Fatty acids are important primary metabolites used for storing chemical energy as well as forming part of the complex membranes surrounding cells.



Aflatoxin B1 is absorbed via G.I TRACT into the PORTAL BLOOD and carried to the LIVER and metabolized. A portion of AFB1 is bound to liver tissues.

Some water soluble conjugates of AfB1 metabolites are excreted into the BILE and go to the FECES.

Dennis, P., et al (1981)

MYCOTOXIN  TRANSFORMATION INTO THE ANIMAL BODY

AFLATOXIN B1 ……… AFM1 (a little more toxic than AFB1).

AFLATOXIN B1 ……… AFB2a (no toxic).

AFLATOXIN B1 ……… AFLATOXICOL (18 times less toxic than Aflatoxin B1 but it can comes to Aflatoxin B1; reversible reaction).

AFLATOXIN B2 ……… AFM2 (more toxic than Aflatoxin B2).

AFLATOXIN G1 ……… AFG2a (no toxic).

ZEARALENONE ……… a and b-ZEARALENOL (toxic).

OCHRATOXIN A ……… a- OCHRATOXIN (no toxic).

VOMITOXIN …………… DOM-1 (toxic).

T-2 TOXIN ……………… HT-2 TOXIN and HT-2 ACETYL (toxic).


PARAMETERS AFFECTING EDIBLE TISSUE RESIDUES OF MYCOTOXINS

1.- Species and breed of the animals consuming the contaminated feed.

2.- Level, mode, and duration feeding with the contaminated feed.

3.- Diet and state of health of the animal.

4.- Time after cessation the consume of contaminated feed that tissues are taken for analysis.

In analytical results

AFLATOXIN M1 IN COW´S MILK

The ratio of AFB1 concentration in feed to AFM1 concentration in milk may be   300:1

However this overall value is very approximate due to the parameters previously mentioned. The ratio ranging from 34 to 1600.

HOLSTEIN  ………………  470 ppb AFB1 (dry.wt) ……… 13.7 ppb AFM1
BRINDLE ………………… 540 ppb AFB1 (dry.wt) ……… 0.92 ppb AFM1
BRINDLE X HOLSTEIN …540 ppb AFB1 (dry.wt) ……… 1.33 ppb AFM1

OTHER COWS ………….  500 ppb AFB1 (dry.wt) ……… 3.75 ppb AFM1

HOLSTEIN ………………  357 ppb AFB1 (dry.wt) ……….10.00 ppb AFM1
HOLSTEIN ………………1089 ppb AFB1 (dry.wt) ……… 20.20 ppb AFM1

dry.wt = dry weight

Rodricks, J.V., et al (1977)

DAIRY CATTLE

With    Aflatoxin   B1  intake   of  2-60 mg  AFB1/COW/DAY   the
concentrations of AfM1 in milk may be 1-50 micrograms of AM1/liter (1)

A milk cow of 35 liters can feed & Ξ 35 Kg final ration/day (Ξ 20 Kg dry.wt), it represent  a range of AFB1 contamination of 57- 1714 ppb of AFB1 (final ration).

A milk cow can transform AFB1 in AFM1 (as an autodetoxification) within de 12 –24 horas during feeding contaminated ration.

THE CONTAMINATION LEVEL OF AFB1 MAY NOT AFFECT TO THE COW, HOWEVER THE MILK APPEAR TO BE CONTAMINATED WITH AFM1

(1) George T.Edds (1979)

SOME AUTHORS (PATTERSON et al, 1980) REFERRED THAT THE DAILY OUTPUT OF AFM1 IN MILK (micrograms) MAY BE APROXIMATELY 2.2% OF THE DAILY INTAKE OF AFB1 IN THE RATION.

THE COEFFICIENT OF VARIATION (CV) WAS RANGING FROM 42 TO 59% AND APPEARED TO BE A MORE CONSISTENT INDEX FOR AFLATOXIN CARRY-OVER THAN THE RATIO OF MYCOTOXIN CONCENTRATIONS IN FEED AND MILK.

