Effect of aflatoxin culture on intestinal function and nutrient loss in laying hens

Aflatoxin B1 Induces Intestinal Barrier Dysfunction by Regulating the FXR-Mediated MLCK Signaling Pathway in Mice and in IPEC-J2 Cells

Aflatoxin B1 (AFB1) is a widespread mycotoxin in food and feed. Although the liver is the main target organ of AFB1, the intestine is the first exposure organ to AFB1. However, the mechanism by which AFB1 induced intestinal barrier dysfunction via regulating the farnesoid X receptor (FXR)-mediated myosin light chain kinase (MLCK) signaling pathway has rarely been studied. In vivo, AFB1 exposure significantly decreased the small intestine length and increased the intestinal permeability. Meanwhile, AFB1 exposure markedly suppressed the protein expressions of FXR, ZO-1, occludin, and claudin-1 and enhanced the protein expression of MLCK. In vitro, AFB1 exposure induced intestinal barrier dysfunction by the elevation in the FITC-Dextran 4 kDa flux and inhibition in the transepithelial electrical resistance in a dose-dependent manner. In addition, AFB1 exposure downregulated the mRNA and protein expressions of FXR, ZO-1, occludin, and claudin-1, redistributed the ZO-1 protein, and enhanced the protein expressions of MLCK and p-MLC. However, fexaramine (Fex, FXR agonist) pretreatment markedly reversed the AFB1-induced FXR activity reduction, MLCK protein activation, and intestinal barrier impairment in vitro and in vivo. Moreover, pretreatment with the inhibition of MLCK with ML-7 significantly alleviated the AFB1-induced intestinal barrier dysfunction and tight junction disruption in vitro. In conclusion, AFB1 induced intestinal barrier impairment via regulating the FXR-mediated MLCK signaling pathway in vitro and in vivo and provided novel insights to prevent mycotoxin poisoning in the intestine.

Can Red Yeast (Sporidiobolus pararoseus) Be Used as a Novel Feed Additive for Mycotoxin Binders in Broiler Chickens?

Mycotoxin-contaminated feeds may negatively affect broiler chickens’ health; hence, a sustainable approach to achieve mycotoxin elimination is necessary. This study aimed to evaluate the efficacy of red yeast (Sporidiobolus pararoseus; RY) as a novel mycotoxin binder in broilers. A total of 1440 one-week-old male broiler chicks were randomly assigned to 12 treatments in a 3 × 4 factorial design. The dietary treatments included three levels of mycotoxin-contaminated diets (0 µg kg−1 (0% of mycotoxin; MT), 50 µg kg−1 (50% MT), and 100 µg kg−1 (100% MT)) and four levels of mycotoxin binders (0.0 and 0.5 g kg−1 commercial binder, and 0.5 and 1.0 g kg−1 RY). Experimental diets were contaminated with aflatoxin B1, zearalenone, ochratoxin A, T-2 toxin, and deoxynivalenol in the basal diet. Furthermore, the parameters including feed intake, body weight, and mortality rate were recorded on a weekly basis. After feeding for 28 days, blood and organ samples were collected randomly to determine the blood biochemistry, relative organ weights, and gut health. The results indicated that mycotoxin-contaminated diets reduced the average daily weight gain (ADG), villus height (VH), and villus height per the crypt depth ratio (VH:CD) of the intestine, as well as the population of Lactobacillus sp. and Bifidobacterium sp. in the cecal (p < 0.05), whereas they increased the mycotoxins concentration in the blood samples and the apoptosis cells (TUNEL positive) in the liver tissue (p < 0.01) of broiler chicken. In contrast, RY-supplemented diets had better ADG values and lower chicken mortality rates (p < 0.05). Moreover, these combinations positively impacted the relative organ weights, blood parameters, bacteria population, intestinal morphology, and pathological changes in the hepatocytes (p < 0.05). In conclusion, RY supplementation effectively alleviated the toxicity that is induced by AFB1 and OTA, mainly, and could potentially be applied as a novel feed additive in the broiler industry.

Nutritional impact of mycotoxins in food animal production and strategies for mitigation

Mycotoxins are toxic secondary metabolites produced by filamentous fungi that are commonly detected as natural contaminants in agricultural commodities worldwide. Mycotoxin exposure can lead to mycotoxicosis in both animals and humans when found in animal feeds and food products, and at lower concentrations can affect animal performance by disrupting nutrient digestion, absorption, metabolism, and animal physiology. Thus, mycotoxin contamination of animal feeds represents a significant issue to the livestock industry and is a health threat to food animals. Since prevention of mycotoxin formation is difficult to undertake to avoid contamination, mitigation strategies are needed. This review explores how the mycotoxins aflatoxins, deoxynivalenol, zearalenone, fumonisins and ochratoxin A impose nutritional and metabolic effects on food animals and summarizes mitigation strategies to reduce the risk of mycotoxicity.

Effect of Dietary L-Threonine and Toxin Binder on Performance, Blood Parameters, and Immune Response of Broilers Exposed to Aflatoxin B1

To evaluate the effect of L-Threonine (L-Thr) and Mycofix® Plus (MP) on aflatoxicosis, an experiment with a 3-way ANOVA model was carried out with 8 replicates and 640 birds. Treatments included two levels of L-Thr (100% and 125% of the requirements, Cobb 500, Cobb-Vantress), Aflatoxin B1 (AFB1) (0, 500 ppb), and MP (0, 1 g/kg). As the main effects showed, AFB1 decreased breast meat yield and carcass percentage (p < 0.001), serum urea, antibody titer against infectious bronchitis virus (IBV), and bone density (p < 0.05), while it increased the plasma concentrations of glucose and alkaline phosphatase (ALP) (p < 0.05). Mycofix Plus improved the grower feed intake (FI), tibia fresh weight, and body weight (BW) to bone weight (p < 0.05). L-Threonine increased the grower FI, breast meat yield, serum aspartate transaminase (AST), and glutathione peroxidase (GPX) (p < 0.05). There were positive interactions with breast meat yield, cholesterol, lactate dehydrogenase (LDH), and IBV titer. Of the treatments used, the combination of L-Thr and MP without AFB1 improved breast meat and carcass percentage. L-Threonine and MP significantly improved IBV titer in birds challenged with AFB1 (p < 0.001). In conclusion, L-Thr and MP were beneficial to improve immunity.

