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Excretion of Aflatoxin M1 in Milk of Dairy Ewes Treated with Different Doses of Aflatoxin B1

G. Battacone^*, A. Nudda^*, A. Cannas^*, A. Cappio Borlino^*, G. Bomboi and G. Pulina^*

^* Dipartimento di Scienze Zootecniche, Università degli Studi di Sassari, Via E. De Nicola 9, 07100 Sassari, Italy
Dipartimento di Biologia Animale, Università degli Studi di Sassari, Via Vienna 2, 07100 Sassari, Italy

	ABSTRACT

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS ACKNOWLEDGEMENTS REFERENCES

 
Two experiments were conducted to study the amount of aflatoxin M1 (AFM1) in milk in response to feeding aflatoxin B1 (AFB1). In experiment 1, four dairy ewes in early lactation received a single dose of pure AFB1 (2 mg). Individual milk samples were collected during the following 5 d to measure AFM1 concentration. The average excretion of AFM1 in milk followed an exponential decreasing pattern, with two intermediate peaks at 24 and 48 h. No AFM1 was detected in milk at 96 h after dosing. The mean rate of transfer of AFB1 into AFM1 in milk was 0.032%, with a high individual variability (SD = 0.017%).

In experiment 2, 16 dairy ewes in midlactation were divided into four groups that received different daily doses of AFB1 (0, 32, 64, and 128 µg for control and groups T1, T2, and T3, respectively) for 14 d. Pure AFB1 was administered to each animal divided in two daily doses. Individual milk samples were collected at 12, 24, 36, 48, 72, 96, 144, 216, and 312 h after the first AFB1 administration, during the intoxication period, and every 24 h for 7 d after the withdrawal of AFB1. AFM1 was detected in the milk of all animals of the treated groups at 12 h after the administration of AFB1. In all treated groups, milk AFM1 concentration increased from 12 to 144 h after the beginning of administration. It then decreased, reaching a stable concentration at 216 and 312 h after the first administration. No AFM1 was detected in milk 3 d after the last administration of AFB1. Milk AFM1 concentration measured at steady-state condition was significantly affected by the AFB1 dose (0.031, 0.095, and 0.166 in T1, T2, and T3 groups, respectively), with a linear relationship between AFB1 dose and milk AFM1 concentration (R² = 77.2%). The carryover (AFM1/AFB1 ratio) was not significantly affected by treatment, and its mean value was 0.112% (SE = 0.011). The carryover was lower than that reported for dairy cattle and goats, suggesting a better ability of sheep to degrade AFB1.

Key Words: aflatoxin • dairy sheep • carryover • milk

Abbreviation key: AF = aflatoxin, ALP = alkaline phosphatase, GOT = glutamic oxlacetic transaminase, GPT = glutamic pyruvic transaminase, HCT = hematocrit, HGB = hemoglobin, MCH = mean corpuscular hemoglobin, MCHC = mean corpuscular hemoglobin concentration, MCV = mean corpuscular volume, RBC = red blood cell count, TMC = total microbial count, WBC = white blood cell count

	INTRODUCTION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS ACKNOWLEDGEMENTS REFERENCES

 
Aflatoxin B1 (AFB1) is a mycotoxin produced by strains of Aspergillus flavus and Aspergillus parasiticus that grow in many animal feeds. Carcinogenic, mutagenic, and teratogenic effects of AFB1 have been reported for several animal species, including humans (Sabbioni and Sepai, 1998). For this reason, this toxin has been included in category 1A of active carcinogenic compounds (IARC, 1993). Lactating animals that eat feed contaminated by AFB1 excrete in milk the aflatoxin M1 (AFM1), a metabolite of AFB1 considered a potential carcinogenic compound for humans and included in the class 2B by IARC (1993). The European Community has fixed at 0.05 µg/kg [Commission Regulation (EC) N. 466/2001] the limit for AFM1 in milk and at 0.05 mg/kg (Council Directive 1999/29/EC) the limit for AFB1 in feeds. The action level for AFM1 in milk and dairy products in the United States is tenfold higher (0.50 µg/kg) than the current level in the EC. The relationship between the amount of AFB1 ingested and quantity of AFM1 in milk is quite variable. In some cases, the intake by dairy cows of AFB1 below the tolerance level led to excretion of AFM1in milk above the EC tolerance limit (Frobish et al., 1986; Veldman et al., 1992). While for lactating cows a large literature exists, in the case of lactating sheep there is very little information on the transfer of AFM1 into milk. Indeed, the AFB1 transferred as AFM1 to milk was measured only by Nabney et al. (1967), who gave a high (1 mg/kg of BW) single dose of mixed aflatoxins to only one animal.

