**5. Legislation in feed and feed ingredients**

persisted in all the tissues except muscle for 10 days. Ciprofloxacin was detected in muscle and skin plus fat 24 h after termination of enrofloxacin administration and it persisted only

A review carried out in Brazil [45] showed high variability among the results (Table 5). For instance, corn contamination with aflatoxins reached 906 ppb, above those levels allowed by legislation (20 ppb). This fact indicates the need for quality control in the reception of this ingredient in the feed mill with the use of rapid tests for mycotoxins. Regarding products of animal origin, major problems were not observed in eggs and tissues of swine and poultry (Table 5). However, among chicken liver samples 50% tested positive but with relatively low levels. Anyway, attention should be paid with liver consumption when there are evidences of corn contamination. From Table 5 data, it can be noted that contaminated feed samples

A survey with hens fed AFB1 via moldy rice powder feed showed residues in eggs and tis‐ sues (kidneys, liver, muscle, blood, and ova) [46]. Hens were fed for 7 days with a contami‐ nated diet (8 µg g-1) followed by additional 7 days on an aflatoxin-free diet. Eggs were collected over the entire 14-day period. The study showed that aflatoxicol (R0), a carcino‐ genic metabolite of AFB1, was found in all samples but blood (Table 6). Levels of R0 and AFB1 were approximately the same in eggs, ova, kidneys, and liver. In eggs, the levels of R0 and AFB1 (0.02 to 0.2 ng g-1) increased steadily for 4 or 5 days until reaching a plateau and then decreased after B1 withdrawal at the same rate as they increased. After 7 days of with‐ drawal, only trace amounts of R0 (0.01 ng g-1) remained in eggs. All samples from hens sacri‐ ficed immediately before aflatoxin withdrawal contained R0 or R0+AFB1. R0 was the only aflatoxin detected in muscle. Seven days after aflatoxin withdrawal, B1 (0.08 ng g-1) was found in one of nine livers and R0 (0.01-0.04 ng g-1) in eight of nine muscles analyzed, but no aflatoxins were found in any other tissues. Interestingly, the transfer of aflatoxins into eggs is right after administration, since B1 (0.03 ng g-1) and R0 (0.02 ng g-1) residues were found in eggs laid 1 day after contaminated feed was administered. This indicates that toxins pene‐ trate the egg through eggwhite since yolk was already formed before this period. Aflatoxin apparently can enter the egg at any stage of its development. This is because it takes 7 to 8 days for each oocyte to develop into a mature ovum (yolk) and 24 hours for the egg oviposi‐

*Tissue R0 AFB1 AFM1* Ova 0.25 0.24 ND Kidneys 0.10 0.25 0.05 Liver 0.20 0.46 ND Muscle 0.08 ND ND Blood ND 0.05 0.10

**Table 6.** AFB1 and its metabolites aflatoxicol (R0) and AFM1 (ng g-1) after contaminated diet ingestion with AFB1 (8 μg

in muscle for 10 days. The metabolite was not detectable in kidney [44].

182 Aflatoxins - Recent Advances and Future Prospects

achieved up to 287 ppb AFB1, above values allowed by legislation.

tion.

g-1). Values in ppb; ND = Not detected [46].

In the last decades, only aflatoxins and, to a lesser extent, ochratoxin A were regulated in foods from animal origin. For other toxins, the risk management was based on the control of the contamination of food from vegetal origin intended for both human and animal con‐ sumption. Nowadays, other mycotoxins are included. Regulatory values or recommenda‐ tions are mainly built on available knowledge on toxicity and potential carryover of these molecules in animal. Therefore, by limiting animal exposure through feed ingestion, one can guarantee against the presence of residues of mycotoxins in animal-derived products. How‐ ever, accidental high levels of contamination may lead to a sporadic contamination of prod‐ ucts coming from exposed animals [41].

Tolerance levels of mycotoxins in foods are needed to ensure product quality and consumer health. The limits differ among countries, i.e., depending on the product and the country there are different tolerance levels for each mycotoxin, but it is certain that their presence in foods has been widely researched and new standards were required over the years, in the last decade. Table 7 shows an average of mycotoxin variation depending on the type of food, required as maximum standard in different countries.


1 Relative to feed and concentrates for all categories and phases of animal

2 Corn and byproducts

3 Soybean and byproducts

\* Source: Adapted from Resolution RDC Nº7 [47] and EUR-LEX [48].

**Table 7.** Variation among different countries regarding maximum tolerance limits of mycotoxins.

In Brazil, the most recent resolution on mycotoxins in food is the RDC 07/2011 [47] which establishes maximum tolerated levels for aflatoxins (AFB1+AFB2+AFG1+AFG2 and AFM1), ochratoxin A, deoxynivalenol, fumonisins (FB1 + FB2), patulin and zearalenone, admissible in ready-to-eat foods and raw materials. To adapt to the new standard required in 2011, the producers of 14 food categories should meet the requirements until 2016. Table 8 shows standard values set for corn, which is the main ingredient added to feed in the country.

Brazil, like different countries, also follows the recommendation to keep mycotoxin levels as low as possible. For that, better practices and technologies in the production, handling, stor‐ age, processing and packaging should be accomplished in order to prevent that contaminat‐ ed food is sold or consumed.

Those researchers find that zeolite and bentonite aflatoxin binding capacity varied according

Aflatoxins Importance on Animal Nutrition http://dx.doi.org/10.5772/51952 185

**Figure 2.** Adsorption percentage of AFB1 (8 µg/ml) to sorbents (0.5% w/v) in simulated gastrointestinal fluid at pH 3

It is important to establish the correct inclusion rate to animal diets in order to optimize the binding response. In Figure 3, it can be observed how those three types of clays perform un‐

It has been shown that montmorillonite (0.5%) added to the diet containing 5 ppm of afla‐ toxin has proven its effectiveness in preventing the effects of aflatoxicosis in broilers [50].

**Figure 3.** Amount of aflatoxin B1 adsorbed on sorbents at different concentrations of the adsorbents in simulated in‐

Based on the data presented in Figures 2 and 3, it is clear that assays condition (especially pH) and toxin:sorbent dosing rate are extremely important. These conditions should be con‐ sidered when product performance reports are compared. However, when evaluating [51] nine different toxin binders (4 activated charcoals, 3 sodium bentonites, 1 calcium bentonite

der the same pH (7.0) when increasing doses are included.

and pH 7 [49].

testinal fluid at pH 7 [50].

to the pH used for the assay, and both clays were less effective than HSCAS (Figure 2).


**Table 8.** Maximum tolerated levels for mycotoxins according to Resolution RDC 07/2011 [47].\*The maximum tolerated levels refer to results obtained by methodologies that comply with the performance criteria established by Codex Alimentarius.
