MycoSafe-South: European–African partnership for safe and efficient use of mycotoxin-mitigation strategies in sub-Saharan Africa
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Item Mycotoxins in Kenyan dairy cattle feed: Occurrence and mitigation using bentonite and fumonisin esterase additives(Thesis, 2023-05-09) Kemboi, D.C.The dairy industry plays an integral role in the economy of most sub-Saharan African countries. Over the years the demand of milk and dairy products has increased leading to movement from pastoralism to intensive and semi-intensive systems. These intensive and semi-intensive systems rely on concentrates as a way of improving productivity. However, these concentrates have been shown to contain mycotoxins which are secondary toxic metabolites of fungi that affect animal health and productivity, as well as food safety.Item Aflatoxins and fumonisins co-contamination effects on laying hens and use of mycotoxin detoxifiers as a mitigation strategy(Journal Article, 2025-02) Ochieng, P.E.; Kemboi, D.C.; Okoth, S.; De Baere, S.; Cavalier, E.; Kang’ethe, Erastus K.; Doupovec, B.; Gathumbi, J.; Scippo, M.-L.; Antonissen, G.; Lindahl, Johanna F.; Croubels, S.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.Item Mycotoxins in Kenyan poultry feeds: Occurrence and use of bentonite and fumonisin esterase as a sustainable mitigation strategy to reduce effects of aflatoxins and fumonisins in broiler chicken and layer hens production(Thesis, 2023-10-18) Ochieng, P.E.This doctoral thesis consists of six chapters. Chapter 1 is a general introduction of what mycotoxins are and their toxicological impacts on poultry, and this is based on a published review paper. Major mycotoxins covered in detail are AFs, FBs, DON, ZEN, OTA, and T-2/HT-2. Some of the frequently occurring and yet neglected mycotoxins are discussed as well, and their toxicities highlighted. These include BEA, ENNs, MON, AME, AOH and modified mycotoxins of ZEN and DON such as deoxynivalenol-3-glucoside and zearalenone-14-sulfate. Also in this chapter, co-occurrence of mycotoxins in feed and feed ingredients is presented and co-contamination by FBs and AFs in feed and feed ingredients from SSA is highlighted with their impact on chickens. Legislation on mycotoxins in poultry feeds are further explored in this chapter, with particular discussion of the regulatory and guidance limits in SSA. Techniques for detecting mycotoxins biological matrices are also presented and sample preparation, clean-up and detection, especially using LC-MS/MS highlighted. Moreover, mycotoxin mitigation strategies for poultry protection are discussed, with the post-harvest methods that employ clay-based compounds, such as bentonite, and fumonisin esterase noted. Lastly, the rationale of this doctoral study is highlighted and objectives of this thesis discussed, with specific objectives being i) To study the prevalence of mycotoxins in Kenyan poultry feeds; ii) To produce sufficient quantities of AFs and FBs in the laboratory to be used in subsequent long-term in vivo trials with broiler and layer chickens; iii) To evaluate the effects of feed contaminated with AFs or FBs, or their combination, on broiler chickens and laying hens’ health and productivity; iv) To evaluate the carry-over of AFs to chicken products in a single or concomitant FBs contamination; and v) To assess the efficacy and safety of bentonite and fumonisin esterase mycotoxin detoxifying agents (feed additives) to protect chickens against negative health and productivity effects of AFs and FBs, respectively, and carry-over of AFs to chicken products. Chapter 2 details a survey of mycotoxin contamination levels in poultry feeds and feed ingredients from Kenya. This study was carried out to give an overview of the mycotoxins levels in feeds sold in Kenya in order to use relevant field concentrations for in vivo trials with broiler and layer chickens. Both feed and feed ingredients had a high prevalence (above 70%) of Fusarium mycotoxins including total FBs (max. level of 14,346 μg/kg), DON (max. level 1,037 μg/kg) and ZEN (max. level 910 μg/kg). Total AFs (max. level 99 μg/kg) were detected in 93% of the feed samples and in 29% of feed ingredients. Low occurrences of OTA (19%), T-2 and HT-2 (4%) were observed in feed and feed ingredients. Neglected and modified mycotoxins including Aspergillus toxins, Fusarium metabolites, Alternaria toxins, Penicillium toxins were also found in the samples. All mycotoxins were detected below EU regulatory limits, except for AFB1, where 16% of the samples had concentrations above the EU and EAC regulatory limits of 20 μg/kg for AFB1 in poultry