Dose-dependent effects on sphingoid bases and cytokines in chickens fed diets prepared with fusarium verticillioides culture material containing fumonisins

Gut-Faecal Microbial and Health-Marker Response to Dietary Fumonisins in Weaned Pigs

This study investigated effects of dietary fumonisins (FBs) on gut and faecal microbiota of weaned pigs. In total, 18 7-week-old male pigs were fed either 0, 15 or 30 mg FBs (FB1 + FB2 + FB3)/kg diet for 21 days. The microbiota was analysed with amplicon sequencing of the 16S rRNA gene V3-V4 regions (Illumina MiSeq). Results showed no treatment effect (p > 0.05) on growth performance, serum reduced glutathione, glutathione peroxidase and malondialdehyde. FBs increased serum aspartate transaminase, gamma glutamyl-transferase and alkaline phosphatase activities. A 30 mg/kg FBs treatment shifted microbial population in the duodenum and ileum to lower levels (compared to control (p < 0.05)) of the families Campylobacteraceae and Clostridiaceae, respectively, as well as the genera Alloprevotella, Campylobacter and Lachnospiraceae Incertae Sedis (duodenum), Turicibacter (jejunum), and Clostridium sensu stricto 1 (ileum). Faecal microbiota had higher levels of the Erysipelotrichaceae and Ruminococcaceae families and Solobacterium, Faecalibacterium, Anaerofilum, Ruminococcus, Subdoligranulum, Pseudobutyrivibrio, Coprococcus and Roseburia genera in the 30 mg/kg FBs compared to control and/or to the 15 mg/kg FBs diets. Lactobacillus was more abundant in the duodenum compared to faeces in all treatment groups (p < 0.01). Overall, the 30 mg/kg FBs diet altered the pig gut microbiota without suppressing animal growth performance.

Nutritional Strategies to Improve Meat Quality and Composition in the Challenging Conditions of Broiler Production: A Review

Poultry meat is becoming one of the most important animal protein sources for human beings in terms of health benefits, cost, and production efficiency. Effective genetic selection and nutritional programs have dramatically increased meat yield and broiler production efficiency. However, modern practices in broiler production result in unfavorable meat quality and body composition due to a diverse range of challenging conditions, including bacterial and parasitic infection, heat stress, and the consumption of mycotoxin and oxidized oils. Numerous studies have demonstrated that appropriate nutritional interventions have improved the meat quality and body composition of broiler chickens. Modulating nutritional composition [e.g., energy and crude protein (CP) levels] and amino acids (AA) levels has altered the meat quality and body composition of broiler chickens. The supplementation of bioactive compounds, such as vitamins, probiotics, prebiotics, exogenous enzymes, plant polyphenol compounds, and organic acids, has improved meat quality and changed the body composition of broiler chickens.

Week-Old Chicks with High Bacteroides Abundance Have Increased Short-Chain Fatty Acids and Reduced Markers of Gut Inflammation

As important commensals in the chicken intestine, Bacteroides are essential complex carbohydrate degraders, and short-chain fatty acid (SCFA) producers that are highly adapted to the distal gut. Previous studies have shown large variation in Bacteroides abundance in young chickens. However, limited information is available regarding how this variation affects the gut microbiome and host immunity. To investigate how elevated or depleted Bacteroides levels affect gut microbial functional capacity and impact host response, we sampled 7-day-old broiler chickens from 14 commercial production flocks. Week-old broiler chickens were screened and birds with low Bacteroides (LB) and high Bacteroides (HB) abundance were identified via 16S rRNA gene amplicon sequencing and quantitative PCR (qPCR) assays. Cecal microbial functionality and SCFA concentration of chickens with distinct cecal Bacteroides abundance were profiled by shotgun metagenomic sequencing and gas chromatography, respectively. The intestinal immune responses of LB and HB chickens were assessed via reverse transcription qPCR. Results showed that the gut microbiota of the LB group had increased abundance of lactic acid bacteria pyruvate fermentation pathway, whereas complex polysaccharide degradation and SCFA production pathways were enriched in the HB group (P < 0.05), which was supported by increased SCFA concentrations in the ceca of HB chickens (P < 0.05). HB chickens also showed decreased expression of interleukin-1β and increased expression of interleukin-10 and tight-junction protein claudin-1 (P < 0.05). Overall, the results indicated that elevated Bacteroides may benefit the 7-day broiler gut and that further work should be done to confirm the causal role of Bacteroides in the observed positive outcomes. IMPORTANCE To date, limited information is available comparing distinct Bacteroides compositions in the chicken gut microbial communities, particularly in the context of microbial functional capacities and host responses. This study showed that possessing a microbiome with elevated Bacteroides in early life may confer beneficial effects to the chicken host, particularly in improving SCFA production and gut health. This study is among the first metagenomic studies focusing on the early life chicken gut microbiota structure, microbial functionality, and host immune responses. We believe that it will offer insights to future studies on broiler gut microbial population and their effects on host health.