HOWEVER THERE ARE OTHER RESULTS AND OPINIONS FROM  DIFFERENT AUTHORS WHICH DON´T AGREE


RESIDUES OF AFB1 IN EGGS OF LAYING HENS

100 – 400 ppb AFB1 (dry. wt) ……….. 0.2 – 3.3 ppb AFB1 (WHOLE EGG)

88000 ppb AFB1 (dry.wt) …………….. 30 ppb AFB1 (EGG WHITE)

dry.wt = dry weight

Rodricks, J.V., et al (1977)

OCHRATOXIN A AND ZEARALENONE IN EGGS OF LAYING HENS

5.2 – 10.0 ppm OA during  1 month ….. 0.7- 4 ppb OA (EGG WHITE)

100 ppm ZEN during  72 hours ……. 2 ppm ZEN (WHOLE EGG)

Prelusky, D.B (1994)



ZEARALENONE IN COW´S MILK

CALCULATING A FEEDING OF Ξ 35 Kg (20 Kg dry.wt) FINAL RATION/COW/DAY

544,5 mg ZEN/COW/DAY ( Ξ 15.6 ppm ZEN, FINAL RATION) during 21 DAYS, the residues were 2.5 ppb ZEN and 3.00 ppb a-ZEARALENOL.

1.8 and 6.0 g ZEN ( Ξ 51- 171 ppm ZEN, FINAL RATION) during 1 DAY, the residues were 4.0-6.1 ppb ZEN and 1.5-4.0 ppb a- ZEARALENOL and 4.1-6.6 ppb b-ZEARALENOL.

ON THE OTHER HAND

200 mg ZEN/COW/DAY ( Ξ 5.71 ppm ZEN, FINAL RATION) during 8 DAYS the residues were 1360 ppb ZEN
dry.wt = dry weight

Prelusky, D.B  (1994)


THERE IS A GREAT DISCREPANCY !!

THEREFORE

The capacity of rumen protozoa to metabolite ZEN once ingested could account for the wide discrepancies in transmissions of mycotoxin residues to cow´s milk, and the rumen microflora would be affected by the animals´diet.

FOR INSTANCE, IN SHEEP THE DIET IS VERY IMPORTANT IN ORDER TO BE TRANSFORMED (BY HYDROLYSIS) THE OCHRATOXIN A TO ALPHA OCHRATOXIN (NO TOXIC).

OCHRATOXIN A TO ALPHA OCHRATOXIN (EXCRETED THROUGH MILK, EDIBLE TISSUES, SERUM, FECES AND URINE)

100% hay diet ….. ruminal fluid (pH = 7.1)….. the OA is hydrolyzed  to   alpha OA in 0.6 hours (1).

30% grains or concentrate (grains and others raw materials) + 70% hay, total diet ….. ruminal fluid (pH = 6.5) ……. The OA is hydrolyzed to alpha OA in 1.3 hours (1).

100% grains or concentrate (grains and others raw materials) diet …… ruminal fluid (pH=5.7) ….. the OA is hydrolyzed to alpha OA in 3.6 hours (1).

 70% grains or concentrate (grains and others raw materials) + 30% hay, total diet ……… the hydrolysis of OA was very low (2).

(1) Xiao, H., et al (1991)
(2) Hohler, D., at al (1999)


The OA is hydrolyzed much faster in the rumen of sheep fed HAY than in sheep fed GRAIN, probably because the different ruminal microbial population, which in turn influenced the rate of hydrolysis of OA (attention with the ruminal fluid pH)

If OA is ingested in combination with CONCENTRATE - rich diets, the hydrolysis in the gastrointestinal tract of sheep is substantially less than in combination with HAY- rich diets.
The rumen fluid had no effect on AFB1 and VOMITOXIN, however the rumen fluid, rumen protozoa and rumen bacteria have a significant effect on the metabolism of OA, ZEN, T-2 toxin and DAS.

The rumen fluid may be considered as a first line of defense against toxic compounds in the diet.

Kiessling, K.H., et al (1984)

THE PREVIOUS REFERRED,  MAY BE EXTENDED TO THE DAIRY CATTLE AND IN GENERAL TO THE RUMINANTS.

α- OCRATOXIN IS NON TOXIC
THE METABOLITES FROM:  ZEN, T-2 TOXIN AND DAS, ARE TOXICS.

THE QUESTION IS THE FOLLOWING:

CAN THE RUMINAL FLUID INCREASE THE CONCENTRATION OF TOXIC METABOLITES IN MILK AND EDIBLE TISSUES ??.

OBIOUSLY THAT WILL BE MORE IMPORTANT, TRY TO BIND THE MYCOTOXIN BEFORE THE AUTODETOXIFICATION, AND GIVE TO THE ANIMAL THE EQUILIBRATED AND APPROPIATE DIET.

