The overall focus of the research of Dr. Kris Sejrsen has been to elucidate the physiological basis for nutritional variation in mammary growth, development and lactation. In this context he has carried out a long series of investigations aimed at clarifying the physiological basis for variation in mammary development in heifers, cows and sows.

The studies originally focused on the GH-IGF-I axis and the ovaries, but recently they have included the role of several other growth factors and cytokines. More recently, he has led a series of studies on the effect of stage of lactation and nutrition on bioactive components in milk (growth factors, fatty acids and phyto-estrogens). The biological effect of the different milk types have been tested in relevant cell lines and in one case in a human intervention trial. In several studies we have investigated the expression of genes involved in de novo milk fat synthesis. In a present study we focus on genes involved in mammary conversion of fatty acids. In this project we also investigate the potential of an in vivo/in vitro model to screen for human health effects of milk with different composition.

Publications

• Tholstrup, T. Raff, M., Basu, S., Nonboe, P., Sejrsen, K. and Straarup, E.M. 2006. Effect of diet high in conjugated linoleic acid on blood lipids, oxidative stress, C-reactive protein, hemostatic markers and fasting insulin in healthy, young men. American Journal of Clinical Nutrition, 83, 237-243
• Sejrsen, K., Bjørn, T. and Jensen, S.K. 2007.  Prospects of obtaining favourable fatty acid composition of cows milk by feeding. Journal of Animal and Feed Sciences, 16, suppl. 1, 7-20.
• J. V. Nørgaard, L. H. Baumgard, T. S. Nielsen, P. K. Theil, M. T. Sørensen and K. Sejrsen. 2008. Mammary Cell Turnover and Expression of Lipogenic Genes in Response to Diet Induced CLA and Diet Energy Density in Lactating Cows. Acta Agr. Scand.