Mitigation Effects of Bentonite and Yeast Cell Wall Binders on AFB1, DON, and OTA Induced Changes in Laying Hen Performance, Egg Quality, and Health

The objective of this study was to evaluate the efficacy of mycotoxin binders in reducing the adverse effects of co-occurring dietary aflatoxin B₁ (AFB₁), deoxynivalenol (DON) and ochratoxin A (OTA) on laying hens. Three hundred and sixty 26-week-old Roman laying hens were randomly allocated into four experimental groups with 10 replicates of nine birds each. The four groups received either a basal diet (BD; Control), a BD supplemented with 0.15 mg/kg AFB₁ + 1.5 mg/kg DON + 0.12 mg/kg OTA (Toxins), a BD + Toxins with Toxo-HP binder (Toxins + HP), or a BD + Toxins with TOXO XL binder (Toxins + XL) for 12 weeks. Compared to the control, dietary supplementation of mycotoxins decreased (P < 0.10) total feed intake, total egg weight, and egg-laying rate, but increased feed/egg ratio by 2.5–6.1% and mortality during various experimental periods. These alterations induced by mycotoxins were alleviated by supplementation with both TOXO HP and XL binders (P < 0.10). Furthermore, dietary mycotoxins reduced (P < 0.05) eggshell strength by 12.3% and caused an accumulation of 249 μg/kg of DON in eggs at week 12, while dietary supplementation with TOXO HP or XL mitigated DON-induced changes on eggshell strength and prevented accumulation of DON in eggs (P < 0.05). Moreover, dietary mycotoxins increased relative liver weight, but decreased spleen and proventriculus relative weights by 11.6–22.4% (P < 0.05). Mycotoxin exposure also increased alanine aminotransferase activity and reduced immunoglobulin (Ig) A, IgM, and IgG concentrations in serum by 9.2–26.1% (P < 0.05). Additionally, mycotoxin exposure induced histopathological damage and reduced villus height, villus height/crypt depth, and crypt depth in duodenum, jejunum and (or) ileum (P < 0.05). Notably, most of these histological changes were mitigated by supplementation with both TOXO HP and XL (P < 0.05). In conclusion, the present study demonstrated that the mycotoxin binders TOXO HP and XL can help to mitigate the combined effects of AFB₁, DON, and OTA on laying hen performance, egg quality, and health.

Comparison of intestinal permeability, morphology, and ileal microbial communities of commercial hens housed in conventional cages and cage-free housing systems

The gastrointestinal health of poultry can be impacted by a variety of factors including their environment. As egg production moves from conventional cage housing (CC) toward cage-free housing (CF), it is important to understand this impact on intestinal health. This study was conducted to determine if housing type impacted intestinal permeability, morphology, and microbial communities in commercial hens across housing systems. Hens were randomly selected from 2 rooms of CC (n = 25) and CF (n = 25) at a commercial facility. Birds were given fluorescein isothiocyanate dextran (FITC-D) by oral gavage to measure intestinal permeability. Jejunal and ileal samples were collected to evaluate villus height, crypt depth, and their ratio. Ileal contents were collected for bacterial DNA isolation and 16S rRNA gene sequencing. Serum FITC-D was similar between housing type (P = 0.709). Hens housed in the CF had increased jejunal villus height and crypt depth compared with hens from the CC (P < 0.002). Hens from the CC tended to have a greater villus height to crypt depth ratio in both the jejunum and ileum compared with the CF (P = 0.064; P = 0.091, respectively). Microbial community diversity measurements favored hens housed in the CC as ileal contents tended to have increased species richness (P = 0.059), had greater alpha diversity (P = 0.044), and had an increased number of over represented operational taxonomic units (46/64), including Romboutsia sp. (30.80%), Lactobacillus kitasatonis (17.16%), and Lactobacillus aviarius (11.15%). Correlations between microbial communities with intestinal traits identified significant association with the greatest number of correlations with FITC-D and ileal morphology. Many of these correlations identified microbial communities associated with expected traits; thus, providing limited functional data to microbial communities with limited information. The greater number of correlations of ileal morphology with ileal microbial communities suggesting local microbial communities contribute to the intestinal environment distant. In this limited study, several parameters favored hens from CC suggesting an advantage of this system for intestinal health. However, the lower intestinal health parameters observed in CF were not at levels to indicate detrimental effects.

The Compromised Intestinal Barrier Induced by Mycotoxins

Mycotoxins are fungal metabolites that occur in human foods and animal feeds, potentially threatening human and animal health. The intestine is considered as the first barrier against these external contaminants, and it consists of interconnected physical, chemical, immunological, and microbial barriers. In this context, based on in vitro, ex vivo, and in vivo models, we summarize the literature for compromised intestinal barrier issues caused by various mycotoxins, and we reviewed events related to disrupted intestinal integrity (physical barrier), thinned mucus layer (chemical barrier), imbalanced inflammatory factors (immunological barrier), and dysfunctional bacterial homeostasis (microbial barrier). We also provide important information on deoxynivalenol, a leading mycotoxin implicated in intestinal dysfunction, and other adverse intestinal effects induced by other mycotoxins, including aflatoxins and ochratoxin A. In addition, intestinal perturbations caused by mycotoxins may also contribute to the development of mycotoxicosis, including human chronic intestinal inflammatory diseases. Therefore, we provide a clear understanding of compromised intestinal barrier induced by mycotoxins, with a view to potentially develop innovative strategies to prevent and treat mycotoxicosis. In addition, because of increased combinatorial interactions between mycotoxins, we explore the interactive effects of multiple mycotoxins in this review.

Effect of Cynara scolymus and its derivatives on broilers: an updated review

Medicinal plants and their derivatives are human-friendly, nutritional supplements, and their use in the poultry industry is increasing today. Cynara scolymus is a very high-quality antioxidant medicine plant that has recently attracted the attention of poultry and nutrition researchers to supplement their rations and reduce feed costs. In the present study, the effect of powder and extract of C. scolymus on broilers has reviewed. This review shows that the impact of C. scolymus on production performance, carcass characteristics, liver enzymes activity, and meat characteristics of broiler chickens are not significant. However, the negative impact of this compound on these properties has not reported. Moreover, cholesterol levels reduced by the dietary C. scolymus supplementation. The impact of C. scolymus powder and extract on chickens' broiler immunity was not significant in the cited literature, but dietary C. scolymus powder increases Newcastle antibody titers and lowers blood pressure. Dietary C. scolymus under heat stress increased anti-sheep red blood cell titers. No substantial studies have conducted on the effect of C. scolymus on broilers. Therefore, it is not possible to determine a single dosage for the use of C. scolymus powder or extract in broiler diets to the improvement of the broiler characteristics. More researches are needed to determining the appropriate dosage to achieve maximum performance.