T-2 TOXIN IN EGGS OF LAYING HENS AND COW´S MILK

1,6 ppm T-2 toxin during 8 days …. 19 ppb T-2 toxin (WHOLE EGG)

50 ppm T-2 toxin during 15 days …. 10 – 160 ppb T-2 toxin (COW´S MILK)

Prelusky, D.B (1994)

VOMITOXIN  IN COW´S MILK AND SHEEP´S MILK

300mg DON/COW/DAY ( @ 66 ppm DON) during 5 days ….. 30 ppb DOM-1 (Cow´s milk)

880 ppm DON during 3 days …. 220 ppb (90% DOM-1) (Sheep´s milk)

Prelusky,D.B (1994)


A CASE OF SYNERGISM BETWEEN AFLATOXIN B1 AND OCHRATOXIN A IN CHICKENS AND LAYING HENS (14 DAYS OLD)

50 ppb AfB1 during  24 days …. 0.02 ppb AfB1 residues in liver and 0.05 ppb AfB1 residues in kidneys (CHICKENS).

50 ppb AfB1 + 50 ppb OA during 24 days ….. 0.15 ppb AfB1 residues in liver and 0.40 ppb AfB1 residues in kidneys (CHICKENS).


50 ppb OA during 24 days …. 5 ppb OA residues in liver (CHICKENS).

50 ppb AfB1 + 50 ppb OA during 24 days …. 40 ppb OA residues in liver (CHICKENS)

50 ppb AfB1 during 35 days …. 0.10 ppb AfB1 residues in liver and 0.08 ppb AfB1 in kidneys (LAYING HENS).

50 ppb AfB1 + 50 ppb OA during 35 days … 0.20 AfB1 residues in liver and 0.32 ppb AfB1 residues in kidneys (LAYING HENS).

Micco,C., et al (1988)

WITHDRAWAL TIME AND OTHERS

AFLATOXIN B1 …… LAYING HENS …. 5-16 DAYS …. NO RESIDUES

AFLATOXIN B1 …. BROILERS ….. 14 DAYS … NO RESIDUES

OCHRATOXIN A …. LAYING HENS ….. 1-14 DAYS …. NO RESIDUES

OCHRATOXIN A …… PIGS …… 28 DAYS …. NO RESIDUES

ZEARALENONE AND METABOLITES … PIGS/SOWS … 5-10 DAYS … NO RESIDUES

T-2 TOXIN AND DIACETOXYSCIRPENOL ARE RAPIDLY AND EXTENSIVELY METABOLIZED IN THE PIG. CONSEQUENTLY, WHILE IS UNLIKELY THAT ACUMULATION OF THE PARENT TOXIN WOULD OCCUR IN NATURALLY EXPOSED ANIMALS.

FUMONISIN B1 …. PIGS …. 9 DAYS …. NO RESIDUES

STERIGMATOCYSTIN …. DAIRY CATTLE …. 10 mg/COW/DAY …. 2 WEEKS …. NO RESIDUES IN MILK


STABILITY OF SEVERALS MYCOTOXINS AT THE TEMPERATURE

AFB1 …………………… 120ºC   ….. > 120ºC ( - 40 to 60% loss)
OA …………………........ 120ºC
ZEN .................................  100ºC
CITRININ .................….    80ºC
PATULIN ..................….    80ºC
PENICILLIC ACID ..…. 100ºC 
FB1 ..............................…. 110ºC
VOMITOXIN ............….  150ºC

AFLATOXIN M1 HAS A GREAT STABILITY IN SEVERAL CHEESES, YOGHOURTS, PASTEURIZED MILK, SKIM MILK OR CREAM, ICE CREAM.

Other parameters such as pH  and the  time that the mycotoxin remains at that temperature has not  been taking into account

AFLATOXIN M1 DISTRIBUTION

CHEESE ………………………….. 40-60%

CREAM …………………………….      10%

BUTTER …………………………        < 2%

Yousef,A.E., et al (1989)



HUMAN HEALTH RISKS FACTORS TO TAKE IN ACCOUNT

1.- The kind of mycotoxin contaminating the food.
2.- Bio-availability and toxicity of the mycotoxins which are contaminating the food.
3.- Contamination levels and synergism between mycotoxins.
4.- Amount of food consumed.
5.- Body weight and physiological state of the individual.
6.- Individual health state at the moment of eat the contaminated food.
7.- Age.

Is clear that infants  and young children may be  more susceptible to the mycotoxins toxic effects, because their basal metabolic rate is greater.

They may not posess the biochemical mechanism to detoxify toxic substances.

In  children, organs such as  the brain continue  development for many years after birth,  and this makes them more susceptible to substances affecting the central nervous system.

Tine Kuiper-Goodman (1994)
Beardall, J.M., et al (1994)

TABLE 1.- NOAEL, TD50, TDI and NEL VALUES  FOR  SEVERAL  MYCOTOXINS CONCERNING HUMAN HEALTH.

