Histological characterization of hemorrhages in muscles of broiler chickens

Hemorrhages in meat of broiler chickens are major quality defects. The objective of our study was to characterize the various types of hemorrhages in thigh and breast muscles with respect to their morphological appearance, location, and origin. Chickens were stunned using a water-bath stunner and were either exsanguinated and fixed or perfused with fixative. The morphological appearance of the hemorrhages was determined by the type of tissue in which they were found and by the amount of extravasating blood. Origins of hemorrhages were found only at sites of rupture of venous structures, such as postcapillary venules and small collecting veins. The absence of significant 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.