Aspergillus species can produce aflatoxins (AFs), which can severely affect human and animal health. The objective was to evaluate the efficacy of reducing AF contamination of a non-aflatoxigenic isolate of A. flavus experimentally coinoculated with different aflatoxigenic strains in whole plant (WP), corn silage (CS), immature grains (IG) and in culture media (CM). An L-morphotype of A. flavus (CS1) was obtained from CS in a dairy farm located in the Mexican Highland Plateau; The CS1 failed to amplify the AFs biosynthetic pathway regulatory gene (aflR). Monosporic CS1 isolates were coinoculated in WP, CS, IG and CM, together with A. flavus strains with known aflatoxigenic capacity (originating from Cuautitlán and Tamaulipas, Mexico), and native isolates from concentrate feed (CF1, CF2 and CF3) and CS (CS2, CS3). AF production was evaluated by HPLC and fungal growth rate was measured on culture media. The positive control strains and those isolated from CF produced a large average amount of AFs (15,622 ± 3952 and 12,189 ± 3311 µg/kg), whereas A. flavus strains obtained from CS produced a lower AF concentration (126 ± 25.9 µg/kg). CS1 was efficient (p < 0.01) in decreasing AF concentrations when coinoculated together with CF, CS and aflatoxigenic positive control strains (71.6–88.7, 51.0–51.1 and 63.1–71.5%) on WP, CS, IG and CM substrates (73.9–78.2, 65.1–73.7, 63.8–68.4 and 57.4–67.6%). The results suggest that the non-aflatoxigenic isolate can be an effective tool to reduce AF contamination in feed and to minimize the presence of its metabolites in raw milk and dairy products intended for human nutrition.

Aflatoxins (AFs) are secondary metabolites of Aspergillus spp. They are highly toxic, carcinogenic, and immunosuppressive; AFs cause nonspecific disorders in humans and animals, which makes their diagnosis complex. The objective was to describe the time course of toxic effects of a single exposure to AFs-contaminated feed. Fifteen male calves (2 weeks old) were examined over 30 days for clinical, biochemical, and pathological changes resulting from the ingestion of AF-contaminated feed (1.0 mg/kg BW). Compared with 15 unexposed calves, exposed calves showed transient depression and rough coat; BW gain, dry matter intake, albumin, total plasma protein, and hepatic and renal glutathione-S-transferase concentrations progressively decreased. However, conversion ratio (feed/BW), total bilirubin, direct bilirubin, alkaline phosphatase, reduced glutathione, gamma-glutamyltransferase, and alanine and aspartate aminotransferases progressively increased. Necropsy and histology at 7 days postexposure (dpe) showed liver with multifocal hemorrhages, yellowish coloration, friable consistency, periportal fibrosis, and steatosis. Kidneys were hemorrhagic, with brush border losses, glomerular atrophy, sclerotic glomerulonephritis, and lymphocytic infiltration. However, at 30 dpe, the liver showed pale discoloration, diffuse macrovesicular steatosis, and periportal fibrosis. The kidneys had mottled appearance and firm consistency, fibrosis, loss of normal architecture, and thickening of Bowman’s capsule. These results suggest that the identification of alterations in animal performance and biochemical and histological characteristics could be useful for integrating a proper diagnosis of bovine aflatoxicosis.

Crops contamination with aflatoxins (AFs) and zearalenone (ZEA) threaten human and animal health; these mycotoxins are produced by several species of Aspergillus and Fusarium. The objective was to evaluate under field conditions the influence of the wet season on the dissemination of AF- and ZEA-producing fungi via houseflies collected from dairy farms. Ten dairy farms distributed in the semi-arid Central Mexican Plateau were selected. Flies were collected in wet and dry seasons at seven points on each farm using entomological traps. Fungi were isolated from fly carcasses via direct seeding with serial dilutions and wet chamber methods. The production of AFs and ZEA from pure isolates was quantified using indirect competitive ELISA. A total of 693 Aspergillus spp. and 1274 Fusarium spp. isolates were obtained, of which 58.6% produced AFs and 50.0% produced ZEA (491 ± 122; 2521 ± 1295 µg/kg). Houseflies and both fungal genera were invariably present, but compared to the dry season, there was a higher abundance of flies as well as AF- and ZEA-producing fungi in the wet season (p < 0.001; 45.3/231 flies/trap; 8.6/29.6% contaminated flies). These results suggest that rainy-weather conditions on dairy farms increase the spread of AF- and ZEA-producing Aspergillus spp. and Fusarium spp. through houseflies and the incorporation of their mycotoxins into the food chain.

Aflatoxins (AFs) represent a major threat to poultry health and food safety due to their hepatotoxic, immunosuppressive, and carcinogenic effects. This study evaluated the chemoprotective potential of ethoxyquin (EQ) and N-acetylcysteine (NAC) in laying hens (80.8 and 33.3 mg/kg BW/d) exposed to chronic dietary AFs contamination (0.0–1.5 mg/kg). A total of 360 Hy-Line W36 Leghorn hens were monitored over 72 weeks using biochemical and histopathological analyses of liver and kidney tissues. NAC significantly (p < 0.01) increased hepatic and renal levels of reduced glutathione (GSH) and stimulated glutathione S-transferases (GST) and gamma-glutamyl transferase (GGT) activity, enhancing detoxification. Both agents significantly (p < 0.05) reduced plasma ALT and AST levels, preserved total protein concentrations, and attenuated liver and kidney hypertrophy. EQ demonstrated antioxidant effects, stabilizing enzymatic responses and limiting tissue damage. Histopathological analysis revealed fewer structural alterations and cellular degeneration, especially in the NAC-treated group (p < 0.01). These results suggest that NAC and EQ activate endogenous detoxification mechanisms, both enzymatic and non-enzymatic, effectively mitigating chronic aflatoxin toxicity. Their dietary supplementation offers a safe and sustainable chemoprotection strategy to support poultry health and productivity, particularly in regions facing high mycotoxin exposure.