Occurrence, transformation, and toxicity of fumonisins and their covert products during food processing

Fumonisins comprise structurally related metabolites mainly produced by Fusarium verticillioides and Fusarium proliferatum. Contamination with fumonisins causes incalculable damage to the economy and poses a great risk to animal and human health. Fumonisins and their covert products are found in cereals and cereal products. Food processing significantly affects the degradation of toxins and the formation of covert toxins. However, studies on fumonisins and their covert mycotoxins remain inadequate. This review aims to summarize changes in fumonisins and the generation of covert fumonisins during processing. It also investigates the toxicity and determination methods of fumonisins and covert fumonisins, and elucidates the factors affecting fumonisins and their covert forms during processing. In addition to the metabolic production by plants and fungi, covert fumonisins are mainly produced by covalent or noncovalent binding, complexation, or physical entrapment of fumonisins with other substances. The toxicity of covert fumonisins is similar to that of free fumonisins and is a non-negligible hazard. Covert fumonisins are commonly found in food matrices, and methods to analyze them have yet to be improved. Food processing significantly affects the conversion of fumonisins to their covert toxins.

Assessment of information as regards the toxicity of fumonisins for pigs, poultry and horses

In 2018, the EFSA Panel on Contaminants in the Food Chain (CONTAM) adopted a Scientific Opinion on the risks for animal health related to the presence of fumonisins, their modified forms and hidden forms in feed. A no observed adverse effect level (NOAEL) of 1 mg/kg feed was established for pigs. In poultry a NOAEL of 20 mg/kg feed and in horses a reference point for adverse animal health effect of 8.8 mg/kg feed was established, referred to as NOAEL. The European Commission (EC) requested EFSA to review the information regarding the toxicity of fumonisins for pigs, poultry and horses and to revise, if necessary, the established NOAELs. The EFSA CONTAM Panel considered that the term reference point (RP) for adverse animal health effects better reflects the uncertainties in the available studies. New evidence which had become available since the previous opinion allowed to revise an RP for adverse animal health effects for poultry from 20 mg/kg to 1 mg/kg feed (based on a LOAEL of 2.5 mg/kg feed for reduced intestinal crypt depth) and for horses from 8.8 to 1.0 mg/kg feed (based on case studies on equine leukoencephalomalacia (ELEM)). For pigs, the previously established NOAEL was confirmed as no further studies suitable for deriving an RP for adverse animal health effects could be identified. Based on exposure estimates performed in the previous opinion, the risk of adverse health effects of feeds containing FB1-3 was considered a concern for poultry, when taking into account the RP of 1 mg/kg feed for intestinal effects. For horses and other solipeds, the risk is considered low, although a large uncertainty associated with exposure was identified. The same conclusions apply to the sum of FB1-3 and their hidden forms.

Toxic Mechanism and Biological Detoxification of Fumonisins

Food safety is related to the national economy and people's livelihood. Fumonisins are widely found in animal feed, feed raw materials, and human food. This can not only cause economic losses in animal husbandry but can also have carcinogenicity or teratogenicity and can be left in animal meat, eggs, and milk which may enter the human body and pose a serious threat to human health. Although there are many strategies to prevent fumonisins from entering the food chain, the traditional physical and chemical methods of mycotoxin removal have some disadvantages, such as an unstable effect, large nutrient loss, impact on the palatability of feed, and difficulty in mass production. As a safe, efficient, and environmentally friendly detoxification technology, biological detoxification attracts more and more attention from researchers and is gradually becoming an accepted technique. This work summarizes the toxic mechanism of fumonisins and highlights the advances of fumonisins in the detoxification of biological antioxidants, antagonistic microorganisms, and degradation mechanisms. Finally, the future challenges and focus of the biological control and degradation of fumonisins are discussed.

Contamination With Fumonisin B and Deoxynivalenol Is a Threat to Egg Safety and Contributes to Gizzard Ulcerations of Newborn Chickens

Fumonisin B (FB) and other fumonisins, deoxynivalenol (DON), and zearalenone (ZEN) are mycotoxins (secondary metabolites of fungi) present at high levels of contamination in poultry diets and threatening the sustainability of the poultry industry and egg safety for consumers. However, residual mycotoxins in breeder eggs and their effects on chicken progeny and gizzard ulcerations remain unclear. To unveil mycotoxin contaminations from daily diets to breeder eggs, 293 poultry feed samples were collected from three large-scale poultry provinces across Northern China to Southern China. Average levels of 1,628 ± 4.36 μg/kg of FB₁, 593 ± 11.16 μg/kg of DON, 69 ± 9.21 μg/kg of ZEN, 52 ± 7.33 μg/kg of OTA, and 24 ± 5.85 μg/kg of AFB₁ were found in feedstuffs and poultry diets using commercial ELISA kits. In terms of residual mycotoxins in breeder eggs, FB₁ and DON contaminations dominated residues in egg albumen and yolk samples. Out of 221 breeder eggs, the average residual of FB₁ in albumen were 320.6 ± 10.12 μg/kg (Hebei), 420.2 ± 10.98 μg/kg (Guangdong), and 549.4 ± 10.27 (Guangxi). Moreover, higher residual of DONs were determined in Guangdong and Guangxi provinces compared to Hebei province. ZEN, ochratoxins A (OTA), and aflatoxin B₁ (AFB₁) contamination at low levels were found in the above samples collected from afronmentioned three provinces. Based on residual mycotoxins in breeder eggs, SPF embryonated eggs aged 11 days were inoculated into albumen with different doses of FB₁, FB₂ or DON, or a combination of FB₁ and DON, or a combination of FB₁ with FB₂ and FB₃. A lower hatching rate was observed in the chicken progenies with the combination of 24 μg of FB₁ and 0.1 μg of DON compared to other treatments. Moreover, typical gizzard ulcerations with hemorrhagic lungs were observed in the progeny of breeder eggs post-inoculation of 24 μg of FB₁ and synergetic inoculation of FB₁ and DON. Finally, residual FB mycotoxins were detected in the gizzards and in the lungs of the progenies. Based on the above evidence, feed-borne FB₁ and DON are dominant mycotoxins in breeder eggs and threatening food security using breeder eggs as a Trojan horse. More importantly, the residual of FB₁ alone and in combination with of DON contamination are associated with low hatching rate and gizzard ulcerations in chicken progenies, hampering sustainable development perspectives of the poultry industry.

