Effect of Dietary Zearalenone on Growing Broiler Chicks ,

Purified zearalenone was fed to broiler chicks from 1 to 21 days of age at levels of 0 (control), 10, 25, 50, 100, 200, 400, and 800 ppm in a diet in order to evaluate its subacute toxicity. Weight gain, feed consumption, and feed/gain ratio were not affected at any of the concentrations administered. Weights of the liver, heart, spleen, testicles, oviduct, comb, and bursa of Fabricius were similar between control and zearalenone treated groups. The leukocytes of chicks fed 400 and 800 ppm zearalenone decreased as compared with that of control chicks due to the decrease in total number of lymphocytes. Hematocrit, hemoglobin, erythrocytes, and serum levels of calcium, phosphorus, total protein, alkaline phosphatase, and cholesterol were not affected by zearalenone. The incidence and size of ovarian cystic development were greater in chicks fed zearalenone, although cysts were found in some of the control group. There were no prominent signs in gross necropsy examinations other than hypertrophy of the oviduct in some birds fed 800 ppm zearalenone. The results of this study suggest that broiler chicks are tolerant of zearalenone and less sensitive than swine and turkey poults.