Ultrastructural abnormalities in seven-day-old broilers reared at high altitude

Fine structural abnormalities in seven-day-old broilers reared at high altitude are described. Tissue changes were seen in the heart, kidney and lung that resembled those previously reported in four-week-old broilers reared at altitude with an ascitic syndrome. Almost half of the hearts examined had myofibril disorganisation and mitochondrial hyperplasia. Renal changes occurred principally in tubule morphology and the lungs showed capillary congestion as well as engorged parabronchi. Increased levels of cartilaginous and osseous nodules in the lungs of 28-day-old ascitic birds reared at high altitude supported observations from a previous study conducted at low altitude. The observations in this study of seven-day-old chicks, may indicate that the embryo is at greater risk of developing abnormalities following exposure to low oxygen tension.