Variations of clinical biochemical parameters of laying hens and broiler chickens fed aflatoxin-containing feed

Two groups of 32 laying hens (Hyssex Brown) and two groups of 32 23-day-old (Hybro) broiler chickens were fed 2.5 and 5 parts/10(6) of aflatoxin in their diet for 4, 8, 16 and 32 days; 16 hens and 32 chicks were maintained as control groups (0 parts/10(6)). After the intoxication period, a clearance period was established of 1, 2, 4 and 8 days. Relative weights of liver and kidneys significantly increased in intoxicated hens, but not in broiler chickens. Histological lesions in both types of bird consisted of hepatic cell vacuolation with fatty infiltration. There was a significant decrease (P< 0.001) in egg production in the 5 parts/10(6) group, which started to recover during the clearance period. No morbidity or mortality due to the aflatoxicosis were observed in either type of bird. In intoxicated laying hens, cholesterol levels were not significantly (P> 0.05) different from control values, but triglyceride levels decreased (P< 0.001) in both intoxicated groups. The effect of aflatoxin on calcium and phosphorus levels was important, because on the 4th day their values decreased significantly. Aspartate aminotransferase (AST) serum levels remained normal, whereas alanino aminotransferase (ALT) activity decreased in both intoxicated groups. The activity of serum lactic dehydrogenase (LDH) and gammaglutamil transferase (GGT) increased significantly. In intoxicated broiler chickens, aflatoxins did not alter (P> 0.05) the biochemical parameters studied, except that the serum calcium concentration was lower in the 5 parts/10(6) group. These data indicated that in intoxicated laying hens, a severe clinical biochemical alteration was produced, and that this together with the hepatic lesions observed in hens and broilers may aid disease diagnosis.