Effects of deoxynivalenol and fumonisins fed in combination on beef cattle: health and performance indices

Interactions between livestock management practices and toxicological outcomes of mycotoxin exposure may explain the range of tolerable toxin levels reported for various species. In the current study, we investigated the effect of concurrent mycotoxin exposure with a high starch diet in 12 beef steers in a partial cross-over experiment using a 21-day treatment period, followed by a 14-day clearance. During the treatment period, animals were assigned to one of two diets: a low mycotoxin control total mixed ration (TMR) (0.2±0.1 mg deoxynivalenol (DON) and 0.2±0.2 mg fumonisins (FUM)/kg TMR) and a high mycotoxin TMR treatment (1.7±0.2 mg DON and 3.5±0.3 mg FUM/kg TMR). We evaluated the impacts of these mycotoxins on performance, physiology and biochemistry; and the ability of the clearance period to return animals to a naïve state in the cross-over model. The lack of acute ruminal acidosis observed indicates that the animals were able to withstand the physiological stresses of the high starch diet, while toxicological outcomes were manifested in minor perturbations of biochemistry and outright performance of exposed animals. Aspartate aminotransferase, cholesterol, fibrinogen and leukocyte count were increased while sorbitol dehydrogenase, bile acids and mean corpuscular volume were decreased in treatment-fed steers, yet were not significantly different than those from control-fed animals. Fusarium toxin exposure significantly decreased ruminal fluid pH, with the clearance period returning animals to a naïve state, as it did for most of the molecular variables measured. Conversely, treatment-fed animals continued to exhibit significantly lower average weekly body weight throughout the treatment period and the first week of the clearance period. While the risk of adverse health effects to fattening cattle from similar doses of DON or FUM as used in the current study is considered low, additional work should be directed towards minimising production losses due to these feed contaminants.

Growth performance and amino acid digestibility responses of broiler chickens fed diets containing purified soybean trypsin inhibitor and supplemented with a monocomponent protease

Trypsin inhibitors (TI) resident in soybeans affects protein utilization. While heat treatment influences residual TI, it simultaneously affects the structure and solubility of the soybean proteins and confounds any response to exogenous proteases. Using purified TI, the effect of exogenous protease to TI can be dissociated from changes in the soybean protein. Thus, the current study was designed to evaluate the growth performance and protein utilization responses of broiler chickens to purified TI and exogenous protease. Soybean meal (SBM) was preanalyzed for basal TI (2,996 TIU/g SBM), formulated into nutritionally adequate experimental diets to contain 1,033 TIU/g diet, and purified TI was added at 9,000 TIU/g diet. A total of 320 Cobb-500 broiler chicks were allocated to 4 diets, each with 8 replicate cages and 10 birds per replicate. The experimental diets were arranged as a 2 × 2 factorial with factors being dietary TI (1,033 or 10,033 TIU/g) and exogenous protease (0 or 15,000 PROT/kg). On day 7, 14, and 21 posthatching, protease supplementation improved the BW gain (P < 0.01) and gain to feed ratio (P < 0.05) of birds. On day 14 and 21 posthatching, the relative weight of pancreas increased (P < 0.05) with added TI but was reduced (P < 0.001) with protease supplementation. Apparent ileal digestibility of all amino acids, except methionine, decreased (P < 0.001) with added TI but increased (P < 0.05) with protease supplementation. Jejunal MUC-2 was downregulated (P < 0.01) and SCL7A-2 was upregulated (P < 0.05) by protease supplementation. Duodenal trypsin and chymotrypsin activities reduced (P < 0.05) with added TI but increased (P < 0.01) with protease supplementation. Exogenous protease produced longer villi (P < 0.05) and deeper crypts (P < 0.01) in the jejunal tissue. In conclusion, dietary addition of purified TI negatively affects nutrient utilization by broiler chickens. Furthermore, the study showed that the efficacy of the exogenous protease might be independent of dietary TI concentration.

