The efficacy of a modified aluminosilicate as a detoxifying agent in Fusarium toxin contaminated maize containing diets for piglets

Comprehensive Review on the Interactions of Clay Minerals With Animal Physiology and Production

Clay minerals are naturally occurring rock and soil materials primarily composed of fine-grained aluminosilicate minerals, characterized by high hygroscopicity. In animal production, clays are often mixed with feed and, due to their high binding capacity towards organic molecules, used to limit animal absorption of feed contaminants, such as mycotoxins and other toxicants. Binding capacity of clays is not specific and these minerals can form complexes with different compounds, such as nutrients and pharmaceuticals, thus possibly affecting the intestinal absorption of important substances. Indeed, clays cannot be considered a completely inert feed additive, as they can interfere with gastro-intestinal (GI) metabolism, with possible consequences on animal physiology. Moreover, clays may contain impurities, constituted of inorganic micronutrients and/or toxic trace elements, and their ingestion can affect animal health. Furthermore, clays may also have effects on the GI mucosa, possibly modifying nutrient digestibility and animal microbiome. Finally, clays may directly interact with GI cells and, depending on their mineral grain size, shape, superficial charge and hydrophilicity, can elicit an inflammatory response. As in the near future due to climate change the presence of mycotoxins in feedstuffs will probably become a major problem, the use of clays in feedstuff, given their physico-chemical properties, low cost, apparent low toxicity and eco-compatibility, is expected to increase. The present review focuses on the characteristics and properties of clays as feed additives, evidencing pros and cons. Aims of future studies are suggested, evidencing that, in particular, possible interferences of these minerals with animal microbiome, nutrient absorption and drug delivery should be assessed. Finally, the fate of clay particles during their transit within the GI system and their long-term administration/accumulation should be clarified.

The administration of diets contaminated with low to intermediate doses of deoxynivalenol and supplemented with antioxidants and binding agents slightly affects the growth, antioxidant status, and vaccine response in weanling pigs

This study aimed to evaluate the impact of grading levels of deoxynivalenol (DON) in the diet of weaned pigs, as well as the effects of a supplementation with antioxidants (AOX), hydrated sodium calcium aluminosilicates (HSCAS), and their combination on the growth, AOX status, and immune and vaccine responses against the porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2). At weaning, 336 piglets were allocated to six dietary treatments according to a randomized complete block design. Treatments were as follows: basal diet (CTRL); basal diet containing DON at 1.2 mg/kg (DON1.2); basal diet containing DON at 2.4 mg/kg (DON2.4); DON2.4 diet + a mix of AOX which included vitamins A and E at 20,000 IU and 200 IU/kg feed respectively, selenized yeast at 0.3 mg/kg, and a grape seed extracts at 100 mg/kg feed (DON2.4 + AOX); DON2.4 diet + the mix of AOX and the modified HSCAS mentioned above (DON2.4 + AOX + HSCAS); DON2.4 + AOX + HSCAS. Pigs were vaccinated against PRRSV and PCV2 at 7 d; on 0, 14, and 35 d, growth performance was recorded, and blood samples were collected in order to evaluate the oxidative status, inflammatory blood markers, lymphocyte blastogenic response, and vaccine antibody response. Increasing intake of DON resulted in a quadratic effect at 35 d in the lymphocyte proliferative response to concanavalin A and PCV2 as well as in the anti-PRRSV antibody response, whereas the catalase activity decreased in DON2.4 pigs compared with the CTRL and DON1.2 groups (P ≤ 0.05). Compared with the DON2.4 diet, the AOX supplementation slightly reduced gain to feed ratio (P = 0.026) and increased the ferric reducing ability of plasma as well as α-tocopherol concentration (P < 0.05), whereas the association of AOX + HSCAS increased the anti-PRRSV IgG (P < 0.05). Furthermore, the HSCAS supplement reduced haptoglobin levels in serum at 14 d compared with the DON2.4 group; however, its concentration decreased in all the experimental treatments from 14 to 35 d and particularly in the DON2.4 + AOX pigs, whereas a different trend was evidenced in the DON2.4 + HSCAS group, where over the same period haptoglobin concentration increased (P < 0.05). Overall, our results show that the addition of AOX and HSCAS in the diet may alleviate the negative effects due to DON contamination on the AOX status and immune response of vaccinated weanling pigs.

Comparative efficacy of commercially available deoxynivalenol detoxifying feed additives on growth performance, total tract digestibility of components, and physiological responses in nursery pigs fed diets formulated with naturally contaminated corn

Comparative efficacy of deoxynivalenol (DON) detoxifying feed additives (FA) was evaluated in growth performance (exp. 1) and apparent total tract digestibility (ATTD; exp. 2) nursery pig studies. Six corn-soybean meal-based diets were used: 1) positive control (PC, formulated with <1.5 ppm DON corn), negative control (NC, formulated with 5.5 ppm DON corn), NC + FA1 (clay plus yeast cell wall extract), NC + FA2 (aluminosilicate), NC + FA3 (aluminosilicate plus fungal extract), and NC + FA4 (sodium metabisulfite, SMB). In exp. 1, 144 pigs (body weight [BW], 10.2 ± 0.1kg) were housed (4 pigs/pen), allocated to diets (n = 6) based on BW, and fed for 4-wk. The BW and feed intake were monitored weekly. On d 7, one pig/pen was bled for plasma and euthanized for organ weight and tissue samples. Assayed DON concentration in PC, NC, NC + FA4 was 0.29, 2.86, and 1.21 ppm, respectively. In wk-1, the average daily gain (ADG) of pigs fed NC + FA4 was not different (P > 0.05) to that of pigs fed PC diet but greater (P = 0.01) than for pigs fed NC without or with other FA. Pigs fed NC and NC + FA2 had lower (P = 0.026) average daily feed intake (ADFI) than pigs fed PC and NC + FA3. Pigs fed NC + FA4 had greater (P = 0.003) G:F than pigs fed the other diets. Diets had no effect (P > 0.05) on ADG, ADFI, and G: F after first week, plasma concentration of urea and creatinine or liver and spleen weight. Pigs fed NC diets had greater (P = 0.01) jejunal mRNA expression of superoxide dismutase 1 relative to pigs fed PC or NC plus FA. Jejunal histomorphology and mRNA expression of nutrient transporters, inflammatory cytokines, and tight junction proteins and ceca digesta concentration of short-chain fatty acids were not affected (P > 0.05) by the diet. In exp. 2, 24 barrows (BW 10.2 ± 0.3 kg) were individually placed in metabolism crates and allocated to four diets: PC, NC, NC + FA3, and NC + FA4 (n = 6) containing TiO₂ as digestibility marker. Pigs were adjusted to diets for 5 d, followed by a 2-d grab fecal sample collection. Pigs fed PC and NC + FA4 diets had higher ATTD of dry matter, gross energy, and crude protein than NC fed pigs. The FA3 was intermediate in digestibility response. In conclusion, FA containing sequestering component plus fungal extract or SMB in DON-contaminated feed resulted in commensurate nursery pig performance to PC. The tested FA mitigated intestinal oxidative stress through decreased expression of genes for superoxide dismutase.

