Haematology and morphological changes in young broiler chicks with experimentally induced hypoxia

The haematology, histology and ultrastructure of day-old broiler chicks subject to experimentally induced hypoxia during incubation were examined. Some birds were allowed to reach five weeks old before examination. All the red blood cell parameters, namely, haemoglobin, packed cell volume and red cell counts were raised significantly in hypoxic birds compared with control material and the results closely resembled the haematological profile of young broilers with an ascitic syndrome. By week 5 these parameters had returned to normal. Morphological changes were seen in all the organs examined from day-old hypoxic chicks. The lungs showed much congestion and large numbers of granulocytes were present in hearts, and testes. In the livers, hepatocytes contained enlarged mitochondria together with a reduction in glycogen content. Congested lungs were seen at five weeks old but recovery to normal morphology was observed in all other organs.