Growth phase and dietary α-amylase supplementation effects on nutrient digestibility and feedback enzyme secretion in broiler chickens

Growth performance, nutrient digestibility, intestinal health, and endogenous enzyme secretion responses to dietary α-amylase supplementation during 4 growth phases of broiler chickens fed corn–soybean meal–based diets were evaluated in the present study. A total of 1,136 male broiler chicks were assigned at day 0 after hatching to 8 treatments in a 2 × 4 factorial arrangement. There were 2 dietary levels of α-amylase supplementation of 0 or 80 kilo-Novo alpha amylase units per kg diet and 4 posthatching growth phases of day 0 to 11, day 11 to 21, day 21 to 42, or day 42 to 56 in a randomized complete block design. Each treatment comprised 8 replicate pens, with either 25 (day 0–11), 20 (day 11–21), 16 (day 21–42), or 10 (day 42–56) birds per pen. Body weight gain and feed efficiency of birds improved (P < 0.01) with α-amylase supplementation. There were main effects of α-amylase, growth phase, and interaction (P < 0.01) on apparent ileal digestibility (AID) of starch. This ranged from 0.8% during day 11 to 21 to 2.8% during day 0 to 11 after hatching. The total tract retention of starch increased (P < 0.05) with amylase supplementation but was not different across growth phases. Amylase supplementation increased (P < 0.05) AID of gross energy, AME (kcal/kg), and AMEn (kcal/kg). Villus height in the jejunal tissue was increased (P < 0.01) by α-amylase supplementation. During day 11 to 21 after hatching, the viscosity of jejunal digesta and pancreatic amylase activity increased (P < 0.01) with amylase supplementation. In conclusion, dietary amylase supplementation improved growth performance, apparent nutrient digestibility, and digestive enzyme activity of broiler chickens fed a corn–soybean diet. The study indicates that the growth phase of birds may affect response to exogenous amylase.

Toxicokinetics of Hydrolyzed Fumonisin B1 after Single Oral or Intravenous Bolus to Broiler Chickens Fed a Control or a Fumonisins-Contaminated Diet

The toxicokinetics (TK) of hydrolyzed fumonisin B₁ (HFB₁) were evaluated in 16 broiler chickens after being fed either a control or a fumonisins-contaminated diet (10.8 mg fumonisin B₁, 3.3 mg B₂ and 1.5 mg B₃/kg feed) for two weeks, followed by a single oral (PO) or intravenous (IV) dose of 1.25 mg/kg bodyweight (BW) of HFB₁. Fumonisin B₁ (FB₁), its partially hydrolyzed metabolites pHFB_1a and pHFB_1b, and fully hydrolyzed metabolite HFB₁, were determined in chicken plasma using a validated ultra-performance liquid chromatography–tandem mass spectrometry method. None of the broiler chicken showed clinical symptoms of fumonisins (FBs) or HFB₁ toxicity during the trial, nor was an aberration in body weight observed between the animals fed the FBs-contaminated diet and those fed the control diet. HFB₁ was shown to follow a two-compartmental pharmacokinetic model with first order elimination in broiler chickens after IV administration. Toxicokinetic parameters of HFB₁ demonstrated a total body clearance of 16.39 L/kg·h and an intercompartmental flow of 8.34 L/kg·h. Low levels of FB₁ and traces of pHFB_1b were found in plasma of chickens fed the FBs-contaminated diet. Due to plasma concentrations being under the limit of quantification (LOQ) after oral administration of HFB₁, no toxicokinetic modelling could be performed in broiler chickens after oral administration of HFB₁. Moreover, no phase II metabolites, nor N-acyl-metabolites of HFB₁ could be detected in this study.

Galacto-Oligosaccharides Modulate the Juvenile Gut Microbiome and Innate Immunity To Improve Broiler Chicken Performance

Improvements in growth performance and health are key goals in broiler chicken production. Inclusion of prebiotic galacto-oligosaccharides (GOS) in broiler feed enhanced the growth rate and feed conversion of chickens relative to those obtained with a calorie-matched control diet. Comparison of the cecal microbiota identified key differences in abundances of Lactobacillus spp. Increased levels of Lactobacillus johnsonii in GOS-fed juvenile birds at the expense of Lactobacillus crispatus were linked to improved performance (growth rate and market weight). Investigation of the innate immune responses highlighted increases of ileal and cecal interleukin-17A (IL-17A) gene expression counterposed to a decrease in IL-10. Quantification of the autochthonous Lactobacillus spp. revealed a correlation between bird performance and L. johnsonii abundance. Shifts in the cecal populations of key Lactobacillus spp. of juvenile birds primed intestinal innate immunity without harmful pathogen challenge.IMPORTANCE Improvements in the growth rate of broiler chickens can be achieved through dietary manipulation of the naturally occurring bacterial populations while mitigating the withdrawal of antibiotic growth promoters. Prebiotic galacto-oligosaccharides (GOS) are manufactured as a by-product of dairy cheese production and can be incorporated into the diets of juvenile chickens to improve their health and performance. This study investigated the key mechanisms behind this progression and pinpointed L. johnsonii as a key species that facilitates the enhancements in growth rate and gut health. The study identified the relationships between the GOS diet, L. johnsonii intestinal populations, and cytokine immune effectors to improve growth.

