Kelly Moura Keller

The Mycobiota and Toxicity of Equine Feeds

Feed contamination can lead to nutrient losses and detrimental effects on animal health and production. The purposes of this study were to investigate the mycobiota in equine mixed feeds and to determine natural contamination with aflatoxin B1 (AFB1) and fumonisin B1 (FB1). Fungal enumeration of equine feed samples was done. A commercially available enzyme-linked immunosorbent assay kit was applied to quantify AFB1 and FB1. A comparison between ELISA and HPLC was carried out. Feed mould counts ranged from <1× 102 to 1× 105 cfu/g. The most frequent genus isolated was Aspergillus (40.54%), followed by Penicillium (18.38%) and Fusarium (16.22%). The most prevalent Aspergillus sp. was A. flavus (36%). AFB1 values ranged between 0.01 and 99.4 μg/kg. FB1 levels ranged between 0.01 and 7.49 μg/kg. HPLC and ELISA methods showed positive correlation for AFB1 and FB1 determinations (r = 0.9851 and r = 0.9791, respectively). The ELISA analytical method was efficient for AFB1 and FB1 detection. The scarcity of studies on natural fungal contamination and on the presence of AFB1 and FB1 in materials used as equine feed ingredients highlights the value and contribution of this study.

An Outbreak of Acute Aflatoxicosis on a Chinchilla (Chinchilla Lanigera) Farm in Argentina

Chinchillas (Chinchilla lanigera) are known to be very sensitive to aflatoxins, and often a large number of animals die if toxicosis occurs. An outbreak of acute aflatoxicosis on a chinchilla farm in Argentina is described in the present study. A commercial feed suspected of causing the death of 200 animals was sampled. Livers from 9 dead chinchillas were analyzed for their macroscopic and microscopic characteristics via necropsy and histopathology. Aflatoxins B1, B2, G1, and G2 were determined, by thin layer chromatography, to be in the feed. Macroscopic inspection of livers revealed general enlargement, pale-yellowish coloration, hypertrophy, rounded borders, and increased friability. Size and color were remarkably different from a healthy organ. Histopathologic analyses of hepatic parenchyma showed severe, diffuse cytoplasmic vacuolation of hepatocytes. Sudan III staining confirmed the presence of lipid within the vacuoles. The feed was positive for aflatoxin B1 in quantities that exceeded the recommended levels. Histologic lesions were typical of aflatoxin intake. Monitoring feed for mycotoxins is crucial to prevent outbreaks of toxicosis, to improve management practices, and to diminish exposure risk of animals and humans to these harmful toxins.

Zearalenone and Its Derivatives α-Zearalenol and β-Zearalenol Decontamination by Saccharomyces cerevisiae Strains Isolated from Bovine Forage

Zearalenone (ZEA) and its derivatives are mycotoxins with estrogenic effects on mammals. The biotransformation for ZEA in animals involves the formation of two major metabolites, α- and β-zearalenol (α-ZOL and β-ZOL), which are subsequently conjugated with glucuronic acid. The capability of Saccharomyces cerevisiae strains isolated from silage to eliminate ZEA and its derivatives α-ZOL and β-ZOL was investigated as, also, the mechanisms involved. Strains were grown on Yeast Extract-Peptone-Dextrose medium supplemented with the mycotoxins and their elimination from medium was quantified over time by HPLC-FL. A significant effect on the concentration of ZEA was observed, as all the tested strains were able to eliminate more than 90% of the mycotoxin from the culture medium in two days. The observed elimination was mainly due to ZEA biotransformation into β-ZOL (53%) and α-ZOL (8%) rather than to its adsorption to yeast cells walls. Further, the biotransformation of α-ZOL was not observed but a small amount of β-ZOL (6%) disappeared from culture medium. ZEA biotransformation by yeasts may not be regarded as a full detoxification process because both main end-products are still estrogenic. Nonetheless, it was observed that the biotransformation favors the formation of β-ZOL which is less estrogenic than ZEA and α-ZOL. This metabolic effect is only possible if active strains are used as feed additives and may play a role in the detoxification performance of products with viable S. cerevisiae cells.

Ochratoxin A in serum of swine from different Brazilian states.

The aims of the current study were to monitor the presence of ochratoxin A (OTA) in the serum of slaughtered swine and to investigate its distribution in 4 major geographical regions of Brazil. A total of 400 samples of serum were collected from 4 major states of Brazil (100 samples each). Ochratoxin A concentrations were determined by high-performance liquid chromatography. In Santa Catarina State, 60% of the samples had OTA concentrations ranging from 4.01 to 75.4 mg/l. In Mato Grosso State, 75% of the samples had OTA concentrations ranging from 0.17 to 46.79 mg/l. Bahia State samples had OTA concentrations ranging from 2.72 to 4.13 mg/l in 36% of the samples, whereas 68% of the samples from Rio de Janeiro State had OTA concentrations ranging from 0.16 to 115 mg/l. Only Santa Catarina State and Rio de Janeiro State had serum samples that exceeded 75 mg/l OTA in 20% and 2% of the samples, respectively. A direct relationship between the higher concentrations of OTA in serum from the States of Santa Catarina and Rio de Janeiro and the highest concentrations of OTA in food intended for animal consumption in the same 2 Brazilian states was found in the present study. Ochratoxin A distribution in foodstuffs is very heterogeneous, and an alternative method by which to monitor the presence of OTA in feed includes analyzing swine serum samples, which reflect the toxin content of the ingested feed. This strategy could prevent the occurrence of ochratoxicosis in animal production, reduce economic losses, and minimize hazards to human health.

Incidence of Mycotoxins (AFB1 and AFM1 ) in Feeds and Dairy Farms from Rio de Janeiro State, Brazil

Brazil has regions located at the largest dairy production and milk derivate industry concentration, supplying the major consumer markets, represented by São Paulo, Rio de Janeiro and Belo Horizonte Cities. The milk is the most important product of Brazilian agriculture, because it is always presents in daily diet. The aim of this research was evaluating the occurrence of mycotoxins in the feed of dairy cattle and the occurrence of AFM1 in milk under field conditions in farms from Rio de Janeiro State, Brazil. The results revealed that, total fungal counts was found in 67% of feed samples which exceeded the recommended limit recommended (1×104 UFC.g-1) and the incidence of AFM1 in all milk samples was 26.7% at concentrations ranging from 0.010 to 1.500 μg.L-1. The study revealed toxigenic fungi and their mycotoxins were present in feed intended for bovine feeding in Rio de Janeiro farms. Evaluations of mycotoxin levels are important to provide information so that the assessments of risk for animal feed and livestock environment can be done.