Effects of Aflatoxins and Fumonisins, Alone or in Combination, on Performance, Health, and Safety of Food Products of Broiler Chickens, and Mitigation Efficacy of Bentonite and Fumonisin Esterase

Multi-mycotoxin occurrence and their risk to poultry health in semi-intensive broiler farms in Kenya

Scarcity of feed ingredients, unregulated feed mills, and limited monitoring of mycotoxin levels in feed increase the risk of mycotoxin exposure for poultry in sub-Saharan Africa. This study examined mycotoxins in feed from 122 Kenyan broiler farms and an association between on-farm feed handling practices and mycotoxin levels. Using a validated multi-mycotoxin liquid chromatography-tandem mass spectrometry method (LC-MS/MS), all feed samples contained at least one mycotoxin and 93 % (n=113) had >3 mycotoxins. The most prevalent EU-regulated mycotoxins detected were fumonisins (93 %; 79.2 - 1285.3 μg/kg), deoxynivalenol (88 %; 96.6 - 2131.2 μg/kg), aflatoxins (34 %; 4.6 - 87.8 μg/kg), and ochratoxin A (4 %; range 14.90 - 59.20 μg/kg). Deoxynivalenol, fumonisins, and zearalenone frequently co-occurred in the feed samples. Among the surveyed farms, 33 % (n= 40) were at risk of subclinical exposure to deoxynivalenol, while 14 % and 7 % faced similar risks from total aflatoxins and fumonisins, respectively. Univariate analysis found no significant associations between farm-specific feed handling practices and mycotoxin levels in feed. This study found a high co-occurrence of mycotoxin at low to moderate concentrations in compound broiler feed from the selected farms. While these levels pose a potential risk, no direct link to broiler health outcomes was found. Our findings highlight the need for further research to explore the effects of subclinical mycotoxin exposure on broilers and to develop context-specific mycotoxin level guidelines for the region.

Are Aflatoxin Residues in Chicken Products a Real or Perceived Human Dietary Risk?

Aflatoxin is a health threat to humans and domesticated animals. Chickens are often fed aflatoxin-contaminated grain and may retain some toxins in muscle, eggs, and other tissues. A critical food safety question is whether tissues from contaminated birds pose a threat to the humans that consume them. We evaluated literature published from 1984 to 2023 to determine the level of aflatoxin residues retained in chicken eggs, muscles, livers, gizzards, and hearts. In the studies evaluated (n = 33), ~8100 chickens in 334 trials were fed feed contaminated with 0.1-6400 µg/kg of aflatoxins for 7-180 days. There was a positive correlation between the level of feed contamination and residual aflatoxin concentrations (r2 = 0.18, p < 0.05), but <1% of the aflatoxin in the feed carried over to edible broiler tissues. Only 0.6% of the trials reported >20 µg/kg of aflatoxin in the tissues, primarily in the muscle tissue, when the chickens were fed feed contaminated with >300 µg/kg of aflatoxins, which is above the US FDA maximum tolerable limit for components of poultry feeds. These composite results suggest a relatively low risk to public health from consuming chickens fed contaminated feed and a relatively high aflatoxin elimination mechanism in chickens that consume feed containing >300 µg/kg of aflatoxins. The data are consistent with chickens fed feed containing up to 500 µg/kg of aflatoxin being allowed in the human food chain without posing a significant health hazard. In reality, the maximum level of aflatoxin allowed in chicken feed will probably be limited by how much the birds can tolerate and still grow at a suitable rate without deformities rather than the risk that processed birds could present to human health. As chickens effectively act as an absorptive buffer for aflatoxin in contaminated feed, we expect that a contamination level that is acceptable for chicken growth performance is likely to be less than the amount that keeps chicken products safe for human consumption.