Development of an in vitro gastro-intestinal pig model to screen potential detoxifying agents for the mycotoxin deoxynivalenol

Deoxynivalenol (DON) is a type B trichothecene mycotoxin with worldwide high incidence in feed which is produced by Fusarium species. Strategies are needed to eliminate its health risk for livestock and to minimise its economic impact on production. In order to assess the efficacy of potential physical, chemical and biological DON detoxifying agents, a good in vitro model is necessary to perform a fast and high-throughput screening of new compounds before in vivo trials are set up. In this paper, an in vitro model was developed to screen potential commercial products for DON degradation and detoxification. Contaminated feed with potential detoxifying agents are first applied to a simulated gastrointestinal tract (GIT) of a pig, after which detoxification is assessed through a robust, inexpensive and readily applicable Lemna minor L. aquatic plant bioassay which enables evaluation of the residual toxicity of possible metabolites formed by DON detoxifying agents. The GIT simulation enables taking matrix and incubation parameters into account as they can affect the binding, removal or degradation of DON. One product could reduce DON in feed in the GIT model for almost 100% after 6 h. DON metabolites were tentatively identified with LC-MS/MS. This GIT simulation coupled to a detoxification bioassay is a valuable model for in vitro screening and assessing compounds for DON detoxification, and could be expanded towards other mycotoxins.

Zearalenone (ZEN) in Livestock and Poultry: Dose, Toxicokinetics, Toxicity and Estrogenicity

One of the concerns when using grain ingredients in feed formulation for livestock and poultry diets is mycotoxin contamination. Aflatoxin, fumonisin, ochratoxin, trichothecene (deoxynivalenol, T-2 and HT-2) and zearalenone (ZEN) are mycotoxins that have been frequently reported in animal feed. ZEN, which has raised additional concern due to its estrogenic response in animals, is mainly produced by Fusarium graminearum (F. graminearum), F. culmorum, F. cerealis, F. equiseti, F. crookwellense and F. semitectums, and often co-occurs with deoxynivalenol in grains. The commonly elaborated derivatives of ZEN are α-zearalenol, β-zearalenol, zearalanone, α-zearalanol, and β-zearalanol. Other modified and masked forms of ZEN (including the extractable conjugated and non-extractable bound derivatives of ZEN) have also been quantified. In this review, common dose of ZEN in animal feed was summarized. The absorption rate, distribution (“carry-over”), major metabolites, toxicity and estrogenicity of ZEN related to poultry, swine and ruminants are discussed.

Potential adverse effects on animal health and performance caused by the addition of mineral adsorbents to feeds to reduce mycotoxin exposure

The contamination of feed with mycotoxins is a continuing feed quality and safety issue, leading to significant losses in livestock production and potential human health risks. Consequently, various methods have been developed to reduce the occurrence of mycotoxins in feed; however, feed supplementation with clay minerals or mineral adsorbents is the most prominent approach widely practiced by farmers and the feed industry. Due to a negatively charged and high surface area, pore volume, swelling ability, and high cation exchange capacity, mineral adsorbents including bentonite, zeolite, montmorillonite, and hydrated sodium calcium aluminosilicate can bind or adsorb mycotoxins to their interlayer spaces, external surface, and edges. Several studies have shown these substances to be partly or fully effective in counteracting toxic effects of mycotoxins in farm animals fed contaminated diets and thus are extensively used in livestock production to reduce the risk of mycotoxin exposure. Nevertheless, a considerable number of studies have indicated that these agents may also cause undesirable effects in farm animals. The current work aims to review published reports regarding adverse effects that may arise in farm animals (with a focus on pig and poultry) and potential interaction with veterinary substances and nutrients in feeds, when mineral adsorbents are utilized as a technological feed additive. Furthermore, results of in vitro toxicity studies of both natural and modified mineral adsorbents on different cell lines are reported. Supplementation of mycotoxin-contaminated feed with mineral adsorbents must be carefully considered by farmers and feed industry.

Biomarkers for Exposure as A Tool for Efficacy Testing of A Mycotoxin Detoxifier in Broiler Chickens and Pigs

Applying post-harvest control measures such as adding mycotoxin detoxifying agents is a frequently-used mitigation strategy for mycotoxins. EFSA states that the efficacy of these detoxifiers needs to be tested using specific biomarkers for exposure. However, the proposed biomarkers for exposure are not further optimized for specific target species. Hence, the goal of this study was a) to evaluate the most suitable biomarkers for deoxynivalenol (DON) and zearalenone (ZEN) in porcine plasma, urine and feces; and DON, aflatoxin B1 (AFB1) and ochratoxin A (OTA) in plasma and excreta of broiler chickens and b) to determine the efficacy of a candidate detoxifier, as a proof-of-concept study. Therefore, a mixture of mycotoxins was administered as a single oral bolus with or without detoxifying agent. In accordance with literature AFB1, OTA, and DON-sulphate (DON-S) proved optimal biomarkers in broilers plasma and excreta whereas, in pigs DON-glucuronide (DON-GlcA) and ZEN-glucuronide (ZEN-GlcA) proved the optimal biomarkers in plasma, DON and ZEN-GlcA in urine and, ZEN in feces. A statistically significant reduction was seen between control and treatment group for both AFB1 and DON in broiler plasma, under administration of the mycotoxin blend and detoxifier dose studied suggesting thus, beneficial bioactivity.

