**4. Aflatoxins occurrence in animal products**

kg-1), inspection of grain regularly for temperature, insects and wet spots will limit the possibil‐ ity of fungal development in feeds and feedstuffs as discussed before. The risk of feed contami‐ nation will be reduced in animal units with rapid turnover of feed because there will be less time for fungal growth and toxin production [17]. Aflatoxin is just one of many mycotoxins that can adversely affect animal health and productivity. Care regarding animal feed must be

Decades of animal studies have demonstrated that chronic exposure to aflatoxins in animals can also cause growth inhibition and immune suppression [18]. Nursing animals may be af‐ fected, and AFM1 may be excreted in the milk of dairy cattle and other dairy animals. This in turn poses potential health risks to both animals and humans that consume that milk. Chronic aflatoxin exposure in animals can result in impaired reproductive efficiency, re‐ duced feed conversion efficiency, increased mortality rates, reduced weight gain, anemia, and jaundice. In the case of laying hens, aflatoxicosis causes an enlarged fatty liver and low‐

Sex and age of animals have also an influence on AFB1 susceptibility. For instance, males are more susceptible than females and young animals of all species are more susceptible than mature animals to the effects of aflatoxin [12,16]. Feed refusal, reduced growth rate and de‐ creased feed efficiency are the predominant signs of chronic aflatoxin poisoning. In addition, listlessness, weight loss, rough hair coat and mild diarrhea may occur. Anemia along with bruises and subcutaneous hemorrhage are also symptoms of aflatoxicosis. The disease may also impair reproductive efficiency, including abnormal estrous cycles (too short and too long) and abortions. Other symptoms include impaired immune system response, increased

A study identified and quantified aflatoxins (AFB1, AFB2, AFG1 and AFG2) from poultry feed and their recovery, together with their metabolites (AFM1, AFM2, AFP1 and aflatoxicol) in litter. Hens were divided in 3 groups and fed with 2 AFB1 concentrations: 30 and 500 ppb, besides the control group. Feed samples of the 3 groups presented significant difference with AFB2 and AFG2, whereas in litter samples, there were significant differences for AFG2 in the 500 ppb group. Poultry litter had traces of AFM1, AFM2, AFP1 (can be considered as a demethylated AFB1) and aflatoxicol with no significant differences among treatments [20].

The presence of molds in foodstuffs causes the appearance of flavors and odors that reduce palatability and affect feed consumption by animals as well as reduce the nutritional value of foods. Mycotoxins, in turn, affect the digestion and metabolism of nutrients in animal production, resulting in nutritional and physiological disorders, besides a negative effect on

It was reported main effects caused by aflatoxins during swine growth and termination phases. When feed was contaminated with 10-100 ppb, productivity losses without noticea‐ ble clinical signs were observed. When this level was 200-400 ppb, reduced growth and feed efficiency occurred. At 400-800 ppb of aflatoxins in feed, there were liver diseases (friable or yellow-tan liver). After 800-1200 ppb of aflatoxins administration in feed, reduction of food intake and growth was observed. Finally, at 1200-2000 ppb, jaundice, coagulopathy, anorex‐

extended not only to the nutritional and economic value, but also to food quality [13].

ered egg production [19].

176 Aflatoxins - Recent Advances and Future Prospects

the immune system [21].

susceptibility to disease, and rectal prolapse [12].

When focusing on how mycotoxins play a role in food safety, attention should be limited to mycotoxins that are known to be transferred from feed to food of animal origin, as this food represents a significant route of exposure for humans [27]. Apart from their toxicological ef‐ fects in affected animals, the carry-over through animal derived products, such as meat, milk and eggs into the human food chains is an important aspect of mycotoxin contamina‐ tion. FAO has estimated that up to 25% of the world's food crops and a higher percentage of the world's animal feedstuffs are significantly contaminated by mycotoxins.

