Technical note: Production of butter with enhanced conjugated linoleic acid for use in biomedical studies with animal models

Cancer models utilize massive doses of carcinogen so that investigations of anticarcinogenic effects require equally large doses. Conjugated linoleic acids (CLA), predominately consumed in dairy products, are thought to be an ticarcinogenic. Our objective was to naturally produce a CLA-enhanced butte r for use in biomedical studies with animal models. To do this, we fed cows a low forage diet supplemented with sunflower oil. This resulted in increa ses in content of CLA of milk fat, but the markedly elevated concentrations were transient and declined over a 3-wk period. By collecting milk fat ove r the first few days on the diet (d 7 to 10) and selecting cows with the gr eatest CLA concentrations, we were able to produce a butter in which CLA co ntent was enhanced sevenfold over control butter (41 vs. 5 mg/g of fatty ac ids) and the cis-9, trans-ii isomer predominated (91%). Thus, butter produc ed by this method can be used to investigate the preventive role of CLA in natural foods with biomedical models of different types of cancer. Furtherm ore, the butter allows examination of the other beneficial health effects o f CLA reported with animal models.