Modified Palygorskite Improves Immunity, Antioxidant Ability, Intestinal Morphology, and Barrier Function in Broiler Chickens Fed Naturally Contaminated Diet with Permitted Feed Concentrations of Fusarium Mycotoxins

This study investigated effects of modified palygorskite (MPal) on immunity, antioxidant capacity, and intestinal barrier integrity in broiler chickens challenged with permitted feed Fusarium mycotoxin concentrations. One-day-old chicks were allocated into three treatments with eight replicates. Chickens in three groups were fed a basal diet with normal corn (control), contaminated diet containing moldy corn, with Fusarium mycotoxins contents in the diets lower than permitted feed mycotoxin concentrations, and the contaminated diet supplemented with 1 g/kg MPal for 42 days, respectively. Compared with control, moldy corn decreased bursa of Fabricius weight, jejunal secreted immunoglobulin A concentration, ileal superoxide dismutase (SOD) activity, jejunal and ileal villus height (VH) and VH/crypt depth (CD) ratio, and jejunal zonula occludens-1 and mucin 2 mRNA abundances at 42 days as well as ileal VH/CD ratio at 21 days; while they increased jejunal malondialdehyde accumulation at 21 and 42 days, jejunal SOD activity at 21 days, and serum diamine oxidase activity at 42 days, which were almost recovered by MPal. Moreover, dietary MPal upregulated ileal claudin-2 mRNA abundance compared with other two groups. The results indicated that MPal addition exerted protective effects on immunity, oxidative status, and intestinal barrier integrity in chickens challenged with permitted feed Fusarium mycotoxins levels.

Circulating zearalenone and its metabolites differ in women due to body mass index and food intake

The environmental estrogen, zearalenone (ZEA), is found in the food supply from Fusarium fungal contamination in grains and sometimes used as a growth promoter for beef cattle. Long-term exposure to ZEA and its metabolites may present health risk due to higher estrogenic activity. Serum ZEA metabolites were measured to determine the exposure and the association with food intake in 48 overweight/obese women (52 ± 9 years). The free and conjugated ZEA indicated the highest detection rate of all the metabolites. Conjugated ZEA and total ZEA metabolites were lower (p = 0.02) in overweight/obese than normal weight women, and free metabolites were either the same or showed a trend to be higher. In addition, those with highest (280-480 g/d) compared those with lowest (<115 g/d) meat consumption had higher conjugated serum ZEA metabolite concentrations (p < 0.05). Intakes of other food groups (i.e., dairy, cereal, etc.) were not associated with ZEA metabolites. These findings indicate that ZEA and its metabolites are detectable in nearly all women and concentrations are associated with greater meat intake, and influenced by body mass index. Determining how the food supply influences human concentrations of ZEA metabolites is warranted, as well as determining vulnerable populations.

A review of the mycotoxin adsorbing agents, with an emphasis on their multi-binding capacity, for animal feed decontamination

Contamination of animal feed with mycotoxins still occurs very often, despite great efforts in preventing it. Animal feeds are contaminated, at low levels, with several mycotoxins, particularly with those produced by Aspergillus and Fusarium genera (Aflatoxin B_1, Ochratoxin A, Zearalenone, Deoxynivalenol and Fumonisina B₁). In animal feed, to date, only Aflatoxin B₁ is limited through EU regulation. Consequently, mycotoxins cause serious disorders and diseases in farm animals. In 2009, the European Union (386/2009/EC) approved the use of mycotoxin-detoxifying agents, as feed additives, to prevent mycotoxicoses in farm animals. The present review gives an overview of the problem of multi-mycotoxin contamination of feed, and aims to classify mycotoxin adsorbing agents (minerals, organic, and synthetic) for feed decontamination, focusing on adsorbents with the ability to bind to multiple mycotoxins, which should have a more effective application in farms but they are still little studied in scientific literature.

Effects of zearalenone on the localization and expression of the growth hormone receptor gene in the uteri of post-weaning piglets

OBJECTIVE

In this study, we investigated the adverse effects of dietary zearalenone (ZEA) (0.5 to 1.5 mg/kg diet) on the localization and expression of the growth hormone receptor (GHR) in the uteri of post-weaning gilts and explored alternative mechanism of the reproductive toxicity of ZEA on piglets.

METHODS

A total of forty healthy piglets (Duroc×Landrace×Large White) aged 28 d were selected for study. Piglets were transferred to single cages after 10 days' adaptation on an obstetric table. The animals were allocated to one of four treatments: a normal basal diet supplemented with 0 (Control), 0.5 (ZEA0.5), 1.0 (ZEA1.0), or 1.5 (ZEA1.5) mg/kg purified ZEA, and fed for 35 d after the 10-d adaptation. Analyzed ZEA concentrations in the diets were 0, 0.52±0.07, 1.04±0.03, and 1.51±0.13 mg/kg, respectively. At the end of the feeding trial, piglets were euthanized after being fasted for 12 h. Two samples of uterine tissue from each pig were rapidly collected, one of which was stored at -80°C for analysis of the relative mRNA and protein expression of GHR, and the second was promptly fixed in Bouin's solution for immunohistochemical analysis.

RESULTS

The relative weight of the uteri and thickness of the myometrium and endometrium increased linearly (p<0.001) and quadratically (p<0.001) with an increasing level of ZEA. The results of immunohistochemical analysis indicated that GHR immunoreactive substance was mainly localizated in the cytoplasm of uterine smooth muscle, glandular epithelial, luminal epithelial, stromal, and vascular endothelial cells. In contrast, nuclear staining was rarely observed. The immunoreactive integrated optic density of GHR in the myometrium, luminal epithelium, glandular epithelium, and whole uteri of weaning gilts increased linearly (p<0.001) and quadratically (p<0.05) with an increasing level of ZEA. The mRNA and protein expression of GHR in the uteri of weaning gilts increased linearly (p<0.001) and quadratically (p<0.05) with an increasing level of ZEA.

CONCLUSION

In conclusion, ZEA at a concentration of 0.5 mg/kg was sufficient to significantly thicken the myometrium and endometrium, and at a concentration of 1.0 mg/kg induced a high level of GHR expression to promote growth and development of the uteri. This revealed an alternative molecular mechanism whereby ZEA induces growth and development of the uteri and provides a theoretical basis for the revision of Chinese feed hygiene standards.

