Evidence has shown that hypoxic chickens have greater heart mass/fetal mass ratio than normoxic ones. But it is still unclear if it is the result of hyperplasia or cardiac hypertrophy. Furthermore, the genes that might be involved in the process have not yet been identified. In the present study, the cardiac transcriptome is analyzed to identify differentially expressed genes that can be linked to hypoxia using mostly two techniques, microarray and qPCR.