Innovative Mycotoxin Detoxifying Agents Decrease the Absorption Rate of Aflatoxin B1 and Counteract the Oxidative Stress in Broiler Chickens Exposed to Low Dietary Levels of the Mycotoxin

Aflatoxin B1 (AFB1) can impair the growth of chickens and reduce the quality of eggs and meat, resulting in significant economic losses. The inclusion of mycotoxin detoxifying agents (MyDA) with binding properties in the diet is an efficient tool to reduce their absorption rate in the gastrointestinal tract. Our aim was to investigate the ability of two innovative MyDA (SeOX, a feed additive featuring a tri-octahedral smectite mixed with lignocellulose, and CHS, a di-octahedral smectite functionalized with an organic non-toxic modifier) in both reducing the bio-accessibility and mitigating the adverse effects of AFB1 in broilers exposed for 10 days to concentrations approaching the European Union maximum limits in feed (0.02 mg/kg). The amount of AFB1 in the excreta of birds, collected over four consecutive days (starting on day 7), was significantly lower (p < 0.001) in the group exposed to AFB1 alone compared to the groups treated with either SeOX or CHS. The calculated bio-accessibility was decreased by nearly 30% with both MyDA. This positive effect was reflected by a significant reduction (p < 0.001) in the oxidative stress (measured as serum antioxidant capacity and hepatic lipid peroxidation) induced by AFB1. Although antioxidant enzyme activities and glutathione levels were unaffected by any treatment, AFB1 significantly induced (p < 0.001) the upregulation of CYP2A6 and the downregulation of Nrf2; the latter was reverted by each MyDA. Overall, these results demonstrate that the selected MyDA are effective in limiting the AFB1 absorption rate, thereby mitigating or even reverting the oxidative stress induced by AFB1 in broilers.

Aflatoxins and fumonisins co-contamination effects on laying hens and use of mycotoxin detoxifiers as a mitigation strategy

This study examined the effects of fumonisins (FBs) and aflatoxin B1 (AFB1), alone or in combination, on the productivity and health of laying hens, as well as the transfer of aflatoxins (AFs) to chicken food products. The efficacy and safety of mycotoxin detoxifiers (bentonite and fumonisin esterase) to mitigate these effects were also assessed. Laying hens (400) were divided into 20 groups and fed a control, moderate (54.6 µg/kg feed) or high (546 µg/kg feed) AFB1 or FBs (7.9 mg/kg feed) added diets, either alone or in combination, with the mycotoxin detoxifiers added in selected diets. Productivity was evaluated by feed intake, egg weight, egg production, and feed conversion ratio whereas health was assessed by organ weights, blood biochemistry, and mortality. Aflatoxins residues in plasma, liver, muscle, and eggs were determined using UHPLC-MS/MS methods. A diet with AFB1 at a concentration of 546 µg/kg feed decreased egg production and various AFB1-contaminated diets increased serum uric acid levels and weights of liver, spleen, heart, and gizzard. Interactions between AFB1 and FBs significantly impacted spleen, heart, and gizzard weights as well as AFB1 residues in eggs. Maximum AFB1 residues of 0.64 µg/kg and aflatoxin M1 (below limits of quantification) were observed in liver, plasma, and eggs of layers fed diets with AFB1. The mycotoxin detoxifiers reduced effects of AFB1 and FBs on egg production, organ weights, blood biochemistry, and AFB1 residues in tissues. This study highlights the importance of mycotoxin detoxifiers as a mitigation strategy against mycotoxins in poultry production.

Awareness of Poultry Farmers of Interconnected Health Risks: A Cross-Sectional Study on Mycotoxins, Biosecurity, and Salmonellosis in Jimma, Ethiopia