The progression of deoxynivalenol-induced growth suppression in nursery pigs and the potential of an algae-modified montmorillonite clay to mitigate these effects

Two experiments were conducted to characterize the progression of deoxynivalenol (DON)-induced growth suppression and to investigate algae-modified montmorillonite clay (AMMC) as a means to alleviate the effects of DON in nursery pigs. In both experiments, naturally DON-contaminated wheat was used to produce diets with desired DON levels. In Exp. 1, 280 barrows and gilts (10.0 ± 0.2 kg BW) were used in a 28-d experiment arranged in a 2 × 2 + 1 factorial design with 8 replicates per treatment. The 5 treatments consisted of 2 positive control (PC) diets with DON below detection limits and with or without 0 or 0.50% AMMC and 3 negative control (NC) diets with 5 mg/kg of DON and containing 0, 0.25, or 0.50% AMMC. No DON × AMMC interactions were observed. Overall, pigs fed DON had decreased ( < 0.001) ADG and final BW regardless of AMMC addition. Feeding DON-contaminated diets elicited the most severe depression ( < 0.001) in ADFI and G:F from d 0 to 3, remaining poorer overall ( < 0.01) but lessening in severity as exposure time increased. Pigs fed DON diets had greater ( < 0.05) within pen BW variation (CV) on d 28. Although the addition of 0.50% AMMC to diets restored ( < 0.05) ADFI from d 14 to 21 to levels similar to the PC, no other differences were observed for AMMC inclusion. In Exp. 2, 360 barrows (11.4 ± 0.2 kg BW) were used in a 21-d experiment with 9 dietary treatments arranged in a 3 × 3 factorial design with DON and AMMC inclusion as main effects. There were 8 replicate pens per treatment. Treatments consisted of 3 PC diets without DON, 3 low-DON (1.5 mg/kg DON) NC diets, and 3 high-DON (3 mg/kg DON) NC diets with 0, 0.17, or 0.50% AMMC incorporated at each DON level. No DON × AMMC interactions were observed. As DON level increased, ADG and final BW decreased (quadratic, < 0.05), driven by decreased (quadratic, < 0.01) ADFI and poorer (quadratic; < 0.05) G:F. At both 1.5 and 3 mg/kg DON, reductions in ADG were most marked from d 0 to 7 (15 to 22% lower) and were least distinct from d 14 to 21 (5 to 6% lower). Incorporating AMMC at increasing levels had no effect on ADG, ADFI, G:F, or final BW. Overall, these experiments reinforce DON effects on feed intake but also indicate that the effects of DON on G:F may be more severe than previously thought. Furthermore, some pigs appear to develop tolerance to DON, as effects on ADFI and G:F lessen over time. However, the addition of AMMC did not offset the deleterious effects of DON.

Deoxynivalenol (DON) Contamination of Feed and Grinding Fineness: Are There Interactive Implications on Stomach Integrity and Health of Piglets?

The common feed contaminant deoxynivalenol (DON) was reported to influence the morphology of the pars nonglandularis (PN) of porcine stomach. Moreover, finely ground feed is known to trigger the development of ulcers and other pathologies of PN while coarsely ground feed protects from such lesions. The interactions between grinding fineness and DON contamination of feed were not examined so far. Therefore, both finely and coarsely ground feeds were tested either in the absence or presence of a DON contaminated wheat on growth performance and health of rearing piglets, including stomach integrity. DON contamination significantly reduced feed intake and serum albumin concentration with this effect being more pronounced after feeding the coarsely ground feed. Albeit at a higher level, albumin concentration was also reduced after feeding the finely ground and uncontaminated feed. Finely ground and DON-contaminated feed caused a significantly more pronounced lymphoplasmacytic infiltration both of PN and pars glandularis, partly paralleled by lymph follicle formation and detritus filled foveolae and tubes suggesting a local immune response probably triggered by epithelial lesions. It is concluded that DON contamination of feed exacerbates the adverse effects of finely ground feed on stomach mucosal integrity.

Grape Pomace, an Agricultural Byproduct Reducing Mycotoxin Absorption: In Vivo Assessment in Pig Using Urinary Biomarkers

The efficacy of four agricultural byproducts (ABPs) and two commercial binders (CBs) to reduce the gastrointestinal absorption of a mixture of mycotoxins was tested in piglets using urinary mycotoxin biomarkers as indicator of the absorbed mycotoxins. Twenty-eight piglets were administered a bolus contaminated with the mycotoxin mixture containing or not ABP or CB. Twenty-four hour urine was collected and analyzed for mycotoxin biomarkers by using a multiantibody immunoaffinity-based LC-MS/MS method. Each bolus contained 769 μg of fumonisin B1 (FB1), 275 μg of deoxynivalenol (DON), 29 μg of zearalenone (ZEN), 6.5 μg of aflatoxin B1 (AFB1) and 6.6 μg of ochratoxin A (OTA) corresponding to 2.2, 0.8, 0.08, 0.02, and 0.02 μg/g in the daily diet, respectively. The percentage of ABP in each bolus was 50%, whereas for the two CBs the percentages were 5.2 and 17%, corresponding to 2.8, 0.3, and 0.9% in the daily diet, respectively. The reduction of mycotoxin absorption was up to 69 and 54% for ABPs and CBs, respectively. White grape pomace of Malvasia was the most effective material as it reduced significantly (p < 0.05) urinary mycotoxin biomarker of AFB1 (67%) and ZEN (69%), whereas reductions statistically not significant were observed for FB1 (57%), DON (40%), and OTA (27%). This study demonstrates that grape pomace reduces the gastrointestinal absorption of mycotoxins. This agricultural byproduct can be considered an alternative to commercial products and used in the feed industries as an effective, cheap, and natural binder for multiple mycotoxins.