feeds. Co-occurrence of mycotoxins in the samples was observed with all 4 major mycotoxins (AFs, FBs, DON and ZEN) detected in 55% of the samples and co-occurrence of AFs with FBs observed in 61% of the samples. In chapter 3, methods for laboratory production of large quantities of AFs and FBs for use in long-term in vivo trials are presented. Factors that affect mycotoxin production such as type of substrate, temperature, light and fungal isolate were optimized to enable maximum production of these mycotoxins. The concentration of AFs and FBs in the culture materials were screened by ELISA methods and confirmed by LC-MS/MS methods. Highest yield of AFB1 (88,174 μg/kg of substrate) was obtained in maize kernels inoculated with three different A. flavus isolates and incubated at 29°C for 21 days. For FBs, the highest yield (1,043,806 μg/kg of substrate) was in cracked maize kernels inoculated with three different F. verticillioides isolates and incubated for 21 days at 22–25°C in a growth chamber with yellow light conditions. Sufficient amounts of AFB1 and FBs were produced in maize, which was then mixed with control feeds (with no added mycotoxins or detoxifiers) to prepare experimental diets for in vivo animal trials. Chapter 4 describes the effects of dietary AFB1 and FBs (FB1+FB2), alone or in combination on broiler chickens’ health and productivity as well as carry-over of AFs from feed to plasma, liver and muscle. Safety and efficacy of bentonite and fumonisin esterase to counteract the effects of AFB1 and FBs were also evaluated. Four hundred one day old chickens were fed 20 diets (20 birds/treatment) from 1 to 35 days of age. The diets were either control or AFB1 (60 or 220 μg/kg feed) or FBs (17.43 mg FB1+FB2/kg feed), alone or in combination, and with bentonite clay (AFs binder) and/or fumonisin esterase (FBs modifier) in selected diets. The results showed that the levels of AFs and FBs used in this study did not affect growth performance of the broiler chickens. Nevertheless, the FCR was poor in broilers fed high AFB1 only when compared to those fed both high AFB1 and FBs. Changes in serum TP and ALB were observed in birds fed FBs alone or in combination with AFB1. The relative heart weight of the birds was increased by dietary high AFB1 and FBs. The efficiency of the bentonite was demonstrated in that the binder reduced the effects of AFB1 on the heart, liver and spleen weights. In-house developed and validated UHPLC-MS/MS methods were used to assess the carry-over of AFs from feed to plasma, breast muscle and liver of the birds. Residues of AFB1 (max: 0.12 ± 0.03 μg/kg) were detected above the limit of quantification (LOQ) in liver only, and from birds fed diets contaminated with high AFB1 (220 μg/kg feed). Supplementing bentonite clay into these diets reduced the accumulation of AFB1 in the liver by up to 50%, although the differences were not significant. No AFs were detected in breast muscles of the broiler chickens whereas AFB1 was detected in plasma of birds fed high AFB1, but below the LOQ. Moreover, at the doses tested, both bentonite clay and fumonisin esterase were found to be safe and did not affect the growth and health of the broiler chickens. In chapter 5, four hundred 21-weeks old laying hens were used to study the effects of AFB1 and FBs, alone or in combination, on health and productivity of the laying hens as well as carry-over of AFs from feed to plasma, liver, muscle and eggs. The safety and efficacy of bentonite and fumonisin esterase to prevent or reduce effects of AFB1 and FBs, respectively, were also evaluated. The hens were fed either the control diet or with AFB1 (54.6 or 546 μg/kg feed) and/or FBs (7.9 mg/kg feed) for 28 days. In selected diets, bentonite clay or fumonisin esterase were added. After 28 days, the results showed that neither AFB1 nor FBs caused an effect on performance, except for egg production which was reduced in hens fed diets with high AFB1 (546 μg/kg feed). Changes in serum TP and ALB levels and relative weights of liver, spleen and gizzard in laying hens fed contaminated diets are discussed. Analysis of residues of AFs in liver, plasma, muscle and eggs using validated UHPLC-MS/MS methods showed that the highest residues of AFB1 (0.66 μg/kg) were present in liver samples of laying hens fed 546 μg AFB1/kg feed and 7.9 mg FBs/kg feed for 28 days. Furthermore, AFB1 was detected in eggs and plasma of layers fed AFB1 (546 μg/kg) alone or with FBs (7.9 mg/kg feed), whereas no AFs were detected in the breast muscles of the laying hens. The efficacy of the two mycotoxin detoxifying agents (bentonite and fumonisin esterase) to reduce or suppress the