Reasons and means for manipulating the micronutrient composition of milk from grazing dairy cattle

Milk and dairy products that are tailored to meet specific nutritional requirements will become more attractive and valuable to major groups of consumers if they can serve as delivery systems for health-promoting nutrients. Nutritional improvement of milk is achievable in several ways, preferably by making the desirable changes in vivo and on-farm to directly enhance the food without the need for subsequent manipulations. Methods that suit typical pastoral farming practices include trait selection for desirable phenotypes, specialised diets, long-acting parenteral supplements and modification of the ruminal flora. Successful techniques to increase concentrations of calcium, selenium, iodine, iron and cobalt/Vitamin B12 in milk are described. However, changing composition is only one step to bringing new foods to market, as their commercial realisation will require the initiative and collaboration of scientists, veterinarians, primary producers and processors responding to market demands. Uptake of future biotechnologies to capture more value inside the farm gate will also be required if dairy industries are to remain competitive.