A review of the efficacy of mycotoxin detoxifying agents used in feed in light of changing global environment and legislation

In the recent years, mycotoxins have undoubtedly gained a keen interest of the scientific community studying food safety. The main reason is their profound impact on both human and animal health. International surveys reveal a low percentage of feed samples being contaminated above permitted/guideline levels, developed to protect consumers of animal derived products. However, the deleterious impact of feed co-contaminated at low levels with numerous both known and regulated as well as novel mycotoxins on producing animals has been described. Associated effects on agro-economics world-wide include substantial pecuniary losses which are borne by the society as a whole. Even though good agronomic practice is thought to be the most effective way of preventing animal feed contamination, the EC have recognised the need to introduce an additional means of management of feed already contaminated with low-levels of mycotoxins to alleviate detrimental effects on agricultural production efficiency. This review discusses types of feed detoxifying agents described in scientific literature, their reported efficacy in both in vitro and in vivo systems, and comparison with available commercial formulations in the light of increasing knowledge regarding mycotoxin prevalence in the changing global environment.

The potential effects of antioxidant feed additives in mitigating the adverse effects of corn naturally contaminated with Fusarium mycotoxins on antioxidant systems in the intestinal mucosa, plasma, and liver in weaned pigs

Seventy-two piglets (6.0 kg BW) were randomly distributed within six different dietary treatments to evaluate the effect of deoxynivalenol (DON) and the potential of four antioxidant feed additives in mitigating the adverse effects of DON on growth performances and oxidative status. Dietary treatments were as follows: control diet 0.8 mg/kg DON; contaminated diet (DON-contaminated diet) 3.1 mg/kg DON; and four contaminated diets, each supplemented with a different antioxidant feed additive, DON + vitamins, DON + organic selenium (Se)/glutathione (GSH), DON + quercetin, and DON + COMB (vitamins + Se/GSH + quercetin from the other treatments). Although DON was the main mycotoxin in the contaminated diet, this diet also contained 1.8 mg/kg of zearalenone (ZEN). The "mycotoxin" effects therefore included the combined effect of these two mycotoxins, DON, and ZEN. The DON-ZEN ingestion did not affect growth performances, average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F ratio), but partially induced oxidative stress in weaned pigs as shown by increased malondialdehyde (MDA) content in the plasma and superoxide dismutase (SOD) activity in liver (P < 0.05). However, no change in the activity of other antioxidant enzymes or GSH concentrations was observed in plasma and liver of piglets fed the DON-contaminated diet (P > 0.05). Supplementation with individual antioxidant feed additive had a limited effect in weaned pigs fed DON-ZEN-contaminated diets. Combination of antioxidants (vitamins A, C, and E, quercetin, and organic Se/GSH) reduced plasma and liver MDA content and SOD activity in liver (P < 0.05) of piglets fed DON-ZEN-contaminated diets. Furthermore, this combination also reduced MDA content in the ileum (P < 0.05), although activity of glutathione peroxidases (GPx), SOD or catalase (CAT) in the ileum was not affected by DON-ZEN contamination or antioxidant supplements. In conclusion, DON-ZEN contamination induced oxidative stress in weaned pigs and combination of antioxidant feed additives restored partially the oxidative status. Further studies will be necessary to assess whether the effects of antioxidant feed additives on oxidative status are specific when feed is contaminated with DON-ZEN.

Efficacy of activated diatomaceous clay in reducing the toxicity of zearalenone in rats and piglets

Two experiments were conducted to evaluate the efficacy of an activated diatomaceous clay (ADC) in reducing the toxic effects of zearalenone (ZEA) in the diet of rats and piglets. In the rat experiment, 90 Sprague-Dawley female weanling rats with an initial BW of 45 ± 1.0 g were assigned to 1 of 6 dietary treatments for 28 d in a completely randomized design (CRD) with a 2 × 3 factorial arrangement (0 or 6 mg ZEA/kg feed and 0, 1, and 5 g ADC/kg feed). In the piglet experiment, 64 female piglets ([Large White × Landrace] × Pietrain with an initial BW of 14.9 ± 1.65 kg) were fed 1 of 8 experimental diets for 26 d in a CRD design with a 2 × 4 factorial arrangement (0 or 0.8 mg ZEA/kg feed and 0, 1, 2, and 5 g ADC/kg feed). The ADFI, ADG, and G:F were determined at the end of each experiment. At the conclusion of studies, serum samples were collected and rats and piglets were euthanized to determine visceral organ weights. The diet contaminated with ZEA did not alter the growth of rats and the relative weight of liver and kidneys. However, ZEA increased ( < 0.05) the relative weight of uterus, ovaries, and spleen and decreased ( < 0.05) the serum activities of alkaline phosphatase and alanine aminotransferase compared to the control group. Supplementation of ADC in the rat diets counteracted ( < 0.05) the observed toxic effects of ZEA on the uterus and ovaries weight. The diet contaminated with ZEA (0.8 mg/kg feed) increased ( < 0.05) the weight of the uterus and ovaries in piglets but did not modify the serum biochemical variables or the relative weight of other visceral organs. The addition of 5 g ADC/kg to the contaminated feed reduced the toxic effects of ZEA on uterus and ovary weights to that of the control group. Zearalenone (10.5 μg/kg bile) and α-zearalenol (5.6 μg/kg bile) residues were detected in the bile of piglets fed the ZEA treatment. Supplementation of ADC to diets contaminated with ZEA reduced ( = 0.001) ZEA content in bile compared to the ZEA treatments. The results of these experiments indicate that a long-term consumption of ZEA-contaminated diets stimulated growth of the reproductive tract in rats and piglets and the presence of ZEA residue in bile in piglets. These effects may be counteracted by the addition of ADC to the diet.