The impact of deoxynivalenol, fumonisins, and their combination on performance, nutrient, and energy digestibility in broiler chickens

This study evaluated the effects of the mycotoxins deoxynivalenol (DON), fumonisins (FUM), and their combination on growth performance, nutrient, and energy digestibility in broilers. A total of 960 Cobb-Cobb male broilers were obtained on the day of hatch and placed 10 birds per cage with 8 cages per treatment. The experiment consisted of 12 treatments: control; DON 1.5 mg/kg; DON 5.0 mg/kg; FUM 20.0 mg/kg; DON 1.5 mg/kg + FUM 20.0 mg/kg; and DON 5.0 mg/kg + FUM 20 mg/kg. The remaining dietary treatments were the correlative nitrogen-free diets (NFD) for determining the endogenous nutrients loss. All birds were fed with a corn-soybean meal diet from days 1 to 15, until birds from latter 6 treatments were switched to their correlative NFD diet from days 15 to 21. Feed and BW were weighed by cage on days 8, 15, and 21. On day 21, ileal digesta was collected for digestibility determination. Both DON 1.5 mg/kg + FUM 20 mg/kg and DON 5.0 mg/kg + FUM 20 mg/kg treatments showed reduced feed intake (P ≤ 0.05) from days 8 to 15 and days 15 to 21. However, no significant effects were noted for BW gain or mortality-adjusted feed conversion ratio after adding single or combined mycotoxin on days 8 and 15. At day 21, cumulative BW gain was less (P ≤ 0.05) in birds fed with the mycotoxin combination diets than the control. No significant changes were shown for ileal endogenous amino acids losses. Control treatment had significantly higher (P ≤ 0.05) apparent ileal energy digestibility than the DON 5.0 mg/kg + FUM 20.0 mg/kg treatment (3,126 vs. 2,895 kcal/kg), representing a 5%-unit loss in apparent DM digestibility. No significant difference was found for standardized crude protein and amino acid digestibility. In conclusion, the combination of DON and FUM (DON 1.5 mg/kg + FUM 20 mg/kg or DON 5.0 mg/kg + FUM 20 mg/kg) reduced DM and ileal energy digestibility, which negatively affected BW gain in broilers.

Effect of age on the relationship between metabolizable energy and digestible energy for broiler chickens

A total of 960 male Ross 308 chicks (day-old) were used to investigate the effect of age on the relationship between metabolizable energy (ME) and digestible energy (DE) for broiler chickens. Bird growth variables, nitrogen retention (NR), nitrogen digestibility (ND), as well as the relative weight of liver, pancreas, and the gastrointestinal tract were determined. Practical diets that compared 2 cereals (corn and wheat) and exogenous xylanase (0 or 16,000 BXU/kg) were evaluated at 5 ages (7, 14, 21, 28, and 35 D) in a 2 × 2 × 5 factorial arrangement of treatments with 8 replicates per treatment and started with 30 birds per replicate. A randomized block ANOVA analysis of repeated measures was performed, and a 2 × 2 × 5 factorial structure was used to investigate the 2 dietary treatment factors (cereal type and the presence of xylanase) within the 5 bird ages (7, 14, 21, 28, and 35 D), and their interactions. Apparent metabolizable energy (AME) increased linearly from 7 until 28 D of age, but (P < 0.05) decreased at 35 D of age. Digestible energy was high at 7 D of age, then dropped and remained similar (P > 0.05) from 14 to 35 D of age. The AME: DE ratio was lowest (P < 0.05) at 7 D of age but there were no (P > 0.05) differences thereafter. Cereal type and xylanase supplementation did not (P > 0.05) change the ME: DE ratio. The results indicate that determining ME before 14 D of age may give absolute values that are lower than would be obtained with older birds. ME values that are determined on older broiler chickens may overestimate the energy availability of practical feeds used in broiler starter feeds.

Effects of T-2 toxin on digestive enzyme activity, intestinal histopathology and growth in shrimp Litopenaeus vannamei

T-2 toxin (T-2), a naturally occurring mycotoxin that often accumulates in aquatic animals via contaminated feed, is toxic to animals, including humans. In this study, six groups of shrimp (n = 30 shrimps/group) were given T-2 in feed at concentrations of 0–12.2 mg/kg for 20 days. T-2 accumulation, intestinal histopathology, digestive enzyme activities and subsequent effects on shrimp are reported. Compared to the control, T-2 significantly reduced weight gain, specific growth rate, and survival. The histopathology of shrimp intestine showed concentration-dependent degenerative and necrotic changes in response to dietary T-2. Progressive damage to the microstructures of shrimp intestine occurred with increasing dietary T-2 concentrations, with initial inflammation of the mucosal tissue at T-2 concentrations of 0.5 and 1.2 mg/kg, progressing to disappearance of intestinal villi and degeneration and necrosis of the submucosa at 12.2 mg/kg. Intestinal amylase and protease activities increased at low T-2 concentrations but showed significant inhibition at high concentrations; however, the opposite trend occurred for lipase activity. Collectively, these results indicate that digestive enzyme activities and mucosal structures are markedly affected by exposure to T-2, and these may have contributed to the lower survival rate of shrimp.

Progress in Mycotoxins Affecting Intestinal Mucosal Barrier Function

Mycotoxins, which are widely found in feed ingredients and human food, can exert harmful effects on animals and pose a serious threat to human health. As the first barrier against external pollutants, the intestinal mucosa is protected by a mechanical barrier, chemical barrier, immune barrier, and biological barrier. Firstly, mycotoxins can disrupt the mechanical barrier function of the intestinal mucosa, by destroying the morphology and tissue integrity of the intestinal epithelium. Secondly, mycotoxins can cause changes in the composition of mucin monosaccharides and the expression of intestinal mucin, which in turn affects mucin function. Thirdly, mycotoxins can cause damage to the intestinal mucosal immune barrier function. Finally, the microbiotas of animals closely interact with ingested mycotoxins. Based on existing research, this article reviews the effects of mycotoxins on the intestinal mucosal barrier and its mechanisms.

Harmful Effects and Control Strategies of Aflatoxin B₁ Produced by Aspergillus flavus and Aspergillus parasiticus Strains on Poultry: Review

The presence of aflatoxin B₁ (AFB₁) in poultry diets decreases the hatchability, hatchling weight, growth rate, meat and egg production, meat and egg quality, vaccination efficiency, as well as impairing the feed conversion ratio and increasing the susceptibility of birds to disease and mortality. AFB₁ is transferred from poultry feed to eggs, meat, and other edible parts, representing a threat to the health of consumers because AFB₁ is carcinogenic and implicated in human liver cancer. This review considers how AFB₁ produced by Aspergillus flavus and Aspergillus parasiticus strains can affect the immune system, antioxidant defense system, digestive system, and reproductive system in poultry, as well as its effects on productivity and reproductive performance. Nutritional factors can offset the effects of AFB₁ in poultry and, thus, it is necessary to identify and select suitable additives to address the problems caused by AFB₁ in poultry.

