## 5 Discussion  
The five species employed as experimental models are farm animals widely used for the production of meat, milk, and their products. The absence of horses as experimental models may be explained by the fact that these animals are generally not considered production animals, but as sport or companion animals [51]. A study carried out by [PERSON] et al. [52] quantified zearalenone biomarkers, \(\alpha\)-zearalenol and \(\beta\)-zearalenol, in the urine of horses using LC-MS/MS and showed that urine is an adequate sample for the measurement of this mycotoxin and its metabolites. The most common technique used in the detection of biomarkers was LC-MS/MS. Its popularity may be due to its high sensitivity and specificity, making it possible to analyze different mycotoxins as parts per billion (ppb) or even parts per trillion (ppt) [1; 53; 54]. As observed in the present review, liquid chromatography coupled with fluorescence detector, as well as ELISA, are also widely used for the detection of mycotoxins and their biomarkers in foods, and in human and animal samples [19; 24; 53; 54; 55; 56; 57]. In some studies, no biomarkers were detected in the samples [29]. For example, RBTC calculation could not be carried out in the study by [PERSON] et al. [33] because levels of T-2 and HT-2 in the viscera analyzed were too low, either undetectable or below the limit of detection of the methods employed. It is important to emphasize that absence of detection of biomarkers may have different meanings. First, it may be related to the sensitivity of the analytical method. Therefore, the absence of detection of biomarkers does not mean absence of biomarkers, but lack of sensitivity of the method. Considering this, LC-MS/MS is, presently, the most sensitive technique for this quantification. Secondly, the amount of mycotoxin offered to the animals may not be enough for the detection of biomarkers. An example for this case is the study by [PERSON] [14]. Although they used LC-MS/MS, OTA was only detected in the eggs of hens that were treated with 1 mg/kg, and not in those that received 0.25 mg/kg of the toxin. A total of 16 different biomarkers were searched for in the samples analyzed, either the unchanged mycotoxin--AFB\({}_{1}\), for example--or its biotransformed form, an adduct or a conjugate, such as hydroxylated AFM\({}_{1}\), AFB\({}_{1}\)-lysin, and ZEN-GlcNAc, respectively. Of all mycotoxins employed in the studies selected here, AFB\({}_{1}\) was the most common one. This may be related to the high carcinogenic potential of AFB\({}_{1}\), to the fact that AFB\({}_{1}\) metabolites (which are also potentially carcinogenic) may be found in different and popular animal products [3; 11], and the possible animal losses caused by acute and lethal intoxication by AFB\({}_{1}\)[9]. AFM\({}_{1}\) and AFB\({}_{1}\) were also the most analyzed and quantified biomarkers, due to the same reasons [11]. Residues of these mycotoxins in animal products were found in many of the studies used in this review, mainly in poultry livers, a food that is widely consumed all over the world [46; 50]. The large number of articles that aimed at testing the reduction in AFM\({}_{1}\) concentration in the milk by mineral adsorbents is due to the great frequency of contamination of cattle feed with AFB\({}_{1}\). Besides, regulations that determine MTLs for AFM\({}_{1}\) in milk (in Brazil, 0.5 ug/kg, in the EU, 0.05 ug/kg) offer economic and commercial reasons for creating and testing products that may reduce the concentration of these mycotoxins in foods and animal feed [16; 18]. In humans, many biomarkers are used in the assessment of mycotoxin exposure. However, there are few studies that used these biomarkers to test the efficacy of a mineral adsorbent. A review by [PERSON] et al. [58] cites the possible use of the adsorbent NovaSilTM and in the reduction of biomarkers in urine and blood of people exposed to high levels of mycotoxins.