negative effects of AFs and FBs was demonstrated in this study. The bentonite binder was also found to be effective in reducing the accumulation of AFs in the liver of laying hens as well as carry-over of AFs into eggs. Furthermore, bentonite clay and fumonisin esterase at the doses tested were safe and had no effect on the health and productivity of the laying hens. In chapter 6, general discussion, relevance of the study, future perspectives and conclusion are presented. The general discussion highlights the mycotoxins of concern in SSA, particularly AFs and FBs and the need to evaluate their effects on animal health and productivity, as well as their carry-over to animal products. Use of laboratory produced mycotoxins in feeding trials are also outlined in the discussion. The parameters to include when assessing toxicological impacts of mycotoxins or potential mycotoxin detoxifiers on chickens are further presented. The parameters include blood biochemical changes, gross pathological changes, organ weights and safety of animal food products. Also, the importance of analysing fecal, Sa/So ratio and microbiota of the GIT to determine the efficacy and safety of a potential mycotoxin detoxifier are further highlighted. Safety of mycotoxins detoxifiers on animals as well as the effects of long-term use are further discussed. The relevance of the current doctoral thesis is discussed on the basis of its contribution towards safe feed and food and linked to the UN SDGs agenda for food security and safety aimed at ensuring provision of sufficient and nutritious food to everyone by 2030. In the section of future perspectives, the research gaps are highlighted for every chapter of this thesis and areas for future studies are suggested. These include collaborations as well as coordination among private and public sectors to ensure continuous monitoring of mycotoxins along the food chain. The need for capacity building for human resources and equipment are also noted. Robust methods for simultaneous detection of multiple mycotoxins in food and feed is suggested. The need to carry out more in vivo animal trials, especially in SSA, to assess effects of mycotoxins on animal health and productivity, and in particular the effects of co-contamination by multiple mycotoxins, under conditions similar to farming practices in SSA is advised. Hindrances to setting regulatory limits for different mycotoxins in feed and food, especially in SSA, are highlighted in this section, and the need to harmonize regulatory limits of mycotoxins in different commodities across regions and trading blocks is also suggested. Some of the sustainable post-harvest mitigation strategies currently being explored to ensure safety of animal feeds and animal food products are explored in this section, particularly those that are cost effective, efficient and readily available in SSA such as clay compounds. In the conclusion, this doctoral thesis provides evidence on effects of AFB1 or FBs or both, on health and productivity of broiler chickens and laying hens as well as transfer of AFB1 to poultry food products. Information on safety and efficacy of bentonite clay and fumonisin esterase to counteract the negative effects of AFB1 and FBs, respectively, is further provided. This thesis also advises on laboratory production of mycotoxins as a cost effective means of producing sufficient quantities of mycotoxins for long-term in vivo animal experiments. The need to continuously monitor for multi mycotoxins contamination of poultry feeds to prevent their effects on animal health and productivity as well as transfer to animal source foods is suggested to prevent the mycotoxins from entering the food chain.Item 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(Journal Article, 2023-09-01) Ochieng, P.E.; Croubels, S.; Kemboi, D.; Okoth, S.; Baere, S. de; Cavalier, E.; Kang'ethe, Erastus K.; Faas, J.; Doupovec, B.; Gathumbi, J.; Douny, C.; Scippo, M.-L.; Lindahl, Johanna F.; Antonissen, G.The current study evaluated the effects of feeding diets contaminated with aflatoxin B1 (AFB1), fumonisins (FBs), or both on the performance and health of broiler chickens and the safety of their food products as well as the efficacy of bentonite and fumonisin esterase to mitigate the effects of these mycotoxins under conditions representative for sub-Saharan Africa (SSA). Four hundred one-day-old Cobb 500 broiler chickens were randomly assigned to 20 treatments with either a control diet, a diet with moderate AFB1 (60 μg/kg feed) or high AFB1 (220 μg/kg feed), or FBs (17,430 μg FB1+FB2/kg feed), alone or in combination, a diet containing AFB1 (either 60 or 220 