The impact of dietary calcium and phosphorus on mitochondrial-linked gene expression in five tissues of laying hens.

Mitochondria and the energy metabolism are linked to both, the availability of Ca and P to provide the eukaryotic cell with energy. Both minerals are commonly used supplements in the feed of laying hens but little is known about the relationship between the feed content, energy metabolism and genetic background. In this study, we provide a large-scaled gene expression analysis of 31 mitochondrial and nuclear encoded genes in 80 laying hens in the context of dietary P and Ca concentrations. The setup included five tissues and gene expression was analysed under four different diets of recommended and reduced Ca and P concentrations. Our study shows, that mitochondrial gene expression is reacting to a reduction in P and that an imbalance of the nutrients has a higher impact than a combined reduction. The results suggest, that both strains (Lohmann Brown and Lohmann Selected Leghorn) react in a similar way to the changes and that a reduction of both nutrients might be possible without crucial influence on the animals' health or gene expression.