Effect of Naturally Contaminated Feed with Aflatoxins on Performance of Laying Hens and the Carryover of Aflatoxin B1 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 AFB₁ residues in eggs as well as the stability of AFB₁ in naturally contaminated eggs to boiling process. Forty, 30 weeks old, White Leghorn laying hens 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 B₁ analysis using ELISA. Average egg 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 B₁ were 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 B₁ was almost stable in naturally contaminated egg for up to 20 minutes of boiling, so avoiding aflatoxin B₁ transmission into egg appears to be the only practical way to ensure their safety for human consumption. Conclusively, the excretion of aflatoxin B₁ residues in hens` eggs might occur at 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.