μg/kg) and/or FBs (17,430 μg FB1+FB2/kg) and bentonite or fumonisin esterase or both, or a diet with bentonite or fumonisin esterase only. The experimental diets were given to the birds from day 1 to day 35 of age, and the effects of the different treatments on production performance were assessed by feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR). Possible health effects were evaluated through blood biochemistry, organ weights, mortality, liver gross pathological changes, and vaccine response. Residues of aflatoxins (AFB1, B2, G1, G2, M1 and M2) were determined in plasma, muscle, and liver tissues using validated UHPLC-MS/MS methods. The results obtained indicated that broiler chickens fed high AFB1 alone had poor FCR when compared to a diet with both high AFB1 and FBs (p = 0.0063). Serum total protein and albumin from birds fed FBs only or in combination with moderate or high AFB1 or detoxifiers increased when compared to the control (p < 0.05). Liver gross pathological changes were more pronounced in birds fed contaminated diets when compared to birds fed the control or diets supplemented with mycotoxin detoxifiers. The relative weight of the heart was significantly higher in birds fed high AFB1 and FBs when compared to the control or high AFB1 only diets (p < 0.05), indicating interactions between the mycotoxins. Inclusion of bentonite in AFB1-contaminated diets offered a protective effect on the change in weights of the liver, heart and spleen (p < 0.05). Residues of AFB1 were detected above the limit of quantification (max: 0.12 ± 0.03 μg/kg) in liver samples only, from birds fed a diet with high AFB1 only or with FBs or the detoxifiers. Supplementing bentonite into these AFB1-contaminated diets reduced the levels of the liver AFB1 residues by up to 50%. Bentonite or fumonisin esterase, alone, did not affect the performance and health of broiler chickens. Thus, at the doses tested, both detoxifiers were safe and efficient for use as valid means of counteracting the negative effects of AFB1 and FBs as well as transfer of AFB1 to food products (liver) of broiler chickens.Item Development of high-throughput sample preparation procedures for the quantitative determination of aflatoxins in biological matrices of chickens and cattle using UHPLC-MS/MS(Journal Article, 2023-01-03) Baere, S. de; Ochieng, P.E.; Kemboi, D.C.; Scippo, M.-L.; Okoth, S.; Lindahl, Johanna F.; Gathumbi, J.K.; Antonissen, G.; Croubels, S.Aflatoxins (AFs) frequently contaminate food and animal feeds, especially in (sub) tropical countries. If animals consume contaminated feeds, AFs (mainly aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1), G2 (AFG2) and their major metabolites aflatoxin M1 (AFM1) and M2 (AFM2)) can be transferred to edible tissues and products, such as eggs, liver and muscle tissue and milk, which ultimately can reach the human food chain. Currently, the European Union has established a maximum level for AFM1 in milk (0.05 µg kg−1). Dietary adsorbents, such as bentonite clay, have been used to reduce AFs exposure in animal husbandry and carry over to edible tissues and products. To investigate the efficacy of adding bentonite clay to animal diets in reducing the concentration of AFB1, AFB2, AFG1, AFG2, and the metabolites AFM1 and AFM2 in animal-derived foods (chicken muscle and liver, eggs, and cattle milk), chicken and cattle plasma and cattle ruminal fluid, a sensitive and selective ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method has been developed. High-throughput sample preparation procedures were optimized, allowing the analysis of 96 samples per analytical batch and consisted of a liquid extraction using 1% formic acid in acetonitrile, followed by a further clean-up using QuEChERS (muscle tissue), QuEChERS in combination with Oasis® Ostro (liver tissue), Oasis® Ostro (egg, plasma), and Oasis® PRiME HLB (milk, ruminal fluid). The different procedures were validated in accordance with European guidelines. As a proof-of-concept, the final methods were used to successfully determine AFs concentrations in chicken and cattle samples collected during feeding trials for efficacy and safety evaluation of mycotoxin detoxifiers to protect against AFs as well as their carry-over to animal products.Item Efficacy of bentonite and fumonisin esterase in mitigating the effects of aflatoxins and fumonisins in two Kenyan cattle breeds(Journal Article, 2023-02-01) Kemboi, D.; Antonissen, G.; Ochieng, P.; Croubels, S.; Baere, S. de; Scippo, M.