Effect of Naturally Contaminated Feed with Aflatoxins on Performance of Laying Hens and the Carryover of Aflatoxin B Residues in Table Eggs

Abstract: The aim of this study was to evaluate the effect of naturally contaminated feed with aflatoxin on
performance of laying hens fed for 60 days and the carryover of AFB residues in eggs as well as the stability 1
of AFB in naturally contaminated eggs to boiling process. Forty, 30 weeks old, White Leghorn laying hens 1
were randomly assigned into four experimental groups and after 2 weeks were given naturally contaminated
feed containing zero (control), 25, 50 and 100 μg aflatoxin/kg feed. Twenty eggs per treatment were collected
on days (1-7); 10; 20, 30, 40, 50 and 60 and submitted to aflatoxin B analysis using ELISA. Average egg 1
production and egg weight were not affected by aflatoxin (P>0.05), while a significant decrease in feed intake
(p<0.05) was appeared in the 2 groups fed on 50 and 100 aflatoxin ug/kg feed. Residues of aflatoxin B were 1
detected in eggs at levels that ranged from 0.02 to 0.09 with a mean value of 0.04, 0.05 and 0.07 μg/kg
respectively. Aflatoxin B was almost stable in naturally contaminated egg for up to 20 minutes of boiling, so 1
avoiding aflatoxin B transmission into egg appears to be the only practical way to ensure their safety for 1
human consumption. Conclusively, the excretion of aflatoxin B residues in hens' eggs might occur at 1
relatively low concentrations under conditions of long term exposure of laying hens to low level of aflatoxin
in naturally contaminated feed with reduction in feed intake started at 50 μg/kg.
Key words: Poultry feed, aflatoxin, laying hens, egg production
Eggs have been an important commodity in international
trade; however, it provides unique well balanced
nutrients for persons of all ages. Their high nutrient
content, low caloric value and ease of digestibility make
egg valuable in many therapeutic diets for adults
(Oliveira et al., 2003; Heranz et al., 2007; Ebubekir et al.,
Presence of fungi and their toxic metabolites (mycotoxin)
in poultry ration is virtually inevitable particularly in tropic
areas. Mycotoxins are unavoidable because they are
naturally occurring compounds. They contaminate crops
before harvest or invade feedstuffs of laying hen during
processing, transport or storage (Liau et al., 2007;
Yaling et al., 2008)
Aspergillus species are common soil fungi; they are
recognized as major contaminant of many grains used
for poultry diets. The aflatoxins are produced by two
molds, Aspergillus flavus and A. parasiticus. Its specific
forms are designated as B , B , G , G , M and M . 1 2 1 2 1 2
Aflatoxin B is the most potent naturally occurring 1
carcinogen known (Moss, 1991; Coulombe, 1993 and
Binder et al., 2007). Aflatoxin affects all poultry species.
Although it generally takes relatively high levels to cause
mortality, low levels can be detrimental if continually fed.
As a general rule, growing poultry should not receive
more than 20 ppb aflatoxin in the diet. However, feeding
levels lower than 20 ppb may still reduce their
resistance to disease, decrease their ability to withstand
stress and bruising and

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