Because the AFM1 is associated with milk protein, its concentration in cheese is 3 to 4 times higher than in milk (Kiermeier and Buchner, 1977). Therefore, the study of the contamination of sheep milk by aflatoxins is particularly important because the majority of the sheep milk produced is processed into cheese (Pulina and Furesi, 2001) and because sheep milk has a higher protein concentration than cows’ milk. The presence of AFM1 in commercial sheep cheese was recently reported by Minervini et al. (2000), with values between 0.050 and 0.210 µg/kg, well above EC limits.

Because of the limited knowledge on the carryover of AFB1 in the milk of sheep, two experiments were conducted to: 1) study the relationship between AFB1 intake and AFM1 excretion in ewes treated with a single dose or continuous dosing; 2) study the effect of continuous dosing of AFB1 on metabolic and health status and on milk production of the animals.

	MATERIALS AND METHODS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS ACKNOWLEDGEMENTS REFERENCES

 
Experiment 1
Four multiparous Sarda ewes in early lactation (average 50 DIM) were used. Daily milk yield and BW averaged 1.7 ± 0.37 and 43.5 ± 6.57 kg (mean ± SD). Each animal received 2 mg of AFB1 in a single dose, per os, after the morning milking of the 1st day of the experimental period. The experiment was conducted in accordance with the guidelines of the Council Directive of EC (86/609/EEC).

Pure AFB1 (SIGMA, A-6636, Sigma Chemical Co, St. Louis, MO) was dissolved in methanol, and dry corn meal was used as the carrier for aflatoxin. Ewes were fed grass hay plus a supplement of 200 g/d per ewe of whole-wheat grain at each milking. After the AFB1 administration, the ewes were milked for 5 d; in the first 2 d the animals were milked every 6 h (4 times a day), whereas in the remaining 3 d they were milked every 12 h (twice a day). Individual milk yield was recorded at each milking, and individual milk samples were collected at 0, 6, 12, 18, 24, 36, 48, 60, 72, 96 h from the administration of AFB1. Milk samples were stored at -18°C until the analyses for AFM1 were performed. During the experimental period, the health of the animals was monitored continuously.

Extraction of AFM1.
The extraction of AFM1 from milk was done using an immunoaffinity technique and the concentration was determined by HPLC. Fifty milliliters of defatted milk was filtered with Whatman 41 filter paper and passed through a immunoaffinity column (Ridascreen Aflatoxin M₁, R-Biopharm, Germany). The column was washed with deionized water and then dried under nitrogen; the toxin was collected with 5 ml of acetonitrile into silanized vials. Elutes from each column containing the analytes were carefully evaporated to dryness under nitrogen and redissolved in methanol and deionized water (250 and 250 µl, respectively).

Chromatography.
The AFM1 was separated on Hewlett Packard 1100 HPLC chromatograph, connected to a reverse-phase C18 column (Merck, 5-µm particle size, 250 x 4 mm i.d.), equipped with a Hewlett Packard 1100 fluorescence detector with excitation at 366 nm and emission at 416 nm. The initial mobile phase was made of methanol and water in the ratio 0:100 (vol/vol), then methanol was raised to 90:10 in 20 min and the flow rate was 1 ml/min. Standard AFM1 (SIGMA, A-6428, Sigma Chemical Co, St. Louis, MO) was dissolved in methanol-water (50:50, vol/vol) to prepare a series of working solutions containing 0.015–0.240 ng of AFM1/ml. Calibration curve was prepared by plotting the peak area for each standard against the quantity of AFM1 injected. The equation of calibration curve was used to compute the AFM1 content in sample extracts.

