Evoluzione delle lesioni macroscopiche e microscopiche da White striping nel broiler

White striping (WS) is an alteration of broiler muscle characterized by the presence of white striations parallel to the direction of muscle bers. WS affects mainly heavi- er birds, and is increasing his economic impact on meat production. To evaluate the evolution of lesions 240 broilers were breed under eld condition and groups of 80 birds were sacri ced at 12, 25 and 51 days. Breast were scored for WS (0=absence, 1=mild, 2=severe) and sampled for histology. Each histological lesion (cell degeneration, presence of adipocytes inside the ber, presence of brosis inside the ber, presence of diffused in ammation, presence of vasculitis) was scored and an overall score was create to summarize microscopic al- terations. The scores of cells degeneration, presence of adipocytes and brosis inside the muscular ber correlates very well, indicating the 3 lesions develops together. In ammation (both diffused and vasculitis) develops independently from others le- sions. The average scores at 12, 25 and 51 days of all parameters, and of macroscopic scores were compared and there was a signi cant difference in all parameters evalu- ated at different ages, con rming the evolution of lesions along time.