A study conducted by researchers from the Wageningen University in the Netherlands revealed that chickens fed with organic feed develop a different process of gene expression in their small intestines than that of chickens which get conventional feed. Specifically, organic chickens have higher expressed genes involved in the creation of cholesterol, albeit they do not have raised cholesterol levels in their blood. Details of the study appear in the British Journal of Nutrition.
"We had not expected much difference in gene expression between the two groups of chickens because the same ingredients were found in both types of feed, and these differed only in the way they are cultivated', says researcher Astrid de Greeff of Livestock Research in Lelystad. The researchers observed 49 genes differently expressed between organic and conventionally grown chicken.
De Greeff pointed out that a differential expression of 49 genes among a total of twenty thousand chicken genes may seem subtle. But she said that this is a big difference considering the fact that the cultivation method is the only difference in the feed. Seven of the 49 genes are involved in cholesterol biosynthesis, when only a total of thirty genes are involved in the process.
"What happens biologically when these genes become expressed higher is still unknown. Cholesterol is a building material for many substances, such as hormones. We don't know yet what the cholesterol does in the chickens," says de Greeff.