Short Communication: Antioxidant capacity in the intestinal mucosa of weanling piglets fed diets containing Fusarium mycotoxins and the efficacy of commercial supplements sold as detoxifiers

Le Thanh, B. V., Lessard, M., Chorfi, Y. and Guay, F. 2015. Short Communication: Antioxidant capacity in the intestinal mucosa of weanling piglets fed diets containing Fusarium mycotoxins and the efficacy of commercial supplements sold as detoxifiers. Can. J. Anim. Sci. 95: 569–575. The ability of commercial feed additives to prevent oxidative damage due to deoxynivalenol (DON) in piglets was studied. Sixty piglets (6.0±0.5 kg) were assigned randomly to six wheat–corn–soybean diets: control (<0.5 mg kg−1 DON), DON-rich diet (4 mg kg−1 DON), and four DON-rich diets supplemented with either glucomannan (DON+GLUC), yeast, live bacteria, enzymes and plant extract (DON+YBP), aluminosilicate (DON+ALS), or a mixture of preservatives (DON+PV). Malondialdehyde concentration (MDA), glutathione peroxidase activity (GPx), catalase activity (CAT) and superoxide dismutase activity (SOD) in the small intestine were measured after 14 d. The DON-rich diet increased MDA in the jejunum while decreasing CAT in the jejunum and SOD in the ileum and increasing GPx in the ileum (P<0.05). The DON+GLUC diet decreased GPx and SOD (P<0.05) and tended to decrease MDA in the jejunum (P<0.10). The DON+YBP, DON+PV and DON+ALS diets all decreased CAT in the jejunum, while DON+YBP and DON+PV also did so in the ileum (P<0.05). DON+GLUC decreased SOD in the jejunum, while DON+YBP increased it (P<0.05). In the ileum, DON+PV decreased SOD, while DON+ALS increased GPx (P<0.05). No significant differences in total antioxidant capacity (TAC) in intestinal tissues were found. This study demonstrates that the mycotoxin DON and anti-mycotoxin additives modify oxidative status, including the antioxidant enzyme activities (CAT, SOD or GPx) in the intestinal mucosa of piglets. However, it was not possible to identify a specific antioxidant enzyme involved in counteracting the effect of DON.

The efficacy of anti-mycotoxin feed additives in preventing the adverse effects of wheat naturally contaminated with Fusarium mycotoxins on performance, intestinal barrier function and nutrient digestibility and retention in weanling pigs

Thanh, B. V. L., Lessard, M., Chorfi, Y. and Guay, F. 2015. The efficacy of anti-mycotoxin feed additives in preventing the adverse effects of wheat naturally contaminated with Fusarium mycotoxins on performance, intestinal barrier function and nutrient digestibility and retention in weanling pigs. Can. J. Anim. Sci. 95: 197–209. This study was designed to determine the effect of feeding deoxynivalenol (DON) contaminated wheat to growing pigs on growth performance, digestibility and retention of nitrogen (N), phosphorus (P) and calcium (Ca). Secondly, we wished to evaluate the potential of four commercial anti-mycotoxin additives in preventing the adverse effects of DON. Sixty piglets (6.0 kg body weight) were assigned to six different corn-soybean meal-wheat diets (control diet: <0.5 mg kg−1 DON; contaminated diet (DON-contaminated): 4 mg kg−1; and four contaminated diets supplemented with a different anti-mycotoxin additive: DON+GLUC (glucomannan), DON+YBP (yeast, live bacteria, enzymes, plant extracts), DON+ALU (aluminosilicate) and DON+PC (preservation components). Piglets were housed individually in pens for 7 d and then transferred to metabolic crates for urine and feces collection for 7 d. At the end of these 2 wk, mannitol and lactulose doses were given by oral administration. Urine was collected for 24 h for an evaluation of barrier integrity of intestinal mucosa. The piglets were then euthanatized and intestinal samples collected for morphology studies. Feeding DON-contaminated wheat reduced average daily feed intake, average daily gain and G:F ratio compared with the control diet (P<0.05). Only DON+PC diet restored the growth performance of piglets fed DON-contaminated diet. Daily retention of N and P was not affected by DON contamination or anti-mycotoxin additives, but retention of Ca was higher in piglets fed the DON-contaminated diets than the control diet. DON-contaminated diet reduced digestibility of dry matter, gross energy and fat, villi height in jejunum, and recovery of mannitol and lactulose compared with the control diet (P<0.05). Finally, DON concentrations in serum from piglets fed the DON-contaminated diets were higher than in the control diet (P<0.05). Piglets fed DON-contaminated wheat had reduced growth possibly caused by impaired jejunal morphology and decreased digestibility of energy and fat.

Assessment of the potential of a boron-fructose additive in counteracting the toxic effect of Fusarium mycotoxins

Trichotecenes are mycotoxins produced by Fusarium sp., which may contaminate animal feeds and human food. A feeding trial was conducted to evaluate the effect of a fusarotoxin-contaminated diet, and to explore the counteracting potential of a calcium fructoborate (CFrB) additive on performance, typical health biochemistry parameters and immune response in weaned pigs. A naturally contaminated maize, containing low doses of deoxynivalenol, zearalenone, fumonisins and T-2/HT-2 toxins (1790, 20, 0·6 and 90 parts per billion), was included in a maize-soyabean meal diet, and given ad libitum to eight weaned piglets (two groups: four pigs/group) for a period of 24 d. CFrB was administered to one of the contaminated groups and to another four piglets as a daily supplement, following the manufacturer's recommendation. A decrease in performance was observed in contaminated animals at this concentration of feed toxins, which was ameliorated by the dietary CFrB supplementation. Fusarium toxins also altered the pig immune response by increasing (P < 0·05) the ex vivo peripheral blood mononuclear cell proliferation (111·7 % in comparison with control), the respiratory burst of porcine granulocytes (15·4 % for responsive cells v. 5·1 % for unstimulated cells and 70·95 v. 22·65 % for stimulated cells, respectively), the percentage of peripheral T, CD3(+), CD3(+)CD4(+) and CD3(+)CD8(+) subsets and the synthesis of IL-1β, TNF-α and IL-8 (123·8, 217·1 and 255·1 %, respectively). The diet containing the CFrB additive reduced these exacerbated cellular immune responses induced by Fusarium toxins. However, consumption of CFrB did not counteract the effect of mycotoxins on biochemistry parameters, and increased plasma IgM and IgG of contaminated pigs.