Statistical Analyses
Time evolution was modeled by regression of AFM1 excretion in milk (µg/kg) over time (h). The percentage of AFB1 excreted in milk as AFM1 was calculated as the ratio between the total output of AFM1 in milk (sum of AFM1 excreted at each milking) and the total AFB1 administered, separately for each ewe. For this purpose, the AFM1 concentration at 30, 42, and 84 h was estimated, separately for each ewe, by regression of AFM1 over time.

Experiment 2
Sixteen multiparous Sarda ewes in late lactation (average 150 DIM) were used. Daily milk yield and BW averaged 0.8 ± 0.16 kg and 40.2 ± 3.58 kg (mean ± SD). Before the experiment started and during the experimental period the health of animals was monitored continuously. The ewes were milked twice a day at 7:30 a.m. and 6:30 p.m. and fed 1.5 kg/d per head of pelleted concentrate plus grass hay ad libitum.

After a 7-d adaptation period, ewes were divided into four groups of four animals each. The control group (C) received an aflatoxin-free diet. The treated groups (T) received the same diet of the C group but immediately before each milking they also were fed per os a pellet artificially contaminated by AFB1. The treated groups received for 14 d (intoxication period) 32 (T1), 64 (T2), and 128 µg (T3) of AFB1/d per head, subdivided in two equal daily doses. At the end of the intoxication period (312 h), the aflatoxin was removed from the diet, and the ewes were monitored for another week (clearance period). Animal experimentation was conducted in accordance with the guidelines of the Council Directive of EC (86/609/EEC).

Pure AFB1 was dissolved in methanol and a concentrate pellet was used as the carrier for aflatoxin (SIGMA, A-6636, Sigma Chemical Co, St. Louis, MO). Milk yield of each ewe was recorded at each milking during the preliminary, intoxication, and clearance periods.

Individual milk samples were collected for 3 d before the first AFB1 administration, at 12, 24, 36, 48, 72, 96, 144, 216, and 312 h during the intoxication period and every 24 h during the clearance period. The samples were stored at -18°C until analyses of AFM1 content. Milk concentration of AFM1 was determined as described in experiment 1.

Milk samples were analyzed weekly for fat, protein (N x 6.38), and lactose with a Milkoscan 605 (Foss Electric, Hillerød, Denmark), for SCC with a Fossomatic 360 (Foss Electric) and for total microbial count (TMC) with a Bactoscan 8000 (Foss Electric).

Body weights of ewes were measured weekly. Blood samples were collected from each ewe by jugular venipuncture at weekly intervals for immediate analyses. Serum samples were analyzed (Photometer 4010 Boehringer Mannheim, Germany) with colorimetric commercial kits (Roche Diagnostics, Mannheim, Germany) for total bilirubin, direct bilirubin, total protein, urea (urea N/0.4665), glutamic pyruvic transaminase (GPT), glutamic oxlacetic transaminase (GOT), alkaline phosphatase (ALP), cholesterol, glucose, albumin, calcium, and phosphorus. Hemoglobin (HGB), hematocrit (HCT), red blood cell count (RBC), white blood cell count (WBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC), were determined with a Baker System instrument (9120 AX, Biochem Immunosystems Italy).

The data were analyzed with the following mixed linear model:

where:

y = dependent variable (AFM1 concentration, carryover, milk yield and composition, BW, blood parameters); µ = overall mean; T_i = fixed effect of AFB1 administered (i = 0, 32, 64, 128 µg); P_j = fixed effect of sampling time (j = h); E_k = random effect of ewe; _ijk = residual error. Milk yield and its composition, and blood components of the preexperimental week were included in the model as covariates. Before statistical analysis, SCC was natural log transformed.

The carryover was calculated, separately for each ewe, as the ratio between the AFM1 in milk and the intake of AFB1 at the time in which a steady-state output of toxin in milk was reached (216 and 312 h). Finally, a regression analysis of AFM1 milk concentration on AFB1 intake was carried out.