Aflatoxin or ochratoxin residues in meat are uncommon and rarely found [28]. However, it's more common in organs especially liver. This organ may have its lipid content increased over three fold when 20 ppm aflatoxin is incorporated in broiler feed [29].

The problem in the egg production is that the long-term or short-term hen's exposure, via dietary sources, to low concentrations of certain mycotoxins causes contamination of eggs. This is the case of aflatoxins, which have a high impact in both, human and animal health, causing significant losses in the egg industry, considering the deleterious effect on egg pro‐ duction and quality.

[33]. The most important economic effect of poultry ingesting AF-contaminated feed would be the increase of the mortality index [34] and in addition, aflatoxins intake can decrease

In a detailed study focusing on the effects of aflatoxin chronic intoxication in renal function of laying hens (13 weeks-old), aflatoxins were evident at 17 weeks of the intoxication period. Fi‐ nal concentrations were 0, 0.46, 0.98 and 1.53 mg of aflatoxins per kg of feed, respectively and birds ingested the contaminated diets during 17 and 42 weeks. Body weight of intoxicated hens, showed a tendency to decrease, being significant in 1.0 and 1.5 mg kg-1 of feed concentra‐ tions in both times of the intoxication period. Evidence of tubular damage in kidney was found

sorption from the gut. Also, microscopic lesions of glomerular and tubular structures like in‐ flammatory and degenerative processes of the renal structures in hens kidneys were found. Additionally, the authors pointed out that the renal lesions occurred more frequently in larger doses of AF and over a long period of exposure to the toxin (42 weeks intoxication period) [38].

Other authors concluded that aflatoxins may have direct or indirect effect or both, on function‐ ality of the gastrointestinal tract. Results indicated that specific activity of the intestinal mal‐ tase and disaccharidase increased quadratically, by feeding up to 1.2 mg kg-1 aflatoxins and declined at 2.5 mg kg-1 concentration in the study and the intestinal crypt depth (but not villus length) increased linearly with increasing the level of aflatoxins in the experimental diets [39].

Hens were fed three levels of aflatoxin that might approximate contamination under field conditions [40]. Pure AFB1 was prepared and mixed in the diet as follows: 0.1 ppm for 10 days; 0.2 ppm for 12 days and 0.4 ppm for 15 days. Results confirmed that AFB1 fed to hens was transmitted into eggs in measurable amounts at all levels and was found in both, albu‐ men and yolks. The average amounts of aflatoxin distributed between albumen and yolk were 2.2 and 3.6 ppb, respectively. Even at the concentration of 0.1 ppm of AFB1 in the layer

Mainly aflatoxins and ochratoxin A may be found as residues at significant levels in muscles and muscle foods when contaminated feed is distributed to farm animals. Meat contamina‐ tion may also result from toxigenic mold development during ripening and ageing. In mus‐ cles, only low levels are found, often below detection limits of the methods used, even after exposure of the animals to high doses of AFB1. In ruminants, many studies evaluated afla‐ toxin transfer into the milk of lactating cows. However, as for other species, residues can be

It was reported [41] that processing conditions during ageing of hams may allow aflatoxin synthesis. Thus, is important to conduct research evaluating the production of AFB1 during meat processing and ageing. Studies show that frequency of processed meat contamination with AFB1 was low and the toxin level within meat was usually <10 ng g-1 (ppb). It is not clear whether AFB1 was produced during meat processing or was present before at the re‐ sidual level in muscles. The contamination of spices and additives added during meat proc‐ essing may also represent a source of mycotoxin. Besides, spice addition may lead to a

diet, the transmission into eggs occurred as an average of 0.23 ppb.

found in liver and kidney that are edible parts of these animals [41].

secondary contamination of the final product with aflatoxins.

