Based on the assumption that the reduction of the use of imported protein concentrates, such as soybean from overseas, is a goal of ecologically sustainable livestock production, this paper is discussing significant aspects of dairy cows’ demand for dietary protein. These aspects are put in a general context of rumen fermentation efficiency. The main question is, whether new perspectives on optimal rumen functioning could be found, which allow to develop low-input feed evaluation systems for dairy cattle, especially in organic livestock systems. It is argued that besides the reduction in concentrated feedstuff, such systems should base on aspects of feeding behaviour and feed diversity. Such approaches are expected to avoid nutrition-based metabolic disorders of the cattle and to generate advantageous side effects regarding food quality and ecology coming along with low-concentrate feeding. An approximate outline of topics for research and development in order to achieve such systems is presented with this paper