Response of broiler chickens to dietary soybean bioactive peptide and coccidia challenge

Growth performance, nutrient digestibility, jejunal morphology, plasma cytokine, and gene expression responses of broiler chickens (Cobb 500) to graded concentrations of dietary soybean bioactive peptide (SBP) and coccidia challenge (CC) were investigated in 2 experiments. In experiment 1, 384 male broiler chicks were used to investigate the effect of graded dietary concentrations of SBP on growth performance, nutrient digestibility, and intestinal morphology in a randomized complete block design with 8 replicate cages and 6 diets. Corn-soybean meal-based diet was supplemented with 0, 1, 2, 3, 4, and 5 g of SBP/kg of diet. There were linear effects (P < 0.05) of graded concentrations of SBP on BW, BW gain, gain:feed, ileal villus height, and jejunal crypt depth at day 22 post hatching. There were linear effects (P < 0.01) of graded SBP concentrations on Ileal DM and energy digestibility. Experiment 2 was conducted to investigate the immune-protective properties of SBP on broiler chickens during a coccidia challenge. A total of 256 male broiler chicks were randomly assigned to 8 replicate cages in a 2 × 2 factorial arrangement of treatments with 2 SBP levels (0 or 4 g/kg of diet) and with or without CC. On day 14 post hatching, birds in the challenged group received 20×, which is twice the recommended coccidia vaccine dose of 25 doses/kg BW, whereas the non-challenged group received physiological saline. Dietary SBP ameliorated the CC-induced effect (P = 0.01) on gain: feed. Coccidia challenge reduced (P < 0.05) jejunal villi height, whereas dietary SBP supplementation increased (P < 0.05) jejunal villi height. Dietary SBP attenuated the CC-induced effects (P < 0.05) on the expression of plasma IL-1β, transforming growth factor-β, claudin-1, and occludin genes. In conclusion, dietary SBP improved growth performance, nutrient digestibility, and jejunal morphology. In addition, dietary SBP reduced the impact of coccidia challenge, and may be beneficial in the feed of broiler chickens for alleviation of health-related effects of coccidia infection.

Mycotoxin Occurrence in Maize Silage-A Neglected Risk for Bovine Gut Health?

Forages are important components of dairy cattle rations but might harbor a plethora of mycotoxins. Ruminants are considered to be less susceptible to the adverse health effects of mycotoxins, mainly because the ruminal microflora degrades certain mycotoxins. Yet, impairment of the ruminal degradation capacity or high ruminal stability of toxins can entail that the intestinal epithelium is exposed to significant mycotoxin amounts. The aims of our study were to assess i) the mycotoxin occurrence in maize silage and ii) the cytotoxicity of relevant mycotoxins on bovine intestinal cells. In total, 158 maize silage samples were collected from European dairy cattle farms. LC-MS/MS-based analysis of 61 mycotoxins revealed the presence of emerging mycotoxins (e.g. emodin, culmorin, enniatin B1, enniatin B, and beauvericin) in more than 70% of samples. Among the regulated mycotoxins, deoxynivalenol and zearalenone were most frequently detected (67.7%). Overall, 87% of maize silages contained more than five mycotoxins. Using an in vitro model with calf small intestinal epithelial cells B, the cytotoxicity of deoxynivalenol, nivalenol, fumonisin B1 and enniatin B was evaluated (0-200 µM). Absolute IC50 values varied in dependence of employed assay and were 1.2-3.6 µM, 0.8-1.0 µM, 8.6-18.3 µM, and 4.0-6.7 µM for deoxynivalenol, nivalenol, fumonisin B1, and enniatin B, respectively. Results highlight the potential relevance of mycotoxins for bovine gut health, a previously neglected target in ruminants.

The role of dihydrosphingolipids in disease

Dihydrosphingolipids refer to sphingolipids early in the biosynthetic pathway that do not contain a C4-trans-double bond in the sphingoid backbone: 3-ketosphinganine (3-ketoSph), dihydrosphingosine (dhSph), dihydrosphingosine-1-phosphate (dhS1P) and dihydroceramide (dhCer). Recent advances in research related to sphingolipid biochemistry have shed light on the importance of sphingolipids in terms of cellular signalling in health and disease. However, dihydrosphingolipids have received less attention and research is lacking especially in terms of their molecular mechanisms of action. This is despite studies implicating them in the pathophysiology of disease, for example dhCer in predicting type 2 diabetes in obese individuals, dhS1P in cardiovascular diseases and dhSph in hepato-renal toxicity. This review gives a comprehensive summary of research in the last 10-15 years on the dihydrosphingolipids, 3-ketoSph, dhSph, dhS1P and dhCer, and their relevant roles in different diseases. It also highlights gaps in research that could be of future interest.