+3 in plasma or even a decreased Ca ++ ab‐

Aflatoxins Importance on Animal Nutrition http://dx.doi.org/10.5772/51952 179

productivity due to hepatic [35]; immunological [36] and renal damages [37].

as a result of a decreased concentration of Ca++ and PO4

In laboratory studies it was proved that aflatoxin can decrease egg production and increase liver fat (fatty liver syndrome). This classical study established the typical symptoms associ‐ ated with acute or chronic aflatoxicosis, observed until today in field conditions [30].

A distinctive sequence of events during acute aflatoxicosis in laying hens (30 weeks-old) in a four week experiment with increasing aflatoxin doses in the diet of 0; 1.25; 2.5; 5.0 and 10.0 µg g-1 [31]. Results indicated that egg production was decreased by about 70% from the con‐ trol value at 10µg g-1 concentration in the diet and the liver size was increased significantly by 5 and 10 µg g-1 dietary concentrations of aflatoxin and the liver lipid increasing dramati‐ cally by a smaller dose of 2.5 µg g-1. Table 3 shows the dramatic effect of aflatoxin in the liver function [31]. The obtained data suggest that plasma and yolk lipids respond to the inhibi‐ tion of lipid synthesis and transport from the liver during aflatoxicosis induced by the diet‐ ary treatments. The liver malfunction results in an increase in its fat content and a decrease in the levels of plasma lipids.


**Table 3.** Response of liver lipid and plasma lipid during aflatoxicosis in laying hens.

Zaghini et al. [32] supported the previous finding showing the effects of AFB1 on egg quality and chemical parameters. In the study, 44 weeks-old laying hens were submitted to a diet containing 2.5 ppm of AFB1 and by the end of the second and third weeks of the trial, changes were observed like decreased egg weight (from 73.76 g to 72.5 g, week 0-4th, respec‐ tively) and reduced shell weight, as indicated by the decline in the percent shell of eggs laid by the hens fed the AFB1 contaminated diet from 10.49% to 10.19%. In the same study, afla‐ toxin also influenced color parameters, which were probably related to interference of AFB1 with lipid metabolism and pigmentary substances deposition in yolk. Additionally, all livers collected from the hens administered the mycotoxin group were positive for AFB1.

Astonishingly, as little as 0.2 mg kg-1 (or 0.2 ppm) of the metabolite AFB1 has been docu‐ mented to reduce egg production and egg mass in laying hens from 22 to 40 weeks of age [33]. The most important economic effect of poultry ingesting AF-contaminated feed would be the increase of the mortality index [34] and in addition, aflatoxins intake can decrease productivity due to hepatic [35]; immunological [36] and renal damages [37].

The problem in the egg production is that the long-term or short-term hen's exposure, via dietary sources, to low concentrations of certain mycotoxins causes contamination of eggs. This is the case of aflatoxins, which have a high impact in both, human and animal health, causing significant losses in the egg industry, considering the deleterious effect on egg pro‐

In laboratory studies it was proved that aflatoxin can decrease egg production and increase liver fat (fatty liver syndrome). This classical study established the typical symptoms associ‐

A distinctive sequence of events during acute aflatoxicosis in laying hens (30 weeks-old) in a four week experiment with increasing aflatoxin doses in the diet of 0; 1.25; 2.5; 5.0 and 10.0 µg g-1 [31]. Results indicated that egg production was decreased by about 70% from the con‐ trol value at 10µg g-1 concentration in the diet and the liver size was increased significantly by 5 and 10 µg g-1 dietary concentrations of aflatoxin and the liver lipid increasing dramati‐ cally by a smaller dose of 2.5 µg g-1. Table 3 shows the dramatic effect of aflatoxin in the liver function [31]. The obtained data suggest that plasma and yolk lipids respond to the inhibi‐ tion of lipid synthesis and transport from the liver during aflatoxicosis induced by the diet‐ ary treatments. The liver malfunction results in an increase in its fat content and a decrease

