ryegrass were each within the range 0.5–1.0 mg/kg DM during this period. Two groups of 30 lambs rotated weekly between two paddocks that offered 6 t DM/ha of mature, low-quality pasture. They received an allowance of crushed barley and peas (80 : 20) at 100 g/head per day. One group was treated with a mycotoxin deactivator, Mycofix® Plus, mixed into their mash during processing (5 g/100 g). No sign of ‘staggers’ was observed in the lambs at any time. Lambs with access to Mycofix Plus made great use of shade; their occupancy of shade increased steeply with ambient temperature over the range 18−38°C (P < 0.001). For the control group, occupancy of shade was low (P < 0.001) and independent of temperature (P < 0.001). Instead of using shade on hot days, the control lambs whose respiration rate was higher than treated ewes (P < 0.001) commonly stood by the wire fence, huddled in the open. Over the first 56 days of treatment, while pasture remained dry, weight change in control and treated lambs was –13 and +16 g/day, respectively (P < 0.010). The need for greater investigation of the effects of endophyte alkaloids on livestock is discussed.

Effects of chronic exposure of diets with reduced concentrations of aflatoxin and deoxynivalenol on growth and immune status of pigs

This study investigated the growth and immune responses of pigs fed diets containing reduced concentrations of aflatoxin (AF) and deoxynivalenol (DON) from naturally contaminated corn. Sixty gilts (13.9 ± 0.2 kg of BW) were randomly assigned to 4 treatments (5 replicate pens per treatment and 3 pigs per pen): A (a control diet without detectable AF and DON); B (a diet with 60 μg of AF/kg and 300 μg of DON/kg); C (a diet with 120 μg of AF/kg and 600 μg of DON/kg); and D (a diet with 180 μg of AF/kg and 900 μg of DON/kg). Pigs were allowed ad libitum access to feed and water for 33 d. Feed intake and BW were measured weekly and pigs were bled (8 mL) on d 33 to measure the numbers of blood cells, to conduct liver function tests, and to measure immunological variables including IgG, IgM, interferon γ, IL4, IL6, and tumor necrosis factor α. One pig representing the average BW of each pen was killed to obtain the liver, kidneys, and spleen for weight, tissue color measurement, and histological evaluation of tissue damage. When compared with A, pigs in C and D tended to have reduced ADG (0.52 vs. 0.43 and 0.41 kg/d, respectively; P = 0.058) and ADFI (1.04 vs. 0.92 and 0.88 kg/d, respectively; P = 0.061). White blood cell count of pigs in D (23.4 × 10(3) cells/μL) was greater (P < 0.05) than those in A, B, and C (18.4, 18.5, and 16.8 × 10(3) cells/μL, respectively. Serum tumor necrosis factor α concentration of pigs in D (335 pg/mL) differed (P < 0.05) from those in A and C (299 and 290 pg/mL, respectively). Pigs in B and D had greater (P < 0.05) fibrosis in liver tissues than those in A. Collectively, this study shows that diets containing both AF and DON greater than 60 and 300 μg/kg, respectively, may reduce growth and decrease feed intake, whereas diets containing 120 μg of AF/kg and 600 μg of DON/kg may result in altered immune health, systemic inflammation, and partial liver damage, causing further reduction in growth of pigs.

Decontamination and detoxification strategies for the Fusarium mycotoxin deoxynivalenol in animal feed and the effectiveness of microbial biodegradation

Trichothecenes are a group of mycotoxins mainly produced by fungi of the Fusarium genus. Deoxynivalenol (DON) is one of the most abundant and important trichothecenes in food and feed, and is a significant contaminants due to its frequent occurrence in toxicologically relevant concentrations worldwide. Since toxin production depends strongly on environmental conditions, such as temperature and humidity, Fusarium toxin contamination can not be avoided completely. Therefore, exposure to this toxin is a permanent health risk for both humans and farm animals. As cereal crops are commonly contaminated with DON and animal diets consist mainly of cereals, it can be assumed that animals are frequently exposed to DON-contaminated feeds. Many strategies can be undertaken to reduce the toxic effect of DON. In addition to the general necessity for minimizing all risk factors that might influence the contamination of cereals with DON, such as the so-called field toxins before harvest, several post-harvest strategies can be applied to counteract possible deleterious effects of this mycotoxin in farm animals. Another approach for decontamination in feedstuffs is the use of adsorbent materials. Adsorbent materials may bind mycotoxins in the gastrointestinal tract and reduce absorption and systemic toxicity. It has been shown that some adsorbents are suitable to alleviate the toxic effects of specific mycotoxins, but its efficacy against trichothecenes is practically zero. Therefore, alternative strategies to reduce animal and human health risk are needed. The use of microbial additives is a method which uses microorganisms having the capability to detoxify mycotoxins by metabolism or degradation prior to their resorption in the gastrointestinal tract. DON has been reported to be completely transformed to de-epoxy-DON by ruminal and intestinal microflora. Eubacterium BBSH 797 was capable of DON degradation and counteracted the toxic effects of DON in animals. This review focuses on the efficacy of microbial feed additives in ameliorating the toxic effects of DON. According to the results of experiments to date, it appears that microorganisms are the main living organisms suitable for this mycotoxin biodegradation. However, the use of this approach depends on its effectiveness from both a practical and economic perspective.

