Identification of differential duodenal gene expression levels correlated with differences in energy utilization in chickens

The amount of energy that can be extracted from a diet varies between individuals. Apparent Metabolizable Energy (AME) is a measure of energy utilization efficiency and represents the difference between the energy consumed and the energy lost via the excreta. There are significant differences in the energy utilization capability of individual birds that have a similar genetic background and are raised under identical conditions. We analyzed duodenal gene expression and microbiota differences between birds with different efficiencies in food to energy conversion using microarrays and sequencing of 16s rRNA genes. Differences were found in duodenal gene expression between high and low AME birds, they were however mostly related to genes of unknown function. The flock of 96 chickens was used to study ability of the bird to utilise the energy from feed. We measured energy content in feed and in excreta of individually housed birds. The microarrays were used to compare expression between the best and worst energy utilisers.