*Dose (µg g-1) Liver lipids (%) Plasma lipids (g 100 g-1)* 0.0 21.2±1.1 2.6±0.3 1.25 24.4±1.8 2.6±0.4 2.5 32.7±1.8 2.1±0.2 5.0 35.6±4.9 1.9±0.1 10.0 46.5±4.7 1.7±0.2

Zaghini et al. [32] supported the previous finding showing the effects of AFB1 on egg quality and chemical parameters. In the study, 44 weeks-old laying hens were submitted to a diet containing 2.5 ppm of AFB1 and by the end of the second and third weeks of the trial, changes were observed like decreased egg weight (from 73.76 g to 72.5 g, week 0-4th, respec‐ tively) and reduced shell weight, as indicated by the decline in the percent shell of eggs laid by the hens fed the AFB1 contaminated diet from 10.49% to 10.19%. In the same study, afla‐ toxin also influenced color parameters, which were probably related to interference of AFB1 with lipid metabolism and pigmentary substances deposition in yolk. Additionally, all livers

Astonishingly, as little as 0.2 mg kg-1 (or 0.2 ppm) of the metabolite AFB1 has been docu‐ mented to reduce egg production and egg mass in laying hens from 22 to 40 weeks of age

collected from the hens administered the mycotoxin group were positive for AFB1.

ated with acute or chronic aflatoxicosis, observed until today in field conditions [30].

duction and quality.

178 Aflatoxins - Recent Advances and Future Prospects

in the levels of plasma lipids.

Adapted from ref. [31]. Values are means ± Standard error of the mean

**Table 3.** Response of liver lipid and plasma lipid during aflatoxicosis in laying hens.

In a detailed study focusing on the effects of aflatoxin chronic intoxication in renal function of laying hens (13 weeks-old), aflatoxins were evident at 17 weeks of the intoxication period. Fi‐ nal concentrations were 0, 0.46, 0.98 and 1.53 mg of aflatoxins per kg of feed, respectively and birds ingested the contaminated diets during 17 and 42 weeks. Body weight of intoxicated hens, showed a tendency to decrease, being significant in 1.0 and 1.5 mg kg-1 of feed concentra‐ tions in both times of the intoxication period. Evidence of tubular damage in kidney was found as a result of a decreased concentration of Ca++ and PO4 +3 in plasma or even a decreased Ca ++ ab‐ sorption from the gut. Also, microscopic lesions of glomerular and tubular structures like in‐ flammatory and degenerative processes of the renal structures in hens kidneys were found. Additionally, the authors pointed out that the renal lesions occurred more frequently in larger doses of AF and over a long period of exposure to the toxin (42 weeks intoxication period) [38].

Other authors concluded that aflatoxins may have direct or indirect effect or both, on function‐ ality of the gastrointestinal tract. Results indicated that specific activity of the intestinal mal‐ tase and disaccharidase increased quadratically, by feeding up to 1.2 mg kg-1 aflatoxins and declined at 2.5 mg kg-1 concentration in the study and the intestinal crypt depth (but not villus length) increased linearly with increasing the level of aflatoxins in the experimental diets [39].

Hens were fed three levels of aflatoxin that might approximate contamination under field conditions [40]. Pure AFB1 was prepared and mixed in the diet as follows: 0.1 ppm for 10 days; 0.2 ppm for 12 days and 0.4 ppm for 15 days. Results confirmed that AFB1 fed to hens was transmitted into eggs in measurable amounts at all levels and was found in both, albu‐ men and yolks. The average amounts of aflatoxin distributed between albumen and yolk were 2.2 and 3.6 ppb, respectively. Even at the concentration of 0.1 ppm of AFB1 in the layer diet, the transmission into eggs occurred as an average of 0.23 ppb.

Mainly aflatoxins and ochratoxin A may be found as residues at significant levels in muscles and muscle foods when contaminated feed is distributed to farm animals. Meat contamina‐ tion may also result from toxigenic mold development during ripening and ageing. In mus‐ cles, only low levels are found, often below detection limits of the methods used, even after exposure of the animals to high doses of AFB1. In ruminants, many studies evaluated afla‐ toxin transfer into the milk of lactating cows. However, as for other species, residues can be found in liver and kidney that are edible parts of these animals [41].

