Histological characterization of hemorrhages in muscles of broiler chickens

Hemorrhages in meat of broiler chickens are major quality defects. The obje ctive of our study was to characterize the various types of hemorrhages in thigh and breast muscles with respect to their morphological appearance, lo cation, and origin. Chickens were stunned using a water-bath stunner and we re either exsanguinated and fixed or perfused with fixative. The morphologi cal appearance of the hemorrhages was determined by the type of tissue in w hich they were found and by the amount of extravasating blood. Origins of h emorrhages were found only at sites of rupture of venous structures, such a s postcapillary venules and small collecting veins. The absence of signific ant leukocyte infiltration strongly indicated that muscle tissue damage and hemorrhage occurred within the 24 h preceding stunning and slaughter. The locations and types of hemorrhages indicate different underlying mechanisms .