Poultry farming in Ethiopia is crucial for food security and income, but it faces significant challenges due to gaps in farmer awareness. A cross-sectional study was conducted using the Biocheck.UGent™ biosecurity scoring system and a questionnaire to evaluate poultry farmers' basic and practical knowledge concerning salmonellosis and mycotoxins. The questionnaire revealed substantial gaps in basic and practical knowledge regarding Salmonella spp infections and mycotoxin among 38 poultry farmers in Jimma. About 68.4% of farmers were unaware of the impact of salmonellosis on both poultry and human health. Moreover, 78.9% had limited basic knowledge of how salmonellosis affects production and the economy. Farmers also showed limited practical knowledge of farm management and hygiene practices essential for preventing Salmonella spp. infections. Regarding mycotoxins, 63.2% of farmers lacked awareness of poultry feed management, 60.5% were unaware of the health risks mycotoxins pose, and 73.7% did not recognize signs of mycotoxin contamination. Although 55.3% of farmers demonstrated acceptable practical knowledge of strategies to reduce the impact of mycotoxin contaminations, there are still concerns, particularly since 65.8% and 55.3% only showed moderate practical knowledge of feed storage and mycotoxin prevention, respectively. The overall biosecurity scores of poultry farms were below the global average, with a score of 41.7 compared to the worldwide average of 64. The overall mean score for external biosecurity was 44.9, below the global average of 63. All 3 scoring platforms and biosecurity parameters indicated that internal biosecurity was the weakest aspect, with a score of 31.6, well below the global standard of 64. The results showed a weak correlation (rₛ = 0.06) between farmers' basic and practical knowledge scores about Salmonella spp. infections and mycotoxins. Similarly, there was a weak correlation between the poor biosecurity score of poultry farms and the basic and practical knowledge of poultry farmers on Salmonella spp. infections (rₛ = 0.17) and mycotoxins (rₛ = 0.25). In conclusion, the study found that poultry farmers in Jimma had poor basic and practical knowledge scores on Salmonella, mycotoxins, and biosecurity measures. Thus, awareness creation is paramount to improve these gaps to reduce the impact of mycotoxin contamination and poultry diseases and consequently to improve food security and food safety.

Dietary Mycotoxins: An Overview on Toxicokinetics, Toxicodynamics, Toxicity, Epidemiology, Detection, and Their Mitigation with Special Emphasis on Aflatoxicosis in Humans and Animals

Mycotoxins are secondary metabolites of filamentous fungi and ubiquitous dietary contaminants. Aflatoxins, a group of mycotoxins with high prevalence and toxicity, have raised a high level of public health concern, the most prevalent and toxic being aflatoxin B1 (AFB1). Many aspects appertaining to AFB1 poisoning are not well understood. Yet this information is necessary to devise appropriate surveillance and mitigation strategies against human and animal aflatoxicosis. This review provides an in-depth update of work carried out on mycotoxin poisoning, particularly aflatoxicosis in humans and animals, to identify gaps in knowledge. Hypotheses explaining the functional significance of mycotoxins in fungal biology and their dietary epidemiological data are presented and briefly discussed. The toxicology of aflatoxins and the challenges of their mitigation are discussed in depth. It was concluded that the identification of potential mycotoxin-hazard-prone food items and quantification of the associated risk of cancer ailments in humans is a prime priority. There is a dearth of reliable sampling methodologies for estimating AFB1 in animal feed. Data update on AFB1 in animal feed and its implication in animal production, mitigation strategies, and elucidation of risk factors to this hazard is required. To reduce the burden of aflatoxins, surveillance employing predictive technology, and biocontrol strategies seem promising approaches.

Turmeric Powder Counteracts Oxidative Stress and Reduces AFB1 Content in the Liver of Broilers Exposed to the EU Maximum Levels of the Mycotoxin

The most frequent adverse effects of AFB1 in chicken are low performance, the depression of the immune system, and a reduced quality of both eggs and meat, leading to economic losses. Since oxidative stress plays a major role in AFB1 toxicity, natural products are increasingly being used as an alternative to mineral binders to tackle AFB1 toxicosis in farm animals. In this study, an in vivo trial was performed by exposing broilers for 10 days to AFB1 at dietary concentrations approaching the maximum limits set by the EU (0.02 mg/kg feed) in the presence or absence of turmeric powder (TP) (included in the feed at 400 mg/kg). The aims were to evaluate (i) the effects of AFB1 on lipid peroxidation, antioxidant parameters, histology, and the expression of drug transporters and biotransformation enzymes in the liver; (ii) the hepatic accumulation of AFB1 and its main metabolites (assessed using an in-house-validated HPLC-FLD method); (iii) the possible modulation of the above parameters elicited by TP. Broilers exposed to AFB1 alone displayed a significant increase in lipid peroxidation in the liver, which was completely reverted by the concomitant administration of TP. Although no changes in glutathione levels and antioxidant enzyme activities were detected in any treatment group, AFB1 significantly upregulated and downregulated the mRNA expression of CYP2A6 and Nrf2, respectively. TP counteracted such negative effects and increased the hepatic gene expression of selected antioxidant enzymes (i.e., CAT and SOD2) and drug transporters (i.e., ABCG2), which were further enhanced in combination with AFB1. Moreover, both AFB1 and TP increased the mRNA levels of ABCC2 and ABCG2 in the duodenum. The latter changes might be implicated in the decrease in hepatic AFB1 to undetectable levels ( Collapse