Biomarker Evaluation and Toxic Effects of an Acute Oral and Systemic Fumonisin Exposure of Pigs with a Special Focus on Dietary Fumonisin Esterase Supplementation

The mycotoxin fumonisin B1 (FB1) is a frequent contaminant of feed. It causes a disruption of sphingolipid metabolism and pulmonary, hepatic, and immunological lesions in pigs depending on the exposure scenario. One sensitive biomarker for FB1 exposure is the sphinganine (Sa) to sphingosine (So) ratio in blood. The fumonisin esterase FumD, which can be used as a feed additive, converts FB1 into the much less toxic metabolite hydrolyzed FB1 (HFB1). We conducted a single-dose study with barrows allocated to one of five treatments: (1) control (feed, 0.9% NaCl intravenously iv), (2) 139 nmol FB1 or (3) HFB1/kg BW iv, (4) 3425 nmol FB1/kg BW orally (po), or (5) 3321 nmol FB1/kg BW and 240 U FumD/kg feed po. The Sa/So ratio of iv and po FB1 administered groups was significantly elevated in blood and Liquor cerebrospinalis, but no fumonisin-associated differences were reflected in other endpoints. Neither clinical lung affections nor histopathological pulmonary lesions were detected in either group, while some parameters of hematology and clinical biochemistry showed a treatment–time interaction. FumD application resulted in Sa/So ratios comparable to the control, indicating that the enzymatic treatment was effectively preventing the fumonisin-induced disruption of sphingolipid metabolism.

Enzymatic hydrolysis of fumonisins in the gastrointestinal tract of broiler chickens

Fumonisins (FB) are among the most frequently detected mycotoxins in feedstuffs and finished feed, and recent data suggest that the functions of the gastrointestinal tract (GIT) in poultry species might be compromised at doses ranging from 10 to 20 mg/kg, close to field incidences and below the US and EU guidelines. Strategies are therefore necessary to reduce the exposure of poultry to FB. In the present study, we assessed the efficacy of fumonisin esterase FumD (EC 3.1.1.87, commercial name FUMzyme®) to cleave the tricarballylic acid side chains of FB, leading to the formation of non-toxic hydrolyzed fumonisins in the GIT of broiler chickens. Broiler chickens were fed for 14 d (7 to 21 d of age) 3 different diets (6 birds/cage, 6 cages/diet), i) control feed (negative control group), ii) feed contaminated with 10 mg FB/kg (FB group), and iii) feed contaminated with 10 mg FB/kg and supplemented with 100 units of FUMzyme®/kg (FB+FUMzyme® group). To determine the degree of reduction of FB in the GIT, 2 characteristics were analyzed. First, the sphinganine-to-sphingosine ratio in the serum and liver was determined as a biomarker of effect for exposure to FB. Second, the concentration of fumonisin B1 and its hydrolyzed forms was evaluated in the gizzard, the proximal and distal parts of the small intestine, and the excreta. Significantly reduced sphinganine-to-sphingosine ratios in the serum and liver of the FB+FUMzyme® group (serum: 0.15 ± 0.01; liver: 0.17 ± 0.01) compared to the FB group (serum: 0.20 ± 0.01; liver: 0.29 ± 0.03) proved that supplementation of broiler feed with FUMzyme® was effective in partially counteracting the toxic effect of dietary FB. Likewise, FB concentrations in digesta and excreta were significantly reduced in the FB+FUMzyme® group compared to the FB group (P < 0.05; up to 75%). FUMzyme® furthermore partially counteracted FB-induced up-regulation of cytokine gene expression (IL-8 and IL-10) in the jejunum. The FB group showed significantly higher gene expression of IL-8 and IL-10 compared to the negative control group (IL-8: fold change = 2.9 ± 1.1, P < 0.05; IL-10: fold change = 3.6 ± 1.4, P < 0.05), whereas IL-8 and IL-10 mRNA levels were not significantly different in the FB+FUMzyme®® group compared to the other 2 groups. In conclusion, FUMzyme® is suitable to detoxify FB in chickens and maintain gut functions.

Risks for animal health related to the presence of fumonisins, their modified forms and hidden forms in feed

Fumonisins, mycotoxins primarily produced by Fusarium verticillioides and Fusarium proliferatum, occur predominantly in cereal grains, especially in maize. The European Commission asked EFSA for a scientific opinion on the risk to animal health related to fumonisins and their modified and hidden forms in feed. Fumonisin B1 (FB 1), FB 2 and FB 3 are the most common forms of fumonisins in feedstuffs and thus were included in the assessment. FB 1, FB 2 and FB 3 have the same mode of action and were considered as having similar toxicological profile and potencies. For fumonisins, the EFSA Panel on Contaminants in the Food Chain (CONTAM) identified no-observed-adverse-effect levels (NOAELs) for cattle, pig, poultry (chicken, ducks and turkeys), horse, and lowest-observed-adverse-effect levels (LOAELs) for fish (extrapolated from carp) and rabbits. No reference points could be identified for sheep, goats, dogs, cats and mink. The dietary exposure was estimated on 18,140 feed samples on FB 1-3 representing most of the feed commodities with potential presence of fumonisins. Samples were collected between 2003 and 2016 from 19 different European countries, but most of them from four Member States. To take into account the possible occurrence of hidden forms, an additional factor of 1.6, derived from the literature, was applied to the occurrence data. Modified forms of fumonisins, for which no data were identified concerning both the occurrence and the toxicity, were not included in the assessment. Based on mean exposure estimates, the risk of adverse health effects of feeds containing FB 1-3 was considered very low for ruminants, low for poultry, horse, rabbits, fish and of potential concern for pigs. The same conclusions apply to the sum of FB 1-3 and their hidden forms, except for pigs for which the risk of adverse health effect was considered of concern.