	RESULTS AND DISCUSSION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS ACKNOWLEDGEMENTS REFERENCES

 
Experiment 1
The average BW of the ewes during the experimental period was 43.5 ± 6.57 kg, therefore each animal received 46.9 ± 8.30 µg of AFB1 per kilogram of BW. No traces of AFM1 were detected in the milk sampled before AFB1 administration. The presence of AFM1 was detected in all ewes from the first milking at 12 h after the AFB1 administration, in agreement with previous observations in sheep (Nabney et al., 1967) and cows (Allcroft et al., 1968; Trucksess et al., 1983) that received a single dose of AFB1. The average excretion of AFM1 in milk (µg/kg) was represented by the following exponential decreasing function:

From the excretion pattern of AFM1 (Figure 1), the maximum concentration occurred in the samples collected at first milking after dosing. Superimposed on this trend was an oscillatory pattern, particularly evident in the ewes 2 and 3, with two peaks around the 24th and the 48th h after dosing was observed (Figure 2). Nabney et al. (1967), using a much higher dose of aflatoxin (1 mg/kg BW of mixed AF) than that used in our experiment, detected only one peak around 96th hour after dosing. An oscillatory pattern similar to that observed in our trial was previously reported in cows (Trucksess et al., 1983) using a single dose equivalent to 0.5 mg/kg BW of AFB1. The oscillatory pattern of the toxin in the milk observed may be related to variations in rumen activity, to the gradual release of the toxin from tissue to the blood, to the liver conversion rate of AFB1 to AFM1, and to the toxin excreted in urine and feces.

View larger version (9K): [in this window] [in a new window]   Figure 1. Average excretion pattern of AFM1 in milk of ewes fed a single oral dose of AFB1.

View larger version (15K): [in this window] [in a new window]   Figure 2. Individual excretion pattern of AFM1 in milk of ewes fed with a single oral dose of AFB1 (Experiment 1).

The average total milk yield in 96 h (Table 1) was 4.77 ± 0.56 kg (mean ± SD). Total output of AFM1 in milk was 0.64 ± 0.33 µg. The average amount of AFM1 excreted at 12 and 24 h after dosing was about 52 and 71%, of the total output of toxin.

Experiment 2
No AFM1 was detected in the milk of the control group. The pattern of AFM1 concentration in milk of T1, T2, and T3 groups is reported in Figure 3. The toxin was detected in the milk of all animals of the treated groups since the first milking, which occurred 6 h after the beginning of AFB1 administration. The passage of the toxin from feed to milk was very rapid, as previously observed in cows that received AFB1 for 8 d (Frobish et al., 1986). During the intoxication period, in all treated groups the milk AFM1 concentration increased from 0 to 144 h (0.057, 0.226 and 0.331 µg/kg, in T1, T2, and T3, respectively). Then, AFM1 concentration decreased and reached a steady-state condition in the interval between 216 and 312 h. Finally, in the clearance period, AFM1 quickly decreased, and it was no longer detected at 72 h post withdrawal (384 h after the first administration).

View larger version (16K): [in this window] [in a new window]   Figure 3. AFM1 concentrations in the milk of ewes fed 32 (•), 64 () and 128 () µg of AFB1 per day. For each treatment, each data point represent the mean of four animals.

The steady-state condition was reached at 216 to 312 h in the present study, so later than in cows, where it was reached after 24 h (Frobish et al., 1986) and 76 h (Polan et al., 1974) from the first intake of toxin. Another difference between our experiment on sheep and the results reported in literature for cows is related to the excretion pattern of AFM1 in milk. In dairy cows the plateau started in correspondence to the highest concentration of AFM1 (Polan et al., 1974; Frobish et al., 1986), while in our experiment, this happened at concentrations lower than the observed maximum.

The time at which AFM1 was no longer detectable in milk was not related to the AFB1 dose or to the concentration of AFM1 before the withdrawal of contaminated feed, as already observed in cows (Frobish et al., 1986). Indeed, in all treated groups, the AFM1 went down to zero at 384 h after the first administration.