Key Words

• aflatoxin B1
• chicken
• curcumin
• drug transporters
• drug-metabolizing enzymes
• liver
• oxidative stress
• turmeric powder

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MESH Headings

• Animals
• Antioxidants/pharmacology
• Antioxidants/metabolism
• Chickens/metabolism
• Curcuma/metabolism
• Powders/metabolism
• Powders/pharmacology
• Mycotoxins/metabolism
• Aflatoxin B1/metabolism
• Liver
• Oxidative Stress
• RNA, Messenger/metabolism

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Grants

• 678781 European Union

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Affiliation(s)

Neenu Amminikutty Department of Veterinary Sciences, University of Torino, 10095 Grugliasco, Italy; (N.A.); (V.S.); (W.J.); (P.B.); (M.T.C.); (E.C.); (A.S.); (F.G.)
Veronica Spalenza Department of Veterinary Sciences, University of Torino, 10095 Grugliasco, Italy; (N.A.); (V.S.); (W.J.); (P.B.); (M.T.C.); (E.C.); (A.S.); (F.G.)
Watanya Jarriyawattanachaikul Department of Veterinary Sciences, University of Torino, 10095 Grugliasco, Italy; (N.A.); (V.S.); (W.J.); (P.B.); (M.T.C.); (E.C.); (A.S.); (F.G.)
Paola Badino Department of Veterinary Sciences, University of Torino, 10095 Grugliasco, Italy; (N.A.); (V.S.); (W.J.); (P.B.); (M.T.C.); (E.C.); (A.S.); (F.G.)
Maria Teresa Capucchio Department of Veterinary Sciences, University of Torino, 10095 Grugliasco, Italy; (N.A.); (V.S.); (W.J.); (P.B.); (M.T.C.); (E.C.); (A.S.); (F.G.)
Elena Colombino Department of Veterinary Sciences, University of Torino, 10095 Grugliasco, Italy; (N.A.); (V.S.); (W.J.); (P.B.); (M.T.C.); (E.C.); (A.S.); (F.G.)
Achille Schiavone Department of Veterinary Sciences, University of Torino, 10095 Grugliasco, Italy; (N.A.); (V.S.); (W.J.); (P.B.); (M.T.C.); (E.C.); (A.S.); (F.G.)
Donato Greco Institute of Sciences of Food Production, Italian National Research Council, 70126 Bari, Italy; (D.G.); (V.D.); (G.A.)
Vito D’Ascanio Institute of Sciences of Food Production, Italian National Research Council, 70126 Bari, Italy; (D.G.); (V.D.); (G.A.)
Giuseppina Avantaggiato Institute of Sciences of Food Production, Italian National Research Council, 70126 Bari, Italy; (D.G.); (V.D.); (G.A.)
Sihem Dabbou Center Agriculture Food Environment (C3A), University of Trento, 38010 San Michele all’Adige, Italy;
Carlo Nebbia Department of Veterinary Sciences, University of Torino, 10095 Grugliasco, Italy; (N.A.); (V.S.); (W.J.); (P.B.); (M.T.C.); (E.C.); (A.S.); (F.G.)
Flavia Girolami Department of Veterinary Sciences, University of Torino, 10095 Grugliasco, Italy; (N.A.); (V.S.); (W.J.); (P.B.); (M.T.C.); (E.C.); (A.S.); (F.G.)

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