It was reported [41] that processing conditions during ageing of hams may allow aflatoxin synthesis. Thus, is important to conduct research evaluating the production of AFB1 during meat processing and ageing. Studies show that frequency of processed meat contamination with AFB1 was low and the toxin level within meat was usually <10 ng g-1 (ppb). It is not clear whether AFB1 was produced during meat processing or was present before at the re‐ sidual level in muscles. The contamination of spices and additives added during meat proc‐ essing may also represent a source of mycotoxin. Besides, spice addition may lead to a secondary contamination of the final product with aflatoxins.


liver, i.e. 22.54±1.48 and 1.44±0.21 ppb, respectively, while a minimum concentration of resi‐ dues of both mycotoxins was found in the breast muscles of the laying hens. Residues of AFB1 in the eggs appeared at day 5 of toxin feeding and disappeared at day 6 of withdrawal of AFB1 contaminated diet. As in case of tissues, residues of OTA and AFB1 are significantly lower in eggs obtained from hens fed both toxins in combination, compared to those fed each mycotox‐

Aflatoxins Importance on Animal Nutrition http://dx.doi.org/10.5772/51952 181

Another study shows that concentration of AFB1 residues in liver and muscles increased with toxin ingestion time and were at its highest levels (6.97 ppb in liver and 3.27 ppb in muscle) on the last day (7th) of feeding AFB1 contaminated ration. Broiler chicks of 7, 14 and 28 days of age fed same level of AFB1 showed lower tissue residues in older birds compared with younger ones. Birds given 1600 and 3200 ppb AFB1 for 7 days at 28 days of age had no detectable AFB1 levels in liver and muscles after 3 and 8 days of withdrawal of contaminat‐ ed feed. A rapid decrease in AFB1 residues below the tolerance limits from muscles and liver within 3 and 7 days of withdrawal of dietary AFB1 in this study confirm the rapid metabo‐ lism of aflatoxins in the body of chicken and that it may not become a significant human health risk. However, in areas with no regulatory limits on AFB1 levels of poultry feed, the secondary exposure to aflatoxins through consumption of chicken liver and meat derived

from the poultry fed contaminated feed may pose a risk to consumers health [43].

*Product Aflatoxin Positive/total of samples Range (ppb) Method* Corn AFs 76 / 246 2-906 TLC or ELISA Corn AFB2 33 / 292 1-17 TLC Feed AFB1 14 / 96 11-287 TLC Eggs AFB1 2 / 210 2-5 TLC Eggs AFM1 0 / 210 - TLC Swine liver AFB1 1 / 43 27 TLC Chicken liver AFB1 3 / 6 1.2-3.2 TLC/HPLC

**Table 5.** Mycotoxin levels in vegetable and animal products. Adapted from ref. [45]. See this review to obtain the

The impact of subchronic exposure of AFB1 on the tissue residues of enrofloxacin and its metabolite ciprofloxacin was examined in broilers. Broiler chickens given either normal or AFB1 (750 ppb diet) supplemented diets for 6 weeks received enrofloxacin (10 mg kg-1 day-1, p.o.) for 4 days and thereafter, residue levels were determined at 1, 5 and 10 days after the last treatment. In AFB1-unexposed broiler chickens, enrofloxacin was detected in all the tis‐ sues. After 24 h of treatment cessation, concentrations of enrofloxacin were up to 0.85 µg g-1 in the following order: liver>skin+fat>muscle>kidney. The parent drug was not found in any of the tissues except liver 10 days after the last dose of enrofloxacin. Ciprofloxacin was not detectable in any tissue. In AFB1-exposed broiler chickens, higher concentrations of enroflox‐ acin and ciprofloxacin were found in different tissues, compared with tissues of control broiler chickens. After 24 h of the last dose of enrofloxacin, concentrations up to 4.53 µg g-1 were found of the parent drug in the order skin+fat>liver>kidney>muscle. The parent drug

in alone, possibly due to their protein binding potentials.

references of original publication.