The relationship between milk AFM1 concentration and AFB1 intake, calculated using the concentrations at 216 and 312 h, can be expressed by the equation:

Therefore, AFM1 concentration increased linearly as AFB1 intake increased. The intercept was not different from zero (P = 0.752). This equation suggests that ewes fed rations contaminated with AFB1 below the EC tolerance level (0.05 mg/kg) may produce milk containing AFM1 concentrations above EC limit (0.05 µg/kg). A similar remark was reported by Veldman et al. (1992) and by Munksgaard et al. (1987) for dairy cattle fed naturally contaminated feeds.

The concentration of AFM1 in milk was significantly influenced by the treatments, whereas the carryover was not associated to AFB1 intake (Table 2), as previously observed in cows (Frobish et al., 1986; Veldman et al., 1992). This suggests that, at least in range of intake from 32 to 128 µg AFB1 per day, the liver activity in the conversion of AFB1 in AFM1 was not a rate limiting step, in accordance with the results of Veldman et al. (1992) for dairy cows. The effect of time and the treatment x time interaction did not differ for any variable considered. The average carryover observed in our experiment (0.112%) was lower than that reported for goats (0.397%; Nageswara Rao and Chopra, 2001) that received feed artificially contaminated with AFB1 doses similar to those used in the T3 group. In cow milk, the carryover ranged from 0.01 to 6.6% (Polan et al., 1974; Patterson et al., 1980; Price et al., 1985; Frobish et al., 1986; Munksgaard et al., 1987; Fremy et al., 1988; Veldman et al., 1992).

Milk yield was lower (P < 0.05) in C and T1 groups in comparison to T2 and T3 groups (Table 3). The effect of the treatments on milk yield over time is reported in detail in Figure 4, and the data were presented as the mean of 3 d of measurements for each group. Before the beginning of the AFB1 administration (0 d), the four groups of animals had similar production levels. During the intoxication period, the lactation curve of the control and of the treated groups did not show a definite trend until the 9th day of the experiment. After 12 d the lactation curves were different for all groups with the milk yield that increased proportionally to AFB1 doses. This trend was maintained in the clearance period (21st day of the experiment). In dairy cows Polan et al. (1974) found that milk production was totally unaffected by level of AFB1 consumption (1.6 to 20 µg of AFB1 per kilogram of BW). Fat, protein, and lactose concentrations (Table 3) did not vary with treatments. These results may be due to the effect of the modifications caused by AFB1 on rumen fermentations, on the digestive tract adsorption or on hepatic metabolism. Rizzi et al. (1995) observed a positive effect of the AFB1 on cellulose and NDF digestibility in lambs which received daily doses of 80 µg of AFB1 per kilogram of BW for 21 d. These results suggest that further investigations are necessary to clarify the reasons for the increase of the milk production (our experiment) and of digestibility (Rizzi et al., 1995) observed in animals that received low doses of aflatoxin. The SCC was not influenced by AF intake, as previously observed in cows (Applebaum et al., 1982), and was under the threshold (300,000/ml) reported for subclinical mastitis in dairy ewes for all groups (Ranucci and Morgante, 1994). The treatment x time interaction was not significant for any variable analyzed.

View larger version (12K): [in this window] [in a new window]   Figure 4. Milk production of ewes fed 0 (), 32 (•), 64 (), and 128 () µg of AFB1 per day. Each data point represents the mean of three days of measurements for each group.

The results of the analysis of variance on serum parameters (Table 4) revealed an influence of aflatoxin treatments only on GPT and ALP (P < 0.001). The treatment x time interaction was not significant for any of the variables analyzed. The covariate was significant for ALP, total protein, urea, and cholesterol. The GPT activity was significantly higher in T3 compared with C, T1, and T2 groups in the second week of intoxication period. During the clearance period (3rd week), when AFB1 was withdrawn from the diet, the GPT value in T3 group decreased to the level of the others experimental groups. The ALP concentration did not vary in the 2 wk of the intoxication period between the control and the treated groups. During the clearance period, the ALP showed the lowest value in T3 and the highest value in T2 groups (P < 0.01), while in C and T1 groups it had intermediate values. Serum enzyme activities are generally elevated in aflatoxicosis, indicating hepatocyte damage (Pier, 1992). No significant differences were observed for the other hepatic enzyme activity (GOT), suggesting that the levels of AFB1 in this trial caused only a low and transient negative effect on hepatocytes. In lambs, a transient alteration of enzymatic activities was reported (Edrington et al., 1994) with higher AF doses (3.85 to 5.42 mg/d) and a longer period of AF administration than those used in our experiment.