Effects of maize naturally contaminated with aflatoxin B1 on growth performance, intestinal morphology, and digestive physiology in ducks

This study was conducted to determine the effects of maize naturally contaminated with aflatoxin B1 (AFB1) on growth performance, intestinal morphology, relative digestive organs weight, digestive enzymes activities, and biochemical index of intestinal development in ducks. A total of 640 ducks was blocked on the basis of sex and body weight, and then allocated randomly to 2 treatments with 20 pens per treatment and 16 ducks per pen. The experiment lasted for 5 wk, and dietary treatments included basal diet (CON) and diets with 100% of normal maize replaced by AFB1 contaminated maize. Detectable levels of other toxins were present but only AFB1 exceeded limits and the level of AFB1 was 195.4 ug/kg in the contaminated maize, and ranged from 2.91 to 120.02 ug/kg in the starter diet and 2.03 to 153.12 ug/kg in the grower diet. Feeding AFB1 contaminated diets decreased (P < 0.05) ADG and ADFI during the whole experiment, whereas F/G during d 15 to 35 and d zero to 35 was reduced (P < 0.05). The mortality of ducks fed AFB1 contaminated diets increased (P < 0.05). Ducks fed AFB1 contaminated diets had greater (P < 0.05) relative weights of proventriculus and gizzard on d 14 as well as the duodenum, jejunum, and ileum on d 14 and 35. Feeding AFB1 contaminated diets increased (P < 0.05) crypt depth, villus width, and surface area in the duodenum on d 35 and villus height, villus width, and surface area in the jejunum on d 14. The activities of alkaline phosphatase and leucine aminopeptidase in the jejunum brush border together with chymotrypsin and trypsin in the pancreas increased (P < 0.05) on d 14 with the inclusion of AFB1 contaminated maize. The jejunum villus became long and wide in ducks fed AFB1 contaminated diets. Taken together, the feeding of maize naturally contaminated with AFB1 caused adverse effects on growth performance and intestinal morphology, and altered digestive physiology and development.

Association of aflatoxin exposure and height-for-age among young children in Guatemala

Aflatoxin exposure has been proposed to affect child height-for-age. The following hypothesized associations were tested in Guatemala: (1) aflatoxin (B₁, B₂, G₁, G₂) exposure and environmental enteric dysfunction (EED) and child height-for-age z-score; and (2) aflatoxin exposures and subsequent symptoms of aflatoxins. Maize consumption data, health data, and samples of maize from households were collected from mothers and their children - under five - in October 2016 (n = 320) and February 2017 (n = 120). Maize samples were tested for aflatoxin levels and maize consumption data were used to compute an aflatoxin exposure level. Results suggest that there was a significant negative correlation between the putative aflatoxin exposure level and child height-for-age z-score (-0.073, p = 0.030), but not for EED. Furthermore, aflatoxin exposure was significantly correlated with aflatoxin symptoms only at the same time point (0.123, p = 0.026). These results support the potential need for engineered solutions to household aflatoxin transmission problems in rural communities of Guatemala.

A study on the expression of apoptotic molecules related to death receptor and endoplasmic reticulum pathways in the jejunum of AFB1-intoxicated chickens

Aflatoxin B₁ (AFB₁) is a common contaminant of poultry feeds in tropical and subtropical climates. Early researches have well established the hepatotoxic, carcinogenic, and immunotoxic effects of AFB₁ on humans and animals. Recently, it has been shown that AFB₁ could cause the up- or down-alteration of mitochondrial pathway molecule expression. However, the information on the expression of death receptor and endoplasmic reticulum molecules in the jejunal apoptosis induced by AFB₁ were unavailable. So the present study was conducted to explore the expression of apoptotic molecules related to death receptor and endoplasmic reticulum in the jejunal cells of chickens exposed to AFB₁ diet for 3 weeks. Total of 144 one-day-old chickens was randomly divided into two groups, namely control group (containing 0 mg/kg AFB₁) and AFB₁ group (containing 0.6 mg/kg AFB₁). Histopathological observation and microscopic quantitative analysis revealed morphological changes in the jejunum such as the shedding of the mucosal epithelial cells in the apical region of villi along with the decrease of villus height, villus area and villus/crypt ratio in the AFB₁ group. Both TUNEL and flow cytometry assays showed that AFB₁ intake induced excessive apoptosis of jejunal cells. Quantitative real-time PCR test displayed the general upregulation of death receptors (FAS, FASL, TNF-α and TNF-R1), endoplasmic reticulum signals (GRP78 and GRP94) as well as initiator and executioner caspases (CASPASE-10, CASPASE-8 and CASPASE-3) in the jejunum of AFB₁-intoxicated chickens. It's the first study demonstrating that AFB₁ induced apoptosis of chickens’ jejunum accompanied by the alteration of death receptor and endoplasmic reticulum molecule expression.

Aflatoxins and Saccharomyces cerevisiae: yeast modulates the intestinal effect of aflatoxins, while aflatoxin B1 influences yeast ultrastructure

The gastrointestinal tract (GIT) is the main site where absorption of food components takes place and the first system coming into contact with mycotoxins of dietary origin. The aim of this work was to study the effect of probiotic Saccharomyces cerevisiae RC016 on intestinal villi of rats exposed to aflatoxins for 60 days. Moreover, the effect of in vitro aflatoxin B1 (AFB1) exposure on yeast cell ultrastructure was evaluated. Six treatments were applied (n=6) to inbred male Wistar rats: (1) uncontaminated feed control (F); (2) yeast control; (3) F + 40 μg/kg AFB1 + 20 μg/kg aflatoxin G1 (AFG1); (4) F + 100 μg/kg AFB1 + 50 μg/kg AFG1; (5) F + 40 μg/kg AFB1 + 20 μg/kg AFG1 + daily oral dose 108 viable S. cerevisiae cells; and (6) F + 100 μg/kg AFB1 + 50 μg/kg AFG1 + daily oral dose 108 viable S. cerevisiae cells. Morphometric measurements (villus length and width, crypt depth, quantification of goblet cells) were assessed using image analysis. S. cerevisiae RC016 cells were exposed to 20 μg/ml of AFB1 in intestinal solutions or in phosphate buffered saline and cells processed for transmission electron microscopy and high resolution light microscopy studies. Dietary exposure to the yeast did not induce significant differences in villus width but increased villus length and crypt depth. Aflatoxin-contaminated diets induced an increase in villus length, width and crypt depth and a significant decrease in the number of goblet cells which were improved by the addition of S. cerevisiae RC016. A significant increase in the yeast cell diameter was observed when RC016 was exposed to aflatoxins, suggesting this as an advantage since a larger cell would be able to adsorb mycotoxins more efficiently. The ability of this strain to act as probiotic and aflatoxin binder makes it a candidate for the formulation of new additives to improve animal performance.