Table 4 shows residues of one or more aflatoxins in different hen tissues.

**Table 4.** Residues of aflatoxin in animal products combined or not with other mycotoxin.

Feeding one mycotoxin alone (OTA) resulted in significantly higher residue levels in liver, kid‐ ney and breast muscles of hens than their counterpart birds kept on a diet concurrently conta‐ minated with both OTA and AFB1 [42]. In this study, a total of 72 White Leghorn layer breeder hens at 45 weeks of age were submitted to diets containing different combinations of these my‐ cotoxins (some are shown in Table 4, focusing mainly on AFB1 residues). In liver of hens fed OTA alone at 5 mg kg-1 (ppm) feed, residues level was 22.54±1.48 (mean±SD) ppb, as compared to significantly lower residual concentration of 2.21±0.42, in the same levels of OTA when ad‐ ministered in combination with AFB1. Residues of OTA were significantly higher in liver than in kidneys of the hens fed OTA alone, in all experimental groups. However, feeding OTA in combination with AFB1 resulted in higher deposition of OTA in kidneys than in livers. Resi‐ dues of AFB1 were significantly higher in liver and breast muscles of the birds kept on AFB1 contaminated feed compared with those fed OTA and AFB1 concurrently. When the maximum dosage (5 ppm) was administered, residues of OTA and AFB1 were also the maximum in the liver, i.e. 22.54±1.48 and 1.44±0.21 ppb, respectively, while a minimum concentration of resi‐ dues of both mycotoxins was found in the breast muscles of the laying hens. Residues of AFB1 in the eggs appeared at day 5 of toxin feeding and disappeared at day 6 of withdrawal of AFB1 contaminated diet. As in case of tissues, residues of OTA and AFB1 are significantly lower in eggs obtained from hens fed both toxins in combination, compared to those fed each mycotox‐ in alone, possibly due to their protein binding potentials.

Table 4 shows residues of one or more aflatoxins in different hen tissues.

Muscle Eggs

Liver Eggs

Liver/Muscle/ Kidney

Muscle Kidney Liver

Muscle Kidney Liver

Muscle Kidney Liver

**Table 4.** Residues of aflatoxin in animal products combined or not with other mycotoxin.

Feeding one mycotoxin alone (OTA) resulted in significantly higher residue levels in liver, kid‐ ney and breast muscles of hens than their counterpart birds kept on a diet concurrently conta‐ minated with both OTA and AFB1 [42]. In this study, a total of 72 White Leghorn layer breeder hens at 45 weeks of age were submitted to diets containing different combinations of these my‐ cotoxins (some are shown in Table 4, focusing mainly on AFB1 residues). In liver of hens fed OTA alone at 5 mg kg-1 (ppm) feed, residues level was 22.54±1.48 (mean±SD) ppb, as compared to significantly lower residual concentration of 2.21±0.42, in the same levels of OTA when ad‐ ministered in combination with AFB1. Residues of OTA were significantly higher in liver than in kidneys of the hens fed OTA alone, in all experimental groups. However, feeding OTA in combination with AFB1 resulted in higher deposition of OTA in kidneys than in livers. Resi‐ dues of AFB1 were significantly higher in liver and breast muscles of the birds kept on AFB1 contaminated feed compared with those fed OTA and AFB1 concurrently. When the maximum dosage (5 ppm) was administered, residues of OTA and AFB1 were also the maximum in the

*Tissues Residues (µg kg-1) Metabolites Reference*

[32]

OTA+AFB1 [42]

