DEFA: Comparison of functional roles of c9,t11/t10,c12 CLA isomers and essential fatty acids in dairy cows to elucidate a minimal uptake level: Part 1: Effects on performance, energy metabolism and fatty acid composition in milk, blood and tissue; Part 2: Effects on metabolic traits, anti-oxidative and immune status and cell membrane integrity
Dairy cows digest high amounts of essential polyunsaturated fatty acids (PUFA) when they are on pasture. However, most of the dairy cows are nowadays in the barn and are fed with total mixed ration that contain low amounts of fat, especially essential fatty acids. The PUFA are precursor for Conjugated linoleic acid that are synthesized in the rumen but also in the mammary gland. Both, PUFA and CLA have important functions on cell integrity, on the immune system and specific CLA isomers are able to relieve energy metabolism in dairy cows during peak lactation. So far it is not clear whether the common feeding management in the barn leads to a shortage of PUFA and CLA supply. We establish an animal model with dairy cows that receive low amounts of PUFA and CLA. By supplementation of specific PUFA and CLA we investigate the importance of these fatty acids on milk performance and energy metabolism in dairy cows during peak lactation.