Tine Kuiper-Goodman (1994)

MYCOTOXINS REGULATIONS AND RECOMMENDATIONS IN FEEDS AND FOODS

FACTORS INFLUENCING THE SETTING OF MYCOTOXINS REGULATIONS

SEVERAL FACTORS, BOTH OF SCIENTIFIC AND NON-SCIENTIFIC NATURE, MAY INFLUENCE THE STABLISHMENT OF MYCOTOXIN LIMITS REGULATIONS.

1.- AVAILABILTY OF TOXICOLOGICAL DATA.

2.- AVAILABILITY OF DATA ON THE OCCURRENCE OF MYCOTOXINS IN VARIOUS COMMODITIES.

3.- KNOWLEDGE OF THE MYCOTOXIN CONCENTRATIONS DISTRIBUTION IN LOTS.

4.- AVAILABILITY OF ANALYTICAL METHODS.

5.- LEGISLATION IN OTHER COUNTRIES WITH WHICH TRADE CONTACTS EXIST.

6.- THE NEED FOR A SUFFICIENT FOOD SUPPLY IN SEVERAL COUNTRIES

Hans P.Van Egmond (1999)



EC, AFLATOXIN B1 REGULATIONS

1.- MIXED FEEDS AND COMPLEMENTARY FEEDS FOR RUMINANTS
(NON - DAIRY CATTLE AND YOUNG ANIMALS) ………………………………… 50 ppb.

2.- MIXED FEEDS FOR PIGS AND POULTRY (NON - YOUNG ANIMALS)… 20 ppb.

3.- COMPLEMENTARY MIXED FEEDS FOR PIGS AND POULTRY (NON-
     YOUNG ANIMALS) ……………………………………………………… 30 ppb.

4.- YOUNG ANIMALS (PIGS, POULTRY, CALVES… etc)………………10 ppb.

5.- DAIRY CATTLE …………………………………………………………… 5 ppb.

6.- OTHER COMPLEMENTARY MIXED FEEDS …………………………. 5 ppb.

EC Regulations (1999)

TABLE 2. Medians and  ranges in 1987 and  1996 of maximum tolerated levels (ppb) for some aflatoxins and numbers of countries that have regulations for these.

Table 3.- Maximum (ppb, micrograms/Kg) tolerated levels for some mycotoxin contamination in mixed feeds and different kind of animals.

Frank T. Jones, et al (1994)

CONCERNING  THE PREVIOUS TABLE  I WOULD LIKE TO REMARK THE FOLLOWING:

In dairy cattle DON is associated with reduced feed intake, lower milk production, elevated milk somatic cel counts, and reduced reproductive efficency.

With diets contain more than 300 ppb DON, milk production loss occur.

Field observations have shown that reductions in milk output of 25 pounds per cow were seen when DON was 500 ppb or more.

Frank T. Jones, et al (1994)



ZEARALENONE CAUSES ESTROGENIC RESPONSES IN DAIRY CATTLE AND IT IS ASSOCIATED WITH ABORTIONS WHEN THE DOSES ARE LARGE.

ZEARALENONE MAY REDUCE FEED INTAKE, DECREASED MILK PRODUCTION, VAGINITIS SECRETIONS POOR REPRODUCTIVE PERFORMANCE, AND MAMMARY GLAND ENLARGEMENT IN VIRGIN HEIFERS.

ESTABLISHMENT OF A TOLERABLE LEVEL OF ZEARALENONE FOR DAIRY CATTLE IS DIFFICULT. HOWEVER IT IS SUGGESTED THAT ZEARALENONE NOT EXCEED 250 ppb IN THE TOTAL DIET.



SOLUTIONS

1.- NON-CONTAMINATED MIXED FEEDS.

2.- RAW MATERIALS AND MIXED FEEDS (MOISTURE = 9-12.5%), STORAGE WITH aw < 0.65. TEMPERATURE = 20ºC. BLOW DRY AIR THROUGH THE RAW MATERIALS IN THE SILO.

3.- HYGIENE AND CLEANING.

4.- FUMIGATION SYSTEMS AGAINST INSECTS, MITES, RODENTS.

5.- MOULD INHIBITORS OF BROAD SPECTRUM (MOULD AND YEAST)(NOT EXACTLY PROPIONIC ACID AND PROPIONATES, ALONE).

6.- TREATMENTS OF THE MIX FACTORY EQUIPMENT WITH A MOULD INHIBITOR OF BROAD SPECTRUM (MOULD AND YEAST).

THE USE OF CHEMICAL-ADSORPTION OF MYCOTOXINS BY THE ADEQUATE SUBSTANCES.


