The present invention relates to a methods of increasing the yield of milk protein in milk produced from a lacerating mammal, and to method of increasing the concentration of milk protein in milk produced from a lactating mammal, and to methods of increasing the yield of milk produced from a lactating mammal, and to maintaining milk yield or maintaining milk protein concentration or yield while reducing nutrient intake, said mammal having a diet that does not meet its nutritional requirements said methods comprising administering to a lactating mammal a compound that suppresses milk fat synthesis. Conjugated linoleic acid (CLA) is the preferred milk fat suppressing compound of the invention.