The effect of ascorbic acid (AA) and butylated hydroxyanisole (BHA) supplementation on aflatoxicosis in broiler chickens (1 to 42 days of age) was investigated (250, 500, 1000 and 2000 ppm for AA and BHA) in diet containing 1 ppm total aflatoxin (AF: 76.45% AFB1, 10.52% AFB2, 9.89% AFG1 and 3.14% AFG2). A total of 300 day-old broiler chicks were divided into ten treatment groups (T1=control; T2= T1+1 ppm AF; T3= T1+250 ppm AA; T4= T1+500 ppm AA; T5= T2+250 ppm AA; T6= T2+5000 ppm BHA; T7= T1+1000 ppm BHA; T8= T1+2000 ppm BHA; T9= T2+1000 ppm BHA; T10= T2+2000 ppm BHA). The results showed that inclusion of 1 ppm of total aflatoxin in the diet resulted in a significant decrease in body weight gain (BWG). Supplementation of AA or BHA to the AF contaminated diets increased BWG of broilers (P<0.05). Additing AA at both levels to the aflatoxin contaminated diet did not ameliorate the adverse effects of aflatoxicosis on FC. Incorporation of AA and BHA each at both levels, in aflatoxin contaminated diet could not ameliorate the ill effects of aflatoxicosis on feed efficiency in broiler chickens. The serum protein content of group T5 did not differ significantly (P<0.05) from that of T2, however, serum protein content in T6 was significantly (P<0.05) higher than that of T2. Indicating that inclusion of 250 ppm AA in the aflatoxin contaminated diet did not improve serum cholesterol content significantly. Inclusion of 500 ppm AA in the aflatoxin contaminated diet improved (P<0.05) the serum cholesterol content, however, the value was lower (P<0.05) than that of control. Serum uric acid content in T6 was higher (P<0.05) than that of T2, however. The aspartate animotransferase (ASAT) values in groups T5, T6 and T9 did not differ significantly (P<0.05) from that of T2. The alanine aminotransferase (ALAT) values in groups T5, T6, T9 and T10 did not differ significantly (P>0.05) from to that of control, indicating that both AA and BHA each at both levels significantly (P<0.05) ameliorated the adverse effects of aflatoxicosis on ALAT activities. It is thus concluded that dietary supplementation of AA at 250 and 500 ppm; and BHA at 1000 and 2000 ppm levels provided partial protection from adverse effects of aflatoxicosis caused by 1 ppm total AF in terms of BWG and blood biochemical parameters. However, inclusion of AA and BHA, each at both levels, in aflatoxin contaminated diet could not ameliorate the adverse effects of aflatoxicosis on feed efficiency. The present study further showed that BHA was more efficacious than AA in ameliorating the adverse effects of aflatoxicosis on BWG in broiler chickens. پرونده مقاله