Impact of mycotoxins and of a mycotoxin deactivator on alpacas grazing perennial ryegrass infected with wild endophyte (Neotyphodium spp.)

Liveweight gain, animal health and the effectiveness of a mycotoxin deactivator were studied on an old pasture that contained 61% perennial ryegrass. Sixty-seven percent of the ryegrass population was infected with endophyte (Neotyphodium spp.). The pasture was fenced into two halves and two groups of 28 alpaca male weaners were rotated between the two plots. Nine to 10 Suris and 18–19 Huacayas were allocated to each group. One group was fed a concentrate supplement (100 g/head per day) and the other was fed the same supplement to which was added the toxin deactivator, Mycofix® Plus (5 g/100 g). Mean liveweight gain on the low-quality pasture over late summer and early autumn was not significantly (P > 0.05) different between the groups. For the control group it was 41 g/day but individual rates of gain ranged from 67 to 0 g/day, depending on the severity of signs of perennial ryegrass toxicosis (r = 0.82, P < 0.001). Liveweight gain was independent of neurotoxic signs in the Mycofix® Plus treated group. Ergovaline concentration in perennial ryegrass varied from 0.43 to a peak in early autumn (March) of 1.05 mg/kg. Mean urine lysergol alkaloid concentration peaked in mid-summer (January) at 109 ng/mg creatinine (control group) and was consistently lower in the Mycofix® Plus group, although the difference approached significance (P = 0.06) only in March. Lolitrem B concentration in perennial ryegrass varied from 0.78 to 1.57 mg/kg. Neurotoxic signs in alpacas were observed throughout the study and peaked in early autumn, coinciding with peak lolitrem B concentration; at this time, 84% of alpacas exhibited neurotoxic signs. Over the 145-day study, the Mycofix® Plus treated group exhibited a lower mean rating of perennial ryegrass toxicosis signs (P < 0.05). Variation in liveweight gain and signs of toxicosis were not associated with significant differences in liver enzyme activity.

A preliminary survey of zearalenone and other mycotoxins in Australian silage and pasture

The oestrogenic mycotoxin zearalenone can occur in pasture and fodder infected with various Fusarium spp., and at concentrations exceeding 1 mg/kg, it has been associated with a reduction in the fertility of grazing ruminants. Pasture and fodder samples collected in four small studies from cattle and sheep farms in south-eastern Australia were tested for zearalenone and other mycotoxins using high performance liquid chromatography. Zearalenone in winter pasture was detected (viz. >0.1 and up to 5.0 mg/kg DM) in 8 of 22 pastures; three exceeded the tolerance concentration, 1.0 mg/kg. Zearalenone was detected in 15 of 24 samples of silage that were submitted by farmers for nutritional assessment, but that were not suspected of toxicity; 12 were in the range 1.0–80 mg/kg. Zearalenone was correlated with crude protein concentration (r = 0.59, P < 0.05); it was high in legume-dominant compared with grass-dominant silage (P < 0.04). In a separate investigation of 28 feed samples submitted for mycotoxin screening by nutritionists/veterinarians, zearalenone was detected in 7 of 13 pastures, in two of two hays and 9 of 13 silages (6 of 28 exceeded 1 mg/kg). Deoxynivalenol was detected in 6 of 13 pastures, one of two hays and 10 of 13 silages. Deoxynivalenol was high (0.64–1.76 mg/kg) in five silages of excellent/average appearance. Ergovaline and lolitrem B were detected at above tolerable concentrations in four of eight perennial ryegrass-dominant samples examined. Aflatoxins, ochratoxin A and fumonisins were detected in some samples although the concentrations were low. Two samples contained either zearalenone and ergovaline, or zearalenone and deoxynivalenol, where both mycotoxins exceeded tolerable concentrations.