-L.; Okoth, Sheila A.; Kang'ethe, Erastus K.; Faas, J.; Doupovec, B.; Lindahl, Johanna F.; Gathumbi, J.The objective of the study was to investigate the efficacy of bentonite and fumonisin esterase, separately or combined, in mitigating the effects of aflatoxins (AF) and fumonisins (FUM) in Boran and Friesian-Boran crossbreed cattle. These effects were studied by measuring mycotoxins, their metabolites, and biomarkers that relate to animal health, productivity, and food safety. The study was divided into three experiments each lasting for 2 weeks. Cows in experiment 1 received in random order aflatoxin B1 (AFB1) [788 μg/cow/day (69.7 μg/kg dry matter intake (DMI)) for Borans and 2,310 μg/cow/day (154 μg/kg DMI) for crossbreeds], bentonite (60 g/cow/day), or both AFB1 and bentonite. Boran cows in experiment 2 received in random order FUM (12.4 mg/cow/day (1.1 mg/kg DMI)), fumonisin esterase (120 U/cow/day), or both FUM and fumonisin esterase. Boran cows in experiment 3 received in random order AFB1 (952 μg/cow/day (84.2 μg/kg DMI)) + FUM (30.4 mg/cow/day (2.7 mg/kg DMI)), bentonite (60 g/cow/day) + fumonisin esterase (120 U/cow/day), or both AFB1 + FUM and bentonite + fumonisin esterase. Feeding AFB1 and/or FUM contaminated feed with or without the addition of the detoxifiers for 14 days did not affect DMI, milk composition, hematology, and blood biochemical parameters. The addition of bentonite in a diet contaminated with AFB1 led to a decrease in milk aflatoxin M1 (AFM1) concentration of 30% and 43%, with the carry-over subsequently decreasing from 0.35% to 0.20% and 0.08% to 0.06% for crosses and Borans, respectively. No significant change was observed in the sphinganine/sphingosine (Sa/So) ratio following feeding with FUM alone or in combination with fumonisin esterase; however, the ability of fumonisin esterase to hydrolyze FUM into less toxic fully hydrolyzed FUM and partially hydrolyzed FUM was evident in the rumen fluid and feces. These results indicate bentonite was effective in decreasing AFM1 concentration in milk, and AFB1 and AFM1 in plasma, while fumonisin esterase can convert FUM into less toxic metabolites and can be a suitable addition to feed cocontaminated with AFB1 and FUM.Item Maximizing laboratory production of aflatoxins and fumonisins for use in experimental animal feeds(Journal Article, 2022-11-30) Ochieng, P.E.; Kemboi, D.C.; Scippo, M.L.; Gathumbi, J.K.; Kang'ethe, Erastus K.; Doupovec, B.; Croubels, S.; Lindahl, Johanna F.; Antonissen, G.; Okoth, S.Warm and humid climatic conditions coupled with poor agricultural practices in sub-Saharan Africa favor the contamination of food and feed by Aspergillus flavus and Fusarium verticillioides fungi, which subsequently may produce aflatoxins (AFs) and fumonisins (FBs), respectively. The growth of fungi and the production of mycotoxins are influenced by physical (temperature, pH, water activity, light and aeration), nutritional, and biological factors. This study aimed at optimizing the conditions for the laboratory production of large quantities of AFs and FBs for use in the animal experiments. A. flavus and F. verticillioides strains, previously isolated from maize in Kenya, were used. Levels of AFB1 and total FBs (FB1, FB2, and FB3) in different growth substrates were screened using ELISA methods. Maize kernels inoculated with three different strains of A. flavus simultaneously and incubated at 29 °C for 21 days had the highest AFB1 level of 12,550 ± 3397 μg/kg of substrate. The highest level of total FBs (386,533 ± 153,302 μg/kg of substrate) was detected in cracked maize inoculated with three different strains of F. verticillioides and incubated for 21 days at temperatures of 22–25 °C in a growth chamber fitted with yellow light. These two methods are recommended for the mass production of AFB1 and FBs for animal feeding trials.Item Mycotoxins in poultry feed and feed ingredients from sub-Saharan Africa and their impact on the production of broiler and layer chickens: A review(Journal Article, 2021-09-08) Ochieng, P.E.; Scippo, M.-L.; Kemboi, D.C.; Croubels, S.; Okoth, S.; Kang'ethe, Erastus K.; Doupovec, B.; Gathumbi, J.K.; Lindahl, Johanna F.; Antonissen, G.The poultry industry in sub-Saharan Africa (SSA) is faced with feed insecurity, associated with high cost of feeds, and feed safety, associated with locally produced feeds often contaminated with mycotoxins. Mycotoxins, including aflatoxins (AFs), fumonisins (FBs), trichothecenes, and zearalenone (ZEN), are common contaminants of poultry feeds and feed ingredients from SSA. These mycotoxins cause deleterious effects on the health and productivity of chickens and can also be present in poultry food products, thereby posing a health hazard to human consumers of these products. This review summarizes studies of major