Aflatoxin exposure during the first 36 months of life was not associated with impaired growth in Nepalese children: An extension of the MAL-ED study

Exposure to aflatoxin, a mycotoxin common in many foods, has been associated with child growth impairment in sub-Saharan Africa. To improve our understanding of growth impairment in relation to aflatoxin and other risk factors, we assessed biospecimens collected in Nepalese children at 15, 24, and 36 months of age for aflatoxin exposure. Children (N = 85) enrolled in the Bhaktapur, Nepal MAL-ED study encompassed the cohort analysed in this study. Exposure was assessed through a plasma biomarker of aflatoxin exposure: the AFB1-lysine adduct. The aflatoxin exposures in the study participants were compared to anthropometrics at each time period (length-for-age [LAZ], weight-for-age [WAZ], and weight-for-length [WLZ] z-scores), growth trajectories over time, age, and breastfeeding status. Results demonstrated chronic aflatoxin exposure in this cohort of children, with a geometric mean of 3.62 pg AFB1-lysine/mg albumin. However, the chronic aflatoxin exposure in this cohort was not significantly associated with anthropometric z-scores, growth trajectories, age, or feeding status, based on the available time points to assess aflatoxin exposure. Low mean levels of aflatoxin exposure and infrequent occurrence of stunting, wasting, or underweight z-score values in this cohort are possible contributing factors to a lack of evidence for an association. Further research is needed to examine whether a threshold dose of aflatoxin exists that could induce child growth impairment.

Interactive effects of dietary protein concentration and aflatoxin B1 on performance, nutrient digestibility, and gut health in broiler chicks

A 20-day trial was conducted to determine the impact of aflatoxin B1 (AFB1) and dietary protein concentration on performance, nutrient digestibility, and gut health in broiler chicks. The 6 dietary treatments were arranged in a 2 × 3 factorial with 3 crude protein (CP) concentrations (16, 22, and 26%) with or without 1.5 mg/kg AFB1 Each diet was fed to 6 replicate cages (6 chicks per cage) from zero to 20 d of age. Endogenous N and amino acid loss were estimated from birds fed a N-free diet with or without 1.5 mg/kg AFB1 A significant interaction between AFB1 and CP concentration was observed for growth performance, where reduction of BW gain, feed intake, gain:feed ratio, and breast muscle weight by AFB1 were most profound in birds fed the 16%-CP diet, and were completely eliminated when birds were fed the 26%-CP diet (AFB1 by CP interaction; P ≤ 0.023). Similarly, AFB1 reduced serum albumin, total protein, and globulin concentrations in birds fed 16 and 22% CP diets, but not in those fed the 26%-CP (AFB1 by CP interaction; P ≤ 0.071). Gut permeability was increased in birds fed AFB1-contamiated diets as measured by serum lactulose/rhamnose ratio (main effect; P = 0.04). Additionally, AFB1 tended to increase endogenous N loss (P = 0.09), and significantly reduced apparent ileal digestible energy and standardized ileal N and amino acid digestibility in birds fed the 16%-CP diet, while birds fed higher dietary CP were not affected (AFB1 by CP interaction; P ≤ 0.01). Further, AFB1 increased the translation initiation factor 4E-binding protein (4EBP1), claudin1, and multiple jejunal amino acid transporters expression (main effect; P ≤ 0.04). Results from this study indicate that a 1.5 mg AFB1/kg diet significantly impairs growth, major serum biochemistry measures, gut barrier, endogenous loss, and energy and amino acid digestibility. Aflatoxicosis can be augmented by low dietary CP, while higher dietary CP completely eliminated the impairment of performance, serum proteins, and nutrient digestibility from aflatoxicosis in zero to 20 d broiler chicks.

The toxic effects of combined aflatoxins and zearalenone in naturally contaminated diets on laying performance, egg quality and mycotoxins residues in eggs of layers and the protective effect of Bacillus subtilis biodegradation product

The toxic effect of aflatoxins (AF) and zearalenone (ZEA) and their combination on laying performance, egg quality and toxins residues in eggs, as well as the efficacy of Bacillus subtilis biodegradation product (BDP) for ameliorating these effects in layers were evaluated. Layers were submitted to a two phase experiment. The first phase was an intoxication period (18-23 wk) with birds fed 7 (3 × 2 + 1) diets (3 treatments with mycotoxins: AF (123.0 μg/kg), ZEA (260.2 μg/kg), or AF + ZEA (123.0 + 260.2 μg/kg); 2 treatments with or without BDP (1000 g/t); and a control group contained no toxins nor BDP). The next phase was a recovery period (24-29 wk) in which birds were fed a toxin-free diet. In the intoxication period, AF and AF + ZEA groups exhibited lower egg production, feed intake and shell thickness, and higher AFB1, AFB2 and AFM1 residues as compared with the control group. In addition, AF and ZEA exerted synergistic effects on egg production and feed intake. Moreover, AF alone or combined with ZEA had a continuous toxic effect on laying performance in the recovery phase. Addition of BDP offset these negative effects, showing that BDP has a protective effect on layers fed contaminated diets.

Leaky Gut and Mycotoxins: Aflatoxin B1 Does Not Increase Gut Permeability in Broiler Chickens

Previous studies conducted in our laboratory have demonstrated that intestinal barrier function can be adversely affected by diet ingredients or feed restriction, resulting in increased intestinal inflammation-associated permeability. Two experiments were conducted in broilers to evaluate the effect of three concentrations of Aflatoxin B1 (AFB1; 2, 1.5, or 1 ppm) on gastrointestinal leakage and liver bacterial translocation (BT). In experiment 1, 240 day-of-hatch male broilers were allocated in two groups, each group had six replicates of 20 chickens (n = 120/group): Control feed or feed + 2 ppm AFB1. In experiment 2, 240 day-of-hatch male broilers were allocated in three groups, each group had five replicates of 16 chickens (n = 80/group): Control feed; feed + 1 ppm AFB1; or feed + 1.5 ppm AFB1. In both experiments, chickens were fed starter (days 1-7) and grower diets (days 8-21) ad libitum and performance parameters were evaluated every week. At day 21, all chicks received an oral gavage dose of FITC-d (4.16 mg/kg) 2.5 h before collecting blood samples to evaluate gastrointestinal leakage of FITC-d. In experiment 2, a hematologic analysis was also performed. Liver sections were aseptically collected and cultured using TSA plates to determine BT. Cecal contents were collected to determine total colony-forming units per gram of Gram-negative bacteria, lactic acid bacteria (LAB), or anaerobes by plating on selective media. In experiment 2, liver, spleen, and bursa of Fabricius were removed to determine organ weight ratio, and also intestinal samples were obtained for morphometric analysis. Performance parameters, organ weight ratio, and morphometric measurements were significantly different between Control and AFB1 groups in both experiments. Gut leakage of FITC-d was not affected by the three concentrations of AFB1 evaluated (P > 0.05). Interestingly, a significant reduction in BT was observed in chickens that received 2 and 1 ppm AFB1. An increase (P < 0.05) in total aerobic bacteria, total Gram negatives, and total LAB were observed in chickens fed with 2 and 1.5 ppm of AFB1 when compared with Control and 1 ppm chickens. The integrity of gut epithelial barrier was not compromised after exposure to the mycotoxin.