Effects of excessive selenium supplementation to diet contaminated with deoxynivalenol on blood phagocytic activity and antioxidative status of broilers

This study examined the effects of excessive dietary supplementation with organic selenium on phagocytic activity and antioxidative status of chickens for fattening fed diet contaminated with deoxynivalenol (DON). Sixty chickens of Ross 308 hybrids were at day of hatching divided into four groups with 15 birds in each. The background DON dietary levels in both negative and positive control groups were 0.2 mg/kg. The complete feed for positive control group was supplemented with Se dose 1 mg/kg in the form of Se-yeast. Group 3 was fed diet with DON level 3 mg/kg while diet for group 4 combined DON level 3 mg/kg with a excessive supplement of Se-yeast (Se dose 1 mg/kg). After 6 weeks of dietary intake, six randomly-chosen chickens from each group were sampled. Feeding of contaminated diet resulted in significantly reduced blood phagocytic activity (19.5 ± 1.1% in the negative control vs. 12.8 ± 0.8% in the DON-treated group, p < 0.05). Se-yeast supplemented to the DON contaminated diet prevented suppression of phagocytic activity. Dietary intake of DON at levels 3 mg/kg did not influence the plasma α-tocopherol level while excessive dietary Se dose reduced it in both Se supplemented groups. Neither the birds of DON-treated group nor the birds from group 4 with DON and Se-yeast showed any response in plasma γ-glutamyltransferase (GGT) activity. Subtoxic dietary level of DON significantly increased the activity of glutathione peroxidase (GPx) in the duodenal mucosa, while additional Se supplementation prevented such a response to mycotoxin. On the other hand, both Se supplemented groups showed significantly elevated GPx activities in blood, liver and kidney, (p < 0.05). The results suggest a potential ability of excessive supplementation of organic selenium to prevent the blood phagocytic activity suppression and changes in GPx activity in duodenal tissue induced in broilers by subtoxic dietary levels of DON.

Aflatoxin toxicity reduction in feed by enhanced binding to surface-modified clay additives

Animal feeding studies have demonstrated that clay additives, such as bentonites, can bind aflatoxins in ingested feed and reduce or eliminate the toxicity. Bentonite deposits are found throughout the world and mostly consist of expandable smectite minerals, such as montmorillonite. The surfaces of smectite minerals can be treated with organic compounds to create surface-modified clays that more readily bind some contaminants than the untreated clay. Montmorillonites treated with organic cations, such as hexadecyltrimethylammonium (HDTMA) and phenyltrimethylammonium (PTMA), more effectively remove organic contaminants, such as benzene and toluene, from water than untreated clay. Similarly, montmorillonite treated with PTMA (K_d = 24,100) retained more aflatoxin B1 (AfB1) from aqueous corn flour than untreated montmorillonite (K_d = 944). Feed additives that reduced aflatoxin toxicity in animal feeding studies adsorbed more AfB1 from aqueous corn flour than feed additives that were less effective. The organic cations HDTMA and PTMA are considered toxic and would not be suitable for clay additives used in feed or food, but other non-toxic or nutrient compounds can be used to prepare surface-modified clays. Montmorillonite (SWy) treated with choline (K_d = 13,800) and carnitine (K_d = 3960) adsorbed much more AfB1 from aqueous corn flour than the untreated clay (K_d = 944). A choline-treated clay prepared from a reduced-charge, high-charge montmorillonite (K_d = 20,100) adsorbed more AfB1 than the choline-treated high-charge montmorillonite (K_d = 1340) or the untreated montmorillonite (K_d = 293). Surface-modified clay additives prepared using low-charge smectites and nutrient or non-toxic organic compounds might be used to more effectively bind aflatoxins in contaminated feed or food and prevent toxicity.

Efficacy of detoxification of deoxynivalenol-contaminated corn by Bacillus sp. LS100 in reducing the adverse effects of the mycotoxin on swine growth performance

Biodetoxification of mycotoxins is a novel strategy to control mycotoxicoses in animals. Bacillus sp. LS100, which transforms deoxynivalenol (DON) to a less toxic chemical de-epoxy DON (DOM-1), was evaluated for its efficacy in reducing the adverse effects of DON on swine growth performance. A feeding trial was conducted in growing pigs with four treatments: (1) corn meal without detectable DON served as control (Non-toxic Corn); (2) Fusarium-infected corn giving a toxic diet containing 5 µg DON g(-1) (Toxic Corn); (3) Toxic Corn detoxified with Bacillus sp. LS100 giving a detoxified diet containing 5 µg DOM-1 g(-1) (LS100-De-toxic Corn); (4) Non-toxic Corn treated with Bacillus sp. LS100 serving as bacterial control (LS100-Non-toxic Corn). During 9 days of exposure to the treatments, pigs on Toxic Corn showed a significant reduction in daily feed consumption, daily weight gain and feed efficiency by 29, 48 and 29%, respectively, compared to pigs on Non-toxic Corn. These parameters of the pigs fed LS100-De-toxic Corn diet were 45, 82 and 32% greater, respectively, than those of pigs fed Toxic Corn diet, and were similar to those pigs fed Non-toxic Corn and LS100-Non-toxic Corn diets. There were no significant differences between the treatments of LS100-Non-toxic Corn and Non-toxic Corn diets, implying that the bacterial isolate might not have significantly affected nutrition and palatability of the feed or had negative effects on the pig's feeding performance. The results have proved that microbial detoxification of DON in contaminated feed can eliminate negative effects of the mycotoxin, and the pre-feeding detoxification approach may be applied in the livestock industry.

Dietary glucomannan improves the vaccinal response in pigs exposed to aflatoxin B1 or T-2 toxin

The aim of the study was to investigate whether dietary supplementation with yeast-derived glucomannan protects pigs against the deleterious effects that exposure to aflatoxin B1 (AFB1) or T-2 toxin has on the vaccinal immune response and drug-metabolising enzymes. Three doses of pure mycotoxin (AFB1 trial: 482, 968 and 1,912 µg/kg feed; T-2 toxin trial: 593, 1,155 and 2,067 µg/kg feed) with or without dietary glucomannan supplementation (2 g/ kg feed) were tested in weaned pigs for 28 days. At days 4 and 15 pigs were immunised with ovalbumin to study the humoral and cell-mediated antigen-specific immune responses. The effects of AFB1 and T-2 toxin intake alone in pigs have already been published. In all parameters investigated no differences were apparent between animals receiving the unsupplemented control diet or the control diet containing glucomannan. In the AFB1 trial glucomannan decreased the severity of liver lesions in animals exposed to 968 µg/kg feed. Exposure to both AFB1 and T-2 toxin were associated with impaired phase I liver enzyme activities, but glucomannan demonstrated a limited protective effect on these enzymes. With regard to the immune defence system, both toxins modulated the vaccinal immune response; AFB1 impaired specific cellular response and T-2 toxin the specific humoral response. Glucomannan supplementation restored the ovalbumin-specific lymphocyte proliferation that was delayed in pigs exposed to AFB1, regardless of dose. In the T-2 toxin trial glucomannan supplementation restored anti-ovalbumin immunoglobulin G production, which was significantly reduced in pigs exposed to both medium and high doses of the toxin. In conclusion, glucomannan dietary supplementation demonstrated no deleterious effects in control animals and protective effects against AFB1 and T-2 toxin immunotoxicity during a vaccinal protocol.