Application of biomarker methods to investigate FUMzyme mediated gastrointestinal hydrolysis of fumonisins in pigs

Fumonisins are among the most prevalent mycotoxins in feedstuffs. They disrupt the sphingolipid metabolism, thereby inducing a plethora of toxic effects in livestock. Supplementation with mycotoxin-degrading enzymes is a promising strategy for the detoxification of feedstuffs in the animals’ gastrointestinal tract. Here, we evaluated the suitability of the fumonisin esterase FumD as a feed additive (FUMzyme®) for the prevention of fumonisin toxicity in pigs by using a combination of different fumonisin biomarkers (sphinganine to sphingosine (Sa/So) ratio in serum and organs, concentrations of fumonisin B1 and hydrolysed derivatives in urine and faeces). In a pre-trial, we exposed pigs to 30 mg/kg fumonisins in feed and found the minimum effective dose of FUMzyme to be 15 U/kg. In a second trial we investigated the long-term efficacy of this minimum effective FUMzyme dose to counteract toxic effects elicited by 6 weeks of exposure to 2.5 mg/kg fumonisins in a diet containing naturally contaminated maize. Supplementation of feed with the minimum effective FUMzyme dose prevented an increase in the Sa/So ratio in serum and kidneys of fumonisin exposed pigs. The Sa/So ratio in serum proved to be the most reliable biomarker. The fumonisin pattern in faeces was less suitable as biomarker for assessing the efficacy of FUMzyme due to natural gastrointestinal hydrolysis of fumonisins. Analysis of urine samples provided additional information about gastrointestinal fumonisin hydrolysis before fumonisin absorption, but was analytically challenging because of low urinary fumonisin concentrations.

Effect of threonine deficiency on intestinal integrity and immune response to feed withdrawal combined with coccidial vaccine challenge in broiler chicks

For this study, threonine (Thr) deficiency was hypothesised to exacerbate the intestinal damage induced by feed withdrawal with coccidial infection because of its high obligatory requirement by the gut; two dietary Thr treatments (0·49 and 0·90 %) were applied to chicks from 0 to 21 d of age. At 13 d of age, feed was withdrawn for 24 h from one-half of birds of each dietary treatment with subsequent gavage of a 25× dose of coccidial vaccine. Overall, there were four treatments with eight replicate cages per treatment. Under combined challenge, birds fed the Thr-deficient diet had 38 % lower 13–21-d body weight gain (P≤0·05) compared with birds fed the Thr-control diet. At 21 d, the challenged group fed low Thr had higher number of oocysts (+40 %, P=0·03) and lower crypt depth (−31 %, P<0·01). In addition, birds fed the low-Thr diet had higher gut permeability as measured after 2 h of administration of fluorescein isothiocyanate-dextran (3–5 kDa, P<0·01), which may be attributed to decreased IgA production (P=0·03) in the ileum. In caecal tonsils, the challenged group fed low Thr had lower CD3:Bu-1 ratio (P≤0·05), along with a tendency for lower CCR9 mRNA expression in birds fed the low-Thr diet (P=0·10). In addition, Thr deficiency tended to increase IL-10 mRNA expression regardless of infection (P=0·06), but did not change interferon-γ mRNA expression upon coccidial infection (P>0·05). Overall, Thr deficiency worsened the detrimental effects of combined feed withdrawal and coccidial infection on growth performance and oocyst shedding by impairing intestinal morphology, barrier function, lymphocyte profiles and their cytokine expressions.

Susceptibility of Broiler Chickens to Coccidiosis When Fed Subclinical Doses of Deoxynivalenol and Fumonisins-Special Emphasis on the Immunological Response and the Mycotoxin Interaction

Deoxynivalenol (DON) and fumonisins (FB) are the most frequently encountered mycotoxins produced by Fusarium species in livestock diets. The effect of subclinical doses of mycotoxins in chickens is largely unknown, and in particular the susceptibility of birds to pathogenic challenge when fed these fungal metabolites. Therefore, the present study reports the effects of DON and FB on chickens challenged with Eimeria spp, responsible for coccidiosis. Broilers were fed diets from hatch to day 20, containing no mycotoxins, 1.5 mg DON/kg, 20 mg FB/kg, or both toxins (12 pens/diet; 7 birds/pen). At day 14, six pens of birds per diet (half of the birds) were challenged with a 25×-recommended dose of coccidial vaccine, and all birds (challenged and unchallenged) were sampled 6 days later. As expected, performance of birds was strongly affected by the coccidial challenge. Ingestion of mycotoxins did not further affect the growth but repartitioned the rate of reduction (between the fraction due to the change in maintenance and feed efficiency), and reduced apparent nitrogen digestibility. Intestinal lesions and number of oocysts in the jejunal mucosa and feces of challenged birds were more frequent and intense in the birds fed mycotoxins than in birds fed control feed. The upregulation of cytokines (interleukin (IL) IL-1β, IL-6, IL-8 and IL-10) following coccidial infection was higher in the jejunum of birds fed mycotoxins. Further, the higher intestinal immune response was associated with a higher percentage of T lymphocytes CD4⁺CD25⁺, also called T_regs, observed in the cecal tonsils of challenged birds fed mycotoxins. Interestingly, the increase in FB biomarker of exposure (sphinganine/sphingosine ratio in serum and liver) suggested a higher absorption and bioavailability of FB in challenged birds. The interaction of DON and FB was very dependent on the endpoint assessed, with three endpoints reporting antagonism, nine additivity, and two synergism. In conclusion, subclinical doses of DON and FB showed little effects in unchallenged chickens, but seem to result in metabolic and immunologic disturbances that amplify the severity of coccidiosis.