0.08±0.03 0.24±0.07 and 0.25±0.09 4.13±1.95 <0.5 and <0.01

ND + ND

ND + 0.03 ND + 0.25 ND + 1.44

0.34 + 0.02 2.80 + 0.27 1.98 + 0.26

0.51 + 0.02 2.81 + 0.27 2.21 + 0.11

*Animal species Dose or exposure*

180 Aflatoxins - Recent Advances and Future Prospects

Laying hens 2.5 ppm AFB1 in

Layer breeder hens OTA+AFB1

*time*

feed for 4 weeks

mg kg-1 0 + 0

0 + 5

3 + 5

5 + 5

Another study shows that concentration of AFB1 residues in liver and muscles increased with toxin ingestion time and were at its highest levels (6.97 ppb in liver and 3.27 ppb in muscle) on the last day (7th) of feeding AFB1 contaminated ration. Broiler chicks of 7, 14 and 28 days of age fed same level of AFB1 showed lower tissue residues in older birds compared with younger ones. Birds given 1600 and 3200 ppb AFB1 for 7 days at 28 days of age had no detectable AFB1 levels in liver and muscles after 3 and 8 days of withdrawal of contaminat‐ ed feed. A rapid decrease in AFB1 residues below the tolerance limits from muscles and liver within 3 and 7 days of withdrawal of dietary AFB1 in this study confirm the rapid metabo‐ lism of aflatoxins in the body of chicken and that it may not become a significant human health risk. However, in areas with no regulatory limits on AFB1 levels of poultry feed, the secondary exposure to aflatoxins through consumption of chicken liver and meat derived from the poultry fed contaminated feed may pose a risk to consumers health [43].


**Table 5.** Mycotoxin levels in vegetable and animal products. Adapted from ref. [45]. See this review to obtain the references of original publication.

The impact of subchronic exposure of AFB1 on the tissue residues of enrofloxacin and its metabolite ciprofloxacin was examined in broilers. Broiler chickens given either normal or AFB1 (750 ppb diet) supplemented diets for 6 weeks received enrofloxacin (10 mg kg-1 day-1, p.o.) for 4 days and thereafter, residue levels were determined at 1, 5 and 10 days after the last treatment. In AFB1-unexposed broiler chickens, enrofloxacin was detected in all the tis‐ sues. After 24 h of treatment cessation, concentrations of enrofloxacin were up to 0.85 µg g-1 in the following order: liver>skin+fat>muscle>kidney. The parent drug was not found in any of the tissues except liver 10 days after the last dose of enrofloxacin. Ciprofloxacin was not detectable in any tissue. In AFB1-exposed broiler chickens, higher concentrations of enroflox‐ acin and ciprofloxacin were found in different tissues, compared with tissues of control broiler chickens. After 24 h of the last dose of enrofloxacin, concentrations up to 4.53 µg g-1 were found of the parent drug in the order skin+fat>liver>kidney>muscle. The parent drug 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 in muscle for 10 days. The metabolite was not detectable in kidney [44].

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

food, required as maximum standard in different countries.

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

**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‐

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

2 Corn and byproducts 3 Soybean and byproducts

ucts coming from exposed animals [41].

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‐

Aflatoxins Importance on Animal Nutrition http://dx.doi.org/10.5772/51952 183

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

*Mycotoxins\* Feed1 Corn2 Soybean3* Aflatoxin B1, ppb 1.5 - 50 1 – 50 30 - 50 Aflatoxin B1, B2, G1 and G2, ppb 0 - 75 5 – 50 20 - 50 Deoxynivalenol, ppb 5 - 1500 - - Toxin HT2, ppb 25 - 100 - - Ochratoxin, ppb 5 - 300 50 – 300 - Zearalenone, ppb - 0.5 – 200 -

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

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‐ tion.


**Table 6.** AFB1 and its metabolites aflatoxicol (R0) and AFM1 (ng g-1) after contaminated diet ingestion with AFB1 (8 μg g-1). Values in ppb; ND = Not detected [46].
