Abstract
Background:
Mycotoxins considered one of the most important problems and threats that face the poultry producers.

Aim:
This study conducted to investigate the pathological, hematological and biochemical alterations in chickens fed on mycotoxins contamination ration.

Methods:
434 feed samples were collected from poultry farms operating in Babil Governorate/Iraq, where feed samples were collected over the course of 2023, and these samples were tested by direct competitive enzyme-linked immunosorbent assay (CD-ELISA) to determine the level of mycotoxins. (Aflatoxin, Ochratoxin and Trichothecin T2) in poultry feed rations, after that, the chickens that were fed on feeds contaminated with mycotoxins were carefully examined to observe clinical signs. Then, blood samples were collected from chickens fed on feeds contaminated with mycotoxins, as well as from chickens fed on uncontaminated feeds (control group). These blood samples were divided to two parts one put in tube contain anticoagulant (EDTA) to examination the complete blood count, while as, the other part was put in gel test tube for separating the serum which used in the biochemical tests which included the total protein and total cholesterol (TC), uric acid and the liver enzymes (ALT, AST). Then, the chickens fed on mycotoxins contaminated feed were humanly sacrificed to observed the gross lesions after that, tissue samples were collected from internal organs (liver, kidneys, bursa of Fabricius and spleen) to exam the microscopic lesions.

Results:
The results showed the percentage of feed samples contaminated with mycotoxins above the limit of quantification (LOQ) values were 22% (94) where the percentage of feed samples contaminated with aflatoxin, ochratoxin and trechothesen T2 were 12% (54), 8% (34) and 2% (6) respectively. the gross lesions were showed on internal organs of chickens fed on mycotoxins contaminated feed paleness, enlargement and friable liver, pale, enlarged and lobulated kidneys, hemorrhage in skeletal muscle as well as showed ascites. Microscopically, the kidneys showed necrosis in some renal tubules and glomeruli. In the liver there was congestion of the portal vein and periportal necrosis with inflammatory cells infiltration. The results showed significant decrease in means values of HB, PCV, RBCS, WBCS, total protein and cholesterol while as there were significant increase in means values of AST, ALT and Uric acid in infected chickens group compared with healthy chicken group.

Conclusion:
Contamination of feed with mycotoxins is one of the most prominent challenges facing poultry producers in Babylon province. In addition, it is important to do pathological, heamatological and biochemical examination for the diagnosis of mycotoxins in broilers.

Key words: Mycotoxins, Pathological lesions, Heamatological and Biochemical parameters, Broiler chickens, Babylon