Is there a feeding strategy to increase milk casein content?

Because more than 60% of milk produced in Italy is transformed into cheese, milk economical value strongly depends on cheese yield. Among the factors that influence cheese yield, milk casein and fat content plays a major role: when milk is converted into Grana Padano and Parmigiano Reggiano, three grams of seasoned cheese are produced from one gram of milk casein. Because casein and, to a lower extent, fat determine the economic value of milk, increasing casein production is an essential goal for dairy farmers. The importance of this subject is confirmed by the fact that several related reviews have been published in the past. In general, there is a strict correlation between milk production and cheese yield and this is the reason why, in the past, research mainly aimed at increasing milk production. Still, in order to increase cheese yield, dairy farmers have to increase also casein and fat milk content. In fact, despite the fact that milk casein and fat are mainly influenced by genetic factors, proper management and feeding strategies can increase their concentration in milk. It is well known that casein concentration as well as milk production are higher during the winter season; furthermore, different farms hosting genetically similar animals can achieve different milk yields, showing that paratypic factors can strongly influence milk production. The present paper presents a review of factors that influence casein production in dairy cows.