Prevalence and effects of mycotoxins on poultry health and performance, and recent development in mycotoxin counteracting strategies

Extensive research over the last couple of decades has made it obvious that mycotoxins are commonly prevalent in majority of feed ingredients. A worldwide mycotoxin survey in 2013 revealed 81% of around 3,000 grain and feed samples analyzed had at least 1 mycotoxin, which was higher than the 10-year average (from 2004 to 2013) of 76% in a total of 25,944 samples. The considerable increase in the number of positive samples in 2013 may be due to the improvements in detection methods and their sensitivity. The recently developed liquid chromatography coupled to (tandem) mass spectrometry allows the inclusion of a high number of analytes and is the most selective, sensitive, and accurate of all the mycotoxin analytical methods. Mycotoxins can affect the animals either individually or additively in the presence of more than 1 mycotoxin, and may affect various organs such as gastrointestinal tract, liver, and immune system, essentially resulting in reduced productivity of the birds and mortality in extreme cases. While the use of mycotoxin binding agents has been a commonly used counteracting strategy, considering the great diversity in the chemical structures of mycotoxins, it is very obvious that there is no single method that can be used to deactivate mycotoxins in feed. Therefore, different strategies have to be combined in order to specifically target individual mycotoxins without impacting the quality of feed. Enzymatic or microbial detoxification, referred to as "biotransformation" or "biodetoxification," utilizes microorganisms or purified enzymes thereof to catabolize the entire mycotoxin or transform or cleave it to less or non-toxic compounds. However, the awareness on the prevalence of mycotoxins, available modern techniques to analyze them, the effects of mycotoxicoses, and the recent developments in the ways to safely eliminate the mycotoxins from the feed are very minimal among the producers. This symposium review paper comprehensively discusses the above mentioned aspects.

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

In chickens, the effect of mycotoxins, especially fumonisins (FB), in the gastrointestinal tract (GIT) is not well documented. Thus, this study in broiler chicks determined the effects of consuming diets prepared with Fusarium verticillioides culture material containing FB on intestinal gene expression and on the sphinganine (Sa)/sphingosine (So) ratio (Sa/So; a biomarker of FB effect due to disruption of sphingolipid metabolism). Male broilers were assigned to 6 diets (6 cages/diet; 6 birds/cage) from hatch to 20 days containing 0.4, 5.6, 11.3, 17.5, 47.8, or 104.8 mg FB/kg diet. Exposure to FB altered the Sa/So ratio in all tissues analyzed, albeit to varying extents. Linear dose-responses were observed in the kidney, jejunum and cecum. The liver and the ileum were very sensitive and data fit a cubic and quadratic polynomial model, respectively. Gene expression in the small intestine revealed low but significant upregulations of cytokines involved in the pro-inflammatory, Th1/Th17 and Treg responses, especially at 10 days of age. Interestingly, the cecal tonsils exhibited a biphasic response. Unlike the sphingolipid analysis, the effects seen on gene expression were not dose dependent, even showing more effects when birds were exposed to 11.3 mg FB/kg. In conclusion, this is the first report on the disruption of the sphingolipid metabolism by FB in the GIT of poultry. Further studies are needed to reach conclusions on the biological meaning of the immunomodulation observed in the GIT, but the susceptibility of chickens to intestinal pathogens when exposed to FB, at doses lower than those that would cause overt clinical symptoms, should be addressed.

The mycotoxin deoxynivalenol predisposes for the development of Clostridium perfringens-induced necrotic enteritis in broiler chickens

Both mycotoxin contamination of feed and Clostridium perfringens-induced necrotic enteritis have an increasing global economic impact on poultry production. Especially the Fusarium mycotoxin deoxynivalenol (DON) is a common feed contaminant. This study aimed at examining the predisposing effect of DON on the development of necrotic enteritis in broiler chickens. An experimental Clostridium perfringens infection study revealed that DON, at a contamination level of 3,000 to 4,000 µg/kg feed, increased the percentage of birds with subclinical necrotic enteritis from 20±2.6% to 47±3.0% (P<0.001). DON significantly reduced the transepithelial electrical resistance in duodenal segments (P<0.001) and decreased duodenal villus height (P = 0.014) indicating intestinal barrier disruption and intestinal epithelial damage, respectively. This may lead to an increased permeability of the intestinal epithelium and decreased absorption of dietary proteins. Protein analysis of duodenal content indeed showed that DON contamination resulted in a significant increase in total protein concentration (P = 0.023). Furthermore, DON had no effect on in vitro growth, alpha toxin production and netB toxin transcription of Clostridium perfringens. In conclusion, feed contamination with DON at concentrations below the European maximum guidance level of 5,000 µg/kg feed, is a predisposing factor for the development of necrotic enteritis in broilers. These results are associated with a negative effect of DON on the intestinal barrier function and increased intestinal protein availability, which may stimulate growth and toxin production of Clostridium perfringens.

Effects of naturally mycotoxin-contaminated corn on nutrient and energy utilization of ducks fed diets with or without Calibrin-A

One hundred sixty-two 21-d-old ducks were randomly allotted to 6 treatments with 3 levels of mycotoxin-contaminated corn (0, 50, and 100% M) and 2 levels of Calibrin-A (CA, a clay mycotoxin adsorbent, 0 and 0.1%) to evaluate the effects of increasing levels of mycotoxin-contaminated corn on nutrient utilization in ducks fed diets with or without CA. Endogenous losses were obtained from another 27 ducks. Excreta samples were collected to determine DM, OM, CP, amino acids, and gross energy. Gross energy was analyzed for computation of AME and TME. The apparent digestibility (AD) and true digestibility (TD) of the nutrients in all treatments with and without CA had common (P > 0.05) intercepts and slopes except Pro (P < 0.05). The AME, TME, AD, and TD of DM, OM, Phe, and Gly were linearly (P < 0.05) decreased as the concentration of contaminated corn in the diet increased. Ducks fed the 100% M diet supplemented with 0.1% CA increased AD and TD of Gly compared with the 100% M diet, and ducks fed 50 and 100% M diet supplemented with 0.1% CA increased AD and TD of Pro compared with 50% M and 100% M diet, respectively. In the present study, ducks fed mycotoxin-contaminated corn decreased nutrient digestibility in dose-dependent manner, and 0.1% CA supplementation improved AD and TD of Gly and Pro.