Fumonisin B₁ (FB₁) Induces Lamellar Separation and Alters Sphingolipid Metabolism of In Vitro Cultured Hoof Explants

One of the most important hoof diseases is laminitis. Yet, the pathology of laminitis is not fully understood. Different bacterial toxins, e.g. endotoxins or exotoxins, seem to play an important role. Additionally, ingestion of mycotoxins, toxic secondary metabolites of fungi, might contribute to the onset of laminitis. In this respect, fumonsins are of special interest since horses are regarded as species most susceptible to this group of mycotoxins. The aim of our study was to investigate the influence of fumonisin B₁ (FB₁) on primary isolated epidermal and dermal hoof cells, as well as on the lamellar tissue integrity and sphingolipid metabolism of hoof explants in vitro. There was no effect of FB₁ at any concentration on dermal or epidermal cells. However, FB₁ significantly reduced the separation force of explants after 24 h of incubation. The Sa/So ratio was significantly increased in supernatants of explants incubated with FB₁ (2.5–10 µg/mL) after 24 h. Observed effects on Sa/So ratio were linked to significantly increased sphinganine concentrations. Our study showed that FB₁ impairs the sphingolipid metabolism of explants and reduces lamellar integrity at non-cytotoxic concentrations. FB₁ might, therefore, affect hoof health. Further in vitro and in vivo studies are necessary to elucidate the effects of FB₁ on the equine hoof in more detail.

Gastrointestinal Degradation of Fumonisin B₁ by Carboxylesterase FumD Prevents Fumonisin Induced Alteration of Sphingolipid Metabolism in Turkey and Swine

The mycotoxin fumonisin B₁ (FB₁) is a frequent contaminant of feed and causes various adverse health effects in domestic animals. Hence, effective strategies are needed to prevent the impact of fumonisins on livestock productivity. Here we evaluated the capability of the fumonisin carboxylesterase FumD to degrade FB₁ to its less toxic metabolite hydrolyzed FB₁ (HFB₁) in the gastrointestinal tract of turkeys and pigs. First, an ex vivo pig model was used to examine the activity of FumD under digestive conditions. Within 2 h of incubation with FumD, FB₁ was completely degraded to HFB₁ in the duodenum and jejunum, respectively. To test the efficacy of the commercial application of FumD (FUMzyme) in vivo, female turkeys (n = 5) received either basal feed (CON), fumonisin-contaminated feed (15 mg/kg FB₁+FB₂; FB) or fumonisin-contaminated feed supplemented with FUMzyme (15 U/kg; FB+FUMzyme) for 14 days ad libitum. Addition of FUMzyme resulted in significantly decreased levels of FB₁ in excreta, whereas HFB₁ concentrations were significantly increased. Compared to the FB group (0.24 ± 0.02), the mean serum sphinganine-to-sphingosine (Sa/So) ratio was significantly reduced in the FB+FUMzyme group (0.19 ± 0.02), thus resembling values of the CON group (0.16 ± 0.02). Similarly, exposure of piglets (n = 10) to 2 mg/kg FB₁+FB₂ for 42 days caused significantly elevated serum Sa/So ratios (0.39 ± 0.15) compared to the CON group (0.14 ± 0.01). Supplementation with FUMzyme (60 U/kg) resulted in gastrointestinal degradation of FB₁ and unaffected Sa/So ratios (0.16 ± 0.02). Thus, the carboxylesterase FumD represents an effective strategy to detoxify FB₁ in the digestive tract of turkeys and pigs.

Mycotoxins Deoxynivalenol and Fumonisins Alter the Extrinsic Component of Intestinal Barrier in Broiler Chickens

Deoxynivalenol (DON) and fumonisins (FBs) are secondary metabolites produced by Fusarium fungi that frequently contaminate broiler feed. The aim of this study was to investigate the impact of DON and/or FBs on the intestinal barrier in broiler chickens, more specifically on the mucus layer and antioxidative response to oxidative stress. One-day-old broiler chicks were divided into four groups, each consisting of eight pens of seven birds each, and were fed for 15 days either a control diet, a DON-contaminated diet (4.6 mg DON/kg feed), a FBs-contaminated diet (25.4 mg FB1 + FB2/kg feed), or a DON+FBs-contaminated diet (4.3 mg DON and 22.9 mg FB1 + FB2/kg feed). DON and FBs affected the duodenal mucus layer by suppressing intestinal mucin (MUC) 2 gene expression and altering the mucin monosaccharide composition. Both mycotoxins decreased gene expression of the intestinal zinc transporter (ZnT)-1 and regulated intracellular methionine homeostasis, which are both important for preserving the cell's critical antioxidant activity. Feeding a DON- and/or FBs-contaminated diet, at concentrations close to the European Union maximum guidance levels (5 mg DON and 20 mg FB1 + FB2/kg feed) changes the intestinal mucus layer and several intestinal epithelial antioxidative mechanisms.