mycotoxins in poultry feeds, feed ingredients, and poultry food products from SSA as well as aflatoxicosis outbreaks. Additionally reviewed are the worldwide regulation of mycotoxins in poultry feeds, the impact of major mycotoxins in the production of chickens, and the postharvest use of mycotoxin detoxifiers. In most studies, AFs are most commonly quantified, and levels above the European Union regulatory limits of 20 μg/kg are reported. Trichothecenes, FBs, ZEN, and OTA are also reported but are less frequently analyzed. Co-occurrences of mycotoxins, especially AFs and FBs, are reported in some studies. The effects of AFs on chickens’ health and productivity, carryover to their products, as well as use of mycotoxin binders are reported in few studies conducted in SSA. More research should therefore be conducted in SSA to evaluate occurrences, toxicological effects, and mitigation strategies to prevent the toxic effects of mycotoxins.Item Multi-mycotoxin occurrence in dairy cattle and poultry feeds and feed ingredients from Machakos Town, Kenya(Journal Article, 2020-12-03) Kemboi, D.C.; Ochieng, P.E.; Antonissen, G.; Croubels, S.; Scippo, M.-L.; Okoth, S.; Kang'ethe, Erastus K.; Faas, J.; Doupovec, B.; Lindahl, Johanna F.; Gathumbi, J.K.Mycotoxins are common in grains in sub-Saharan Africa and negatively impact human and animal health and production. This study assessed occurrences of mycotoxins, some plant, and bacterial metabolites in 16 dairy and 27 poultry feeds, and 24 feed ingredients from Machakos town, Kenya, in February and August 2019. We analyzed the samples using a validated multi-toxin liquid chromatography-tandem mass spectrometry method. A total of 153 mycotoxins, plant, and bacterial toxins, were detected in the samples. All the samples were co-contaminated with 21 to 116 different mycotoxins and/or metabolites. The commonly occurring and EU regulated mycotoxins reported were; aflatoxins (AFs) (70%; range 0.2-318.5 μg/kg), deoxynivalenol (82%; range 22.2-1037 μg/kg), ergot alkaloids (70%; range 0.4-285.7 μg/kg), fumonisins (90%; range 32.4-14,346 μg/kg), HT-2 toxin (3%; range 11.9-13.8 μg/kg), ochratoxin A (24%; range 1.1-24.3 μg/kg), T-2 toxin (4%; range 2.7-5.2 μg/kg) and zearalenone (94%; range 0.3-910.4 μg/kg). Other unregulated emerging mycotoxins and metabolites including Alternaria toxins, Aspergillus toxins, bacterial metabolites, cytochalasins, depsipeptides, Fusarium metabolites, metabolites from other fungi, Penicillium toxins, phytoestrogens, plant metabolites, and unspecific metabolites were also detected at varying levels. Except for total AFs, where the average contamination level was above the EU regulatory limit, all the other mycotoxins detected had average contamination levels below the limits. Ninety-six percent of all the samples were contaminated with more than one of the EU regulated mycotoxins. These co-occurrences may cause synergistic and additive health effects thereby hindering the growth of the Kenyan livestock sector.Item A review of the impact of mycotoxins on dairy cattle health: Challenges for food safety and dairy production in sub-Saharan Africa(Journal Article, 2020-04-02) Kemboi, D.C.; Antonissen, G.; Ochieng, P.E.; Croubels, S.; Okoth, S.A.; Kang'ethe, Erastus K.; Faas, J.; Lindahl, Johanna F.; Gathumbi, J.K.Mycotoxins are secondary metabolites of fungi that contaminate food and feed and have a significant negative impact on human and animal health and productivity. The tropical condition in Sub-Saharan Africa (SSA) together with poor storage of feed promotes fungal growth and subsequent mycotoxin production. Aflatoxins (AF) produced by Aspergillus species, fumonisins (FUM), zearalenone (ZEN), T-2 toxin (T-2), and deoxynivalenol (DON) produced by Fusarium species, and ochratoxin A (OTA) produced by Penicillium and Aspergillus species are well-known mycotoxins of agricultural importance. Consumption of feed contaminated with these toxins may cause mycotoxicoses in animals, characterized by a range of clinical signs depending on the toxin, and losses in the animal industry. In SSA, contamination of dairy feed with mycotoxins has been frequently reported, which poses a serious constraint to animal health and productivity, and is also a hazard to human health since some mycotoxins and their metabolites are excreted in milk, especially aflatoxin M1. This review describes the major mycotoxins, their occurrence, and impact in dairy cattle diets in SSA highlighting the problems related to animal health, productivity, and food safety and the up-to-date post-harvest mitigation strategies for the prevention and reduction of contamination of dairy feed.