MICROSCOPIC CHANGES IN MUSCLES AND PERIPHERAL NERVES OF BROILER CHICKENS CAUSED BY MONENSIN AND ROXARSONE5

Abstract

Anticoccidial agents are commonly used in the poultry industry. One of them, Monensin, is widely used, and in toxic levels can induce lesions in cardiac and skeletal muscle. Roxarsone can be used in addition to Monensin, increasing its efficacy. Peripheral neuropathy has been shown in chickens that were fed roxarsone supplemented diets and subjected to stress. This paper shows the effects of Monensin in association with Roxarsone in broiler chicken to develop an experimental model that concerns gross and microscopic study of lesions in peripheral nerves and cardiac and skeletal muscle. Broiler ckickens are select due to fast growing and developing. 360 chickens were fed either Monensin and Roxarsona for a period of thirty five days with two regimens (Monensin 300 ppm /Roxarsone 80 ppm ; Monensin 300 ppm /Roxarsone 0 ppm; Monensin 150 ppm /Roxarsone 80 ppm; Monensin 150 ppm /Roxarsone 0 ppm; Monensin 0 ppm /Roxarsone 80ppm and Monensin 0 ppm /Roxarsone 0ppm). After this period, birds were euthanatized and muscles and nerves were removed to submit to microscopic examination. The histopathologic findings showed necrosis and myodegeneration in cardiac and skeletal muscle, and macrophages between the fibers. Microscopic lesions were observed in peripheral nerves and cardiac and skeletal muscles consisting in degeneration of and infiltration of inflammatory cells. The use of the association of these drugs in broilers showed to be adequate as a model for nerve and muscle lesions.109