Alimentação de leitoas pré-púberes com dietas contendo zearalenona

O desempenho, o peso de alguns órgãos e a morfologia vulvar de leitoas pré-púberes, alimentadas por 28 dias com dietas contendo zearalenona, foram avaliados. O delineamento experimental utilizado foi inteiramente ao acaso, com dois tratamentos, dieta controle (DC) e dieta controle + 2mg kg-1 de zearalenona (DZ), e seis repetições cada. Não houve diferença (P>0,05) entre os tratamentos para consumo médio diário de ração (1,24 x 1,19kg), ganho médio diário de peso (0,68 x 0,71kg), conversão alimentar (1,86 x 1,71) e peso vivo (PV); (30,9 x 30,4kg). A zearalenona não alterou (P>0,05) os pesos absoluto e relativo do coração (137 x 141g e 0,45 x 0,45% PV), fígado (699 x 699g e 2,31 x 2,26%PV), rins (47 x 49g e 0,15 x 0,16%PV) e baço (166 x 171g e 0,55 x 0,55%PV). Houve aumento (P<0,05) no comprimento (17 x 27cm) e no peso (23 x 157g e 0,07 x 0,51%PV) do trato reprodutivo das leitoas do grupo DZ. O volume vulvar ao final do período foi 820% maior (P<0,05) nos animais alimentados com zearalenona (941 x 8658mm³/kgPV0,6). Os resultados indicam que em suínos a zearalenona e seus metabólitos possuem atividade estrogênica, mas não interferem no desempenho dos animais.

Carry-over of Fusarium toxins (deoxynivalenol and zearalenone) from naturally contaminated wheat to pigs

The frequent contamination of grain with the Fusarium toxins, deoxynivalenol (DON) and zearalenone (ZON), is an important issue in animal and human nutrition. However, data on the exposure of humans to these toxins through consumption of animal tissues exposed to Fusarium toxins (carry-over) are fragmentary. Therefore, residues of DON, ZON and their metabolites were determined in tissues and body fluids of pigs (female and castrated male) from a fattening trial. Pigs were fed a control (n = 6, 0.24 mg DON and 0.009 mg ZON per kg diet as fed) or a Fusarium toxin-contaminated diet (n = 12, 6.68 mg DON and 0.056 mg ZON per kg diet as fed) either ad libitum or for restrictive consumption for 12 weeks. After slaughter (96.3 +/- 11.6 kg live weight), the concentrations of DON and its metabolite, de-epoxy-DON, were measured in serum, bile, liver, kidney, musculus longissimus and back fat, while ZON and its metabolites, alpha- and beta-zearalenol (alpha-/beta-ZOL), were determined in serum, bile and liver. The mean carry-over factor of DON + de-epoxy-DON, defined as the concentration of both substances in the tissue/fluid divided by the DON concentration in the diet, for all pigs decreased from bile (0.1046 +/- 0.0653) >> kidney (0.0151 +/- 0.0070) > liver (0.0057 +/- 0.0043) > serum (0.0023 +/- 0.0018) > muscle (0.0016 +/- 0.0016) >> back fat (0.0002 +/- 0.0004). The time interval between the end of feeding and slaughter had no consistent effect on DON + de-epoxy-DON concentrations in the analysed specimen of Fusarium toxin-exposed pigs fed restrictively. No transfer of ZON and its metabolites could be observed into serum of pigs, while the mean carry-over factors of ZON + alpha-ZOL + beta-ZOL were 0.0094 +/- 0.0123 and 4.0 +/- 2.2 for liver and bile, respectively. Therefore, it can be concluded that serum is a reliable indicator for DON exposure, but an inappropriate parameter to deduce ZON exposure, which is better represented by bile concentration of ZON + alpha-ZOL + beta-ZOL. However, the exposure risk to humans by consumption of edible tissues of animals exposed to Fusarium toxins is negligible compared to the direct consumption of grain-based food.

In vitro assessment of adsorbents aiming to prevent deoxynivalenol and zearalenone mycotoxicoses

The high prevalence of the Fusarium mycotoxins, deoxynivalenol (DON) and zearalenone (ZON) in animal feeds in mild climatic zones of Europe and North America results in considerable economic losses, as these toxins affect health and productivity particularly of pigs from all age groups. The use of mycotoxin adsorbents as feed additives is one of the most prominent approaches to reduce the risk for mycotoxicoses in farm animals, and to minimise carry-over of mycotoxins from contaminated feeds into foods of animal origin. Successful aflatoxin adsorption by means of different substances (phyllosilicate minerals, zeolites, activated charcoal, synthetic resins or yeast cell-wall-derived products) has been demonstrated in vivo and in vitro. However, attempts to adsorb DON and ZON have been less encouraging. Here we describe the adsorption capacity of a variety of potential binders, including compounds that have not been evaluated before, such as humic acids. All compounds were tested at realistic inclusion levels for their capacity to bind ZON and DON, using an in vitro method that resembles the different pH conditions in the gastro-intestinal tract of pigs. Mycotoxin adsorption was assessed by chemical methods and distinct bioassays, using specific markers of toxicity as endpoints of toxicity in cytological assays. Whereas none of the tested substances was able to bind DON in an appreciable percentage, some of the selected smectite clays, humic substances and yeast-wall derived products efficiently adsorbed ZON (>70%). Binding efficiency was indirectly confirmed by the reduction of toxicity in the in vitro bioassays. In conclusion, the presented test protocol allows the rapid screening of potential mycotoxin binders. Like other in vitro assays, the presented protocol combining chemical and biological assays cannot completely simulate the conditions of the gastro-intestinal tract, and hence in vivo experiments remain mandatory to assess the efficacy of mycotoxin binders under practical conditions.