	CONCLUSIONS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS ACKNOWLEDGEMENTS REFERENCES

The continuous administration of AFB1 for 14 d in different doses showed that the milk AFM1 concentration was significantly affected by the AFB1 dose, whereas the carryover was not significantly affected.

In practice, the administration to lactating dairy ewes of feeds contaminated with AFB1 under the threshold admitted by the EC can involve the production of milk with a content of AFM1 above the threshold allowed by EC.

	ACKNOWLEDGEMENTS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS ACKNOWLEDGEMENTS REFERENCES

 
This research was supported by the Consiglio Nazionale delle Ricerche (Agenzia 2000 program) and by the Ministero dell’Istruzione, dell’Università e della Ricerca and Ministero delle Politiche Agricole e Forestali (SISPROLAT project). The authors gratefully acknowledge the contributions of M. Palomba, R. Rubattu, F. Porcu and P. Sechi for the assistance in the chemical analyses.

Corresponding author:
G. Pulina; e-mail:
gpulina{at}ssmain.uniss.it.

Received for publication July 4, 2002. Accepted for publication February 18, 2003.

	REFERENCES

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS ACKNOWLEDGEMENTS REFERENCES

 


Allcroft, R., and B. A. Roberts. 1968. Toxic groundnut meal: The relationship between aflatoxin B1 intake by cows and excretion of aflatoxin M1 in milk. Vet. Rec. 82:116–118.

Applebaum, R. S., R. E. Brackett, D. W. Wiseman, and E. H. Marth. 1982. Responses of dairy cows to dietary aflatoxin: Feed intake and yield, toxin content, and quality of milk of cows treated with pure and impure aflatoxin. J. Dairy Sci. 65:1503–1508.

Armbrecht, B., W. T. Shalkop, L. D. Rollins, A. E. Pohland, and L. Stoloff. 1970. Acute toxicity of aflatoxin B1 in wethers. Nature 225:1062–1063.[Medline]

Commission of the European Communities. 2001. Commission Regulation (EC) N. 466/2001 of 8 March 2001 setting maximum levels for certain contaminants in foodstuffs (Text with EEA relevance). Official J. Eur. Communit. L77:1–13.

Council of the European Union. 1986. Council Directive 86/609/EEC of 24 November 1986 on the approximation of laws, regulations and administrative provisions of the Member States regarding the protection of animals used for experimental and other scientific purposes. Official J. Eur. Communit. L358:1–28.

Council of the European Union. 1999. Council Directive 1999/29/EC of 22 April 1999 on the undesirable substances and products in animal nutrition. Official J. Eur. Communit. L115:32–46.

Edrington, T. S., R. B. Harvey, and L. F. Kubena. 1994. Effect of aflatoxin in growing lambs fed ruminally degradable or escape protein sources. J. Anim. Sci. 72:1274–1281.[Abstract]

Fernandez, A., M. Hernandez, M. T. Verde, and M. Sanz. 2000. Effect of aflatoxin on performance, hematology, and clinical immunology in lambs. Can. J. Vet. Res. 64:53–58.[Medline]

Fremy, J. M., J. P. Gautier, M. P. Herry, C. Terrier, and C. Calet. 1988. Effects of ammoniation on the carryover of aflatoxins into bovine milk. Food Addit. Contam. 5:39–44.[Medline]

Frobish, R. A., D. D. Bradley, D. D. Wagner, P. E. Long-Bradley, and H. Hairston. 1986. Aflatoxin residues in milk of dairy cows after ingestion of naturally contaminated grain. J. Food Prot. 49:781–785.