BIBLIOGRAPHY

Dennis,P., Hsieh,H (1981) International Symposium and Workshop on Mycotoxins, September 6‑16, Cairo, Dokki, Egypt, Proceedings International Symposium on Mycotoxins (1983), pp.151-165.

Prelusky, D.B. (1994) "Residues in Food Products of Animal Origin" in Mycotoxins In Grain, Compounds Other Than Aflatoxin. J.D.Miller and H.L.Trenholm (Eds). Eagan Press, St.Paul, Minnesota, USA. Chapter 10, pp. 405-419.

Rodricks J.V., and Stoloff,L. (1977) “Aflatoxin Residues from Contaminated Feed in Edible Tissues of Food-Producing Animals” in Mycotoxins in Human and Animal Health. Edited by : Joseph V.Rodricks,  Clifford H.Hesseltine and Myron A.Melhman. Pathotox Publishers, INC  . Park Forest South Illinois., pp.67-79.

George T.Edds (1979) "Aflatoxins" in Conference on Mycotoxins in Animal Feeds and    Grains Related to Animal Health. PB‑300 300. Sponsored by: Bureau of Veterinary Medicine. Food nd Drug Administration, June 8, Rockville, Maryland (USA), pp.80‑164.

Patterson, D.S., Glancy, E.M., and Roberts, B.A (1980) Food Cosmet. Toxicol. 18(1): 35-37.

Xiao,H., Marquardt, R.R., Frohlich,A.A., Phillips,G.D and Vitti,T.G. (1991). J.Anim.Sci., 69(9) : 3706-3714.

Xiao,H., Marquardt, R.R., Frohlich,A.A., Phillips,G.D and Vitti,T.G. (1991). J.Anim.Sci., 69(9) : 3715-3723.

Hohler,D., Sudekum,K.H., Wolffram,S., Frohlich,A.A., and Marquardt,R.R. (1999). J.Anim.Sci. 77(5) : 1217-1223.

Kiessling,K.H., Pettersson,H., Sandholm,K., and Olsen,M. (1984). Appl.Environ. Microbiol., 47(5) : 1070-1073.

Micco,C., Miraglia,M., Benelli,L., Onori,R., Ioppolo,A., and Mantovani,A. (1988) Food Addit. Contam. 5(3): 309-314.

Yousef,A.E., and Marth,E.H (1989) “Stability and Degradation of Aflatoxin M1” in Mycotoxins in Dairy Products. Hans P.Van Egmond (Ed.) Elsevier Applied Science, London and New York. Chapter 5, pp.127-161

Tine Kuiper-Goodman (1994) "Prevention of Human Mycotoxicoses Trough Risk Assesment and Risk Management" in Mycotoxins In Grain, Compounds Other Than Aflatoxin. J.D.Miller and H.L.Trenholm (Eds). Eagan Press, St.Paul, Minnesota, USA. Chapter 12, pp. 439-469.

Beardall,J.M., and Miller,J.D (1994) "Diseases in Human with Mycotoxins as Possible Causes" in Mycotoxins In Grain, Compounds Other Than Aflatoxin. J.D.Miller and H.L.Trenholm (Eds). Eagan Press, St.Paul, Minnesota, USA. Chapter 14, pp.487-539.

Hans P. Van Egmond (1999) Worldwide Regulations for Mycotoxins. Third Joint FAO/WHO/UNEP International Conference on Mycotoxins (MYC-CONF/99/8a). Tunis, Tunisia, 3-6 March. p. 1-8 in Internet:
http://www.fao.org/WAICENT/FAOINFO/Economic/ESN/mycoto/mycoto-s.htm

Regulamento Relativo às Substáncias e Produtos Indesejáveis nas Matérias Primas para Alimentação Animal e nos Alimentos Compostos para Animais, aprovado pelo Decreto-Lei nº 442/89 de 27 de Dezembro, alterado pelo Decreto-Lei nº 206/94, de 6 de Agosto. Diario da Republica (1999) – I Serie A, nº 119/99, 22 de Maio de 1999. Decreto lei nº 182/99: 2829-2835 (Portugal).

Frank T.Jones, Mary Beth Genter, Winston M.Hagler, Jeff A.Hansen, Bob A.Mowrey, Matt H.Poore and Lon W.Whitlow (1994). Understanding and Coping with Effects of Mycotoxins in Livestock Feed and Forage. Published by North Carolina Cooperative Extension Service (North Carolina State University, Raleigh, North Carolina). Electronic Publication DRO-29, December, publication number AG-523, p. 1-31 in Internet: http://www.ces.ncsu.edu/drought/dro-29.html