There have been discussions over the years whether the diets of cows can be enhanced to encourage production of conjugated linoleic acid, which has health benefits for consumers.
See, Is CLA-fortified milk on the horizon? The goal of a recent study from Cornell University and Ohio State University was to increase the CLA content of milkfat while avoiding a reduction in milkfat synthesis. Yet, they weren’t able to overcome a reduction in milkfat yield using certain supplements, such as soybean oil and vitamin E. Further research is needed.
Read an abstract in the December edition of the Journal of Dairy Science.