Effects of aflatoxin B1 exposure and sodium selenite supplementation on the histology, cell proliferation, and cell cycle of jejunum in broilers

The aim of this study was to investigate the effects of aflatoxin B1 (AFB1) exposure and sodium selenite supplementation on the histology, cell proliferation and cell cycle of jejunum in broilers. A total of 240 1-day-old male AA broilers were divided into four groups of 60 each, fed with basal diet (control group), 0.3 mg/kg AFB1 (AFB1 group), 0.4 mg/kg supplement Se (Se group), and 0.3 mg/kg AFB1 + 0.4 mg/kg supplement Se (AFB1 + Se group) for 21 days, respectively. Compared with the control group, decreased jejunal villus height, villus height/crypt ratio, and proliferation cell nuclear antigen (PCNA)-positive cells, and G2/M phase arrest and shedded epithelial cells on the tip of jejunal villus were observed in AFB1 groups at 7 and 14 days of age. However, the villus/crypt ratio, PCNA-positive cells and cell percentage of G0/G1, S, and G2/M phases had no significant differences between AFB1 group and control group at 21 days. Simultaneous supplementation with sodium selenite restored these parameters to be close to those in control group. In conclusion, 0.3 mg/kg AFB1 in the diet inhibits the development of broiler's jejunum by reducing cellular proliferation and inducing G2/M arrest during only the first 2 weeks after hatching. Supplementation of dietary sodium selenite at the concentration of 0.4 mg/kg Se had protective action against these toxic effects of AFB1.

Dietary arginine supplementation enhances intestinal expression of SLC7A7 and SLC7A1 and ameliorates growth depression in mycotoxin-challenged pigs

This study tested the hypothesis that dietary L-arginine supplementation confers beneficial effects on growing pigs fed a mold-contaminated diet. The measured variables included: (1) the average daily weight gain and feed:gain ratio; (2) activities of total superoxide dismutase, glutathione peroxidase, diamine oxidase, as well as amino acid and D-lactate concentrations in serum; (3) intestinal morphology; (4) expression of the genes for SLC7A7 (amino acid transporter light chain, y(+L) system, family 7, member 7), SLC7A1 (cationic amino acid transporter, y(+) system, family 7, member 1), SLC1A1 (neuronal/epithelial high affinity glutamate transporter, system XAG, member 1), SLC5A1 (sodium/glucose cotransporter, family 5, member 1) in the ileum and jejunum. Mycotoxins in feedstuffs resulted in an enlarged small intestine mass, oxidative injury in tissues, and reduced growth performance in pigs. Dietary arginine supplementation enhanced (P < 0.05) expression of jejunal SLC7A7 and ileal SLC7A1, in comparison with the control and mycotoxin groups. In addition, supplementing 1% L-arginine to the mycotoxin-contaminated feed had the following beneficial effects (P < 0.05): (1) alleviating the imbalance of the antioxidant system in the body; (2) ameliorating intestinal abnormalities; and (3) attenuating whole-body growth depression, compared with the mycotoxin group without arginine treatment. Collectively, these results indicate that dietary supplementation with L-arginine exerts a protective role in pigs fed mold-contaminated foods. The findings may have important nutritional implications for humans and other mammals.

Lipid metabolism of commercial layers fed diets containing aflatoxin, fumonisin, and a binder

Aflatoxins (AF) and fumonisins (FU) are a major problem faced by poultry farmers, leading to huge economic losses. This experiment was conducted to determine the effects of AF (1 mg/kg of feed) and FU (25 mg/kg of feed), singly or in combination, on the lipid metabolism in commercial layers and investigate the efficacy of a commercial binder (2 kg/t of feed) on reducing the toxic effects of these mycotoxins. A total of 168 Hisex Brown layer hens, 37 wk of age, were randomized into a 3 × 2 + 1 factorial arrangement (3 diets with no binder containing AF, FU, and AF+FU; 3 diets with binder containing AF, FU, and AF+FU; and a control diet with no mycotoxins and binders), totaling 7 treatments. The hens contaminated with AF showed the characteristic effects of aflatoxicosis, such as a yellow liver, resulting from the accumulation of liver fat, lower values of plasma very low-density lipoprotein and triglycerides, and higher relative weight of the kidneys and liver. Hepatotoxic and nephrotoxic effects of FU were not observed in this study. On the other hand, the FU caused a reduction in small intestine length and an increase in abdominal fat deposition. The glucan-based binder prevented some of the deleterious effects of these mycotoxins, particularly the effects of AF on hepatic lipid metabolism, kidney relative weight, and FU in the small intestine.

Modulation of intestinal functions following mycotoxin ingestion: meta-analysis of published experiments in animals

Mycotoxins are secondary metabolites of fungi that can cause serious health problems in animals, and may result in severe economic losses. Deleterious effects of these feed contaminants in animals are well documented, ranging from growth impairment, decreased resistance to pathogens, hepato- and nephrotoxicity to death. By contrast, data with regard to their impact on intestinal functions are more limited. However, intestinal cells are the first cells to be exposed to mycotoxins, and often at higher concentrations than other tissues. In addition, mycotoxins specifically target high protein turnover- and activated-cells, which are predominant in gut epithelium. Therefore, intestinal investigations have gained significant interest over the last decade, and some publications have demonstrated that mycotoxins are able to compromise several key functions of the gastrointestinal tract, including decreased surface area available for nutrient absorption, modulation of nutrient transporters, or loss of barrier function. In addition some mycotoxins facilitate persistence of intestinal pathogens and potentiate intestinal inflammation. By contrast, the effect of these fungal metabolites on the intestinal microbiota is largely unknown. This review focuses on mycotoxins which are of concern in terms of occurrence and toxicity, namely: aflatoxins, ochratoxin A and Fusarium toxins. Results from nearly 100 published experiments (in vitro, ex vivo and in vivo) were analyzed with a special attention to the doses used.

