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.

Little is known about the effects of commonly found levels of Fusarium mycotoxins on the performance, metabolism, and immunity of dairy cattle. We investigated the effects of regular contamination levels, meaning contamination levels that can be commonly detected in dairy feeds, of deoxynivalenol (DON) and fumonisins (FB) in total mixed ration (TMR) on the performance, diet digestibility, milk quality, and plasma liver enzymes in dairy cows. This trial examined 12 lactating Holstein dairy cows using a 3-period × 3-treatment Latin Square design. The experimental period was 21 d of mycotoxin exposure followed by 14 d of washout. During treatment periods, cows received one of 3 diets: (1) CTR (control) diet of TMR contaminated with 340.5 µg of DON/kg of dry matter (DM) and 127.9 µg FB/kg of DM; (2) MTX diet of TMR contaminated with Fusarium mycotoxins at levels higher than CTR but below US and European Union guidelines (i.e., 733.0 µg of DON/kg of DM and 994.4 µg of FB/kg of DM); or (3) MDP diet, which was MTX diet supplemented with a mycotoxin deactivator product (i.e., 897.3 µg of DON/kg of DM and 1,247.1 µg of FB/kg of DM; Mycofix, 35 g/animal per day). During washout, all animals were fed the same CTR diet. Body weight, body condition score, DM intake, dietary nutrient digestibility, milk production, milk composition and rennet coagulation properties, somatic cell count, blood serum chemistry, hematology, serum immunoglobulin concentrations, and expression of multiple genes in circulating leucocytes were measured. Milk production was significantly greater in the CTR group (37.73 kg/d) than in the MTX (36.39 kg/d) and the MDP (36.55 kg/d) groups. Curd firmness and curd firming time were negatively affected by the MTX diet compared with the other 2 diets. Furthermore, DM and neutral detergent fiber digestibility were lower after the MTX diet than after the CTR diet (67.3 vs. 71.0% and 42.8 vs. 52.3%). The MDP diet had the highest digestibility coefficients for DM (72.4%) and neutral detergent fiber (53.6%) compared with the other 2 diets. The activities of plasma liver transaminases were higher after the MTX diet than after the CTR and MDP diets. Compared with the CTR diet, the MTX diet led to slightly lower expression of genes related to immune and inflammatory functions, indicating that Fusarium mycotoxins had an immunosuppressive effect. Our results indicated that feed contaminated with regular levels of Fusarium mycotoxins adversely affected the performance, milk quality, diet digestibility, metabolic variables, and immunity of dairy cows, and that supplementation with mycotoxin deactivator product counteracted most of these negative effects.

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.

The aim of the study was to evaluate the effects of low to moderate oral exposure to the Fusarium toxin deoxynivalenol (DON; derived from culture material) on performance, water intake, and carcass parameters of broilers during early and late developmental phases. A total of 160 Ross 308 broilers were randomly allocated to four different feeding groups (n = 40/group) including 0 (control), 2.5, 5, and 10 mg DON/kg wheat-soybean meal-based feed. Three consecutive replicates of the experiment were performed. Half of the broilers were slaughtered in week 3 of the trial whereas the other half were slaughtered in week 5. Dry matter intake (DMI) and water intake (WI) were recorded on a daily basis and the body weight (BW) and BW gain (BWG) were determined weekly. The following carcass traits were recorded and calculated in absolute and relative data: dressed carcass weight, breast muscle weight, leg weight, and liver weight. Data showed that BW (P < 0.001), BWG (P = 0.005), and DMI (P < 0.001) were reduced by DON-feeding during the entire feeding period. The ratio of DMI to body weight gain (DMI/BWG) was not affected by the treatment. However, the ratio of water to DMI (WI/DMI) increased in DON-treated birds (P = 0.021). Contrast analysis showed that DON tendentially reduced slaughter weight (P = 0.082) and decreased leg yield (P = 0.037) in DON-fed chickens in week 5 of the experiment. Liver organ weight decreased in the 3-week-old DON-fed broilers compared to that in the control-fed birds (P = 0.037). In conclusion, the study suggests that DMI and BW were negatively affected under the experimental conditions at DON levels lower than the current guidance value in the European Union of 5 mg/kg feed. The study also indicates that broilers fed on low to moderate level DON-contaminated diets showed increased WI/DMI ratio which might have negative influence on wet litter syndrome.

In recent years, the deleterious effects attributed to mycotoxins, in particular on the intestine, faced increased attention and it was shown that deoxynivalenol (DON) causes adverse effects on gut health. In this context, it has been repeatedly reported that DON can alter the intestinal morphology, disrupt the intestinal barrier and reduce nutrient absorption. The underlying mechanism of a compromised intestinal barrier caused by DON in chickens has yet to be illustrated. Although, DON is rapidly absorbed from the upper parts of the small intestine, the effects on the large intestine cannot be excluded. Additionally, a damaging effect of DON on the gut epithelium might decrease the resistance of the gut against infectious agents. Consequently, the objectives of the present studies were: (1) to investigate the impact of DON on the epithelial paracellular permeability by demonstrating the mucosal to serosal flux of 14 C-mannitol in the small and large intestine applying Ussing chambers and (2) to delineate the effects of DON on the colonization and translocation of Escherichia coli. Both parameters are well suited as potential indicators for gut barrier failure. For this, a total of 75 one-day-old Ross 308 broiler chickens were housed in floor pens on wood shavings with feed and water provided ad libitum. Birds were randomly allocated to three different groups (n = 25 with 5 replicates/group) and were fed for 5 weeks with either contaminated diets (5 or 10 mg DON/kg feed) or basal diets (control). Body weight (BW) and BW gain of birds in the group fed with 10 mg/kg DON were significantly lower than in group with 5 mg/kg DON and the control group. Moreover, the mannitol flux in jejunum and cecum was significantly (P < 0.05) higher in DON-fed groups compared to control birds. Consistent with this, DON enhanced the translocation of E. coli with a higher number of bacteria encountered in the spleen and liver. Altogether, the actual results verified that DON can alter the intestinal paracellular permeability in broiler chickens and facilitates the translocation of enteric microorganisms such as E. coli to extra-intestinal organs. Considering that moderate levels of DON are present in feed, the consumption of DON-contaminated feed can induce an intestinal breakdown with negative consequences on broiler health.