Guerre, P., P. Galtier, and V. Burgat 1996. Le métabolisme: Un facteur de susceptibilité à la toxicité des aflatoxines. Rev. Med. Vet. 147:879–892.

IARC. 1993. IARC Monographs on the evaluation of carcinogenic risks to human. Vol. 56. Some naturally occurring substances: food items and constituents, heterocyclic aromatic amines and mycotoxins. International Agency for Research on Cancer, Lione.

Kiermeier, F., and M. Buchner. 1977. On the Aflatoxin M1 content of the cheese during ripening and storage. Z. Lebensm. Unters.-Forsch. 164:87–91.

Minervini, F., L. Monaci, M. T. Montagna, I. Dragoni, and A. Visconti. 2000. On the occurrence of aflatoxin M and toxigenic fungi in sheep and goat dairy products collected from southern Italy. Pages 145–148 in Proc.14th Natl. Congr. Società Italiana di Patologia e Allevamento degli Ovini e dei Caprini. Vietri sul Mare, Salerno, Italy.

Munksgaard, L., J. Larsen, H. Werner, P. E. Andersen, and B. T. Viuf. 1987. Carry over of aflatoxin from cows’ feed to milk and milk products. Milchwissenschaft 42:165–167.

Nabney, J., M. B. Burbage, R. Allcroft, and G. Lewis. 1967. Metabolism of aflatoxin in sheep: Excretion pattern in the lactating ewe. Food Cosmet. Toxicol. 5:11–17.[Medline]

Nageswara Rao, S. B., and R. C. Chopra. 2001. Influence od sodium bentonite and activated charcoal on aflatoxin M1 excretion in milk of goats. Small Rumin. Res. 41:203–213.

Patterson, D. S. P., E. M. Glancy, and B. A. Roberts. 1980. The carry over of AFM1 in to the milk of cows fed ration containing a low concentration of AFB1. Food Cosm. Toxicol. 18:35–37.[Medline]

Pier, A. C. 1992. Major biological consequences of aflatoxicosis in animal production. J. Anim. Sci. 70:3964–3967.[Abstract]

Polan, C. E., J. R. Hayes, and T. C. Campbell. 1974. Consumption and fate of aflatoxin B1 by lactacting cows. J. Agric. Food Chem. 22:635–638.[Medline]

Price, R. L., J. H. Paulson, O. G. Lough, C. Gingg, and A. G. Kurtz. 1985. Aflatoxin conversion by dairy cattle consuming naturally-contaminated whole cottonseed. J. Food Prot. 48:11–15.

Pulina, G., and R. Furesi. 2001. L’allevamento e la produzione di latte ovino in Italia. Scienza e Tecnica Lattiero-Casearia 52:209–216.

Ranucci, S., and M. Morgante. 1994. Sanitary control of the sheep udder: total and differential cell counts in milk. Pages 5–16 in Proc. International Symposium on Somatic Cells and Milk of Small Ruminants. Bella, Potenza, Italy. R. Rubino, ed. Europa, Potenza, Italy.

Rizzi, L., L. Lambertini, L. Marchesini, and A. Gramenzi. 1995. Effects of aflatoxin B1 and alluminosilicate on in vivo digestibility in lambs. Pages 839–840 in Proc. 49th Natl. Congr. Società Italiana delle Scienze Veterinarie. Salsomaggiore Terme, Italy.

Sabbioni, G., and O. Sepai. 1998. Determination of human exposure to aflatoxins. Pages 183–226 in Mycotoxins in Agriculture and Food Safety. K. K. Sinha and D. Bhatnagar, ed. Marcel Dekker Inc., New York.

Trucksess, M. W., J. L. Richard, L. Stoloff, J. S. Mcdonald, and W. C. Brumley. 1983. Absorption and distribution patterns of aflatoxicol and aflatoxins B1 and M1 in blood and milk of cows given aflatoxin B1. Am. J. Vet. Res. 44:1753–1756.[Medline]

Veldman, A., J. A. C. Meijs, G. J. Borggreve, and J. J. Heeres-van der Tol. 1992. Carryover of aflatoxin from cows’ food to milk. Anim. Prod. 55:163–168.

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