Mycotoxin-contaminated diets and deactivating compound in laying hens: 1. effects on performance characteristics and relative organ weight

The current experiment was conducted to determine the effect of mycotoxin-contaminated diets with aflatoxin (AFLA) and deoxynivalenol (DON) and dietary inclusion of deactivation compound on layer hen performance during a 10-wk trial. The experimental design consisted of a 4 × 2 factorial with 4 toxin levels: control, low (0.5 mg/kg AFLA + 1.0 mg/kg DON), medium (1.5 mg/kg AFLA + 1.5 mg/kg DON), and high (2.0 mg/kg AFLA + 2.0 mg/kg DON) with or without the inclusion of deactivation compound. Three hundred eighty-four 25-wk-old laying hens were randomly assigned to 1 of the 8 treatment groups. Birds were fed contaminated diets for a 6-wk phase of toxin administration followed by a 4-wk recovery phase, when all birds were fed mycotoxin-free diets. Twelve hens from each treatment were subjected to necropsy following each phase. Relative liver and kidney weights were increased (P < 0.05) at the medium and high toxin levels following the toxin phase, but the deactivation compound reduced (P < 0.05) relative liver and kidney weights following the recovery period. The high toxin level decreased (P < 0.05) feed consumption and egg production during the toxin period, whereas the deactivation compound increased (P < 0.05) egg production during the first 2 wk of the toxin phase. Egg weights were reduced (P < 0.05) in hens fed medium and high levels of toxin. An interaction existed between toxin level and deactivation compound inclusion with regard to feed conversion (g of feed/g of egg). High inclusion level of toxins increased feed conversion compared with the control diet, whereas deactivation compound inclusion reduced feed conversion to a level comparable with the control. These data indicate that deactivation compound can reduce or eliminate adverse effects of mycotoxicoses in peak-performing laying hens.

Food chain mycotoxin exposure, gut health, and impaired growth: a conceptual framework

Childhood stunting is an important and intractable public health problem that underlies ~20% of deaths among children aged <5 y in developing countries. Environmental enteropathy (EE), a subclinical condition of the small intestine characterized by reduced absorptive capacity and increased intestinal permeability, is almost universal among children in developing countries and may mediate stunting. However, the etiology of EE is poorly understood. Mycotoxins are metabolites of fungi that frequently contaminate the staple foods of children living in developing countries. We review evidence from human and animal studies that exposure to mycotoxins, particularly aflatoxin (AF), fumonisin (FUM), and deoxynivaenol (DON), may impair child growth. Although these toxins have distinct actions, they all mediate intestinal damage through: 1) inhibition of protein synthesis (AF, DON); 2) an increase in systemic proinflammatory cytokines (DON); and 3) inhibition of ceramide synthase (FUM). The intestinal pathology that arises from mycotoxin exposure is very similar to that of EE. We propose that future studies should address the role of mycotoxins in the pathogenesis of EE and evaluate interventions to limit mycotoxin exposure and reduce childhood stunting.

Gross intestinal adaptations in relation to broiler performance during chronic aflatoxin exposure

The present trial was conducted to study some morphological, digestive, and electrophysiological variables of the small intestine during chronic exposure of broilers to aflatoxin B(1) (AFB(1)). Ross 308 male chicks (7 d old) were randomly allotted to control (no AFB(1)), low AFB(1) (0.07 mg of AFB(1)/kg), or high AFB(1) (0.75 mg of AFB(1)/kg) diet. The high AFB(1) diet resulted in reduced (P ≤ 0.002) bird performance during the first 4 wk of exposure, whereas the low AFB(1) diet temporarily reduced (P = 0.034) the bird performance during wk 3 of exposure. During wk 4 of exposure, a linear (P ≤ 0.013) decrease in the unit weight of both the duodenum and jejunum was observed with increasing levels of AFB(1). This reduction in unit weight appeared to progress from the proximal (duodenum) to the distal (jejunum) small intestine with increase in the length of exposure and was not accompanied by modulation of electrophysiological variables in jejunal epithelium. Response from amiloride, a specific blocker of epithelial sodium channel, was also similar among jejunal epithelia of birds under different treatments. Interestingly, a compensatory linear (P ≤ 0.002) increase in the length of the duodenum and jejunum under high AFB(1) diets was noted to occur during wk 4 of exposure. Thus, retention of DM and nitrogen was not negatively affected by the AFB(1) diets. These data indicate that the intestine in broilers may adapt to an ongoing dietary challenge to AFB(1).

Aflatoxin B(1) in affecting broiler's performance, immunity, and gastrointestinal tract: a review of history and contemporary issues

Aflatoxin B(1) is a common contaminant of poultry feeds in tropical and subtropical climates. Research during the last five decades has well established the negative effects of the mycotoxin on health of poultry. However, the last ten years of relevant data have accentuated the potential of low levels of aflatoxin B(1) to deteriorate broiler performance. In this regard, any attempt to establish a dose-effect relationship between aflatoxin B(1) level and broiler performance is also complicated due to differences in types of broilers and length of exposure to the mycotoxin in different studies. Contrary to the prevalent notion regarding literature saturation with respect to aflatoxicosis of chicken, many areas of aflatoxicosis still need to be explored. Literature regarding effects of the mycotoxin on the gastrointestinal tract in this regard is particular scanty and non-conclusive. In addition to these issues, the metabolism of aflatoxin B(1) and recently proposed hypotheses regarding biphasic effects of the mycotoxin in broilers are briefly discussed.

Comparison of hydrated sodium calcium aluminosilicate and yeast cell wall on counteracting aflatoxicosis in broiler chicks

The objective of this research was to determine the efficacy of 2 types of adsorbents [hydrated sodium calcium aluminosilicates (HSCAS) vs. a combination of clay and yeast cell wall] in preventing aflatoxicosis in broilers. A total of 275 one-day-old birds were randomly divided into 11 treatments, with 5 replicate pens per treatment and 5 chicks per pen. The 11 treatments included 3 diets without any adsorbent containing either 0, 1, or 2 mg/kg of aflatoxin B1 (AFB1) plus 8 additional treatments employing 2 dietary levels of AFB1 (1 or 2 mg/kg), 2 different adsorbents [Solis (SO) and MTB-100 (MTB)], and 2 different levels of each absorbent (0.1 and 0.2%) in a 2×2×2 factorial arrangement. Solis is a mixture of different HSCAS and MTB is a combination of clay and yeast cell wall. Feed and water were provided ad libitum throughout the 21-d study period. Body weight gain and feed intake were depressed and relative liver weight was increased in chicks fed AFB1 compared with the positive control (P<0.05). Severe liver damage was observed in chicks fed 2 mg/kg of AFB1 with lesions consistent with aflatoxicosis, including fatty liver and vacuolar degeneration. Serum glucose, albumin, total protein, Ca, P, and alkaline phosphatase concentrations were reduced by AFB1 (P<0.05). The addition of either SO or MTB ameliorated the negative effects of 1 mg/kg of AFB1 on growth performance and liver damage (P<0.05). However, supplemental MTB failed to diminish the negative effects of 2 mg/kg of AFB1, whereas SO was more effective compared with MTB at 2 mg/kg of AFB1 (P<0.05). These data indicate that the HSCAS product effectively ameliorated the negative effect of AFB1 on growth performance and liver damage, whereas the yeast cell wall product was less effective especially at the higher AFB1 concentration.